NATIONAL BUREAU OF STANDARDS REPORT

Protection of Glass and Metal Surfaces

From Wind-Blown Sand

By

William C. Cullen

and

Raymond E. Myers

Report to

Materials Division

U. S. Naval Civil Engineering Research & Development Laboratory

Construction Battalion Center

Port Hueneme, California

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

2803
NATIONAL BUREAU OF STANDARDS

A. V. Aslin, Director

U. S. DEPARTMENT OF COMMERCE

Sinclair W^ks, Secretary

cover of this report.

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Development.

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Instrumentation.

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. Ordnance Development. These three divisions are engaged in a broad program of research

Electromechanical Ordnance, and development in advanced ordnance. Activities include

Ordnance Electronics. basic and applied research, engineering, pilot production, field testing, and evaluation of a wide variety of ordnance materiel. Special skills and facilities of other

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instrumentation, evaluation. Combustion in jet engines. These activities are sponsored by the

Department of Defense. • Office of Basic Instrumentation • Office of Weights and Measiues.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1004-10-4708 September 18, 1953 2803

Protection of Glass and Metal Surfaces

From Wind-Blown Sand

By

William C. Cullen

and

Raymond E. Myers

To

Materials Division

Structures Research Department

U. S. Naval Civil Engineering Research & Development Laboratory

Construction Battalion Center

Port Hueneme, California

<N^>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

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PROTECTION OF GLASS AND METAL SURFACES

FROM WIND-BLOWN SAND

by

William Co Cullen and Raymond Ro Myers

Abstract

An abrasion apparatus ^ - employing an unsupported abrasive 5 is described By

using the apparatus described 2 4-1 commercially available protective coatings for

glass and metal were evaluated for their

abrasion reslstanceo Specimens of I8 of

the materials submitted were evaluated for

their probable durability by exposing them

to both out“door and accelerated tests,,

Data are also presented on the formulationj

method of application 2 and spreading rates

of a number of the coatings

o

lo INTRODUCTION

In March 1952 5 the Department of the Navy discussed with

representatives of the National Bureau of Standards two

problems encountered in desert area operations e They were as

follows g ( 1 ) the protection of glass and metal surfaces from

the abrasive action of wind-blown sand and ( 2 ) the protection

of tools and other metal objects to permit comfortable handling

when they are subjected to intense heating upon exposure to

direct sunlight

o

The solution to the first problem^ namely 2 the protection

of glass and metal surfaces from abrasionj was the primary

objective of the Investlgatlono Of lesser importance was the

reduction of the searing effect caused by solar heated tools

o

Consequentlyj the experimental work was directed toward the

assembly of equipment to simulate and measure abrasion of the

type encountered in desert areas j and the evaluation of coated

glass panels in this equipment o Incidental to the abrasion

studies were the evaluation of weathering and adhesion of the

materials
» 2 »

The First and Second Progress reports and this final

report are confined to the abrasion problemo In regards to

the solar heating problem^, a theoretical analysis will be

furnished in a supplementary report

2o REVIEW OF LITERATURE

A comprehensive study was made of the abstracted literature

on abrasion resistance from 1907 to 1950 o The most Important

publications pertaining to this subject are listed in Appendix

lo A brief statement of their scope ^ presented categorically^

follows § 2ol Theory of Abrasion

Kuroda (1)* in discussing the mechanism of the abrasion

of metals proposes the following system of classificationg

lo Pure dynamic abrasion

Ao Abrasion between solids

(1) Elastic abrasion

(2) Scratching abrasion

The author theorized that abrasion between solids is the result

of fatigue failure o He calculated the pressure at the contact

surface between two abrading bodies followed Heitz's formulao

This pressure becomes quite large and as It is added to every

point on the surface successively ^ the material receives a

severe repeated loado The result is that the surstained

fatigue failure causes the abrasiono

The relationship between hardness and abrasion resis=

tance of plastics is ^discussed by Boor^ Ryan^ Marks » and

Bartoe (2)o The authors define the "hardness*' of plastics

as resistance to indentation and observed that this hardness

is not necessarily a measure of mar^ scratch or wear resls=

tance

*Figures in parenthesis indicate literature references .in

Appendix lo
- 3

“

Fo Campus 5 Ro Dantirme^ and Ro Jacquemin (3) reported

that a linear relationship exists between the quantity of

abrasive used and the thickness of the specimeno They also

observed that the base to which the coating is applied has

an influence on the quantity of abrasive lisedo For example

the quantity of sand for the same wear is much greater for

a steel base than for a bright iron base^ and yet greater

for a bright iron base than for a glass basOo The authors

also reported that if the quantity of abrasive (ordinate)

is plotted as a function of film thickness (abscissa)^ the

line (for the same base) intersects the abscissa axis at a

value which can be considered as an expression of abraslono

In a paper published in 1936 ^ Milligan (4-) demonstrated

a relationship between crystallographic orientation and

abrasion hardness in the case of feldspar and quartz crystals

by producing impact abrasion by an accurately controlled

blast of "Standard Ottawa quartz sand" (24-=30 meshj round^grainj

silica=quartz sand)o In his experiments with abrading grains

other than quartz sand^ he showed that corresponding hardness

values for such hard materials as crystalline x=alumina and

silicon carbide came much closer together when hard artlfi^

clal abrasive grains are used for bias ting

o

2o2 Test Methods Utilizing Unsupported Abrasives

The results of work done by the Bell Telephone Laboratories

were reported by A« Eo Schuh and Zo Wo Kern (5) in March 1931°

The measurement of abrasion resistance of paints ^ varnishes

and lacquers was determined by the employment of the following

test methods Carborundum powder of uniform particle size

was admitted at a constant rate to a directed stream of air

under constant pres sure o The resulting blast was allowed to

impinge upon a film of the test material at a fixed angle

The abrasion resistance was evaluated in terms of the weight

of carborundum required to wear through a unit thickness

of the materlalo For the testing of paints, varnishes and

lacquers 5 the authors observed that the following conditions

of operation were well adapted

g
1 o Position of Test Specimen - Flush against the edge

of nozzle at an angle of ^5® Inclinationo

2o Air Pressure = 6 cmo of mercuryc

3o Rate of Flow of Carborundum » 2^ g per minuteo

Particle Size - 170=200 mesho

Spencer “Strong ( 6 ) described a method in which he em=

ployed a simple inexpensive apparatus for determining relative

abrasion resistance of enamels » He obtained abrasion by flx=

Ing the specimen in the path of a stream of sand^ propelled

by a rapidly“revolving disco He reports that the severity

of the abrasive action is dependent upon the particle size

of the abrasive

In June 1939 § the Scientific Section^ National Paint 5 Varnish and Lacquer Asslciatlon^ Inc ,

issued a circular

covering an improved abrasion apparatus. Sward (7) described

improvements in the operation of the falling sand abrasion

apparatus and outlines an Indirect method of indicating

abrasion resistance by means of gloss measurements

Marks and Conrad (8) described an abrasion tester

utilizing an emery blast as the abrasive. The abrasive

action was evaluated in terms of scattered light. The

authors observed that the amount of light scattered was

proportional to the abrading action on the specimen,

2,3 Results of Abrasion Tests by Others

In a memorandum report Issued in August 19^^ by Materiel

Commandj Army Air Forces (9)| it was reported that of 15

transparent plastics tested by a modified test procedure of

A,SoT,Mo D673“^2T_^ only three indicated good mar resistance.

