U. S. DEPARTMENT OF COMMERCE

National Bureau of Standards

ANTISCATTER TREATMENTS FOR GLASS

Miscellaneous Publication M175

U. S. DEPARTMENT OF COMMERCE

JESSE H. JONES, Secretary

NATIONAL BUREAU OF STANDARDS

mill J. BRIGOS, Director

NATIONAL BUREAU OF STANDARDS MISCELLANEOUS PUBLICATION MI75

ANTISCATTER TREATMENTS OF GLASS

by

Frank W. Reinhart, Ruth A. Kronstadt, and Gordon M. Kline

Issued June 19, 1944

UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1944

ale by the Superintendent of Documents, Washington 25 Price 10 cents
PREFACE

The widespread use of glass in all types of buildings and transportation vehicles

presented a critical problem in providing measures for protection against air raids.

Glass splinters projected through the air by bomb explosions have resulted in personnel

casualties, damage to machinery, and disruption of blackout facilities. At the start of

the war in this country many different materials and methods were proposed for treating

glass to prevent scattering. The Office of Civilian Defense requested the National Bureau

of Standards to evaluate these and submit recommendations concerning their use. The

results of this investigation are reported in this publication to supplement the information already distributed to State and local defense councils, Government agencies, business

firms, and individual inquirers. In addition to its significance in protection against

flying glass during air raids, the paper also will be of interest to manufacturers con- cerned with general problems relating to adhesion of materials to glass.

Lyman J. Briggs, Director.

(XV)
ANTISCATTER TREATMENTS FOR GLASS

Iff Frank W. Reinhart, Ruth A. Kronstadt, a+*JL Gordon M. Kline

CONTENTS

Page Preface iv

I. Introduction............... 1

II. Review of literature..... 1 III. Description of apparatus...... 3

IV. Method of test 4

V. Description of materials 5

Page VI. Results of burst tests 5 VII. Results of accelerated aging tests....... 7 VIII. Discussion g

IX. Summary 9

X. References 10

XI. Tabulation of data (tables 1 to 31) 17

ABSTRACT

The relative effectiveness of various commercial

and experimental antiscatter treatments for glass

was investigated at the request of the United States Office of Civilian Defense. A vacuum- concussion

apparatus was used to test glass treated with lacquers, tapes, plastic films, and adhesive-fabric

combinations. The materials which gave satisfactory results as initially applied were subjected to wet-dry cyclic and heat tests to determine the aging characteristics of the antiscatter materials.

Only a few materials retained the particles of

glass satisfactorily In the vacuum test after sub- jection to the two accelerated aging tests. A re- view is included of the experimental work and ex- periences of the British in developing treatments

for glass to prevent it from scattering when fractured by bomb explosions.

I. INTRODUCTION

An investigation to determine the relative effectiveness of various commercial

and experimental antiscatter treatments for

glass was undertaken by the National Bureau

of Standards at the request of the United

States Office of Civilian Defense. To facilitate the work, a study was made of the

results of the experiments and experiences

of the British which were available in various technical publications. A short review of the more pertinent references is

given in one section of this report. As a result of this study, a vacuum-concussion

apparatus similar to that used by one group

in England was built. The results of the

tests made on this apparatus are presented

in this report. In addition, results of

accelerated aging tests made on the materials that gave promising results in the vac- uum test are presented.

Some tests were made on special types of

glass and replacements for glass in window

enclosures for comparative purposes, and

the results are included herein. In general, methods for protecting against flying

glass that do not involve a treatment ap- plied to the glass are not covered in this

report.

II. REVIEW OF LITERATURE

Moore 1 [1] in discussing the effects of

an explosion on windows observed that the

effectiveness of any coating applied to the

glass surface depends on (a) the adhesion

of the coating to the glass and (b) the

strength and toughness of the coating.

Sheets of transparent cellulose, fabric,

and nettings of heavy mesh were effective

when bonded properly to the glass. The

"all-over" treatments were superior to the

tape treatments. Moore recommends that

these treatments not only cover the glass

completely but that they "should be carried

well over and securely fixed to the edges

of the window frame." Varnish and lacquer

coatings, if thick enough, were effective

1 Figures in brackets indicate the literature references at the end of this paper. A few references not cited in the text are given following the bracketed

re ferences.

(1)
2 Miscellaneous Publications of

when fresh. He used a round-bottom glass

flask containing 2 pounds of blasting powder for his bomb.

An apparatus developed in England for

studying the scattering of glass particles

produced by rupturing glass by a concussion was described [2,3] in December 1940. The

glass pane, which may be treated with an "antiscatter" material, is used to cover

one end of a cylindrical transparent box,

the other end of which is connected through

a quick-acting release valve to a large

evacuated chamber. When the valve is

opened the sudden reduction of pressure in

the transparent box gives the effect of a

blow on the outside.

The results of work done by the Building

Research Station (England) were reported by

H. M. Llewellyn [4] in the spring of 1941.

The data were obtained by high-explosive

blasts and blasts from balloons filled with

electrolytic gas. Liquid antiscatter

treatments were found to give a good degree

of protection when coatings of sufficient

thickness were applied. Most of these

treatments lost their initial effective- ness when exposed indoors for a short time

(4 months was regarded as a minimum requirement) . Transparent plastic films of adequate thickness applied to glass with suitable adhesives also gave a good degree of

protection. A varnish or lacquer, which

may be used as the adhesive also, needs to be applied over the film to make it waterproof. Textile fabrics when securely

fastened to the glass give some protection.

The application of varnish or lacquer over

the fabric enhances the protective value of

the treatment as well as rendering it waterproof. Experiments showed that the use of

tapes was not very effective unless the

tape material was very strong and closely

spaced. In any case, they were less effective than the "all-over" treatments. In

the discussion, it was noted that from re- ports received and examinations made of

actual bombing damage, the use of good

treatments was fully justified.

Llewellyn [5] made another report in

April 1942 of the work carried out at the

! Motional Bureau of Standards

Building Research Station (England) . He

states that varnishes, lacquers, etc.,

"when used alone, usually proved unreliable,

owing to the difficulty of obtaining a coating of sufficient thickness and one which would remain tough and elastic for a reasonably long period under normal conditions of exposure; only a small minority

of those tested showed anything like satisfactory performance. Textile fabrics, on

the other hand, when merely stuck to the

glass with aqueous adhesives are susceptible to damp conditions; they tend to peel

off and also become mildewed." Combinations

of varnishes and fabrics were tested with

the following results: (!) Each individual

varnish-fabric combination must be tested

to determine its effectiveness, (2) lacquers

which deposit soft, tacky films are superior

to those which give dry, hard films, and (3) the most satisfactory type of treatment

consists in covering the glass with a coat of lacquer, quickly applying the fabric,

allowing to dry, and finally applying an- other coat of lacquer.

Butterworth [6] of the Building Research

Station (England) published in August 1942 a brief discussion of the theories concern- ing adhesion and of the properties of the

various commercial types of adhesives.

Although this is a general treatise on adhesives, one significant comment on antiscatter treatment is made, as follows:

" Fabric-varnish treatments have in fact

been used successfully for the protection

of windows, notably those of passenger

transport vehicles." The second part of

his report Q7] discusses the following properties that an adhesive should have to hold

textile fabrics and transparent films to window glass: (1) It should hold the protective material to the glass with sufficient strength initially to be effective.

Provided the glass is clean, there is no

great difficulty in obtaining adhesion to the glass. The fabric can be imbedded in

the adhesive layer to ensure its firm attachment. With regenerated cellulose

sheets the choice of adhesives is severely

restricted, whereas cellulose acetate film
Antiscatter Treatments for Glass 3

presents an even more difficult problem.

(2) It should have no effect on the

strength of the fabric or film. Watersoluble adhesive s reduced the strength of

the transparent films. Some nonaqueous

adhesives were satisfactory with films but

were expensive. Fabrics are adversely affected by adhesives containing acids or oxidizing agents. (3) It should not injure

the glass. Adhesives containing sodium

silicate were the only ones which gave an etched appearance to the glass. Some un- plasticized glues, applied hot, pluck

pieces from the surface of the glass. (4) It should not become brittle or flake away

from the glass on exposure. Many of the

adhesives became dry and brittle and flaked

off of the glass in summer weather. This

is particularly true of adhesives made of

vegetable gums, dextrins and animal glue.

All adhesives should be adequately plasticized. (5) It should not be unduly weakened by exposure to very humid atmosphere.

It is doubtful if any adhesives will retain

any useful degree of adhesiveness under

conditions of continuous condensation. (6) It should not encourage the growth of

molds. Many aqueous adhesives are favorable media for the growth of molds, particcularly when moist, in which case preservatives should be used.

In May 1942, the British Standards

Institution issued a specification covering

antiscatter fabrics [8]. This specification covers adhesive fabric, for use with

or without a coating of protective varnish,

and nonadhesive fabric, which is applied by

means of a lacquer or varnish type of adhesive. The detail specifications cover

weight and bursting strength of the fabric,

the adhesion to glass, and resistance to mildew. It is further pointed out that

varnishes or lacquers for use with fabrics must be tested and approved for this purpose. For windows not subject to condensation an adhesive made of tapioca starch

mixed with one-quarter to one- third of its

weight of glue is recommended. A soluble

starch may be used with the glue, but the

resistance to high humidities is not as

good as the tapioca starch and glue mixture.

Tapioca or soluble starch may be used alone,

but the adhesion is not as good as that obtained with the mixtures of starch and glue.

To obtain resistance to mildew, an antiseptic should be added to the adhesive. A

supplement to this specification gives information that is useful in selecting and

in applying antiscatter treatments to glass.

