GB 25970-2010Non-combustible inorganic compound board (English PDF)

4.1 Classification and requirements for physical and mechanical properties

Press the apparent density of the product is divided into seven categories, their category and the basic physical and mechanical properties are shown in Table 1.

Table 1 Category and physical and mechanical properties

category

Apparent density rho /(Kg/m3) Dry bending strength/MPa 3.0mm<= thickness e <=7.0mm 7.0mm 2000 ± 5 <=2000 ± 3 1. The nominal thickness of no more than ± 10%, the maximum does not exceed ± 1.5mm;

2. Plate the largest measured difference of the same minimum thickness does not exceed the nominal thickness ± 10%, the maximum does not exceed 1.0mm rho > 1500 > 2000 ± 5 <=2000 ± 5 1. The nominal thickness of no more than ± 15%, the maximum does not exceed ± 2.0mm;

2. Plate the largest measured difference of the same minimum thickness does not exceed the nominal thickness ± 15%, a maximum 1.5mm

4.3.3 Differential edge flatness and diagonal allowable value

Poor flatness and diagonal edges of the allowed values shall conform to Table 3.

Differential edge table flatness and diagonal allowable value Project rho<=1500kg/m3 rho > 1500kg/m3 Edge straightness <=0.2%, the maximum distance to the reference sheet edge does not exceed 3.0mm <=0.3%, the maximum distance to the reference sheet edge does not exceed Over 5.0mm Diagonal difference the length of <=2000mm, does not exceed the difference between the diagonal 3.0mm;

Length > 2000mm, does not exceed the difference between the diagonal 5.0mm the length of <=2000mm, does not exceed the difference between the diagonal 5.0mm;

Length > 2000mm, does not exceed the difference between the diagonal 7.0mm

4.4 Mechanical Properties Physical

Physical and mechanical properties shall conform to Table 4.

Table 4 Mechanical Properties Physical

Item Index

Dry bending strength/MPa in line with the values specified in Table 1 the saturated water absorption Flexural strength/MPa of not less than 70% of the value specified in Table 1 Moisture deformation rate /% <=0.20 Halogen-free anti-reversion resistance drops, no damp Note. The anti-reversion properties only apply to the halogen magnesium plate glass.

4.5 Combustion performance

Combustion performance should be consistent with the GB 8624 of homogeneous material A1 level requirements.

5.1 Appearance quality

Appearance quality by visual inspection sheet manner.

5.2 Size and size bias

5.2.1 Measuring Tool

Measurements should be used as precision measuring different.

a) an accuracy of 1mm steel tape measure;

b) not more than 0.1mm accuracy caliper.

5.2.2 The length and width measurements Length and width steel tape measure at the midpoint of the plate edge and 25mm from both ends of the measurement, each measured twice, accurate to 1mm. measuring should avoid visible local defects, the arithmetic mean of six measurements, that is, as the length or width of the plate, and shall meet Table 2 Requirements.

5.2.3 Thickness Measurement

One side of the board, according to the measuring position shown in Figure 1, with a caliper thickness measuring 8 points, accurate to 0.1mm. 8 measurements If the average value shall meet the requirements of Table 2.

1 thickness measurement location map

5.2.4 Edge flatness measurement

The plates were followed by four sides over the plate against a long reference line, with a vernier caliper plate edge and the reference line from the edge of the largest from the nearest 0.1mm. The distance and the edge length ratio shall meet the requirements of Table 3.

5.2.5 Diagonal length measurement

Steel tape measure diagonal length plate, accurate to 1mm. Diagonal length difference between the two should meet the requirements of Table 3.

5.3 Mechanical Properties Physical

5.3.1 Preparation of test pieces

Physical and mechanical properties of the specimen shall be in a position not less than 200mm from the edge of the plate interception. Among them, the dry bending strength and water saturated state Interception position bending strength test piece shown in Figure 2.

Figure 2 flexural strength specimens intercept position

5.3.2 Apparent density

According to GB/T 7019-1997 the provisions of Chapter 5 of the method for the determination.

5.3.3 Dry flexural strength

When the specimen thickness e<=20.0mm, Figure 2a) from the position shown in solid lines per board intercepted two specimens; e > when 20.0mm, according to FIG.

2b) from the position shown in solid lines in each panel intercepted four specimens, specimen size shown in Table 5. The specimen is placed in a temperature of 100 °C ~ 105 °C Oven and bake until the rate of change in mass 2h interval between two successive weighing no more than 1%. The drying of the specimen into the dryer, cooled to room temperature , Press GB/T 7019-1997 test specified in 9.3.4 and 9.4.2 and calculate the bending strength of the test piece. Two specimens taken 4 tests as a result, four specimens taken eight times the average of the test results as a dry flexural strength of the test piece.