They are (1) an allyl base plastic 5 (2) methyl methacrylate

coated with an abrasive resistant material manufactured by

du Pone and (3) plate glass. The remaining materials gave

results which indicated poor to fair abrasion resistance.

It was further reported that in field tests (one year out=

door exposure in Mojove Desert^ Blythe Field, California),

not one of a variety of plastic specimens exposed showed any
“ 5 "

but minor abrasion caused by sand» However ^ in actual service tests (windows installed on a C-^0 airplane polished

plate glass was about four times as abrasion resistant as any

plastic usedo

Preliminary results reported by Robertson^ Libisser and

Stein (10) showed that rubber-coated glass cloth laminates

give complete protection when they are used for air-borne

radar antenna housings flown at high speeds through raino

Al^ter subjecting twenty-nine coatings « spun on glass,

to various mar and abrasion tests

Coles, Schulz, Levy

and Wheatley (11) concluded that Allymer C-39 (Columhia

Chemo DiVo

,

Pittsburgh Plate Glass COo

)

was most resistant to marring o An alkyd modified melamine (Strathmore

Products) was second best, followed by Yibrin 1305

(Naugatuck Chem® Co®), diallyl Phtholate (Shell Development COo) and a combination of CR-39 (Dd) and diallyl

phtholate

o

Marks and Conrad (8), using an emery blast method,

reported that CR-39 showed the best results of some 18

plastics tested®

3o MATERIALS

3®1 Types of Coatings

The discovery of an easily applied, inexpensive material

of Mohr hardness 6 or above did not seem likely at the inception of this work^ consequently, the search was narrowed to

organic coatings® In the hopes of discovering a film of

sufficient resiliency to withstand abrasion, the types of

materials employed were confined largely to organic polymers

®

Tvro means of application of polymers were considered g a) As preformed films, in which case an adhesive would be

required^ and b) From solution or suspension, in which ease

the preparation could be sprayed, brushed, printed, or applied

by immersion® Considerable practical difficulty was envisioned in the mounting of preformed films, with the result

that the bulk of the work was done with fluid preparations

®
- 6 «

3o2 Procurement and Identification of Materials

Unless otherwise indicated^ materials were obtained

directly from manufacturers in response to a National Bureau

of Standards letter a A -copy of the letter was included in

the First Progress Reporto

Table 1^ lists the materials ^ together with their

manufacturers j brand names ^ formulation^ recommended application^ and code numbers « The numbers were assigned in

the order of the receipt of the materials ^ Formulations

were obtained either directly from the manufacturer or

taken from the labels of the containers

The following classification was made of the materials

submitted in this investigations

All materials 5 except NBS numbers 31 to 36 inclusive j fall

in classification Is

The test surfaces used in the abrasion tests were

5“ X 2"3/^" X l/8“ln„ panels of double“thickness window

glass®

The coating materials were applied to the test surfaces

by one of the following methods?

3«3 Classification of Materials

1) Transparent

2) Translucent or opaque

ABRASION

^ol Test Surfaces

^o2 Preparation of Test Specimens

1) Brush application

2) Spray application

3 ) Dip coating loying the Flsher^Payne

Dip Coater

*AU tables and figures are attached to this report as

Appendix 2*
" 7

“

In the case of 17 materials 5 Including the 6 opaque

coatings c, duplicate specimens were prepared by the manU”

facturer

o

Tables 2 and 3 list the method of application as well

as the thickness of the dried film for the abrasion resls^

tance tests

o

4-o 3 Abrasion Apparatus

The abrasion apparatus employed in the Investigation

consisted of three parts as follows g 1) the air supply

systemj 2) the abrasive supply system^ and 3) the specimen

chamber® The apparatus is pictured in Figure 1®

The air 5 taken from a high-pressure air line^, was reduced to the desired pressure by means of a valve and

Introduced through the pressure gauge CiD into a 1/8 In®

brass tube fitted with a tee (not shown in photograph)

which serves as a chamber for mixing air with the abradant®

The mixture of air and abradant was then passed out through

a 1/8 in® brass nozzle into the specimen chamber DJ Where

it impinged upon the test specimen®

The abrasive supply system consisted of a sand reservoir aj, constructed from a one-pint oil can inverted over

a tee in the air line® The downstream section of this line

served as a mixing cham_bero The sand 5, thoroughly dried

^ p

__ was fed by gravity from the reservoir through a glass tube^^

having an orifice of approximately 1/32 in® diameter into

this tee® The rubber tubing extending from the air supply

system to the sand reservoir equalized the pressure on both

sides of the 1/32 in® orifice so that the rate of sand feed

was independent of the pressure in the mixing chamber®

•The specimen chamber (see Figure 2) consisted of an

electrical junction box 12 x 10 x 6 in® 5 in which the sand

blast nozzle recess centrally located on the 12 x 6

in® dimension® The test specimen was mounted on a stage of

a 1/8 in® brass plate on the opposite side of the test chamber

and at a distance of ten inches from the sand blast nozzle

recess® The specimen was masked bv a rubber-coated ^ I/I6 in®

brass plate ^ having an aperture C/J of one inch in diameter 5 which sharply defined the abrasion pattern on the test specimen® This is shown in Figures 3 and 4®
8

The specimen chamber was equipped with a shutter "like

arrangement constructed of a rubber "Coated^ 1/16 In, brass

plate CO, actuated by a control lever [29J located on the

outside of the chamber. The exposure time of the specimen

to the sand blast was accurately controlled by this arrange"

ment o Evaluation of Abrasion

In order to obtain a quantitative measurement of abra"

slon^ two methods were adopted to determine the extent of

attrition? 1) Haze determinations^ and 2) Gloss determlna"

tlonSo The six opaque materials were rated by visual examlna"

tlon In addition to the gloss determination,

^Aol Haze

The fraction of the total transmitted light from a

normally Incident beam^ which Is not transmitted In a

straight llne^ Is defined as the haze of a sample. It was

calculated as follows ( 13 )s

Ts

Haze %

- X 100

where Ts = amount of light transmitted In all directions

except rectilinearly

Td = amount of light transmitted In a straight line.