Bleached and dyed fabrics are not recom- mended unless a dark color is necessary for

blackout protection. Plain weaves not too closely woven (varnish or lacquer must

penetrate readily) are recommended. Moisture resistant varnishes or lacquers should

be used where condensation or high humidities are likely to be encountered. These

can be used as adhesives for fabric or can be applied over an adhesive-fabric treatment. Where condensation is exceptionally

heavy, the treatments should be applied to the dry side of the glass.

III. DESCRIPTION OF APPARATUS

For the tests described in this report,

a vacuum-concussion apparatus was built

similar in principle to one developed

and used in England [2], but modified to insure rigidity of the testing frame

during application of the load to the

glass. This equipment, shown in figures 1 and 2, consists of a steel tank (vacuum

reservoir) connected by means of pipe

through a quick-acting release valve to

the concussion chamber. The concussion

chamber was made by welding two pieces of

flat steel onto the ends of half of a 16-inch piece of 12-inch-diameter steel

pipe so cut that two semicircular pieces

were obtained. A steel facing frame was

then welded around the opening. Another

frame, identical with the one welded to the steel box, was also made to clamp

the glass panel to the steel concussion

chamber. These steel frames were faced

with thin rubber sheeting. The glass

test specimen was placed on the frame at- tached to the semi cylindrical steel box

and the clamping frame placed on top of

the glass. A wire basket was placed inside
4 Miscellaneous' Publications of the National Bureau of Standards

the concussion chamber to catch the glass

fragments

.

The reservoir was connected to a vacuum pump and to a manometer. The connections

between the concussion chamber and the

vacuum tank were made of 1 Vz -inch pipe.

The quick-acting release valve has an

opening 2 inches in diameter. The lever to open the valve was operated by means of a weight attached to a small rope running

over a pulley. The weight was supported by

another rope attached to a pin. When the

pin was knocked out, the weight dropped,

thereby opening the valve. This insured

the same rate of valve opening throughout

the tests. The capacities of the various parts of

the apparatus are as follows:

Vacuum reservoir.. 5.56 Connections to pump and valve................. 0.06

Total volume on vacuum side 5.62

Concussion chamber 0.52 Connections to valve 04 Total volume on concussion side 0.56

The ratio of the volume of the vacuum

side to that of the concussion side is

therefore 10 to 1.

The various treatments submitted for

evaluation were applied to one side of 14-

by 19-inch panes of double strength, grade

B window glass, the type commonly used for

glazing. The test specimen was placed over

the opening of the concussion chamber with

the treated side of the glass pane facing

inwardly and was clamped lightly between

the two frames. The reservoir was evac- uated to the selected manometer reading and

the quick release valve was opened. The

glass fragments caught in the wire basket were weighed and an estimate of the size

and number of the larger pieces was made.

Photographs of the specimens that held to- gether reasonably well were made. The

relative effectiveness of the treatments

was judged by the types of failure and the amounts of flying glass.

Most of the tests were made at a mano- meter reading of 20 inches of mercury,

which is equivalent to a pressure of approximately 10 lb/in 2

. It was found that at a manometer reading of 15 inches, untreated double-strength window glass would

always break, whereas at 14 inches the

glass usually would not break. The 20

inches was selected because it was desired

to break the glass in each test so that the

amount of flying glass could be measured,

and it was realized that the treatments might increase the breaking strength of the

glass to some extent. In more than 500

tests, the double- strength window glass

coated with various antiscatter treatments failed to break in only two instances at

the 20-inch vacuum. Some special types of

glass required more pressure to break and

when this was necessary, it is indicated in

the tables. The approximate air pressures

on the outside of the glass corresponding

to various manometer readings are as

follows

:

Manometer reading Air pressure

Inches lb/in. 2 29.9 14.7

28.0 13.8 24.0 11.8 20.0 9.8 15.0 7.4 14.0 6.9 10.0 4.9

The treatments that gave promising results in the initial vacuum tests were applied to glass and subjected to accelerated aging tests. Test I consisted in exposure to approximately 100-percent relative humidity and 70° F for 8 hours, followed by drying at ordinary interior con- ditions for 16 hours. This cycle was re- peated 10 times. Test II consisted in con- tinuous exposure to a temperature of 160°F

in a forced-draft oven. Two different

periods of exposure were used in the latter

test, namely, 2 days and 7 days. Test I evaluates the treatments where the windows

IV. METHOD OF TEST
Antiscatter Treatments for Glass 5

to which they will be applied will be subjected to high humidities. Test II evaluates the treatments where the interior of

the windows will be exposed to low relative

humidities and to heat from the sun; this

is probably the most common condition.

After the panels were subjected to these

accelerated aging conditions, they were

tested on the vacuum- concussion apparatus.

V. DESCRIPTION OF MATERIALS

The various antiscatter coating materials received for test were classified into seven groups. These are listed below,

together with the number of samples tested

and the table references in which detailed

descriptions of the samples and the results

of the burst tests are presented.

Type of material Designation

of treatment

Vumber of

samples

Sample

described

in table

Test results

in table

Liquid

Sheetings, plastic

Tapes Fabrics Asphalt-asbestos

Special products

Glass, special

Replacements for glass.

.

Home-prepared adhesives.

25

2336

214

18

18

6

10, 15, 19, 25

11, 15, 20, 26

12, 15, 21, 27

13, 22, 28

14, 23, 29

16, 24, 30 17

18

13

A total of 156 materials were submitted

for test, but many combinations were made

possible by using lacquers with films,

tapes, or fabrics. Many of these combinaions were prepared and tested.

VI. RESULTS OF BURST TESTS

The results of the burst tests made on

Lass treated with the various materials

re given in tables 10 to 18. It was found

it the breaks could be classified into

>ix types. The types of breaks are described as follows:

The best type of break is A; next best, B; etc., up to E, inclusive. F is misleading

when only the amount of glass thrown into

the basket is considered. The film might

break in an actual bomb explosion which

would result in the F type becoming an E

type break.

For purposes of studying the data in the

tables, the following tentative basis is

used:

Break

designation Description

Break Amount of glass

Type of break designation in basket

Grams

A, B, C to 20

D, E, F >20

Glass cracked, but practically intact. Glass cracked and backing material punctured; small hole in glass. Glass cracked and backing material punctured; same type as B but hole larger. Glass shattered and part of pane in basket; remaining part hanging in large

flaps or strips. Glass shattered and most of pane in basket. Glass shattered badly and separated from

plastic backing, but backing material

did not break and hence kept glass from falling into the basket.

It should be noted that when a treatment is

placed in the "good break" group here on

the basis of these initial tests, it may be

construed as meaning that the treatment is

satisfactory if it also has satisfactory

aging properties. Those placed in the "bad

break" group certainly cannot be considered

effective in any case.

597753 - 44 -2
6 Miscellaneous Publications of the National Bureau of Standards

Some lacquers meet the requirements of

the good break group when applied in thick- nesses of 12 mils or more; others do not

meet these requirements regardless of the

thickness (table 10) . The effect of thick- ness on the type of break is illustrated in

figure 3. Film sheetings of the vinyl acetal type,

ranging in thickness from 15 to 60 mils,

ntet the requirements of the good break

group (table 11) . These film sheetings, in

all cases but one, were applied to the

glass by the manufacturers.

Tests were made on a 2.5-mil sheeting of

regenerated cellulose having a watersoluble adhesive on one side (table 11)

.

Some test specimens were prepared by applying the sheeting to the glass with water,

and others with a warm iron. The film

thickness was increased by applying several

sheets, one over the other. This material

in thicknesses from 2.5 to 15 mils did not

give good breaks. The one case in which

the material did give a good break could

not be duplicated. This sheeting was also

tested in combination with lacquers; these

results are discussed in another paragraph

in this section of the report.

A. transparent film, 2 mils thick, with a pressure-sensitive adhesive was tested and

failed (table 11). Few of the tapes tested gave good breaks

(table 12) . Those tapes which did

pass were applied as an over-all treatment in which the strips were lapped. In some instances better results were

obtained when a narrow slit was cut in the

middle of the tape layer or when a double Y pattern, ^> <^ , was cut in the tape lay- er. The results of some of these

tests on tapes are shown in figures

4 and 5. The results of tests made on combinations of fabrics with lacquers and watersoluble adhesives indicate that such combinations give good breaks in only a few in- stances (table 13) . One lace type fabric

used with lacquers L-EI-2 and L-GI-2 in

film thicknesses of 15 mils gave good

breaks. However, these lacquers gave similar results when tested without fabric.

One water-soluble adhesive, a tapioca-glue

mixture, used in combination with two

fabrics, gave good breaks, but it has a

disadvantage in that it chips the surface

of the glass. Lacquers that gave bad breaks

when tested independently, also failed when

tested in combinations with fabrics. Some

lacquers which passed when tested independently failed when tested with some fabrics,

probably because the lacquer film was too

thin. This leads to the conclusion that

each fabric lacquer combination must be

considered individually. The effect obtained with one fabric bonded to the glass

with various adhesives is shown in figure 6. Tests were made on four types of asphaltasbestos combinations that had been applied

to the glass by the manufacturer (table 14) . Three of the four gave good breaks ; the

fourth failed by a small margin.

Tapes, film sheetings and lacquers,

which, with the exception of the cellulose

acetate film, were tested separately, were

also tested in various combinations (table

15) . The cellulose acetate sheetings were tested in combination wi th several lacquers, and the results indicate that the

effectiveness of such combinations is largely dependent on the lacquer used as the

adhesive. When an adequate thickness is

used the combination of sheeting and a lacquer passes if the lacquer alone passes the

test. If the lacquer, when used by itself,

fails, the combination employing this lacquer with tapes and films will also fail.