Table 5 flexural strength specimen size in millimeters

thickness

Specimen size

Length and width

The distance between the fulcrum <=20.0 250 250 215 > 20.0 span between the supports 40 3e (minimum of not less than 100) 10e Flexural strength 5.3.4 water saturation Specimen thickness e<=20.0mm, Figure 2a) from the broken line position shown in each panel intercepted two specimens; e > when 20.0mm, according to FIG.

2b) from the position shown in dashed lines per board intercepted four specimens, specimen size shown in Table 5. Specimens placed in water greater than 5 °C more than 24h , Remove with a wet towel to wipe the surface of water droplets, immediately press GB/T 7019-1997 test specified in 9.3.4 and 9.4.2 and calculate specimens Flexural strength. The average of two specimens taken 4 times the test results, four specimens taken eight test results as the water saturation of bending strength.

5.3.5 Moisture absorption rate of deformation

With an accuracy of 0.02mm vernier caliper 300mm × 300mm interception of two specimens, the specimen surface as shown in Figure 3 to determine the four Reference points, reference points sequentially spaced 250mm. The test piece was immersed in 5 °C ~ 35 °C water for more than 24h, remove the specimen by measuring 1-2,2-3,3-4,4-1 accurately measure the distance between. The specimen is then placed in 60 °C ± 3 °C oven drying 24h ~ 28h After removal, cooled to room temperature, then measure the distance between 1-2,2-3,3-4,4-1, accurate to 0.02mm.

Calculated moisture absorption rate of deformation.

S = L1-L2L2 ×

100% (1)

Where.

S --- moisture deformation rate,%;

Ll --- reference point after moisture absorption of the distance in millimeters (mm);

After the distance L2 --- reference point drying, in millimeters (mm).

8 sets of data taken as the arithmetic mean of the absorbent rate of deformation of the sample.

3 moisture absorption rate of specimen deformation

5.3.6 Anti-reversion of halogen

In a set of three plates each sample cut any piece of 150mm × 150mm specimen, and placed in a relative humidity of 90% to 95% Temperature of 40 °C ± 2 °C constant temperature and humidity chamber (24 ± 2) h after removal, to observe whether the phenomenon of water droplets or damp.

5.4 Combustion performance

The average temperature measured in the furnace according to the provisions of GB/T 5464, the average duration of burning time, the average mass loss rate; according to GB/T 14402 of Determination of heat of combustion predetermined value.

6.1 Inspection classification

Sub-type test non-combustible inorganic composite board testing and factory inspection.

6.2 Type inspection

When sampling the product base is not less than 6.2.1 appraisement 50, of the following circumstances, type of inspection should be carried out.

a) production of new products or old products to the plant trial to identify stereotypes;

B) after the official production, product formulations, technology and raw materials have greater changes;

c) Product Discontinuance when more than one year to resume production;

d) factory inspection and type inspection last time are quite different;

e) when normal production for two years;

f) the product quality supervision department requirements.

6.2.2 Type inspection items include all items specified in Section 4.

6.3 Factory inspection

Each batch factory inspection should be carried out before the product is shipped. Appearance quality specified in this standard, the size deviation, edge flatness deviation, diagonal the difference between the dry and wet bending strength, water absorption saturation bending strength, moisture absorption rate of deformation factory inspection items.

6.4 Batch and sampling

6.4.1 Inorganic non-combustible composite panels should be 150 batch. Randomly selected from each batch as a set of three specimens shall be taken from the three groups, two of which Set for a retest.

6.4.2 appearance quality factory inspection, dimensional variations, edge flatness, three sheets of a difference between the diagonal group of specimens shall be tested, and from Extract a plate, according to the requirements of 5.3.1 intercepted production specimens were dry flexural strength, water absorption saturation bending strength, moisture deformation Rate test.

6.5 Test results to determine the principles

Type test all items seized qualified is determined that batch of qualified, otherwise unqualified. Factory inspection qualified products batch determined in accordance with Table 6 Regulation to determine the number given judgment. The total number of unqualified and qualified individual items does not exceed the sentence specified in Table 6 when batch conformity.

Table 6 factory inspection lot acceptance number

Project samples

Factory inspection

The total number of individual items unqualified rejection number Appearance Quality Size deviation Edge straightness Diagonal difference Dry flexural strength Water saturation bending strength Moisture absorption rate of deformation Anti-reversion of halogen Combustion performance <=2

6.6 Retest

6.6.1 convicted of batches of substandard products, you can use two retest samples from the same batch of defective items recheck, all sample groups Eligible then this batch is qualified.

6.6.2 for factory inspection by the appearance of quality, size deviation unqualified convicted of substandard batches, allowing the batch-by-article inspection, by Check qualifying sheet remained qualified.