Some standard content:
National Standard of the People's Republic of China
Polyvinyl chloride artificial leather
Polyvinyl chloride artificial leather1 Subject content and scope of applicationbzxZ.net
GB/T 8948--94
Replaces GB894888
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of various cloth-based polyvinyl chloride artificial leathers other than knitted fabrics.
This standard applies to polyvinyl chloride artificial leather (hereinafter referred to as artificial leather) made by calendering or coating with polyvinyl chloride resin as the main raw material and adding plasticizers and other additives. 2 Reference standards
GB 251
Grey scale for assessing staining
Determination of bursting resistance of paperboard
GB 1539
GB 2828
GB2918
Count sampling procedure and sampling table for batch inspection (applicable to inspection of continuous batches)Standard environment for conditioning and testing of plastic specimensGB3920Test method for colour fastness of textiles to rubbingGB4689.9Determination of folding fastness of leather
GB 7565
GB 8808
Textiles - Test for colour fastnessSpecifications for cotton and viscose adjacent fabricsTest method for peeling of soft composite plastic materialsGB13022Test method for tensile properties of plastic films
HG2--162Test method for low-temperature impact compression of plastics3 Product classification
Products are classified according to the weaving method of the base fabric as shown in Table 1. Table 1
4 Technical requirements
4.1 Specifications
Various city cloths
Canvas, twill, double-sided cloth, etc.
4.1.1 Width and limit deviation shall comply with the provisions of Table 2. Approved by the State Bureau of Technical Supervision on November 16, 1994 Fabric varieties
Implementation on April 1, 1995
GB/T 8948—94
Superior products
Thickness and limit deviation shall comply with the provisions of Table 3. Table 3
Foamed leather
Non-foamed leather
Foamed leather
Non-foamed leather
4.1.3 The negative limit deviation of each roll length is 0.1m4.1.4 The number of sections and the minimum length of each roll shall comply with the provisions of Table 4. Length of each roll
20m/roll
30m/roll
40m/roll
Superior product
Note: 0.1m should be added for each additional section.
4.2 The appearance shall comply with the provisions of Table 5.
Pattern and color difference
Number of sections per roll, section
First-class products
Superior products
The pattern is clear, the depth is consistent, and there is no color difference
Not allowed
Limit deviation
First-class products
0.70~1.60
0.35~~0.65
0.80~1.40
0.70~0.90
Qualified products
First-class products
Superior products
The pattern is clear, the depth is consistent, and there is no color difference
The width of each side is ≤1 cm, and the length is ≤40 cm. No more than 1 place for a 20m roll, no more than 2 places for a 30m-
roll, no more than
Qualified products
Limit deviation
Minimum segment length, m
First-class products
Qualified products
Qualified products
The pattern is clear, the depth is slightly inferior to the first-class products, and the color difference is not obvious
The width of each side is ≤2cm, and the length is ≤40cm.
No more than 1 defect for a 20m roll, no more than 2 defects for a 30m roll, no more than 40m roll
Material blocks, burn marks, impurities
Oil stains, stains and color stains
Oil penetration of cloth base
Base cracks
Superior products
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Note: For each defect mentioned above, 0.1m should be added. 4.3 Physical and mechanical properties should comply with the requirements of Table 6. Item
Tensile load, N
Elongation at break, %
Tear load, N
Peel load, N
Surface color fastness, grade
Non-adhesive
Cold resistance
Aging resistance
Folding fastness
Superior product
≥250
≥200
GB/T 8948—94
Continued Table 5
Not allowed
Not allowed
Length <50cm, no more than
1 place for a 20m roll, no more than 2 places for a 30m roll,
no more than 3 places for a 40m roll
Qualified products
≤1cm2. No more than 1 place for a 20m roll,
no more than 2 places for a 30m roll,
no more than 3 places for a 40m-
roll||not obvious
Length ≤50cm, no more than
2 places for a 20m roll, no more than
3 places for a 30m roll,
40m-roll no more than 4 places
2.5cm2 or less, no more than
2.5cm2 or less for a 20m roll, m roll no more than
2 places, 30m roll no more than 3 places,
40m roll no more than 4 places
Not allowed
Not allowed
Not allowed
First-class products
Qualified products
≥150
≥100
No abnormality on the surface
No cracks on the surface
No cracks on the surface
3 places, 30m roll no more than 4 places,
40m roll no more than 5 places
Allowed length ≤4 cm live fold exists
Obvious existence is not allowed
Slight existence is allowed
Superior product
30,000 times without surface cracking
First-class product
≥400
≥300
Qualified product
≥350