Although the use of a tape or film with a good lacquer may result in a combination

which passes, the thickness required to pass is so great that there is little advantage in these combinations. In the use of opaque tapes and fabrics, the decrease in

light transmission may be an important factor.Vinyl acetal resin film, previously discussed with respect to its application to double-strength window glass was also ap- plied to single-strength glass, Vi-inch
Antlscatter Treatments for Glass 7

plate glass, and Vk-inch tempered glass by

manufacturers in their laboratories (table

16) . The film thicknesses of these sheetings varied from 8 mils on some singlestrength glass to 60 mils on the plate and

tempered glass. Most of the treatments

gave good breaks, although some of those

applied to the %-inch plate glass gave

bad breaks. The plate glass in most in- stances did not break at a manometer reading

of 20 inches but required 28 inches. The

tempered glass could not be broken on the vacuum-concussion apparatus.

For purposes of comparison with, treated

and untreated double-strength window glass,

tests were made on various types of glass

(table 17) . All but two of these gave bad

breaks; the two which gave good breaks involved the use of plastic film. The tem- pered glass could not be broken even with a pressure differential of 28 inches of mercury and therefore could not be rated.

Three replacement materials for glass

windows were tested (table 18) . One was a combination of wire screen and transparent

plastic, another cotton scrim coated with a

thin layer of transparent plastic, and the

other a combination of asphalt, asbestos,

and paper. The wire and scrim materials

and all except one of the asphalt-asbestospaper combinations gave good breaks.

gave good breaks were put through the two accelerated aging tests described in section IV to determine their performance after

exposure to ordinary indoor conditions of

temperature and humidity. The materials

VII. RESULTS OF ACCELERATED

AGING TESTS

selected for accelerated aging were applied

to the glass in the combinations and thick- nesses that gave the best results in the

initial vacuum-impact tests. Many of the treatments applied by the manufacturers

were not aged because some of them were very

much alike, e.g., identical materials ap- plied in various thicknesses. The results

of these tests are presented in tables 19

to 30.

Failure of antiscatter material as a re- sult of exposure to cycles of high and low

humidity (accelerated aging test I) was

always associated with a loosening of

the bond between the glass and the backing

material, as evidenced by shrinkage, roughening, and peeling of the material. Heat aging caused many failures of the

backing material tested, apparently because

of loss of flexibility. The materials that

passed may be divided into two classes:

(1) Plastic materials of a rubber-like con- sistency which did not become brittle as a

resul t of heat, and (2) fabrics and fabric

tapes applied to the glass with watersoluble adhesives. Although the water- soluble adhesive s may themselves have be- come brittle, apparently they did not penetrate the fiber sufficiently to impair the

flexibility of the fabric.

These accelerated aging tests indicate

that many of the treatments will not have

good aging properties. Only 6 of the 26

treatments tested, not counting those ap- plied by the manufacturers, maintained

their effectiveness on exposure to the

accelerated aging tests. The results of all the tests made on the

antiscatter materials may be summarized

briefly as follows:

Liquid materials

Film

sheetings

Tapes

Fabricadhes ive combination

Asphaltasbestos

Number of materials tested initially in vacuum chamber... 24 19 32 52 4

Number of materials which gave good breaks initially 10 13 3 12 2 Number subjected to the humidity accelerated aging test.. 6 9 9 5 4

Number 3 7 3 4 2

Number 5 7 8 6 4

Number giving good breaks after exposure to dry heat 2 4 1 3 2 Number giving good breaks after exposure to both accel2 4 1 3 1
8 Miscellaneous Publications of the National Bureau of Standards

VIII. DISCUSSION

Experience in England indicates that

short of blocking up the window with brick,

thick timbers, or heavy steel, it is practically impossible to reinforce the glass

to such an extent that it will not break.

Consequently, it can be assumed that any treatments that may be applied to windows

in homes, offices, schools, etc., cannot

keep the glass from breaking. The problem

resolves itself, therefore, into one of

finding a treatment for glass which (1) will

not allow much glass to fly when the glass

breaks, (2) will reduce the velocity of the

particles of glass which do fly, and (3) will be strong enough to hold most of the

pane in one piece or a few large pieces if

the blast is strong enough to blow the window out completely.

The degree of effectiveness in actual

service of any antiscatter treatment is

difficult to evaluate because of the nature

of the destructive wave emanating from an explosion. The wave starts in a small area and expands, and as it expands the intensity

decreases. The contour of the land and obstructions, such as buildings, will effect

the distribution of the forces in the wave, resulting in irregularities. It appears

that nothing will withstand the shock at or very near the area (I, fig. 7) where the

explosion takes place.

In an annular area (II, fig. 7) adjoining the explosion area, any treatment ap- plied to glass will not give protection.

It seems reasonable that there must be some area (III, fig. 7) beyond this one in which

the wave is strong enough to break and

scatter ordinary untreated window glass but

not strong enough to scatter appreciably

glass that is protected with a good antiscatter treatment.

It is believed that the results obtained

with the vacuum-concussion apparatus evaluate the effectiveness of a treatment for use at some distance away from the center of the explosion. It is impossible to place

even approximately the distance from the

explosion where a treatment would be effective, since the force of the explosion of a bomb varies, depending on many factors.

However, it can be assumed that treatments which do not give good results in this test

will not be effective at any reasonable

distance. The treatments which give good

results should give some measure of protection over part of the area affected by

the* explosion, although it must not be as- sumed that any treatment will give complete

protection. It is recommended that individuals take shelter, wherever possible,

away from glass-enclosed spaces, even though

the glass may be covered with an antiscatter

treatment similar to one of the types tested

in this investigation.

Based on the results obtained in this

investigation on treatments applied and

tested without aging, the following were

found to be the most effective of those

which could be applied to glass already installed. The designating letters are those

used in tables 1 through 9, which describe

the treatments.

1. Lacquers —minimum thickness of film,

12 rails:

L-AR-5 L-FC-1 L-NS-1 L-EI-3 L-EI-1 L-GI-1 L-NS-2 L-EI-2 L-GI-2 L-PP-1

2. Sheeting, plastic:

S-EI-I

3. Tapes— applied as over-all treatments:

T-GP-3

T-OP-4 T-MM-9

4. Combinations of adhesives or lacquers

with sheetings, tapes, and fabrics:

L-NS-3 and 8-CC-l

L-OI-l and T-MM-9

Js-SC-l and T-GP-3

F-MP-1 and F-MA-2

F-AH-1 and F-MA-i L-EI-2 and F-MF-2

L-OI-l and F-MF-2

Z-4 and F-MF-2

Z-4 and F-XX-3

Z-6 and F-XX-3
Antiscatter Treatments for Glass 9

Lacquer treatments and fabric-adhesive

treatments predominate in this group of

materials, which are effective as initially applied. The Z-4 and Z-5 adhesives can- not be recommended, since they deface the

glass permanently, i.e., they break pieces

out of the surface of the glass on drying.

To be considered satisfactory, an anti- scatter treatment must retain its effectiveness for a reasonable length of time

under normal aging. The accelerated aging

methods used in the work reported herein

give some indication of aging resistance of

a treatment. Method I (wet-dry cycles)

evaluates materials for use on windows subject to wetting with condensed moisture,

e.g., windows in homes during cold weather.

Method II (baking) evaluates materials for use in windows subject to dry heat, e.g.,

windows exposed to the rays of the sun in

the summer. Of the treatments subjected to the accelerated aging tests, the following were found

to maintain satisfactory breaking characteristics after exposure to both sets of

aging conditions listed above:

1. Liquid treatments—minimum thickness

of film 20 mils:

L-GI-2

2. Tapes—applied as over-all treatments:

T-GP-4

3. Combinations:

I-EI-2 and F-MF-2 The results of the tests on the glass

panes that were coated with lacquer may be

broken down as shown in table 31. These

data show that of the 10 lacquers which

gave good breaks initially, five were polyvinyl butyral, three polyvinyl acetate, one cellulose nitrate, and one a protein. The

I two which gave good breaks after aging were

polyvinyl butyral lacquers. It should also

be noted that the lacquer of the fabriclacquer combination which gave good breaks

after aging was based on polyvinyl butyral.

Since all the treatments depend to some extent on the action of an adhesive, the

following general remark on this subject

seems pertinent. For effective treatment

the adhesive should remain tacky after the

solvent has escaped; this will hold the

glass particles to the adhesive film when

the glass is shattered. In addition, the

film must be strong enough so that large

pieces do not tear loose. Although tacky

films are generally weak, the strength

necessary for effective results may be obtained by using an adhesive layer of adequate thickness or by reinforcing the adhesive.

It was observed that when the glass

breaks readily there is less tendency for

the glass particles to separate from the

plastic.

In most cases more coats of lacquer are required to obtain an effective treatment

than the number recommended by the manufacturers. The number of coats necessary

to obtain the minimum thickness will vary

with the Individual lacquer; the thickness

of the coat deposited is a function of the

solids content and the viscosity of the solution.

The method of applying an antiscatter

treatment is an important factor in obtaining the maximum effectiveness. The treat- ment should be applied on the frame beyond

the glass area, so that the pane will not

break along the edge where there is no ap- plication. When the glass breaks along the

entire edge, the whole pane is likely to be

blown into the room by the blast.

Any antiscatter treatment applied to glass will reduce the light transmission.

This is particularly true of fabrics and

tapes applied as over-all treatments.