For the determination of the extent of haze due to

abrasion on the specimen^, the Integrating sphere method for

photometric measurements was adopted. The abraded surface

was evaluated in terms of the transmitted light scattered

l,e ,5 the amount of diffusion of the parallel light incident

on the specimen.

The Pivotable”Sphere Hazemeter^ manufactured by the

H, A, Gardner Laboratories ^ Bethesda^ Maryland^ was used for

the haze determinations.
” 9

“

hr 0^0 2. Gloss

Since haze is a measurement which is dependent upon

light transmissionj it was necessary to employ another

means of evaluation for surfaces which are translucent

or opaque « The method selected was the determination of

gloss which was described by Sward (7) in 1939° This

method was employed also with the transparent specimens

o

Gloss is defined as one thousand times the ratio of

brightness of the sample when illuminated unldirectionally

and viewed in the direction of the specular reflection

less the brightness of the sample when illuminated in the

same direction and viewed normally ^ to the brightness of

the Idealj completely reflecting ^ perfect mirror ^ similarly

illuminated and viewed in the direction of specular reflec'=

tlon (l^)o

Gloss measurements were made with, a Photovolt Photc=

electric Glossmeterj Model 665 manufactured by The Photonvolt Corporation^ using the 60® gloss attachment <, ho5 Test Conditions

The following conditions were determined experimentally

to give the most uniform abrasions

a) Abradant —- 60-100 mesh„ Ottawa silica sando

b) Rate of sand feed 5^9 grams per minute (gravity)

o

c) Air pressure 6 psio

d) Distance from nozzle to specimens == 10 Inches o e) Exposure times == 10 5 20. and ^0 seconds.

f) Size of abraded area “= 1 inch in diameter.

4.6 Test Procedures for Abrasion

Duplicate test specimens of each material were prepared

by methods described in Section 4„2. They were allowed to

age at room temperature for a period of at least twenty days

before testing. One speclm.e.n of each sample was subjected to

abrasion by exposing three separate areas of each specimen to

the sand blast for periods of 10

5

20

5

and 40 seconds respec-=

tlvely. A control specimen^ consisting of an uncoated panel

of double^thlckness window glass ^ was exposed to the blast

for similar periods at the start and at the completion, of
- 10

each series of tests to Indicate any variable present in

the abrasion apparatus « Four abrasion patterns resulting

from the exposure of uncoated glass for periods of 10 ^ 20

40, and 80 seconds , respectively^ were magnified 30 times

and photographed with the results shown in Figures 5 to 8^

Figure 9 shows quantitatively the effect of exposure time

and resulted in the decision to employ 10 ^ 20 ^ and ^0 second

exposure times as standards. By averaging the results obtained at each of the exposure times ^ the performance of the

test specimen under optimum working conditions was rated.

The selection of 6 psl as the standard pressure was

based on the findings displayed in Figure 10 ^ in which the

optimum pressure for haze readings near the center of the

scale was found to lie between 6 and 8 psi. The lower

value was selected because the conditions of abrasion were

realized at the outset to be too rigorous for plastic

materials if based indiscriminately upon the performance

of glass.

Table 4 Illustrates typical haze values obtained

upon exposing the working standard to the selected

conditions. The determinations were made at different

times by different operators. The data obtained show

the abrasion apparatus gives reproducible results.

After abrasion^ the specimens were wiped free of

loose abradantj and gloss and haze determinations were

made on each of the 'exposed areas as well as on the

unabraded portion of the surface. At a later date 5, duplicate specimens of each sample were subjected to

the abrasion tests in order to determine the effect

of aging on the specimen,

'Tables 2 and 3 list method of preparation^ age

at testj, film thickness ^ gloss and haze test results

for each specimen.

4,7 Abrasion Results

4,7 o 1 Haze

The results of abrasion in terms of haze are given

in Table 2, The values in the table are uncorrectefl.

for the original haze of the materlalj which was suffi“

clently low to be neglected in all but three cases.
= 11 -

The results are also presented graphically 5

, for the first

19 materials submitted ^ in Figure 29

o

Also listed In Table 2. are the comparisons of haze

readings with the glass standard^, whose performance was

arbitrarily assigned the value of 100 o Materials rated

above 100 are more resistant to abrasion than the glass

standard

o

Figures 11 to 285 inclusive ^ are photomicrographs

of the abraded areas of glass and typical plastic films

after exposures of 10

5

20 and 4-0 seconds duratlono

4o7o2 G3.0SS

The results of abrasion on the transparent specim,ens 5 in terms of gloss ^ are described in Table 2o The original

gloss of each material is taken as 100 and each area of

exposure is rated in terms of percent of original gj.oss

retained o These results are presented graphically in

Figure 3 O 0 Ratings comparing each transparent material to the

standard were made as described in Section 4o?ol abovSo

No standard was employed in rating the opaque coat‘d

ingSo The ratings were made both In terms of gloss and

by visual inspectiono A rating of 1 indicates the best

performance to abrasion resistance,, The ratings are

presented in Table 2o

kfEATHERING

5.1 Outdoor Exposure Tests

5olol Test Surfaces

The test surfaces employed in outdoor exposure tests

were 6 x 2=3/4 x 1/8 in® panels of double=thickness window

glass o
12 c=

5olo2 Preparation of Test Specimens

The coating materials were applied as described in

Section ko2o

Table 5 lists the method of application as well as

film thickness for the specimens exposed in the outdoor

weathering tests

5olo3 Exposure Conditions

The coated specimens were exposed on elevated racks

from ^ to 5 feet above the roof deck of the Industrial

Building 5 National Bureau of Standards^ Washington* Do Co

The coated surfaces of the specimens faced south at an

angle of inclination of approximately 4-5® o 5olo4 Results of Outdoor Exposure

The results of outdoor exposure on the transparency

(in terms of haze) before and after exposure* together

with the time and type of initial and final failures are

described in Table 5.,.

