GB/T 17841-2008Heat strengthened glass (English PDF)

6.1 Thickness deviation

The Thickness deviation of the products shall meet the requirements of the standards

applying the adopted glass sheets.

6.2 Dimensions and allowable deviation

6.2.3 Round hole

6.2.3.1 General

This article is only applicable to the products of which the normal thickness is not less

than 4mm. The edge processing quality of round hole shall be negotiated by the

supplying and demanding parties.

6.5 Tortuosity

The tortuosity factor of flat product made with horizon method shall meet the

requirements of Table 6; the tortuosity factor of flat product with perpendicular method

shall be negotiated by the supplying and demanding parties.

6.7 Surface stress

Inspected in accordance with 7.7, the surface stress shall meet the requirements in

Table 8.

6.8 Splinters statue

The splinters statue of the glass of which the thickness is not larger than 8mm shall be

inspected in accordance with 7.8; the splinters statue of each test sample shall meet

the requirements in 6.8.1.The splinters statue of the glass of which the thickness is

larger than 8mm shall be negotiated by the supplying and demanding parties.

6.8.1 Requirements in splinters statue

6.8.1.1 At least a side of splinter shall extend into non-inspection area.

6.8.2 Acceptance provisions of splinters statue

6.8.2.1 At least a side of splinter shall extend into non-inspection area.

6.8.2.2 When all sides of splinter are not able to extend into the non-inspection area,

then this splinter is classified into "islet" splinter and "grain" splinter.

Above-mentioned splinter shall meet the following requirements.

6.9 Heat shock resistance

This article shall be negotiated by the supplying and demanding parties, and

inspected in accordance with 7.9.The test sample can resist the temperature

difference of 100°C without damage.

7.1 Thickness inspection (test)

With outer-diameter micrometer (meet the requirements of GB/T1216) or the

instrument with same precision, measure the test sample (product) on center-points of

four sides 15 mm from the edge.

7.2 Dimensions and allowable deviation

7.2.1 Inspection of Side length allowable deviation

With straight steel ruler or steel tape of which the minimum scale is 1mm, measure the

test sample (from products).

tape with the minimum scale of 1mm.

7.3 Edge processing

Under the condition of good natural light or scattered light, do visual test on the

position 600mm away from the front of the test sample (from products).

7.4 Visual testing

Under the condition of good natural light or scattered light, do visual test on the

position 600mm away from the front of the test sample (from products).

7.5 Measurement of tortuosity

Before the measurement, place test sample (from products) under room temperature

for 4h or more; for the measurement, place the test sample vertically; arrange two

cushion blocks on the 1/4 lower position of the test sample; cling a ruler or metal wire

on two sides of diagonal; measure the distance between the straight line and the

glass with thickness gauge; use the length ratio of arc height and the chord length to

indicate the tortuosity.

7.8 Splinters state test

7.8.1 test sample

The test sample (1100mm X 360mm) is same to the product in thickness and

technical conditions; it is rectangle flat pattern test sample without round hole and

groove.

7.8.2 Testing procedure

7.8.2.1 Lay test sample on test stand; restrain the periphery of the glass with scotch

tape or other means to prevent glass fragment from splashing.

7.8.2.3 Complete exposition or photographing within 5 min after crashing, as well as

counting and weighing of "islet" splinter and "grain" splinter.

7.8.2.4 In the inspection, the area in 100mm radius from the impact point and 25mm

away from the edge (hereafter referred to as "non-inspection area") shall be excluded.

If there is "islet" or "grain" splinter after crashing, counting and weighing of "islet"

splinter and "grain" splinter shall be completed within 5 min.

7.8.2.5 The weighing method is adopted to measure the area of "islet" and "grain"

splinter according to the following formula.

8.1 Testing items

Inspection refers to exit-factory inspection and type inspection.

8.1.1 Type inspection

The testing items cover all technical requirements specified in this Standard, except

bending strength and heat shock resistance. The type inspection shall be done if any

one of the following conditions occurs.

8.2 Batch sampling method

8.2.1 Random sampling shall be done for appearance quality, size (dimension),

allowable deviation, and tortuosity in accordance with the requirements in Table 9.

8.3 Decision rules

8.3.1 For inspection (test) of appearance quality, dimensions, allowable deviation,

and tortuosity, the result of the test item is accepted if the reject number is not larger

than the Acceptance Number in Table 9; the products of this batch are rejected if the

reject number is larger than the Acceptance Number in Table 9.

8.3.2 For bending strength test, all test samples shall meet the requirements;

otherwise, the products are rejected.

8.3.3 For surface stress test, all test samples shall meet the requirements; otherwise,

the products are rejected.

9.1 Package

Glass shall be packaged with wooden case or container case (frame); and case

(frame) shall be convenient for loading, unloading and transporting. A case (frame)

shall be used for glass with same thickness and dimension.

9.2 Packing mark

The packing mark shall meet the requirements of the relevant national standards; the

marks or phrases like "Upward ", "Handle with care", and "Rain-proof and keep dry"

shall be indicated on each case.

9.3 Transportation

In the course of transportation, glass shall be fixed firmly to prevent slipping or

pumping; rain-proofing measures shall be available.

Annex A

(Normative)

Test Method of Bending Strength

A.1 Test conditions

Environmental temperature. 23°C±5°C; environmental humidity. 40%~ 70 %.

A.2 Test sample

Prepare at least 13 pieces of test samples for test. The test sample is 1100mm± 5mm

in length and 360mm± 5mm in width. In the preparation, the cutting points of parting

tool shall be on same surface of the test sample; and the edge shall be processed

with rough edge grinding.

The test samples shall be processed or treated within 24h before the test. if the shield

film is covered on test sample, it shall be wiped off 24 h before the test. Before the test,

the test samples shall be placed under the condition specified in A.1 for at least 4 h.

A.3 Test equipment

Material testing machine is adopted for test. The testing machine can load test sample

continually and evenly, and minimize shocking caused by loading. Testing machine

can be equipped with metering equipment and the error within its measurement range

shall be less than ±2%. The diameter support roller and loading roller shall be 50mm

and the length shall not be less than 365mm. Support roller and loading roller all can

rotate around the roll shaft line.

A.4 Test procedure

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