IX. SUMMARY

1. The vacuum-concussion apparatus used

to evaluate the effectiveness of antiscatter

treatments applied to glass is' described in

this report. The results of tests of various types of materials to determine their
10 Miscellaneous Publications of the national Bureau of Standards

suitability as antiscat tering agents are

reported.

2. Some of the liquid materials (lacquers) gave satisfactory results as initially applied when the film thicknesses

were 12 mils or greater.

3. None of the tapes gave satisfactory

results when applied in patterns which cover only part of the glass. Three tapes gave

satisfactory results as initially applied

when all of the glass was covered by the

material

.

4. Some adhesive-fabric combinations

gave satisfactory results as initially applied. The effectiveness of a particular

combination cannot be evaluated from the

behavior of the adhesive separately or the

fabric with other adhesives. Each combination must be tested to determine its antiscatter effectiveness.

5. Antiscatter treatments must maintain

their protective action after a reasonable

aging period in order to be suitable for

general use. Wet-dry cyclic and heat tests were made to determine the aging characteristics of the various types of antiscatter

materials. Only a few materials gave sat- isfactory results after subjection to the

accelerated aging test. The lacquers which

gave "good breaks" after aging were made

with polyvinyl butyral.

6. It should be recognized that no antiscatter treatment can be expected to give

complete protection from the hazards of

flying glass.

X. REFERENCES

[l] H. Moore, Physics and windows in war-time,

J. 8cl. Instruments 17, 237-241 (Oct. 1940).

[2] Anonymous, Thermoplastics under vacuum, Plastics %, 263 (Dec. 1940).

[3] Anonymous, Blast tests on glass, Plastics 5, 23-25 (Feb. 1941) . [4] H. M. Llewellyn, Antiscatter treatments for

windows, Chemistry and Industry 60, 433-4

(June 7, 1941).

[5] H. H. Llewellyn, The testing of varnishes for

use in conjunction with antiscatter fabrics,

J. Soc. Chem. Ind. 61, 60-63 (April 1942).

[6] B. Butterworth, Adhesion and adhesives, with

special reference to antiscatter treatments for windows. Part I. Adhesion and adhesives,

Chemistry and Industry 61, 339-341 (Aug. 8,

1942) . [7] B. Butterworth, Adhesion and adhesives, with special reference to antiscatter treatments for windows. Part II. Properties required in adhesives for window protection. Chemistry and

Industry SI, 360-51 (Aug. 15, 1942).

[8] British Standard Specification (ARP Series) for Antiscatter Fabrics, BS/ARP45 (May 1942; . Prepared by the British Standards Institution at the request of the Ministry of Home Security.

Additional References

H. Schardin, D. Elle, and W. Struth, On the prop- agation of shattering in glass and in glass substitutes, Z. Tech. Phys. 21, 393-400 (1940). Anonymous, Windows and bomb blast, - Nature |i|6, 435-6 (Sept. 28, 1940). Anonymous, The protection of windows against airraid damage, Engineering 150, 275-7 (Oct. 4, 1940).

D. Bernal, The physics of air raids, (report of

a lecture) Engineering 1 50, 514 (Dec. 27, 1940)

.

R. J. Moore and H. W. Mackinney, Information on flexible -transparent and trans lucent substitutes for window glass, Trans. Am. Inst. Chem. Eng. 38, 237- 244 (Feb. 1942)

.

Anonymous, Testing window glass for concussion

damage, Eng. News-Record 128, 521 (April 2, 1942). Glass and Glass Substitutes, prepared under di- rection of Chief of Engineers, 0. 'S. Army, for the United States Office of Civilian Defense, Protective

Construction Series No. 1, for sale by the Superintendent of Documents, Washington 25, D. C. , for 10

cents

.

0. Petzold, Anti-Splinter Coatings for Glass, The

Oil and Colour Trades Journal 98, 144-45, 180-84,

259-60, 330-31, 471-72, 611, 613, 763-65 (July 26,

Aug. 2, 16, aO, Sept. 27, Oct. 28, and Nov. 22,

1940) . F. W. Adams, Behavior of Glazing Material Subjected to Explosion, ASTM Bui. No. 122, p. 15-23 (May 1943).
ILLUSTRATIONS

and

TABLES

Aniiscatter Treatments for Glass 13

Figure 1.

Diagram of vacuum-concussion apparatus.

1, Specimen; 2. quick-acting release valve; 3. concussion chamber: 4. to manometer; 5, to vacuum pump;

6, vacuum storage tank; 7. trigger mechanism for quick-acting release valve.

Figure 2. —Vacuum-concussion apparatus.

~>9"-,:i — 44 3


16 Miscellaneous Publications of the National Bureau of Standards

S %//,in\# c -

'/ /

:

i tin v>

Figure 7.Explosion-area diagram.

I. Area of explosion; walls will not withstand this force.

II. Windows blow out regardless of treatment.

III. All ordinary window glass broken. Untreated glass scattered. Glass covered with a good treatment

scattered only a small amount. Some types of glass, e. g., tempered and heavy plate, may not break. IV. Glass may or may not be broken, depending on the type of glass and treatment.
Antiscatter Treatments for Glass 17

XL TABULATION OF DATA

In the accompanying tables 1 to 31, inclusive, the following letters are used to designate the types of treatments noted:

A = Asphalt-asbestos. F = Fabrics.

G = Glazing materials (glass) other than double strength window glass. Not treated. L = Commercial liquid materials. P = Treatments applied to other than double strength window glass. R = Glazing materials, plastic.

S - Sheetings or films, plastic.

T = Tapes.

Z = Home-formulated adhesives for fabrics.

Table 1. — Description of liquid materials tested for antiscatter effectiveness

Sample

nation Description of material

Sample

nation

L-AA-1.

.

Opaque, black, reclaimed- rubber dispersion. L-IX-1.. Transparent, colorless chlorinated rubber lacquer.

L-AR-1..

L-A R-2.

.

L-A R-3.

.

L-AR-1..

L-AR-5..

Transparent, colorless acrylic resin lacquer.

Do. Transparent, colorless ethylcellulose lacquer. Transparent, colorless polyvinyl acetate lacquer.

White, creamlike, cellulose nitrate emulsion; dried

colorless and transparent.

L-MC-1..

L-NS-1..

L-NS-2..

L-NS-3.

.

Transparent, colorless polyvinyl butyral lacquer.

White, creamy, polyvinyl acetate adhesive; dries clear. Translucent, brown protein glue; applied in hot aqueous

solution.

White, creamy, polyvinyl acetate adhesive; dries clear.

L-C P-1.. L-CP-2..

L-EI-1.

.

L-EI-2.. L-EI-3- •

Transparent, colorless ethylcellulose lacquer.

Do..

Transparent, colorless, polyvinyl butyral lacquer.

Do.

Do.

L-PP-1..

L-RF-1.

.

L-RF-2..

L-RM-1.

.

Transparent, colorless polyvinyl acetate lacquer.

Transparent, colorless polyvinyl butyral lacquer. Transparent, colorless ethylcellulose lacquer.

Transparent, colorless lacquer.

L-FC-1.. Transparent, colorless polyvinyl acetate lacquer. L-SC-1.. Do.

L-CI-1..

L-GI-2..

Transparent, colorless polyvinyl butyral lacquer. Same as L-GI-1, except more viscous (higher solids content)

.

L-WP-1.

.

1-WW-l.

.

Do.

Transparent, colorless ethylcellulose lacquer.

Table 2.Description of plastic sheetings tested for antiscatter effectiveness

Sample

designation Description of material

Transparent, colorless cellulose acetate. Do.

Transparent, colorless, thin cellulosic plastic sheet.

Translucent, colorless,

Transparent, colorless, Transparent, colorless, Transparent, colorless, Transparent, colorless, Transparent, colorless,

15-mil-thick vinyl butyral resin sheet. 5-mil-thick vinyl butyral resin sheet. 10-mil-thick vinyl butyral resin sheet. 15-mil-thick vinyl butyral resin sheet. 20-mil-thick vinyl butyral resin sheet. 25-mil-thick vinyl butyral resin sheet.

Transparent, colorless, rubbery, 20-mil-thick vinyl butyral resin sheet. Transparent, colorless, rubbery, 30-mil-thick vinyl butyral resin sheet. Transparent, colorless, rubbery, 45-mil-thick vinyl butyral resin sheet. Transparent, colorless, rubbery, 60-mil-thick vinyl butyral resin sheet. Transparent, colorless, rubbery, 15-mil-thick vinyl butyral resin sheet.

Translucent, rubbery, 25-mil-thick vinyl butyral resin sheet. Translucent, rubbery, 25-mil-thick vinyl butyral resin sheet covered with a layer of thin cellulose acetate sheet. Translucent, rubbery, 15-mil-thick vinyl butyral resin sheet. Translucent, rubbery, 15-mil-thick vinyl butyral resin sheet covered with a layer of thin cellulose acetate sheet. Translucent, rubbery, 8-mil-thick vinyl buytral resin sheet. Translucent, rubbery, 8-mil-thick vinyl butyral resin sheet covered with a layer of thin cellulose acetate sheet. Transparent, colorless thin cellulose acetate sheet.

Transparent, colorless regenerated cellulose sheet coated on one side with a water-soluble adhesive.

Transparent, colorless, thin cellulosic plastic sheet; pressure-sensitive adhesive.
18 Miscellaneous Publications of the National Bureau of Standards

Table 3.

Description of tapes tested for antiscatter effectiveness

Sample designation

Description of material

T-GP-1.

T -GP-2. T-GP-3.

T-GP-4.

T-GP-5.

T -GP-6. T-GP-7. T-IP-1.

T-IP-2.

T-IP-3.

T -IP-4. T-IP-5.

T-IP-6., T-IP-7.

