KENYA STANDARD    DKS 649 -2: 2020  
  ICS 81.040  
 
 
 
 
 
 
 
 
 
 
 
Automobile windscreens - Specification  
 
Part 2.   
 
Laminated automobile windscreens  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
No copying of this standard without KEBS permission except as permitted by copyright law  
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
TECHNICAL COMMITTEE REPRESENTATION  
 
The following organizations were represented on the Technical Committee:  
 
Toyota Kenya Ltd  
D.T Dobie  
Mitsumoto  
Isuzu E.A  
Kenya Association of Bus Manufacturers (KABM)  
Kenya Motor Repairers Association (KEMRA)  
Nissan  
Numerical Machining Complex (NMC)  
Gede Enterprises  
Mobius Motors  
KUMPIA  
Kenya Industrial Research and development Institute (KIRDI)  
Technical University of Kenya (TUK)  
Motorwise Valuers  
Kenya Auto Bazaar Association  
Honda (Nairobi)  
Egerton Universit y 
Olive Technical Services Ltd  
Kenya Jua Kali Association  
MCI Ltd  
Kenya Bureau of Standards — Secretariat  
 
 
 
 
 
REVISION OF KENYA STANDARDS  
 
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for impro vement to published standards, addressed to the Managing Director, Kenya Bureau of Standards, 
are welcome.  
 
 
 
©Kenya Bureau of Standards, 2020  
 
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 12 of 2001 of  the Laws of Kenya, copyright 
subsists in all Kenya Standards and except as provided under Section 26 of this Act, no Kenya Standard produced by Kenya Bure au of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without pr ior permission in writing 
from the Managing Director . 
 
 
 
 
 
 
  
 KENYA STANDARD    KS 649 -2:2020  
  ICS 81.040  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Specification for automobile windscreens  
 
Part 2.  
 
Laminated automobile windscreens  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA BUREAU OF STANDARDS (KEBS ) 
 
Head Office:  P.O. Box 54974, Nairobi -00200, Tel.: (+254 020) 605490, 602350, Fax: (+254 020) 604031  
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
Coast Region     Lake Region          Rift Valley Region  
P.O. Box 99376, Mombasa -80100   P.O. Box 2949, K isumu -40100        P.O. Box 2138, Nakuru -20100  
Tel.: (+254 041) 229563, 230939/40   Tel.: (+254 057) 23549, 22396        Tel.: (+254 051) 210553, 210555  
Fax: (+254 041) 229448    Fax: (+254 057) 21814  
 
 
 
 
  KS 649 -2:2020                           ©KEBS  
 
 2 Foreword  
 
This Part 2 of this Kenya Standard was prepa red by the Technical Committee on Glass and Glass Products, 
under the guidance of the Chemical Industry Standards committee, and is in accordance with the procedures 
of the Bureau.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ©KEBS        DKS 649 -2: 2020  
 
 3 KENYA STANDARD  
 
SPECIFICATIO N FOR AUTOMOBILE WINDSCREENS  
 
PART 2.  LAMINATED AUTOMOBILE WINDSCREENS  
 
 
1. SCOPE  
 
This Part 2 of this Kenya Standard specifies requirements for laminated automobile windscreen 
made of float glass.  
 
NOTE:   Sheet glass shall not be used for the manufactu re of automobile windscreens.  
 
2. DEFINITIONS  
 
For the purpose of this standard, the following definition and the ones defined in Part 1 of this 
standard shall apply:  
 
2.1 laminated glass  — A glass consisting of two or more layers held together by two or m ore layers of 
plastics material.  
 
3 REQUIREMENTS  
 
3.1 Thickness  — Shall comply with 3.1 of KS 649 Part 1 . 
 
3.2 Ball Impact Test — Shall pass the ball impact test for mechanical strength prescribed in A1. 
 
3.3 Head Form Test  — Shall pass the head form test  prescribed in A2. 
 
3.4 Abrasion Test  — Shall pass the abrasion test prescribed in A3. 
 
3.5 High Temperature Test  — Shall pass the test prescribed in A4. 
 
3.6 Resistance to Radiation Test  — Shall pass the test prescribed in A5. 
 
3.7 Humidity Test  — Shall p ass the test prescribed in A6. 
 
3.8 Light Transmission Test  — Shall pass the test prescribed in A3 of Part 1 of this standard.  
 
3.9 Optical Distortion Test  — Shall pass the test prescribed in A4 of Part 1 of this standard.  
 
3.10 Secondary Image Test  — Shall pass the test prescribed in A5 of Part 1 of this standard.  
 
3.11 Identification of Colours Test  — Shall pass the test prescribed in 3.7 of Part 1 of this standard.  
 
4. DEFECTS  
 
4.1 Inspection of Defects  — Inspect defects as described in 4.2 of Part 1 of this standard.  
 
4.2 Requirements for Defects  — All windscreens shall have limited defects as specified in Table 1.  
 
 
 