Note: The folding fastness in the above table is a must-test item for artificial leather for shoe uppers, and artificial leather for other purposes is not subject to assessment. In addition to folding fastness, the physical and mechanical properties of artificial leather for shoe uppers also include rubbing resistance, bursting resistance and low-temperature folding fastness, which need to be negotiated and determined by the supply and demand parties. Indicators and test methods are shown in Appendix A (reference), Appendix B (reference) and Appendix C (reference). 353
5 Test method
5.1 Preparation of test specimens
GB/T 8948—94
Cut a length of more than 1 m from the product in the warp direction as the sample. After removing 50mm of width from both ends of the sample in the weft direction, the sample is prepared. The number and size of the sample shall be as specified in Table 7 and the figure below. Table 7
Specimen name
Tensile load and elongation at break
Tear load
Peel load
Surface color fastness
Non-adhesion test
Cold resistance test
Aging test
Rubbing test
Folding fastness and low-temperature folding fastness
Burst resistance test
Specimen size
(length×width), mm
200×30
200×30
150×30
150×30
150×30
220×60
9 0×60
60×20
200×50
120×30
120×30
70×45
100×100
GB/T8948—94
Ar, A—tensile load and elongation at break test specimen; B, Bz tear load specimen C peel load specimen; D—surface color fastness specimen; E—non-adhesion test specimen; F—cold resistance specimen; G aging specimen; Hi, H2—rub resistance test specimen; I, I2—folding fastness and low-temperature folding fastness specimen; L bursting resistance specimen 5.2 Sample state adjustment and test environment
According to the standard environment and normal deviation range in GB2918, the sample state adjustment time shall not be less than 4h, and the test shall be carried out under this condition.
5.3 Width
Use a steel tape measure or meter with an accuracy of 1mm to measure 3 random points along the length direction, and take the maximum or minimum value, accurate to 1mm. 5.4 Thickness
5.4.1 Instrument
Dial gauge thickness gauge.
Measuring force: 0.8~1.5N;
Probe diameter: 7~10mm;
Graduation value: 0.01mm;
Measurement limit: 0~10mm.
5.4.2 Test steps: Use the dial gauge thickness gauge to measure along the width direction of the product at three points: left, middle and right. The measurement results are expressed as the arithmetic mean, accurate to 0.01 mm.
5.5 Length
Measure with a measuring tool or instrument with an accuracy of 1mm, and the result is accurate to 1cm. 355
5.6 Appearance
GB/T8948—94
Visual inspection under natural light and measurement with corresponding measuring tools. 5.7 Tensile load and elongation at break
Carry out in accordance with the provisions of GB13022. The spacing between the sample markings is 100mm, and the test speed is 200mm/min. 5.8 Tear load
Cut 75mm in the direction parallel to the length at the center line of the sample width, clamp the two ends of the cut in opposite directions on the tensile testing machine fixture that meets the requirements of Article 5.7, and test at a tensile speed of 200mm/min. Record the maximum tear load of the sample. The test results are expressed as the arithmetic mean of three samples in the warp and weft, accurate to 0.1N. 5.9 Peel load
Carry out in accordance with the provisions of GB8808.
5.10 Surface color fastness
Carry out in accordance with the provisions of GB3920, among which the standard adjacent fabric for friction should comply with the provisions of GB7565. 5.11 Non-adhesiveness
5.11.1 Instrument
Constant temperature drying oven with a blast device.
5.11.2 Test steps
Put the PVC coating surfaces of two samples together, align them with the width of the sample with two smooth glass plates with a length and width of about 60mm, and then clamp the sample between the two glass plates. Then use a weight with a bottom length and width of 60mm and a mass of 3kg to press on the glass plate, and place them together in a constant temperature drying oven at 70±2℃. Take them out after 24 hours, remove the weight, and cool them at room temperature for 1 hour. Then slowly peel off the two samples and observe whether there is any damage or other abnormality on the film surface. 5.12 Cold resistance
Perform according to HG2-162, and the test temperature should comply with the provisions of Table 8. In the test results, if one of the three samples is broken, the cold resistance is unqualified.
5.13 Aging
5.13.1 Instrument
Heat aging test chamber: with rotating air blowing device. 5.13.2 Test steps
Hang the sample in a heat aging test box at a temperature of 100±2℃, keep it under rotating blast conditions for 24 hours, then take it out and cool it at room temperature for more than 0.5 hours. Then cut a sample of 60mm long and 20mm wide from each sample, and keep it in the low-temperature liquid specified in Table 8 for 5 minutes according to the method in Article 5.12 for cold resistance test. The result judgment is the same as that in Article 5.12. Table 8
Test temperature
Cold resistance
Aging
5.14 Folding fastness
Perform according to the provisions of GB4689.9.