T -IP-8. T-IP-9. T-IP-10

T -IP-11

T-MM-1.

X -UM-2.

T -MM-3.

T-tfll-4. T -MM-5.

T -MM-6.

T -MU-7. T -UM-8.

T -UU-9.

T -MU-10 T-UM-11

T -US-1. T-MS-2.

T-US-3.

T -US-1.

T -PB-1.

T -PB-2. T-PB-3.

Opaque, brown, l"-wide paper; water-soluble adhesive. Opaque, brown, 2"-wide paper; water-soluble adhesive.

Opaque, tan-white tweed, 1" cloth; water-soluble adhesive. Opaque, tan-white tweed, 2" cloth; water-soluble adhesive. Opaque, brown, l"-wide, 35-lb paper; water-soluble adhesive.

Opaque, brown, l"-wide, 60-lb paper; water-soluble adhesive. Opaque, brown, l"-wide, 90-lb paper; water-soluble adhesive.

Transparent, colorless, l"-wide thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 3/4"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, l"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 1 l/8"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 1 l/2"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 2"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 4"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 2"-wide, thin plastic sheeting; pressure-sensitive adhesive. Transparent, colorless, 4"-wide, thin plastic sheeting; pressure-sensitive adhesive. Opaque, brown, 2"-wide paper; pressure-sensitive adhesive. Opaque, black, 1 l/2"-wide, thin plastic sheeting; pressure sensitive adhesive.

Translucent, gray, l"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive. Translucent, gray, 2"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive. Translucent, gray, 4"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive.

Opaque, black, 2"-wide paper, photographic; pressure-sensitive adhesive. , Opaque, white, rough grain, 2"-wide paper masking; pressure-sensitive adhesive.

Opaque, black, 2"-wide paper, photographic; pressure-sensitive adhesive. Translucent, white, 4"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive. Translucent, colorless, 4"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive.

Do. Transparent, colorless, 4"-wide cellophane; pressure-sensitive adhesive. Transparent, colorless, 4"-wide cellulose acetate and cellulose fiber; pressure-sensitive adhesive.

Opaque, brown, l"-wide paper with white cord sewn down middle; water-soluble adhesive. Opaque, brown, 2"-wide paper with white cord sewn down middle; water-soluble adhesive.

Opaque, brown, l"-wide paper with white rope sewn down middle; water-soluble adhesive. Opaque, brown, 2"-wide paper with white rope sewn down middle; water-soluble adhesive.

Transparent, colorless, 2"-wide cellulose acetate; pressure-sensitive adhesive. Opaque, yellow, l"-wide, cellophane; pressure-sensitive adhesive. Opaque, white, 2"-wlde fabric, surgeons; pressure-sensitive adhesive.

Table 4.—Description of fabrics and adhesives specified for fabrics tested for antiscatter effectiveness

Sample

designation Description of materials

Sample designation Description of materials

F-AU-1..

F-AB-1.

.

F-CS-1..

White, close-weave, stiff scrim.

Opaque, brown vegetable adhesive.

Opaque, black paper, adhesive on one side.

F-UC-1..

F-UF-1.

.

F-MF-2..

White, close-weave scrim impregnated with polyvinyl butyral

.

White, small mesh lace curtain.

White, large mesh lace curtain. F-DC-1.

.

White, 1/4-ln. netting. F-MP-1.. Opaque, grey-brown liquid.

F-II-1.. F-II-2..

F-LO-1.

.

White, large mesh lace. Green, l/4-in. netting.

Black, close-weave scrim.

F-NS-1..

F-NS-2.. F-NS-3-

.

F-NS-4..

Opaque, white, wet-converted starch paste. Opaque, white, vegetable-base plastic adhesive. Opaque, brown, vegetable-base plastic adhesive.

Opaque, tan, plastlclzed flour paste.

F-MA-1.

.

F-IIA-2.

F-yA-3.

.

Brown, close-weave, heavy needlepoint canvas. Brown, close-weave, heavy needlepoint canvas, one coat of plastic. Brown, close-weave, heavy needlepoint canvas, two coats

of plastic.

F-iKX-1.. F-XX-5.

.

F-XX-3.. F-XX-4.

.

Natural, cheesecloth.

Green, 1/4—in. netting.

Natural, close-weave muslin. Natural, 3/32-ln. netting.

TABLE 5.—Description of asphalt-asbestos combinations tested for antiscatter effectiveness

Sample

designation Description of material

A-SU-1.

A-SM-2, A-SM-3.

A -SM-4.

Opaque, black, 6-lb reinforced asbestos paper, asphalt-clay emulsion adhesive.

Opaque, black, asphalt cutback base coating with asbestos fiber filler. Opaque, black, 50-lb unsaturated rag felt, asphalt-clay emulsion adhesive. Opaque, black, 15-lb asphalt saturated rag felt, asbestos fiber and asphalt-cement adhesive.
Anti8catter Treatments for Glass 19

Table 6.—Description of treataents applied to single strength vlndov glass, 7/32-inch glass, plate glass,

and tempered glass, and tested for anttscatter effectiveness

Sample designation Description of material

P- AW-1..

p-LO-1..

P-LO-S...

P-LO-3..

P-LO-4..

P-LO-5.. P-LO-6.

.

P-LO-7.

P-LO-8..

P-LO-9..

P-LO-10.

P-LO-11.

P- U C-l.

.

p-yc-2..

P-MC-3..

P-MC-4..

P-MC-5.. P-MC-6.

.

P- M C-7.

.

Opaque, black paint, applied Over transparent, colorless, polyvinyl butyral lacquer, applied to 7/32"

glass.

Transparent, colorless, 30-mil-thick polyvinyl butyral resin sheet applied to single-strength window

glass. Transparent, colorless, 45-mil- thick polyvinyl butyral resin sheet applied to single-strength window

glass. Transparent, colorless, 60-mil-thick polyvinyl butyral resin sheet applied to single-strength window

glass. Transparent, colorless, 20-mll- thick polyvinyl butyral resin sheet applied to l/4"-thick plate glass. Transparent, colorless, 30-mil-thick polyvinyl butyral resin sheet applied to l/4"-thick plate glass. Transparent, colorless, 45-mil-thick polyvinyl butyral resin sheet applied to l/4"-thick plate glass. Transparent, colorless, 60-mil-thick polyvinyl butyral resin sheet applied to l/4"-thick plate glass. Transparent, colorless, 15-mil-thick polyvinyl butyral resin sheet applied to l/4"-thick plate glass. Transparent, colorless, 20-mil- thick polyvinyl butyral resin sheet applied to l/4"-thick tempered

glass. Transparent, colorless, 15-mil-thick polyvinyl butyral resin sheet applied to 1/4" - thick tempered

glass. Black, close-weave scrim impregnated with polyvinyl butyral resin applied to l/4"-thick plate glass.

Translucent, colorless, 25-mil- thick polyvinyl butyral resin sheet applied to single-strength- window

glass. Translucent, colorless, 25-mil-thick polyvinyl butyral resin sheet covered with a layer of thin cel- lulose acetate sheet and applied to single-strength window glass. Translucent, colorless, 15-mil-thick polyvinyl butyral resin sheet applied to single-strength window

glass. Translucent, colorless, 15-mil-thick polyvinyl butyral resin sheet, covered with a layer of thin cel- lulose acetate sheet and applied to single-strength window glass. Translucent, colorless, 8-mil-thick polyvinyl butyral resin sheet, applied to single-strength window

glass. Translucent, colorless, 8-mil-thick polyvinyl butyral resin sheet covered with a layer of thin cellu- lose acetate sheet, and applied to single-strength window glass.

White, close—weave, scrim impregnated with polyvinyl butyral resin and applied to single-strength window

glass.

Table 7.

Description of special glass products tested for scatter resistance

Sample designation Description of material

G-An-1.

C-PG-1.

G-PG-2.

G-PG-3.

G-PG-4.

G-LO-1.

G-PG-5.

G-M G-l, G-MG-2

G-An^2

G-Aw-3

G-L 0-2

G-PG-6

G-PG-7

G-PG-8

G-PG-9

Double-strength window glass, 1/8" thick.

Single- strength window glass, 3/32" thick. Double- strength window glass, 1/8" thick. Heavy window glass, 3/16" thick. Plate glass, 1/4" thick.

Tempered glass, 1/4" thick.

Do.

Wire glass, 1/4" thick. Translucent wire glass, 1/4" thick.

Laminated glass, Laminated glass,

one pane single-strength and the other pane double-strength window glass, one pane, 7/32" thick; other pane, lantern-slide glass.

Laminated glass, one pane each, l/8"-thick tempered glass, l/8"-thick heat-treated glass, tempered glass, l/4"-thick tempered glass, three plastic interlayers.

Laminated glass, two panes l/8"-thick photo glass. Laminated glass, two panes of either single-strength or double-strength window glass. Laminated glass, one pane 5/32"-thick window glass, other pane 7/32"-thick window glass. Laminated glass, one pane 7/32"-thick window glass, other pane 9/32"-thlck window glass.

1/8 "-thick

G-AW-5. Single-strength glass, two panes coated with polyvinyl butyral plastic on sides facing out, 1/2" air

space between two panes.
20 Miscellaneous Publications of the National Bureau of Standards

TABLE 8 Description of replacements for glass in windou enclosures tested for blast resistance

Sample

ilesAgnfiti en Description of material

Opaque, black, 1/8"*- thick asphalt board containing organic- fiber reinforcing and mineral matter.

