HG/T 4070-2008Silicone rubber sheets (English PDF)

3.1 Classification

Silicone rubber boards are divided into three categories, according to tear strength: low tear resistance silicone rubber boards, medium tear resistance silicone rubber boards,

6.1 Group-batching and sampling

For the silicone rubber boards of the same formula, same specification, same variety, 200 m² shall form a batch (if less than 200 m², the contracted quantity shall be counted as a batch). Specifications, deviations, appearance quality are inspected piece by piece (strip). Enough specimens are taken from each batch, for physical and mechanical property inspection.

6.2 Inspection classification

6.2.1 Exit-factory inspection

The inspection items include: specification and deviation, appearance quality, hardness, tensile strength, elongation at break, tear strength of the rubber board.

6.2.2 Type test

All the technical requirements, which are listed in this standard, are type inspection items. Usually, type inspection shall be carried out, in one of the following situations:

a) Type finalization of trial production of new products or trans-plant production of old products.

b) After the formal production, where there are major changes in the structure, material, process, which may affect the performance of the product.

c) During normal production, inspection is carried out once a year.

d) When the production is restored, after suspension for more than half a year;

e) When there is a big difference between the exit-factory inspection results and the last type inspection.

f) When the national quality supervision agency proposes a type inspection requirement.

6.3 Judgment rules

If one of the specifications, deviations, appearance quality is unqualified, the piece (strip) of silicone rubber board is an unqualified product.

If one of the physical and mechanical properties, which are listed in Table 2, does not meet the requirements, take another double quantity of specimens, to re-inspect the […]