5o2 Accelerated Weathering Tests

5o2ol Test Surfaces

The test surfaces used In the accelerated weathering

test were similar to those described In Section 5olol above*

5o2o2 Preparation of Test Specimens

The test specimens were prepared by one of the methods

described in ho2^ Tab§Le 6 lists the method of application

and thickness of the dried film of the specimens used in the

accelerated exposure tests*

5*2*3 Exposure Conditions

The accelerated exposure tests were made in a low«

intensity g enclosed carbon arc unit« "Weathar^ometer*

Type manufactured by the Atlas Electric Devices

Company^ Chicago « Illinois* Only one arc lamp^ centrally

located 5

, was used as a source of radiation* The power

consumption of the arc was approximately 1*8 kw* per hour*
- 13 -

The unit was operated five days per week^ 22-1/2 hours

per day» Each daily run was started with a nine^minute

water spray period ^ which was repeated every houro The

water was introduced through four spray nozzles at a line

pressure of twenty pounds » The volume of water was such

that the specimens were thorouglily washed by flowing water

during each pass under the spray unito The water temper a°

ture at the spray unit was approximately 77® F and was

essentially metal and mineral free (total solids were

less than 0„2 grains per gallon)

o

All piping 5 valves and spray jets were constructed

of aluminumo The position of the test specimens was

changed daily to insure uniform, wreathering and washing

o

Specimens were exposed in duplicate for a maximum

exposure period of 1000 hours,

5o2,4 Results of Exposure

Table 6 lists the haze of the original coating as

well as after periods of 2^0 ^ 500 5, 750 5 and 1000 hours

of exposure. The table also includes the time and type

of initial and final failure,

60 DISCUSSION OF RESULTS

60 1 Abrasion Resistance

A number of materials indicated either that abrasion

resistance varies with the age of the set film or that

reproducibility of abrasion was poor. Other materials

gave virtually constant test results :regard.less of the

time of agl.ng. The coating that indicated the greatest

change was coating No, 1^ a polymerized acrylic type

resin. The changes that ' occurred are show^n In Table 7o

During the test 5 control specimens were abraded at

intervals to demonstrate that variables were not present

in the apparatus or in the test procedure.
- Ih

60I0I Transparent Materials

The abrasion tests gave a wide range of values for the

transparent materia3.So There was no general trend as to

which resin base was the best or which formulation produced

the most resistant coatings This inform.ation was not avails

able for the majority of the materials as shown in Table 1 , Coatings NoSo I5 2 ^ 3 5 5 ? l^c, and 40 indicated the best re-= slstance^ while coatings NoSo 7j He, l^j 17j 23 5 and 2h

fell in the lower ranges of abrasion resistanceo The remaining coatings were approximately equal to the glass

standardo In the case of nine samples 5 NoSo 10 5 12 5 20 5 21 , 2^5 2^5 265 285, and 30 5 sand etched completely through the

coating to the glass baseo It is believed that this type of

failure can be attributed to the tliinness of the protecting

film 5 which was 0,001 in, or less in thickness in eight of

the nine cases.

6 olo 2 Opaque Materials

The opaque coatings were subjected to the abrasion test

procedure, after which they were rated both by visual inspection and in terms of percentage of gloss retained after

abrasion. Coating No, 36 had excellent abrasion resistance

when compared to other materials tested. The abrasion

pattern was barely visible to the naked eye even after hO

seconds of abrasion. Coatings Nos, 3^ and 35 followed in

abrasion resistance^ while NOs, 3I5 32, and 33 were the

least resistant of the opaque coatings. Gloss determinations

were not possible on coating No, 31 since its original gloss

was Oo

6,2 Weathering

6 , 2,1 Outdoor Exposure

The following discussion is limited to coatings Nos, 1

to 195 inclusive, since samples Nos, 20 to 4- 1 , inclusive,

were submitted too late for the exposure tests.
Evaluation of weatheraMlits?' in terms of haze was im=

possible in many cases ^ owing to failure of the films,,

Instead 5 ratings were made in terms of initial and final

failurSo The former was selected as the point at which

irregularities appeared in the film^ which could serve as

nuclei for complete removal or breakdown of the filmi the

latter was construed as the time at which a significant

area of glass wras exposed o The interpretation of what

constituted a significant area was subjective in a few

cases 5 but 5 in general^ was not subject to serious doubto

The materials were exposed for 80 days^ during which

time various criteria of failure were observed® Loss of

adhesion was most common^ followed in frequency by discoloration and clouding of the filmo Spalling of the film

was observed in a few instances

®

Table 5 lists the type of failures encountered and^

in general^ may be taken as a log of the happenings on

outdoor exposure of the films

„

6e2o2 Accelerated Weathering Exposure

The following discussion is limited to coatings Nos® 1

to 195 inclusive 5 for reasons stated in Section 6o2ol above®

All materials indicated initial failure in this series

of tests 5 in periods of exposure ranging from 30 hours in

the case of coating No® l?^ to 6OO hours for coating No® 8®

Final failures w-ere evident in 12 of the coatings while only

6 survived the maximum of 1000 hours exposure®

Loss of adhesion was the most common reason for failure

followed by discol. oration and clouding of the film®

7o CONCLUSIOI^S

7=.! Transparent Materials

a) None of the 35" transparent materials tested was

perfectly resistant to abrasion by wind-blown sand® However 5 a number of those tested were superior to window

glass (standard) 5, when evaluated in terms of haze and gloss®
- 16 =

b) Materials that were applied in thicknesses of

0,003 in, or more protected glass from abrasion by windblown sand.

c) A thin film of oil or glycerol applied to a glass

panel reduced abrasion appreciably 5 especially after long

periods of exposure.

7o2 Opaque Materials

a) All materials tested protected glass from abrasion

by sando

b) One coating was far superior to the other five

tested as the abrasion pattern was barely evident after

as much as 4-0 seconds abrasion,

8 , REG OMME-NDAT IONS

8,1

Glass Surfaces

80

1,1

Permanent Type Coating

To qualify as a permanent coating 5 the material must

possess the following requirements

g

a) good weatherablllty

b) good adhesion

c) good transparency

d) an abrasion resistance superior to plate glass.

None of the materials tested in this study fulfils all

the above requirements,

8,1,2

Semi-Perm.anent Type Coating

In lieu of a permanent type coating, there are a number

of possibilities for protecting windshields and other glass

surface from attrition by employing a semi-permanent film.