 
 
 
 
TABLE 1. DEFECTS LIMITS — LAMINATED GLASS — WINDSCREENS  KS 649 -2:2020                           ©KEBS  
 
 4  
SL 
No. DEFECTS  AREA   A  AREA   B  AREA   C  
1 Bubbles  4 max. of which 2 may ex ceed 0.8 
mm dia. To a max. of 1.5 mm dia. 
Minimum separation 100 mm  6 max. of which 2 may 
exceed 0.8 mm dia. To a 
max. of 1.5 mm dia.  
Minimum separation 100 mm  See 
Note 1  
2 Seed  2 to a max. of 1.0 mm dia. 
Minimum separation 300 mm  4 to a max. of 1.5 mm d ia.  
Minimum separation 300 mm  “ 
3 Dimple  2 to a max. of 1.0 mm dia.  
Minimum separation 100 mm  2 to a max. of 1.0 mm 
diameter.  
Minimum separation 300 mm  “ 
4 Scratches  Non visible when viewed as 
detailed in 4.2, KS 03 -649: Part 1  Non visible when viewed  as 
detailed in 4.2 of Part 1 of this 
standard  “ 
5 Hair Cracks & 
Sleeks  “ “ “ 
6 Rub “ “ “ 
7 Dig “ “ “ 
8 Dirt Cullet and 
Scum  “ “ “ 
9 Ripple  “ Occasional medium.   
No undue distortion  “ 
10 Stones  “ Non visible when viewed as 
detailed in 4.2 of Part 1 of this 
standard  “ 
11 Fibre  Non visible when viewed as 
detailed in 4.2 of Part 1 of this 
standard  Maximum of 3 not exceeding 
6 mm length  “ 
12 Haze  “ Occasional not exceeding 1.5 
mm dia.  “ 
13 Spot 4 max. not exceeding 0.8 mm dia.  
Minimum separation 300 mm Occasional not exceeding 1.5 
mm dia.  
Minimum seperation 300 mm  “ 
14 Finger Marks  Non visible when viewed as 
detailed in 5.6. Non visible when viewed as 
detailed in 5.6 “ 
15 Chips  “ “ “ 
16 Dry Marks and 
Short Plastic  “ “ 6 mm depth 
and 75 mm 
length m ax. 
Total not to 
exceed 2.5 % 
of periphery  
17 Overlap  – – 0.8 mm max.  
 
NOTE:  The above glass imperfections are permitted in Area C (concealed edges) provided they 
do not affect the function of the glass or impair the sealing.  
 
5. MARKING  
 
The following p articulars shall be  legibly and  indelibly marked on the laminated windscreen:  
 
 (a) Manufacturer’s name and/or registered trade mark  
 
 (b) The words ‘Laminated Windscreen’ or the letter ‘WL’;  
 
c)  Country of origin  
 
 ©KEBS        DKS 649 -2: 2020  
 
 5 Annex      A1 
 
A1. BALL IMPACT TEST  
 
A1.1 Principle of Test  
 
A1.1.1  The test shall be carried out by means of a falling solid ball made of hardened steel, the mass of 
which shall be defined for the different types of glass; the ball shall fall within 25 mm of the centre of 
the test piece or sam ple. 
 
A.1.1.2  The ball shall be released without any impetus being given to it (e.g. by using an electromagnet).  
 
A1.2  Supports for  Samples  
 
A1.2.1  The sample shall rest freely on a strip of rubber, of hardness 50 IRHD and about 3 mm thick, placed 
on a sup port, the width of contact all round the perimeter being about 15 mm.  
 
A1.2.2  The support shall be rigid, shall conform to the shape of the sample, and shall be arranged in such a 
way that the ball strikes the outer face of the sample.  Care shall be taken  to ensure adequate 
contact between the sample and the support.  
 
A1.2.3  The support shall rest on a sheet of rubber, of hardness 50 IRHD and about 3 mm thick, placed on a 
rigid base, e.g. a substantial concrete base.  
 
A1.2.4  The ball used shall have a mass  of 227  2 g and a diameter of approximately 38 mm.  The height of 
the drop (from the lower part of the ball to the upper surface of the sample) shall be 2.5 m + 5 - 0 
mm. 
 
A1.2.5  Interpretation of Results  — The ball impact test shall be deemed to have gi ven a positive result if the 
sample is not broken.  
 