Opaque, black, l/8"-thick, 3-ply construction—asbestos felt, rag felt, and asbestos paper. Opaque, black, 9/64"-thick, 4-ply construction—asbestos felt, 2 rag felt, and asbestos paper. Transparent, colorless, cellulose acetate sheet reinforced with metal screening. bo.

Table 9.

Description of pastes readily prepared in the home

Sample designation Description of materials

Flour paste: Prepared by heating with constant stirring, a mixture of flour and water in the following proportions: 1 lb of flour, 1 gal of water. A small amount of cold water is mixed with the flour and the rest of the water heated to boiling. The flour and cold-water mixture is added to the boiling water and heated until

thickened.

Tapioca paste I: Prepared by heating with constant stirring, a mixture of tapioca starch, phthalic anhydride, and water in the following proportions: 1 lb of tapioca starch, 0.2 oz of phthalic anhydride, 8 lb of water.

Tapioca paste II: Prepared by heating with constant stirring, a mixture of potato starch, tapioca starch, alum, and para- formaldehyde in the following proportions: 1.9 lb of potato starch, 5.4 lb of tapioca starch, 0.03 lb of

alum, 0.02 lb of paraformaldehyde, 8 lb of water.

Tapioca-glue combination I: Prepared by heating with constant stirring, a mixture of tapioca starch, animal glue, and water in the following proportions: 1 lb of tapioca, 1/3 lb of animal glue, 2 lb of water.

Tap I oca-glue combination II: Prepared in the same manner as Z-4, using instead 1/4 lb of glue to 1 lb of tapioca starch.

Table 10.— Vacuum-impact tests made on glass treated with liquid materials

Sample

designation Method of application to glass Film

thickness Descriptionof break11

L -AB -1 L -AB -2 L -AB -3 L -AB -4

L -All -5

L-CP-2.

L-EI-2.

L-EI-1. L-EI-3.

L-FC-1.

One coat applied with a doctor blade.. do Two coats applied with a doctor blade. do

One coat applied with a doctor blade.. !One coat brushed on Two coats brushed on Six coats brushed on; dried 2 weeks...

Five coats brushed on fTwo coats brushed on.....

\ do

One coat applied with doctor blade; second coat brushed on. One coat applied with doctor blade (Two coats brushed on Four coats brushed on

frjne coat applied with doctor blade

(Three coats brushed on

fOne coat brushed on

, ..do

..do

. . .do

!Two.coa.ts brushed on

jOne coat brushed on L-GI-1.. (Two coats brushed on

...do ..do /Three coats brushed on f

. . .do 20 A

...do 19 A

\Three coats brushed on; dried 2 weeks 24 ' A *The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

Htls 12 to 14

119.5 11.5

184.5

5.5

17

1115

1525

25

12

19

10

181.5

3.5 5.5

6

67.5

10

1214.5

1520

1924

'
Antiscatter Treatments for Glass

Table 10.—Vacuum-impact tests made on glass treated vith liquid materia Is—Continued

21

Method of application to glass mi

thickness Description of break2

Three coats brushed on . .... ... 'One coat brushed on... . .

, do

i, One coat brushed on; dried 2 weeks .... Six coats brushed on...

'Thijined out 1:1 by weight with T25; three coats brushed on. thinned out 1:1 with T25; nine coats brushed on

iThinned out 3:1 by weight with T25; one coat brushed on....

v Thinned out 2:1 by weight with T25; two coats brushed on... One coat applied with doctor blade

One coat brushed on « > • fTwo coats brushed on do

^Five coats brushed on............

'Three coats brushed on - Four coats brushed on Nine coats brushed on Five coats brushed on

•dp. 'Three coats brushed on

...do One coat applied with doctor blade... Six coats brushed on. Four coats applied with doctor blade.

k Four coats brushed on; dried 2 weeks.

("One coat brushed on Two coats brushed on.

(.Four coats brushed on One coat applied with doctor blade...

Mils

1115.5

1933

10.5 2.5 12.5

9.5 10

( C

) 157.5

725

1.5

5.5 11.5 20

95.5 5.5

8.5 920

26

3.5 10

25

6.5

E The descriptions of break corresponding to the various letter designations are described on p. 5. of break; B is next, etc.

b Dried too unevenly to determine.

A is the most preferred type

TABLE 11 Vacuum- impact tests made on glass treated with plastic sheetings

Method of application to glassb Film

thickness

Hits

15 A

15 A

5 D

10 E

15 C 20 D

25 D 20 A 30 A

45 A

60 MA;,

15 c

25 A 25 B

15 C

15 A

8

8 B

B

2.5 E

5 DE

7.5 E

c 10 E 10 C 2.5 C

Description

of break8

Coat of A adhesive brushed on glass; sheeting rolled on over A. Coat of B adhesive brushed on glass; sheeting rolled on over B.

'Glass pane wet with water; sheet of S-SI-1 rolled on Glass wet with water; two sheets of S-SI-1 rolled on

...do

I Glass wet; three sheets rolled on , )Two sheets rolled on each side of we! Glass wet; four sheets rolled on Glass wet; one sheet rolled on; two diagonal lines, from opposite corners cut into S-SI-1 with knife.

glass.

'Glass-wet; two sheets rolled on diagonals cut. One sheet pressed on glass with a warm iron... Four sheets pressed on with warm iron

1 do ^Six sheets pressed on with warm iron Waxed paper pulled off film as film was rolled on glass; 48 hr drying time.

52.5

10

10

15

'The descriptions of break corresponding to the various letter designations are described on p. 5. A is the nost preferred type of break; B is next, etc. °P= treatments applied to glass by manufacturers in thefr laboratories. c 5 mils on each side.
22 Miscellaneous Publications of the National Bureau of Standards

TABLE 12. —Vacuum-impact tests made on glass treated with tapes

Method of application to glass Description

of break"

Basket-weave pattern; strips applied 1 in. apart. Overlapping strips applied to glass widthwise. . .

.

Overlapping strips applied to glass lengthwise...

Basket-weave pattern; strips applied 2 in. apart Overlapping strips applied widthwise Overlapping strips applied lengthwise ,. Overlapping strips applied lengthwise; 4 in. slit cut in center widthwise.

Parallel strips 1 in. apart, applied lengthwise Four strips applied in Union Jack pattern

Basket-weave pattern; strips applied 1 in. apart Basket-weave pattern; strips applied 2 in. apart, reinforced at edges. Overlapping strips applied lengthwise to glass Overlapping strips applied widthwise Overlapping strips applied lengthwise; 4 in. slit in center widthwise.

Overlapping strips applied lengthwise; ^> <^ pattern cut

Basket-weave pattern; strips applied 2 in. apart

Overlapping strips applied lengthwise; pattern cut.

I Overlapping strips applied widthwise; <^ pattern cut..

Overlapping strips applied widthwise

Overlapping strips applied lengthwise Overlapping strips applied widthwise; 5 in. slit in center lengthwise.

Overlapping strips applied widthwise; ^> patte:rn cut.

Basket-weave pattern; 1 in. between strips. Basket-weave; 1-in. space between strips... do »

Strips applied lengthwise, 3/4 in. between each; insufficient material for basket-weave

pattern.

(Basket-weave pattern; all strips applied lengthwise first, then widthwise. Basket-weave; alternating 1 strip lengthwise, 1 widthwise

Basket-weave; 2-in. space between strips Overlapping strips applied lengthwise

Basket-weave, 75% coverage

Basket-weave; 2-in. space between strips Overlapping strips applied lengthwise

Basket-weave; 1-in. space between strips Basket-weave; 2-in. space between strips Basket-weave; 1 in. between strips; rope removed from strips 1 in. from ends

Basket-weave; 2-in. space between strips; rope removed from strips 1 in. from ends.

Basket-weave; 1-in. space between strips. Basket-weave; 2-in. space between strips. do Overlapping strips applied lengthwise Overlapping strips applied widthwise Overlapping strips applied lengthwise Overlapping strips applied lengthwise; reinforced around border with extra strips. Basket-weave pattern; 2-in. space between strips.... do

Basket-weave; 2-in. space between strips

Overlapping strips applied lengthwise.

Basket-weave pattern; 1/2 in. between strips... Basket-weave pattern; 1 1/2 in. between strips.

* The descriptions of break corresponding to the various letter designations are described on p. 5. A is the »ost preferred type of break: B is next, etc.
Antiscatter Treatments for Glass 23

Table 13.—Vacuum- impact tests made on glass treated vitti fabrics, and adhesives specified for fabrics

Method of application to glass Film

thickness Description

of break"

i Coat of L-MC-1 applied to glass. Two halves of F-AM-1 smoothed over.

F-AR-1 spread on glass Rolled on glass Coat of adhesive brushed on. F-DC-1 pressed down over it. F-IT-1 applied to glass with water

t L-GI-1 brushed on glass. F-IT-2 smoothed over. Another coat L-GI-1 applied.

C)

F-AR-1 spread on glass. F-MA-1 smoothed over

L-MC-l brushed on glass. F-MA-1 smoothed over

L-RF-2 brushed on glass. F-MA-1 smoothed over. Two more coats L-RF-2 brushed on.

.

do

Coat of L-SC-1 brushed on. F-MA-1 smoothed over. One more coat L-SC-1 brushed on.

Z-l spread on glass. F-MA-1 smoothed over

F-MP-1 spread on glass. F-WA-2 pressed down over.

F-AR-1 spread on glass. F-MF-1 smoothed on

do

L-EI-2 brushed on glass. F-MF-1 smoothed over. Another coat L-EI-2 brushed on

L-GI-1 brushed on glass. F-MF-1 smoothed over. Another coat of L-GI-1 brushed on.