In utilizing such a protecting fllmg the material could be

removed and reapplied when it became marred or unserviceable due to abrasion.5 weather 5 etc, 5 thus eliminating the

replacement of the glass unit. Semi-permanent protection

may be attained by the following methods

g
- 17 “

1) A preformed sheet of plastic material of high

abrasion resistance (vinyl^ polyethylene^ etCo) may be

applied using a suitable adhesive « The plastic film

should have a minimum thickness of O 0 OO3 iuo and should

be capable of being rem.ov6d easilyo Materials similar

to this type are available co.mmereially for Interior

application to automotive glazing ^ for example 5 sun

visorSji anti=fog filmSj etCo

2) A protecting filmg in solution or dispersion

form^ may be applied by brush or spray to a thickness

of at least 0c003 in® (dry film thickness )o The film

should be capable of being removed easily^ This can

be accomplished either by the use of a solvent or by

stripping of the film 5 depending upon the nature of

the materialo The latter method is preferred since it

eliminates the hazard of employing a vol^atile solvent

and provides a cleaner operation, A number of materials,

or variations thereof 5 tested in the Investigation would

meet the requirements I For convenience 5 Table 2 classifies

the materials as strippable^ non>=strippable or strippable

with difficulty.

In general 5 any material used for the protection of

a glass surface should be clear and transparent when

applied 5 1 , 6 ,, the har;e of the combination (glass coating)

'Should be less than 5^ and preferably less than 1^, The

thickness of the film in place should be a minimum of

O 0 OO3 in. In addition^, it should have a reasonable resistance to abrasion and weathering,

8,1,3 Field Expedient

In the event of an emergency^, the application of a

thin film of oil, glycerol^ or similar substance will

reduce abrasion appreciably ^ although it will not prevent

it entirely. The disadvantages of this procedure ares

1 ) abrasive particles adhere to the oil^ glycerolg etc ,

5

and 2 ) difficulty of applying to obtain good vlslbllityo
» 18 -

8 o 2 Metal Siorfaces

Metal surfaces or glass surfaces where transparency

Is not a requirement^ may be protected by applying a

coating similar to NbS No, 385 by brush or spray applica-=

tion^ to a thickness of approximately 0,010 in.

In the event that protection is required for articles

in storage 5 it is recommended a strippable material be

used.
19 -

APPENDIX lo

LITERATURE REFERENCES
APPENDIX lo

LITERATURE REFERENCES

(1) ”0n the Mechanism of the Abrasion of Metals’*, Masais Kuroda

Trans o Soc, Mech. Engs„ Japan, 5$ ^“99? 1939®

(2) ’’Hardness and Abrasion Resistance", T„ Boor, J® Do Ryan,

Mo Eo Marks and W„ F® Bartoe, AoSoToMo Bullo, 68“735

19^7.

(3) "Testing of Paints and Lacquers", P» Campus, Ro Dantinne,

and Ro Jacquemin, ReVo Universslle Mines, 19, ^27-39,

193 9 o

(4) " Impact“Abrasion Hardness of Certain Minerals and Ceramic

Products"

5

To Ho Milligan, JquTo Amero Ceramo Soco, 19 (7)

187-91, 19360

(5) "Measurement of Abrasion Resistanceo Paints, Varnishes

and Lacquers", Ao E„ Schuh and Eo Wo Kern, Indo Engo

Chem» , Analo Ed« 3, 72“6, 1931°

( 6 ) "Some Experiments in the Development of a Sand Abrasion

Machine "

5

Go H» Spencer-Strong , J» Am* Ceramo Soc., 19,

112==li+, 193 60

(7) "Improved Abrasion Apparatus", g° Go Sward, Natlo Paint,

Varnish and Lacquer Assoc.* Sclo See., Giro 98l, 60-3,

1939 o

( 8 ) "Resistance of Plastics to Abrasive Particles", MoE. Marks

and Paul Conrad, Modern Plastics, 23, 169, March 19^6*

(9) "Abrasion Tests for Transparent Plastics", Memorandum

Report. Engo Div* » Materiel Command, Army Air Forces.

18 August 19Mfo

(10)

"High Speed Rain Abrasion of Glass Cloth Laminates",

Ro McC. Robertson, R. Jo Lobisser, and Ro E» Stein,

Indo Engo Chemo , 38 , 990=1, 19^60
21 »

Literature References (Continued)

(11) "Optical Lens Coatings" 5 H<, ¥» Coles, W, F® Schulz^

S„ Levy, and T. Ac Wheatley, Modern Plastics, 25,

123, July 19^6.

(12) Fisher Payne Dip Coater

(a) Ind. and Eng® Chenic , Analc Ed* 15, 48, (19^3)o

(b) Indo and Eng» Chenio , Anal. Ed. 13 9 ^^7? (19^1)

(c) Industrial Finishing, Page 26, M3.y 19^3

®

(d) BeU. Labs. Record, l4, 210, (1936).

(13) 19^8 Book of A.ScTcMc Standards, Part III B, pc 87O0

(14) Federal Specification TT-P-l^lb, Method 610. lo

22 -

APPENDIX 2c

TABLES AND FIGURES
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rH W \TN IT\ J± nO J" sO CO

CO

COCOo • o o o o o o o o o o

o o w oo o o o o o o o

CO H fH iH rH rH rH rH 1—1

1—

1

I I

I I

ON On (JN CJN ON

CO CO

CO CO CO CO CO

a CO 00 CO o 1>- CO oo o o o rH o o o o • o o o o o o o l-l s o o o o o o o

W M * 0 • • • • • EH o o o o o o o

g

CO CQ

w tx: H! w

CO CO CO

:=) to to to Q

rt « pc; pc; W

m m m pq PQ Eh

CO =<: pp < c

CQ O o O- oo o 5

rH g ;s; ro m rO CO Jr

>HEHoM

Ix, h

a

0,M 8

« • EH X o

CO w

g b

a • O

K O o

II EHO rH a

CO a CO a |x] II a

rH o

CO

CO CO CO s

rH CiJ "3! EH

EH a

<U CO Q

p. O fT~| a. M «<a a M Q Cl o « a w EH EH M o a

CO c

II aCtI P

PI

CO EH X a

J-l
TABLE

3

.

ABRASION

RESISTANCE

OF

OPAQUE

COATINGS

CO

M

ca

EH O < O o

m M

Eh

W C>

0, s D3

CO

J"

II

I

1 mil o o

1 CM CM

s

r>il O O

1 ^ JI N*r<il O O 1 MD \0

i

9

I

1

o o

o o

I

i

II

I ir\ UM ir\ rO m I ro rO

I

1

t

I

I

II

I

I CO CO ! CO 00 S S 1 s s

CT\ IfN o o ) o O 1 CO 00 o o o o

J- rH rH 1 o O 1 H iH rn on CM CM o o o 1 H H 1 O O o o r—

1

rH o o o o i o O 9 O O o o o o • • 1 • • J • • • • • o o o o 1 o O 9 o o o o o O

=i! a.