 
 
 
 
Annex     A2 
 
A2. HEAD FORM TEST  
 
Carry out the head form test as described in Part 1 of this standard from a height drop of 1.5. m + 0 
– 5 mm.  
 
A2.1  International of Results   —   The head form test s hall be deemed to have given satisfactory 
result if:  
 
(a) The sample breaks displaying numerous circular cracks centre approximately on the point of 
impact, the nearest cracks being not more than 80 mm from the point of impact;  
 
(b) The glass fragments rem ain attached (except as defined in A2.1.1 ) to the plastics interlayer.  
Partial separation from the interlayer within a distance of 4 mm on either side of a crack is 
permitted.  Within a 60 mm diameter circle centred is permitted beyond the point of impact , 
partial separation is permitted beyond a distance of 4 mm on either side of a crack.  
 
A2.1.1  On the side of the impact not more than 2 000 mm2 of interlayer is exposed.  
 
A2.1.2  A split in the interlayer does not exceed 35 mm in length.  
 
 KS 649 -2:2020                           ©KEBS  
 
 6 Annex    A3 
 
A3. ABRASION TEST  
 
A3.1  Apparatus   — The following apparatus is required:  
 
A3.1.1  Abrading Instrument* , shown diagrammatically in Figure 1, and consisting of the following:  
 
A horizontal turntable and centre clamp which revolves counter -clockwise at 65 r/min  to 75 r/min.  
 
Two weighted parallel arms, each carrying a special abrasive wheel rotating freely on a ball -bearing 
horizontal spindle; each wheel rests on the specimen under the load exerted by a mass of 500 g.  
 
The turntable of the abrading instrument sh all rotate regularly and substantially in one place.  The 
deviation from this plane shall be not greater than 0.05 mm at a distance of 1.6 mm from the 
turntable periphery.  
 
A3.2  Preparation of Test Pieces  
 
A3.2.1  Immediately before and after the abrasion, clean the test pieces in the following manner:  
 
 (a) Wipe with a linen cloth under clean running water;  
 
 (b) Rinse with distilled or deminerilized water;  
 
 (c) Blow dry with oxygen or nitrogen;  
 
(d) Remove possible traces of water by dabbing softly with a damp linen cloth; if necessary, dry 
by pressing lightly between two linen cloths.  
 
 Any treatment with ultrasonic equipment shall be avoided.  
After cleaning, the test pieces shall be handled only by their edges and shall be stored to prevent 
damage to, o r contamination of, their surfaces.  
 
A3.2.2  Condition the test specimens prior to testing for a minimum time of 48 h at 20  5 C and 50  2 per 
cent relative humidity.  
 
A3.3  Test Method  
 
A3.3.1  Immediately after completion of the conditioning period place  the test piece against the entrance port 
of the integrating sphere.  The angle between the normal to the surface of the test piece and the axis 
of the beam shall not exceed 8 . 
 
 Take four readings as indicated in Table 2.  
 
TABLE 2.  READINGS REQUIRED FOR  ABRASION RESISTANCE TEST  
 
READING  WITH 
SPECIMEN  WITH LIGHT 
TRAP  WITH 
REFLECTANCE 
STANDARD  QUANTITY 
REPRESENTED  
T1 No No Yes Incident light  
T2 Yes No Yes Total light 
transmitted by test 
specimen  
T3 No Yes No Light scattered by 
instrument  
T4 Yes Yes No Light scattered by 
instrument and test 
piece  ©KEBS        DKS 649 -2: 2020  
 
 7  
Repeat reading for T 1, T2, T3, and T 4 with additional specified position of the test piece to determine 
uniformity  
 
The wheels shall be mounted in such a way that, when they are in contact with the rotating te st 
specimen, they rotate in contrary direction so as to exert a compressive and abrasive action along 
curved lines over an annular area of about 300 mm2, twice during each rotation of the test specimen.  
 
A3.3.2  Abrasive wheels*, each 45 mm to 50 mm in diam eter and 12.5 mm thick, composed of a special 
finely screened abrasive embedded in a medium -hard rubber.  The wheels shall have an IRHD 
hardness of 72  5, measured at four points equally spaced on the centre line of the abrading 
surface with the pressure applied vertically along a diameter of the wheel, the readings being taken 
10 s after full application of the pressure.  
 
The abrasive wheels shall be prepared for use by very slow rotation against a sheet of flat glass.  
 