Z-l spread on glass. F-MF-1 smoothed over

Z-2 spread on glass. F-MF-1 smoothed over

F-AR-1 spread on glass. F-MF-2 smoothed over

do

L-EI-2 brushed on glass. F-MF-2 smoothed over

L-EI-2 brushed on glass. F-MF-2 smoothed over. Another coat L-EI-2 brushed on....

L-GI-1 lacquer brushed on glass. F-MF-2 smoothed over

L-RF-2 brushed on glass. F-MF-2 smoothed on. Two more coats L-RF-2 brushed on....

L-SC-1 brushed on glass. F-MF-2 smoothed over. Two more coats L-SC-1 applied

Z-3 spread on glass. F-MF-2 smoothed over

Z-4 spread on glass. F-MF-2 smoothed over

F-AR-1 spread on glass. F-XX-1 smoothed over

do

F-NS-1 brushed on glass. F-XX-1 smoothed over

F-NS-3 brushed on glass. F-XX-1 smoothed over

F-NS-4 brushed on glass. F-XX-1 smoothed over

L-GI-1 brushed on glass. F-XX-1 smoothed over

L-SC-1 brushed on glass, F-XX-1 smoothed over

F-XX-2 stretched over glass. L-NS-2 brushed on

* The descriptions of break corresponding to the various letter designations are described in the text on p. 5. A is the most

preferred type of break; B is next, etc.

6 Treatments applied to glass by manufacturers In their laboratories.
24 Miscellaneous Publications of the National Bureau of Standards

Table 13.—Vacuum-impact tests made on glass treated, with fabrics, and adhesives specified for fabrics —Con.

Method of application to glass Film

thickness Description of break3

His

F-XX-2 stretched over glass. F-NS-2 brushed on

F-NS-3 brushed on glass. F-XX-2 smoothed over.

WlF-2 brushed on glass. F-XX-2 smoothed over. Two coats L-RF-2 brushed on.

Z-l spread on glass. F-XX-2 smoothed over

Z-2 spread on glass. F-XX-2 smoothed over

£-3 spread on glass. F-XX-2 smoothed over

F-AR-1 spread on glass. F-XX-3 smoothed on

do

do

do

do

10-15

F-AR-1 spread on glass. F-XX-3 smoothed over. L-CP-2 brushed on

F-AR-1 spread on glass. F-XX-3 smoothed over. Four coats L-CP-2 brushed on.

F-AR-1 spread on glass. F-XX-3 smoothed over. L-EI -2 brushed on

F-AR-1 spread on glass. F-XX-3 smoothed over. Four coats L-GI-1 brushed on.

F-AR-1 spread on glass. F-XX-3 smoothed over. One coat L-GI-1 brushed on...

Thin coat L-CP-2 brushed on glass. F-XX-3 smoothed over.

do

.do.

.do.

L-CP-2 brushed on glass. F-XX-3 smoothed over. Another coat L-CP-2 brushed on....

Two coats L-CP-2 brushed on. F-XX-3 smoothed over. Two more coats L-CP-2 applied.

do

L-CP-2 brushed on glass. F-XX-3 smoothed over. Four coats L-CP-2 brushed on

Three coats L-CP-2 brushed on glass. F-XX-3 smoothed over Three coats L-CP-2 brushed on glass. F-XX-3 smoothed over. Three more coats L-CP-2 brushed on.

.do.

.do.

One thin coat L-Cl-1 brushed on. F-XX-3 smoothed over

Thin coat L-GI-1 brushed on glass. F-XX-3 smoothed over...

do

Five coats L-GI-1 brushed on glass. F-XX-3 smoothed over..

Three coats L-GI-1 brushed on glass. F-XX-3 smoothed over.

'The descriptions of break corresponding to the various letter designations are described in the text on p. 5. A

preferred type of break; B is next, etc.
Antiscatter Treatments for Glass 25

Table 13.

Vacuum-impact tests made on glass treated uith fabrics, and adhesives specified for fabrics —Con.

Method of application to glass Film

thickness Descriptionof break3

Klls Two coats L-GI-1 brushed on glass. F-XX-3 smoothed over. Another coat L-GI-1 brushed on.

Two coats L-GI-1 brushed on. F-XX-3 smoothed over

Two coats L-GI-1 brushed on. F-XX-3 smoothed over. Two more coats L-GI-1 brushed on.

L-GI-1 brushed on. F-XX-3 smoothed over. Another coat L-GI-1 brushed on

L-GI-1 brushed on glass. F-XX-3 smoothed over. Three additional coats L-GI-1 brushed on. Three coats L-GI-1 brushed on glass. F-XX-3 smoothed over. Two coats L-GI-1 brushed on.

Thin coat L-SC-1 brushed on glass. F-XX-3 smoothed over.

Z-l spread on glass. F-XX-3 smoothed over

do '.

do

Z-l spread on glass. F-XX-3 smoothed over. Two coats L-CP-2 brushed on.

Z-2 spread on glass. F-XX-3 smoothed over

Z-3 spread on glass. F-XX-3 smoothed over

do

do

Z-4 spread on glass. F-XX-3 smoothed over

do

do

£-5 spread on glass. F-XX-3 smoothed over -

do

L-CP-2 brushed on glass. F-XX-4 smoothed over. Another coat L-CP-2 brushed on.

do

15

15

a The descriptions of break corresponding to the various letter designations are described in the text on p. 5. A is the most

preferred type of break; B is next, etc.

Table 14.Vacuum- impact tests made on glass treated uith aspha It-asbestos combinations

Sample designation Method of application

to glass*

Film thickness Description of break6 Weight of fragments of glass in basket

PP

P

P

Ml Is C

ADD

Crams

30

< 1

2.466.5

P= Treatments applied to glass by manufacturers in their laboratories. "The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break, B is next, etc.
26 Miscellaneous Publications of the National Bureau of Standards

Table 15.-Vacuum- impact tests made on glass treated with combinations of liquid materials, films, and tapes

Sample

designation

Method of application to glass Film

t hicknsss Description of break?

Weight of

fragments of glass

in basket

L-CP-1

T-GP-3

1 Coat of L-CP-1 brushed on and allowed to dry. Strips of T-GP-3 applied in basketj weave pattern 2" between strips.

Mils

j 3.5 (L-CP-1) E

Grans950

L-CP-1 T-GP-1

1 3.5 (L-CP-1) D 135

L-GI-1 S-SI-1

(One coat L-GI-1 brushed on and allowed to dry. One sheet S—SI-1 pressed on with

s warm iron. } 6

14

D

C

146

45

L-GI-1

T-GP-3

\ Coat of L-GI-1 brushed on and allowed to dry. Strips of T-GP-3 applied in basket-

/ weave pattern 2" between strips. j 3.5 (L-GI-1) F 183

L-GI-1 T-GP-3 6-5 (L-GL-1

)

C 115

L-GI-1 T-GP-4 4 (L-GI-1) D 117

L-GI-1 T-MM-9 ICoat of L-GI-1 brushed on and allowed to dry. Overlapping strips of T-MM-9 applied

/ lengthwise. J 3.5 (L-GI-1) C 20

L-MC-1 S-DC-1\ Coat of L-MC-1 brushed on glass followed by S-DC-1 film rolled on over the

/ L-MC-1. h D 185

L-MC-1 S-MC-7 7.5 E 945

L-NS-3 S-CC-1

\ Adhesive L-NS-3 brushed on glass, followed by S-CC-1 film rolled over the

/ L-NS-3. / 4.5 (S-CC-1)

I 4.5 (S-CC-1) B

C <1

20

L-NS-3 S-CC-2

1 adhesive L-NS-3 brushed on glass, followed by S-CC-2 film rolled on over

j L-NS-3. J 3.5 (S-CC-2) D 3

L-SC-1 T-GP-31 Coat of L-SC-1 brushed on and allowed to dry. Strips of T-GP-3 applied in basket-

/ weave pattern 1" between strips. j 4 (L-SC-1) B 5

L-SC-1

T-GP-3

1 T-GP-3 applied in basket-weave pattern 2" between strips. 2 coats L-SC-1 brushed on.

.

/ T-GP-3 applied in basket-weave pattern 1" between strips. 2 coats L-SC-1 brushed on.

.

E

C

33060

a The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break, B is next, etc.

Table 16. Vacuum- impact tests made on treatments applied to single strength vlndow glass, 7/32-lnch glass,

plate glass, and tempered glass

Sample designation Method of application

to glassa Film thickness Description of break" Weight of fragments

of glass in basket

P-AW-1..

P-L0-1.. P-L0-2.. P-LO-3.. P-LO-4.

.

P-LO-5.. P-LO-7..

P-LO-8..

P-LO-9..

P-LO-10. P-L0-11

P-HC-1..

P-MC-2.. P-MC-3..

P-MC-4..

P-UC-5.,

P-MC-6..

p-yc-7..

3045

60

20

3060

1520

15

2525

1515

8

8

A

A

CF (28" Hg) F (28" Bg) D (24" Hg)

(C)

( e) C

B

A

BA

A

D

C

Grams

1,020

<1

<1

<1

56

< 1 <1

378

5 <1

< 1

< 1

< 15

16

*P = treatments applied to glass by manufacturers in their laboratories. The descriptions of break corresponding to the various letter designations are described on p. 5. of break; B is next, etc. °Did not break.

A is the most preferred type
Anttscatter Treatments for Glass

TABLE 17. — Vacuum-Impact tests made on special glass products

27

Sample designation Type of glass Manometer

reading Description

of break3 Weight of fragments of glass in basket

G-AW-1. G-PG-1. G-PG-2.

G-PG-3.

G-LO-1.

G-PG-5.

G-MG-1.

G-MG -2. G-AW-2.