CO

< m <J eq

CM

O <X) CM H

o m IfN ro

lr\ CT\ ir\ u^

O OO

XfN IfN cn ro

CO CO

!z; s

<i! pq

ro

ro

m

CM

CM U^

rO rn

^ JH f<-> vD

O O

o o

H H

IT\ Ifs ro rr>

a a

CO CO

<ij pq

J"ro 1

CM

rn

CM CO

CM H

CM IT\

\r\ JON J-

^£l sO

O O

O O

r-H iH

\r\ u>. m rn

CO CO a s

C pq

\r\ m

iH rH J- J" m t>~ sO MO

Os rn

CO CJN

o o

o o

tH rH

rO rO

CO CO

<J pq

sDrn

iq II ^ CO ^ C^ ^ ^

GLOSS

DETERMINATION

NOT

POSSIBLE.

RATING

OF1

INDICATES

BEST

ABRASION

RESISTANCE
> CM o O l>- ro U^ CO rH ^

o • • • • • • • • Q CM iH ICN no O CM o CM

• O

0 0 l>- CO O J- ro ro ITN \0 rH ^ OD •

C/D 0 J" rO vO O ro 1—

1

CM 1 1 ro

C/D M O O- l>. (>~ O- l>- O- O- O- CN- <

i-:i c5

• g > vO C>-CO J- ro J- CO O ^

0 • • • • • • • • Q ro J- nO o ro CM o

Q

• M O

<5 0 0 -J" rO CDN H \0 ro O IN. (JN

E-i Nod • • • • • • • • • 0 O ro CDN rH ro o I—

1

rH O wo J" ro J- J" J"

C\J cn1 • > > J" CM ro rH u^ CDN l>- \0 ^

0Q CM NO ro L\. o CM ITN o

<«j • o

0 0 ITN ro O- IfN iH \D 00 IN- o

Nod • • • • • • • • • o 0 rH CM iH CJN rH iH o o 1—

1

M wo CM CM CM iH CM CM H CM CM Ps (H

>H

Fho

• 0

Pi rH CM CM rH CM rH CM iH

PP 0

t-P <§

EH

CM

lr\ ro ro 0

0 0 1 ro lc\ In tuO t3 Lr\ lr\ 1 1 0

0 0 H Z. • 1 “ CM — O Ph Q P 1 [N. CM CM 0

W1 CM 1 1 1 >

<4 iH rH rH CM
TABLE

5.

OUTDOCR

WEATHERING

OF

PROTECTIVE

COATINGS

8

<

PlH s

1-^

sM

EHS

wo

a.

EH

sst-H <

EH Q

w

ft

EH

S >H H <3 EH Q

<1^

W

C

a,

s

PlH

ON

J"

§

M • CO Pt<

EH S

Ixh

«

Cd

ltnoj iT\ H (>- H

O.

s

rip^

IT\

O

wo

e

COM • O H

S (d

i <i! ^ Cc4 a. d • (d M < So S O O M

a EH (d

rvi

§

c/3 • W

gs 8

QO. O

^ CQ h3

fH

vO

oo

Eh H

8s

C3S CX3

o a. o -£> o IfN lr\ Id R • • • • • • w w

ffl CM o H rH c\J

a,

&H

(d

CO

ro

o

M

o

a

0s

xrs CO

0

0

c

ON

J"

ON 00

« • CM H

J"

<U0

s1-3 C

[d

CM

IN.

§

1-3

03 Id g&

03 Id Eh 5 Q

EH 2 EH 2

cu

1-3 •

t-3 Id ^h3 8^^

PC4

h3 pt, 1-3 CO

j- NO 1 IfN

• • • 1 • o CM 1 H

oo

JCM

W

<0

00 M ft 0o

aM ft > fd Id Id oo\

Id Id o s o o O o SM a I—

a a

td

(d5

Q

g

ft

t-3 • CO 1-3 si

Id

Cn-CM Cn. oo 00

CM CM CM \TN

00 ro ON \r\

• • • • o m o H

a • oo rH CM oo CM CM OO oo CM oo oo 1—

oo § ftft O o O o O O O o O o o o o O O O O o O o O o O o o o o M a • • • • • • • • • • • • • EH o o o o o o o o o o O o o

a, a a a a a >H H

a

8

a

EH

Qd °

EH a EH a EH EH EH EH EH EH § a < M o fti bI ft§ ft^ ft^ fti • o CO aM ^o

EH Q o S o Q O a u a C3 QO Q O « u Q O Q Q S o a o

a a a a

oo CM rO H rH CM (H ro m •H oo

O

w • So

03 S

oo oo CM xr\ rH a

1 t>.1 a

1 iTv1 H

a a a CO CO CO a

1—

CM oo ir\ sO

CM CO ir\ o- ON o

J1 m1 ro

t a1 CN.

1 1 1 a CO CO a CO CO

00 <JN o fH CV rO H H rH rH

(CCKTINOED

ON

NEXT

PAGE)

TABLE

6.

ACCELERATED

WEATHERING

OF

PROTECTIVE

COATINGS

lAM

<Jj

2:M

w

Ct)

aM

a

a.

B

a,§

w&•H

w

O • M a

a M

H

e

a

o

S o

a a

a

^ =a SgS

a cj'ij a CO

• • • • • • ao a • •

(X4 a a a a M pLj s 8 888 C EH t-H cc a a a O S EH 8 8

s 222 >-l S

g^^3

a a

2 2 3M a aaa Hum S g

aM

a a a a P a a a

CM \r\ O CJSC3S c^ o tN- CM vO o o sO o

CM CM UN UN J- UN

a • • a CO

•4 a s

a o o

a M M

• • EH H

a a

a a a a

E O O jx] aa

a

a a a a

fe & fe

o

a

Eh

o»o

a

a a

a a

a

EHa

a

a

w a

Eh 3 a

a o a

a 3 a a 2

a a

2 2

M MH

a a

a a

a a

§

a

g

o

g

a

a

Qa

a

o

a

la

a

a o

aa o

oo o

a a

mo oTO OCX) oco a mcs-tN- m m m rO COs COS J- CS- O o CM 00 mo mo CM C CM O ! j-aa m m m ro Os COS rH o o sO CN. H pg CM mcM m CM m CM m a CM CM CM CM CM CM rH sD sO Css. J~