A3.3.3  Light source. consisting of an incandescent lamp, the filament of which is contained within a parallel 
piped 1.5. mm x 1.5 mm x 3 mm.  The voltage at the lamp terminals shall be such that the colour 
temperature is 2 856  50 K.  This voltage shall be stabilized within  per cent.  Th e instrument used 
to check the voltage shall be of appropriate accuracy.  
 
A3.3.4  Optical system, consisting of a lens with a focal length of at least 500 mm an corrected for chromatic 
aberrations.  The clear aperture of the lens shall be adjusted in order to obtain a light beam that is 
substantially parallel.  
 
A diaphragm shall be inserted to limit the diameter of the light beam to 7  1 mm.  This diaphragm 
shall be situated at a distance of 100  50 mm from the lens on the side remote from the light 
source . 
 
A3.3.5  Equipment for measuring scattered light (hazemeter) ( see Figure 2), consisting of a photoelectric cell 
with an integrating sphere of diameter of 200 mm to 250 mm.  The sphere shall be equipped with 
entrance and exit ports for the light.  The entr ance port shall be circular and have a diameter at least 
twice that of the light beam.  The exit port of the sphere shall be provided with a light trap and with a 
reflectance standard.  The light trap shall absorb all the light when no test specimen is ins erted in the 
light beam.  
 
The axis of the light beam shall pass through the centre of the entrance and exit ports.  The 
diameter, b, of the light exit port shall be equal to 2a tan 40, where a is the diameter of the sphere.  
The photoelectric cell shall be  mounted in such a way that it cannot be reached by light coming 
directly from the entrance port or from the reflectance standard.  
 
The surfaces of the interior of the integrating sphere and the reflectance standard shall be of 
substantially equal reflecta nce, and shall be matt and non -selective.  
 
The output of the photoelectric cell shall be linear within 2 per cent over the range of luminous 
intensity used.  The design of the instrument shall be such that there is no galvanometer deflection 
when the spher e is dark.  The whole apparatus should be checked at regular intervals by means of 
calibration standards of defined haze.  
 
If haze measurements are made using equipment or methods differing from the above, the results 
shall be corrected in order to be in a greement with those obtained by the apparatus described.  
 
A3.4  Test Pieces  — The test pieces shall be flat squares of side 100 mm having both surfaces 
substantially plane and parallel, and with a 6.5  0.1 mm diameter hole drilled in the centre.  
 
                                                 
*  A suitable abrading instrument is supplied by Teledy ne Taber (USA) from whom abrasive wheels  
may also be obtained.  KS 649 -2:2020                           ©KEBS  
 
 8 A3.4.1  Determine the initial haze of the test specimen at a minimum of four equally spaced points in the un -
braded area in accordance with the formula in A4.5.1 . 
 
Average the results for each test specimen.  As an alternative to making four separate 
measurements an  average value may be obtained by rotating the test piece uniformly at 3 r/s or 
more.  
 
A.3.4.2  For each type of safety glass, carry out three tests with the same load on the side representing the 
outer surface of the glass.  Use the haze as a measure of th e surface abrasion after the test piece 
has been subjected to abrasion for 1 000 cycles.  
 
A.3.4.3  Determine the light scattered in the abraded track at a minimum of four equally spaced points along 
the track in accordance with the formula in A4.5.1 .  Avera ge the results for each test piece.  As an 
alternative to making four separate measurements an average value may be obtained by rotating the 
test piece uniformly at 3 r/s or more.  
 
A3.5  Calculation and Interpretation of Results  
 
A3.5.1  Calculate the total transmittance Tt = T2/T1. 
 
 Calculate the diffuse transmittance T d as follows:  
 
  

1123 4
d/
TTTTTT     
 
 Calculate the percentage haze or light scattered, or both, as follows:  
 
 Haze or light scattered, or both = 
100% x 
td
TT  
 
A3.5.2  Subtract  the average initial haze from the average total light scattered, the difference representing 
the light scattered as a result of abrading the test piece.  Calculate the difference for the surface 
abrasion.  
 
A3.5.3  Safety glass shall be considered satisfact ory from the point of view of abrasion resistance if the light 
scattered as a result of abrading the test piece does not exceed 2 per cent.  
 
 
 
 
 
 
Annex     A4 
 
A4. HIGH TEMPERATURE TEST  
 
A4.1  Test Method  
 
A4.1.1  The test pieces shall be immersed vertically for 3 min in water at approximately 66 C, then plunged 
rapidly in the same way into boiling water and kept there for 2 h.  
 
A4.1.2  If the test is carried out on a test piece cut from a windscreen, the surface area shall be not less than 
300 mm x 300 mm, bo unded on one side by the upper edge of the windscreen.  
 