G-AW-3. G-LO-2.

G-PG-6.

G-PG-7.

G-PG-8.

G-PG-9.

G-AW-5.

Double-s trength

.

Single-s trength. Double-s trength Glazing quality.

Tempered.

do.

.

Polished wire glass. Hammered wire glass.

Double and single

7/32" and lantern slide. Laminated

do

.do.

.do.

.do.

Single-strength double-glazed unit.

20 E 20 E 20 E 20 E

20;24;28 C)

20;24;28 C)

28 E 20 E

20 E 24 E

20;24;28 C)

20 A

20 E 20 B

20 D 20 D 20 E

20 A

Grams

925 725

940

1,710

1,987 1,740

1,360

1,962 <1

960

75

10

1,320 <1

"The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

6 Did not break.

TABLE 18.— Vacuum-Impact tests made on replacements for glass In uindou enclosures

Sample designation Description of break1 Weight of fragments of

material in basket

CD

DD

A

Grams <1

<1<1

686 <1

8 The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

TABLE 19.Vacuum-Impact tests made on glass treated vith liquid materials and subjected to cycles of high and

low humidity (accelerated aging test I,

Sample designation

Film

thickness Appearance after accelerated

aging test I

a Description

of break6

Weight of

fragments of glass

in basket

L-EI-2.

L-GI-l, L-GI -2, L-CP-1, L-SC -1 L-RF -2,

Mils 25

2440

2324

20

No change

do

do

Peeled off entirely

Bond weakened; little peeling

Peeled around edges less than 6 in.

A

BB

(

c

) F

E

( c)

<1

32

2

1,287

•Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions.

b The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

c No vacuum-impact test possible.
28 Miscellaneous Publications of the National Bureau of Standards

Table 20 Vacuum-impact tests made on glass treated with plastic sheets and subjected to cycles of high and tow humidity (accelerated aging test I)

Sample designation

Film

thickness Appearance after accelerated aging test I

a Description

of break 6

Weight of fragments of glass

in basket

S-EI -1. .

.

S-EI-3...

S-EI-4... S-EI-5. .. S-LO-1. .. S-LO-5... S-MC-6. .

.

S-SI-1...

S CC 1...

Mils

15

10

1520

2015

8 10

C

BA

A

B

A

DD

Grams

< \5

32

317

3 51 379

rtn

Cellulose acetate sheet peeled off vinyl resin layer. Vinyl resin did not change. .

.

do ;.

a Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions.

b The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

Table 21. — Vacuum-impact tests made on glass treated with tapes and subjected to cycles of high and low humidity

(accelerated aging test I)

Sample designation Method of application to glass Appearance after accelerated aging test l a Description

of break

1 -GP -1. T -CP -2. T -GP -3. T -GP -3. T -GP -4. T -GP -4. T -MS -1. T -MS -2. T -MM -3.

T -MM -9. T -MM -1

1

Basket-weave

Basket-weave

Basket-weave Overlapping s Basket-weave Overlapping s Basket-weave

Basket-weave Overlapping s

strips 1" apart

strips 2" apart strips 1" apart

trips applied lengthwise, strips applied 2" apart.,

trips applied widthwise.

.

strips applied 1" apart.

.

strips 2" apart

trips applied lengtnwise.

-do.

.do.

No change do

Peeled around edges less than 2".. do

do

dodo

No cnange. Peeled around edges less than 6". wavy surface. Tape shrank

No change

Peeled in spots;

a Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions.

B The descriptions of break corresponding to the various letter designations are described on p. 5. A is tne most preferred type of break; B is next, etc.

Table 22. — Vacuum-impact tests made on glass treated with fabrics and adhesives specified for fabrics and subjected to cycles of high and low humidity (accelerated aging test I)

Sample

designation Appearance after accelerated aging test I

a Description of break"

F-LO-1.

F-MC-1. F-AR-1.

F-XX-3. F-AR-1..

F-XX-3.. L-EI-2.

.

L-EI-2. F-MF-2.

No change.

do...

s Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions.

6 The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B Is next, etc.
Antlscatter Treatments for Glass 29

Table 23. —Vacuum- impact tests made on glass treated with asphalt-asbestos combinations and subjected to cycles of high and low humidity (accelerated aging test I)

Sample designation Appearance after accelerated aging test I a Description of break"

Weight of

fragments of glass

in basket

A

D

D

Grams

5

2

3

10

a Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions. "The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

Table 24.

Vacuum-impact tests made on special glass products subjected to cycles of high and low humidity

(accelerated aging test 1/

Sample designation Appearance after accelerated aging test I

a Description of break"

Weight of

fragments of glass

in basket

G-AW-5 B

Grams

2

a Accelerated aging test I was made by exposing the treated glass panes to 10 repeated cycles of 7 hr in a fog chamber at 70° F, followed by 17 hr at ordinary interior conditions.

b The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

Table 25.

Vacuum-impact tests made on glass treated with liquid materials and subjected to heat aging

(accelerated aging test II)

Sample designation Film

thickness

48 hours at 160° F

Film

thickness

168 hours at 160° F

Description

of breaka

Weight of

fragments of glass

in basket

Description

of break"

Weight of

fragments of glass

in basket

Mils

32

/ 20

I 252620

24

AB

AA

> <; E

E

Grams Mils 24

1422

26

21

21

D

FA

A

EE

Grams

185

3 <1

<1

1,145

1,025

3

11 1,190

785

a The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred type of break; B is next, etc.

Table 26.

Vacuum-impact tests made on glass treated with plastic sheets and subjected to heat aging

^accelerated aging test II)

Sample designation Film

thickness

48 hours at 160° F

Film

thickness

168 hours at 160° F

Description of break4

Weight of

fragments of glass

in basket

Description

of breaka

Weight of

fragments of glass

in basket

Mils

15

10 CE

Grams 2

725

15 D

Grams

8

15 20 B

A

< 1 20 < 1 15 AD

1 265

15 C 2

25 A 1 25

10 AE

D

2

880

18

10 DD

260

14

a The descriptions of break corresponding to the various letter designations are described in the text on p. 5. A is the most preferred type of break; B is next, etc.
30 Miscellaneous Publications of the National Bureau of Standards

Table 27. — Vacuum-impact tests made on glass treated with tapes and subjected to heat aging I accelerated aging

test II)

Sample designation Method of application to glass

48 hours at 160° JF

Description

of break*

Weight of

fragments of glass

in basket

168 hours at 160° F

Description

of break a

Weight of fragments of glass

in basket

T-GP-l.

T-GP-2. T-GP-3.

T-GP-3.

T-GP-4. T-GP-4.

T-MS-1.

T-MM-3..

T -MM-9.

.

T -MM-11.

Basket-weave strips 1" apart

Basket-weave strips 2" apart Overlapping strips applied lengthwise. Basket-weave strips 1" apart Basket-weave strips 2" apart Overlapping strips widthwise

Basket-weave strips 1" apart

Overlapping strips applied lengthwise. dodo

741 E

470 E

147 D 1,085 D 685 B

1 A

576 E

535 D

425 E

715 E

582

638

30325

20<1

595

72 510

567

a The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred

type of break; B is next, etc.

Table 28. -Vacuum-impact tests made on glass treated with fabrics and adhesives specified for fabrics, and subjected to heat aging (accelerated aging test II)

Sample

designation Method of application to glass

48 hours at 160° F

Description

of break8

Weight of fragments of glass

in basket

168 hours at 160° F

Description

of break8

F-LO-1.

L-SC-l. F-XX-3.

L-EI-2.

F-MF-2.

F-AR-1.

F-XX-3.

L-EI-2.

-RF-2.

-XX -3.

F-AB-1.

F-XX-3.

Grams

L-SC-l brushed on glass. F-XX-3 smoothed

over. Two more coats L-SC-l applied. L-EI-2 brushed on glass. F-MF-2 smoothed

over. Two more coats L-EI-2 applied.

I F-AR-1 applied to glass. F-XX-3 smoothed

over. Coat of L-EI-2 brushed on.

L-RF-2 brushed on glass. F-XX-3 smoothed

over. Two more coats L-RF-2. F-AR-1 applied to glass. F-XX-3 smoothed

over.

'The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred

type of break; B is next, etc. "P=treatments applied to glass by manufacturers in their laboratories.

TABLE 29.

yacuum-impact tests on glass treated with asphal t-asbestos combinations and subjected to heat aging /accelerated aging test II)

Sample

designation

48 hours at 160° F 168 hours at 160° F

Description

of break"

Weight of fragments

of glass in basket Description

of break 8 Weight of fragments of glass in basket

D

Grams 160 D

AB

A

Grams

8 <1

65

C 10 4

8 The descriptions of break corresponding to the various letter designations are described on p. 5. A is the most preferred"

type of break; B is next, etc.
Anttscatter Treatments for Glass 31

Table 30.

Vacuum-impact tests on special glass products subjected to neat aging (accelerated aging test II)

Staple designation

48 hours at 160° F 168 hours at 160° F

Description

of break*

Weight of fragments

of glass in basket Descriptionof break*

Weight of fragments of glass in basket

B

Grass

1 D

Gram3 35

*The descriptions of break corresponding to the various letter designations are described on p. 5. A is the oost preferred

type of break; B is next, etc.

Table 31.

Summary of results of tests made vith glass coated with lacquer

Resin base of lacquer Number of tested

samples

Good breaks

Initially After aging

Acrylic , Cellulose nitrate. Chlorinated rubber. Ethylcellulose

Polyvinyl acetate.

,

Polyvinyl butyral .

.

Protein Reclaimed rubber . .

.

Unknown ,

Total 10

Washington, July 3, 1913

o