EH a

Cn. ir\ rH [N- CM Jr CM sO ro J~ CM iH sO (ON o ON

<i 3

• • • • i } • • • • • • • • • • • • rO CM sO I a a ITS ITN (Os OO 00 sO CM j- Cs. sO J~ CM a H rH H iH H H iH o • IN- o ON CM sO sO Its CO irs o a • • s 1 1 a a a • • • • 1 1 a a • • • • o a J" CO 1 1 1 a li Cs- SO CM o a a a a Vrs J^ ro H H r-i H iH CM Oi H I—

• CM Jr CO rO j- m o o cos o a • 1 1 I a a a • • • • a a a 1 • • • • iTspc; J- m 1 1 1 a 1 XfN ITN o cos a a 1 CM H sD \rs tN-a •H H rH CM CM

• C7N CO J- J- J" sO 00 oo sO CO cs. " CM o a • « 1 ; 1 a a 9 6 • • • a • a • • • • • o a m rH a 1 a a a a m rO sO a 00 a CM ro m ro ro unS r—

iH iH H iH rH

• rH 00 oo ITN oo sD sO (N. ITN COs CM sO J- CM CM o a • • • • a a a 1 • • • • • • • • • 9 • • UNg CJN a !>- a a a a H H J- ro o Cs- sO COS (OS cos iH rH

CM a rH

• o Os Cn 00 rH CJssO UN 00 ITN o o CM J- rH Cs. O sO CO sO H d O CD H OOO iH rH rO CM CM CM os 00 Cs. 00 o o

m ro o o

o

o

a

a EH a o o

a H Q ro

CO Jvr\ a I I a a

o

o

a

^c §o

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a cvj

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o

o

o

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CM

I a

CMo

o

CM CM CM O O O

O• • • ooo

ro ro O O

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o

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CMOO

CMO

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CMo

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CMOO

rO rO O O

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CMo

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i . . . Oi oO o o M Q Q Q Q rO

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a o a o

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M Q Q rO

a

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M Q

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sO

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CO

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1 CO CO CO CO CO CO CO CO CO CO CO CO CO CO

CM rO MD 00

(CONTINUED

ON

NEXT

PAGE)
TABLE

6.

ACCELERATED

WEATHERING

OF

PROTECTIVE

COATINGS

(CONTINUED)

M

CU

<M

wo

a

S’Ai

<i!

a,

S’&

a CO

o • O CO o pc?

O CO

lf\QC?

O CO

O CO ^pc?

CM S

CO

W

CJ) • M a

m M

8

KEH

W O

S a

CO

CO

fe fe o o

CM

CO

O

• • rO

ro

ro

I CO

H EH 8 8

a a

g .5 . cr8

(L E<h 8 8ai Ixt 88

o

<«

CJ

CO CO

o» <« oS

CO CO »co • CO s a

B B • • O 3 O 3 B

o

M

o

M M M fG M C3 M C3 M CO

O C5 c3

EH EH P4 • ^ • Pco B CO esss e a CO CO ieSg

' CO

1 CO

I pc? M M

a

3 a3 ma m a m CO EH m M CO 0 0

8 8 82 3*^ am 3a m

D

m

D

m a EH a EH PQ^-5 8 8

hd hd >A CO CO m m CO CO CP m m

\r\ \T\ nOnD o o CO CO ON CJN o CM j" j"

CM CO CM CM CM CM CN. Cn. Cn. CN. CM Cv. CM CM

lr\ IT\ CM CM CM CM j" J- CM CM CO

ro nO nO CO rH Cn. J" O o\ CM CM

• • 1 1 • • • • • • • • • • 1 CM CM 1 1 iH rH CM UN rH Cn ro CN o O 1 rH H rH rH

.

f ro ro 00

1 1 1 t • • 1 I • 1 1 1 1

1 1 1 1 CO CO 1 1 1 1 ro 1 1 1 iH rH rH O -4* CM ITN

• • 1 1 • • 1 1 1 • • 1 1 1 ro ro 1 1 rH rH 1 j 1 1 rH rH 1 1 rH rH rH rH

CO ro CO CM Cn. o ro CJN •NsO J*

• • 1 1 • • • • • • • • 1 1 1 m ro 1 1 o O ro nO o o o 1 1 1 rH rH rH rH rH rH o ITk ro ro Cn. CO nO o ro CM ro

• • • • • • • • • • • • • • 1 fH iH iH 1—

1

IT\ IT\ 1—

1

CM CJ\ Cn \rs sO rH rH 1

C^ C7N NO C^ ON CJN \0 UN CO ITN o rH nO

• • • • « • • • • • • • • • • O O CM ro o o o o CO ro O rH 1—

!

rH Cnro ro roro rH rH ro ro ro ro rH rH CM CO rH O O O O o O O O o O o o O Q o o O OO o o O O o O o o O o O • • • • • • • • • • • • • • o o o o o o o O o O o o o o o

COo • Q ro

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o o

Q O

sOsO

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COrH

Cv.

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t>-

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COH

S • &"§

Q m

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CM

CO

EHg . QsD

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JrH

CO a § CO 3 • aoo

^ <=• « ro QW

8

CMrO

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ro W CO

CMO

CO

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8

a

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a

g

EH

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MD M3Jr-dCM O O

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c». H

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CM H

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00

rH

8

s

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a<?a<! s a s 2 aa O' a H

ri 3

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PM 00 <

a, 0

COO

Q Q P*4 ai (x< o fx< a

j- nOnO CM CM rH rH rO Cn J" CM 00 nD

\r\ CM CM nO nO ro ro ITN CJN On rH HCM ITN CJN rH ON C7N CCNUN Cn Cn Cv 00 J- -d" CM o c5 0 g

a a

w w 8 8

o o

d l-d

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po S M

CD o CJ mqmq EH H EHW

8 feB&H

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CJS CJN

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CMOCMOCMO

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CO

CO o • so • D O O (1, CD O

« Q

pq H Q ro

CO

EHg . Oh O O M Q Q ro

NO

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CM

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9

tiD O

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o3 nJ I—1 c/5 fr; O cti

o o o

O o I>7 H H

O

00

CO CD • CO SH o

O *H CD

I—1 CO O -P

CD O

CM

!>- m

m rn

CM

ITN CM

ITN

TOi CO CD • m ^ o

O *H 0 H cd CO

cD -P0 o

^pc; H

\D

LPv CT\ CMo- rO

CiO O

a 0 q •H 0 H

-P cd 0 1—10

pc; o 0

o

o

I—

o o O

o o CO

1—rH 1—

o

0 0

N CO 0

W O

CM

o

0 0

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qI—

0

O

0 "Hm

0 0

CuO P

<5 rP

<S

>-< 0

a

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0 s

CO

1—

o CO IfN

• • • • o o o 1—

rO rH CM

O o 1—

(JN

• • • •

1—

ro r—

H

CM CM 1—

1—

m m m m

0 0 0 0

Td tO Td Td o CM CTN [>• ITN

ro

1

1—

1 J1 CM

1

1 CO CO CO CO
Figure 2. Specimen Chamber
Figure 3.

Specimen Before Abrasion.

