QB/T 2490-2000Polyethylene (PE) Extruded Sheets (English PDF)

5.1 Sampling

For rolled sheet sampling, it shall discard the surface layer; while preparing samples, the

distance from the samples to the sheet edge shall be not less than 50mm.

5.2 Sample conditioning and standard test environment

The samples shall be placed in the environment at a temperature of (23±2)°C for more

than 16h; and conduct the test under such condition.

5.3 Visual inspection

Conduct visual inspection to 1m2 sheets under normal natural light.

5.4 Thickness determination

Use a measuring instrument, accurate to 0.02mm, to measure three points at

even-intervals, in the direction along the width of a sheet; the measuring points at ends

shall be 20mm away from the edges of the sheet.

5.5 Width and length determination

Measure with a steel tape, accurate to 1mm.

5.6 Determination of diagonal difference

Measure the difference between the two diagonals of a sheet that is 1000mm long,

accurate to 1mm.

5.7 Density determination

Measure according to 4.1.3.2 in GB/T 1033-1986.

5.8 Determination of tensile yield strength

Measure according to GB/T 1040; use Type I samples at a test speed of 50mm/min.

5.9 Inspection of hygienic requirements

Determine according to GB/T 5009.60.

5.10 Determination of simply supported beam impact strength

Measure according to GB/T 1043; use Type A notched specimen of Type I sample, with

the pendulum impacting energy as 4J.

6.2 Factory inspection

Factory inspection includes the items in 4.1, 4.2, and table 2 in 4.3; it can also be agreed

upon between the seller and the buyer.

6.3 Type inspection

The type inspection includes all the technical requirements in Chapter 4 in this standard.

They shall be tested at least once a year.

A type inspection shall be made in case of one of the following situations.

a) When trial identification appraisement is made for new products or old products are

transferred to another plant for production;

b) When it may affect the product properties due to major changes in, for example,

structure, material, and process after formal production;

c) When production recovers after a long-time shutdown;

d) When there are significant differences between the factory inspection results and

the last type inspection results;

e) When national quality supervision agencies require to make a type inspection.

6.4 Sampling

6.4.1 The appearance and specifications adopt single sampling inspection plan according

to GB/T 2828 and are based on general inspection level I. The acceptable quality level

AQL is 6.5, as required in Table 4. The unit of test pieces is piece.

6.5.2 The inspection of physical and mechanical properties shall be conducted on a sheet

taken from the samples at random.

Table 4

Lot range N Sample size n Acceptance number Ac Rejection number Rc

26~150 8 1 2

151~280 13 2 3

281~500 20 3 4

501~1200 32 5 6

1201~3200 50 7 8

3201~10000 80 10 11

10001~35000 125 14 15

> 35000 200 21 22

6.5 Judgment rules

For 4.1 and 4.2, it can be decided according to Table 4. In case one of the rest items fails

to meet the standard, then double samples can be taken from the original lot for

re-inspection; if it still fails to meet the standard, then this lot is deemed as unacceptable.

7.1 Marking

Every package shall be accompanied with a certificate, which includes.

a) names of product and manufacturer;

b) product specifications;

c) date of production, lot, and net weight;

d) product trademark and inspector code;

e) adopted standard number.

7.2 Packaging

Flake sheets are packaged with gunny bags, boxes, or other materials; the mass of every

box is not more than 100kg.

Rolled sheets shall be curled and bound with bundling ropes at both ends, and then

packaged with plastic film; the mass of every box is not more than 50kg.

7.3 Transport

The product shall be free of contamination, pressure, collision, and sunshine, rain; the

package shall be intact and complete.

7.4 Storage

The product shall be stored in a dry and clean room or a warehouse at appropriate

temperature. The product shall be at least 1m away from heat source in storage.

The storage period shall not be more than two years from the date of production.

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