A4.2  Interpretation of Results  
 ©KEBS        DKS 649 -2: 2020  
 
 9 A4.2.1  The test shall be deemed to have given a positive result if bubbles or other defects are not formed 
more than 15 mm from the outer edge of the test piece or more  than 10 mm from any cracks which 
may occur during the test.  
 
A4.2.2  No account shall be taken of bubbles or defects within 25 mm of the cut edge of a test piece cut from 
a windscreen.  
 
 
 
 
 
 
A P P E N D I X    A5  
 
A5. RESISTANCE TO RADIATION TEST  
 
A5.1  Purpose of Test  —  The purpose of this test is to determine whether exposure to radiation over an 
extended period of time produces any appreciable decrease in regular luminous transmittance or 
any pronounced discoloration of the safety glass.  
 
A5.2  Apparatus  
 
A5.2.1  Radiation source consisting of a medium -pressure mercury vapour are lamp with a tubular quartz 
bulb of ozone -free type; the bulb axis shall be vertical.  The nominal dimensions of the lamp shall be 
360 mm in length by 9.5 mm in diameter.  The arc length shall be 300 mm  14 mm.  The lamp shall 
be operated at 750  50 W.  
 
Any other source of radiation which produces the same effect as the lamp specified above may be 
used.  To check that the effects of another source are the same, a comparison shall be made by 
measuring the amount of energy emitted within a wavelength range of 300 mm to 450 mm, all other 
wavelengths being removed by the use of suitable filters.  The alternative source shall then be used 
with these filters.  
 
In the case of safety glass  for which there is no satisfactory correlation between this test and the 
conditions of use it will be necessary to review the test conditions.  
 
A5.2.2  Power supply transformer and capacitor capable of supplying to the lamp ( A5.2.1 ) a starting peak 
voltage  of 1 100 V minimum and an operating voltage of 500  50 V.  
 
A5.2.3  Device for mounting and rotating the test specimens at 1 rev/min to 5 rev/min about the centrally 
located radiation source in order to ensure even exposure.  
 
A5.3  Test Specimen  —  The siz e of the test specimens shall be 76 mm x 300 mm.  
 
A5.4  Procedure  —  Check the regular light transmittance, determined according to A3 of Part 1 of this 
standard, of three test specimens before exposure.  Protect a portion of each test specimen from the 
radiation, and then position the test specimen in the test apparatus 230 mm from, and with its 300 
mm dimensions parallel to, the lamp axis.  Maintain the temperature of the test specimens at 45  5 
C throughout the test.  That face of each test specimen wh ich would represent the glazed exterior 
part of the motor vehicle shall face the lamp.  For the type of lamp specified in A5.2.1 , the exposure 
time shall be 100 h.  
 
After exposure, measure the light transmittance again on each test specimen in the exposed area.  
 
A5.4.1  Interpretation of Result  —  The test for resistance to radiation shall be deemed to have given 
positive result when the total luminous transmittance does not fall below 9 per cent of the original 
valve before irradiation or below 70 per cent , the transmittance being measured in accordance with 
Clause A3 of Part 1 of this standard.  
 KS 649 -2:2020                           ©KEBS  
 
 10  
 
A P P E N D I X    A6  
 
A6. HUMIDITY TEST  
 
A6.1  Purpose of Test  —  The purpose of this test is to determine whether the safety glass will 
successfully withstand the effects of humidity in the atmosphere over an extended period of time.  
 
A6.2  Procedure  —  Keep one or more test specimens of at least 300 mm x 300 mm vertically for 2 
weeks in a closed container in which the temperature is maintained at 50  2 C and the relative 
humidity at 95  4 per cent.  
 
 NOTE:  These test conditions exclude any condensation on test specimens.  
 
In the event that several test specimens are tested at the same time, adequate spacing shall be 
provided between the test specimens.  
 
Preca utions shall be taken to prevent condensate from the walls and ceiling of the test chamber from 
falling on the test specimens.  
 
If the test specimens are cut from windscreens, one edge of the test specimen shall be part of an 
edge of the windscreen.  
 
A6.3  Expression of Results  —  The resistance to humidity shall be evaluated visually by reference to 
change in the appearance of the safety glass after testing, i.e.:  
 
 — separation of materials;  
 
 — loss of transparence according to Clause A3 of Part 1 of thi s standard.  
 
The changes shall be assessed over the whole test specimen, except within 10 mm of the uncut 
edges or within 15 mm of the cut edges.  
 
 
 
 
 
 
 
 ©KEBS        DKS 649 -2: 2020  
 
 11  
 
 
 
 
 
 
FIG. 1 — DIAGRAM OF ABRADING INSRUMENT