Figure

Specimen After Abrasion
Figure 5*

10 Seconds

Haze - 21.5^

Figure 6.

20 Seconds

Haze -

Figure ?•

ho Seconds

Haze 73

Figure 8.

80 Seconds

Haze 93>»0%

Figures 5 - S. Photomicrographs of Abrasion Patterns of Glass

at 10, 20, 40, and 80 Seconds Exposure,
%

‘3ZVH

100

FIGURE 9. HAZE VS. EXPOSURE TIME

FIGURE 10. HAZE VS. AIR PRESSURE
Figure 11.

Coating No. 7

Haze 3^.3^

Figure 12.

Coating No. 11

Haze 3 d *9^

Figure 13.

Coating No. 4

Haze 22.3^

Figure 14.

Glass

Haze 19.8^

Figure 15. Figure 16.

Coating No. 5 Coating No. 3

Haze 16.2^ Haze 12.7^

Figures 11 - 16. <n^>

Abrasion Patterns of Glass and Five Coatings

at 10 Seconds Exposure.
Figure 17#

Coating No. 7

Haze - 58.1^

Figure 19.

Coating No. 4

Haze - hl,l%

Figure 18.

Coating No. 11

Haze - 56.4^

Figure 20.

Glass

Haze - 4o,95^

Figure 21.

Coating No. 5

Haze - 26.5^

Figure 22.

Coating No. 3

Haze - 26.05^

<^BS>

Figures I7 - 22. Abrasion Patterns of Glass

and Five Coatings at 20 Seconds Exposure.
*.

.1 '.y.;^.

”v^‘'

*"*'

, c

%%>

'. .» ^

1 , t i- ^ '

5 1‘ %£’ i

'•' >•

_

- <5^ / V- -T"

:^-'”'A'4€-.l'*

%tj2' * - ’i.wafe>. If* f.'i'.

> j;vvr'

•^/-' *i- rV\^- »^-)C.'

l-v '-

*l!!f"'' »

'-^- *>U

‘ f%l .' Y'i- £yr^^''&'=

Figure 23 , Coating No, 7

Haze - 80, 7J^

Figure 25.

Coating No, ^

Haze - 67,S%

' .•• '* V - ^15^“^-^'

^^'4

.

j ^

V

' ij' ^ ?

'f '•. >

-

' J , w ,. -

• % -, /

t'-y *:

. <*»

V, > -

'4': . A

f -’

, \''-:i : ' 1. '^>-r-:sk ,.'X

’.'Mm'.

Figure 2*+,

Coating No, 11

Haze - 78,5^

Figure 26,

Glass

Haze “ 70.4^

*" '=-' V

-

4 T-ii ,' »i! y ' * /\^' ' ''* ^ r*“<" > * r^'

yj^7 4f ,v% '- ‘- >1 " ?«

. ' \ '^-\ ’ *- Xl

^

i:

; V<

'•

'. .1,.^, Sf- ' *' -'-iv

*?>4

;| W»

.*r 'v • 'V?'

*

f.v

' "< 4.4 '/ -'-.Wv-,

".'Ar,\-

, j «w'’'V"

i , '

/

'.. " 4?^

•i

' ^ •

.-; • •.. . '^'.Xy ,;<" W '" --4??’ V

' -y 'y>^ ,

' '•

4"'

^ A... Figure 27 , Coating No, 5

Haze - 46,5^

V.. ! r

’

>

• V

-• >4. •

'S, *•> - : >,

' ;S , ** 3

'/.' /'

. 4

*'> -"“A, t>. .

1

;-

it-4 >

l*f i‘-; 4> % f 'ji*. '• 3>>

Figure 28 , Coating No,

Haze -

Figures 23 - 28, Abrasion Patterns of Glass

and Five Coatings at 4o Seconds Exposure,

<NBS>
GLASS

!9

HAZE, %

10 20 30 40 50 60 70 80 90 100

2

V////////M

LILJ J

( 1 1

! T7V7)>’>//* 1 3

\ |4 1

i 5 1

izzyzzzzzyzzzzyzi

10 20 30 40 50 60 70

HAZE, %

10 SECONDS ABRASION

vzzzm

20 SECONDS ABRASION

40 SECONDS ABRASION

80 90 100

<@>

FIGURE 29. ABRASION RESISTANCE IN TERMS OF HAZE OF

COATINGS COMPARED WITH DOUBLE -THICKNESS WINDOW GLASS.
N.B.S.

NUMBER

0

LOSS OF GLOSS, %

legend:

10 SECONDS ABRASION

xzzzzzzi

20 SECONDS ABRASION

40 SECONDS ABRASION

10 20 30 40 50 60 70 80 90

LOSS OF GLOSS. %

100

<NBS>

FIGURE 30. ABRASION RESISTANCE IN TERMS OF GLOSSCOATINGS COMPARED WITH DOUBLE -THICKNESS WINDOW GLASS.

THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March

3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and

maintenance of the national standards of measurement and the provision of means and methods

for making measmements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials,

devices, and structures; advisory services to Government Agencies on scientific and technical

problems; invention and development of devices to serve special needs of the Govenunent; and the

development of standard practices, codes, and specifications. The work includes basic and applied

research, development, engineering, instrumentation, testing, evaluation, calibration services, and

various consultation and information services. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the front cover.

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journals of professions) and scientific societies. The Bureau itself publishes three monthly peri»

odicals, available from the Government Printing Ofl&ce: The Journal of Research, which presents

complete papers reporting technical investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in progress; and Basic Radio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in NBS Circular 460, Publications of

the National Bureau of Standards ($1.00). Information on calibration services and fees can be

found in NBS Circular 483, Testing by the National Bureau of Standards (25 cents). Both are

available from the Government Printing Office. Inquiries regarding the Bmreau’s reports and

publications should be addressed to the Office of Scientific Publications, National Bureau of Standards, Washington 25, D. C.