6 Inspection rules
6.1 Inspection categories
6.1.1 Type inspection
Superior products
20±1℃
—10±1℃
First-class products
-10±1℃
—5±1℃
Qualified products
-5±1℃
-5±1℃
When any of the following conditions occurs, the product should be inspected. Type inspection: a.
GB/T8948-94
Trial design and identification of new products or old products transferred to the factory; after formal production, if there are major changes in structure, materials, and processes that may affect product performance; when normal production lasts for more than three months;
When production is resumed after a suspension of more than three months for some reason; when the results of the factory inspection are significantly different from the last type inspection; when the superior quality supervision agency proposes a type inspection requirement. 6.1.2 Factory inspection
The factory inspection items are all items in the technical requirements except non-adhesiveness and aging. 6.2 Factory inspection
6.2.1 Batching and sampling
6.2.1.1 Batching
Artificial leather should be accepted in batches. Products with the same base fabric, the same color, the same pattern, the same specification, and the same shift are one batch, and the quantity of each batch shall not exceed 15,000m.
6.2.1.2 Sampling
The inspection of specifications and appearance adopts the general inspection level I specified in GB2828, the secondary sampling plan, and the AQL is 6.5, see Table 9. Physical and mechanical properties are inspected by randomly selecting one roll from each delivery batch, Table 9
26～50
91~～150
151~280
281~500
501~1200
6.2.2 Judgment rules
6.2.2.1 Judgment of qualified items
Sample size
Cumulative sample size
GB/T8948--94
The judgment of specification and appearance sample units shall be carried out in accordance with the provisions of Articles 4.1 and 4.2 respectively. If the test results of the sample units meet the requirements of Table 9, the specifications and appearance are judged to be qualified.
If there are unqualified items in the physical and mechanical properties test results, double sampling should be taken from the original batch and the unqualified items should be retested. If all the retest results are qualified, the physical and mechanical properties are judged to be qualified. 6.2.2.2 Determination of qualified batches
If all the items in the test results are qualified, the batch of products is judged to be qualified. If there are unqualified items, the batch of products is judged to be unqualified. 6.3 Type inspection
6.3.1 Sampling
Randomly select one roll from the products that have passed the factory inspection for the inspection of appearance and specifications, and take 1m for the inspection of physical and mechanical properties. 6.3.2 Determination rules
Appearance and specifications shall be carried out in accordance with the provisions of Articles 4.1 and 4.2. If unqualified, three rolls should be randomly selected from the original products for retesting. If all the retest results are qualified, the appearance and specifications are judged to be qualified. If any item in the physical and mechanical properties test results is unqualified, double sampling should be taken from the original product, and the unqualified items should be retested. If all the retest results are qualified, the physical and mechanical properties are judged to be qualified. If all the test results are qualified, the type inspection is judged to be qualified. 7 Marking, packaging, transportation, storage
7.1 Marking
Each roll of product should be accompanied by a certificate of conformity and have the following markings: a.
Manufacturer name and address;
Product name;
Product specifications (thickness, width, length, color, pattern, etc.); production date and production batch number;
Registered trademark;
Implemented product standard number;
Inspector code.
7.2 Packaging
The product should be coated inward, rolled into a neat round roll with a roll core, and packaged with plastic film or kraft paper. 7.3 Transportation
When transporting the product, load and unload it gently, do not press it heavily, and do not expose it to the sun or rain. Keep the packaging intact. 7.4 Storage
The product should be stored in a ventilated and dry warehouse, and should not be close to heat sources. The storage period is one year from the date of production. 358
A1 Testing instrument
Rubbing test machine (Scott type rubbing test machine). A2 Test steps
GB/T8948—94
Appendix A
Rubbing resistance
(reference)
Overlap the two sample fabrics in the same direction, and then load them into the rubbing test machine fixture with a fixture spacing of 30mm. Gradually reduce the distance between the fixtures until the fabric surfaces of the two samples touch lightly and then apply the load. The distance is reduced until the load is 1kg. Under the conditions of a frequency of 120 times/min and a stroke of 50mm, reciprocate 1000 times to observe whether there are cracks, damages or separation of the cloth base and the coating on the surface of the artificial leather. If one of the samples has the above phenomenon, the rubbing resistance of the sample is judged to be unqualified. Appendix B
Burst resistance
(reference)
B1 Test instrument
Mullen bursting strength tester shall comply with the provisions of GB1539. B2 Test steps
Put the sample with the coating side facing down, clamp it with a ring clamp, and apply uniform pressure until the sample is burst. The burst resistance is expressed by the pressure when the sample is burst, which shall comply with the provisions of Table B1. The test results are the arithmetic mean of the three samples, accurate to 0.1MPa. Table B1
C1 Test instrument
Greater than 1.0MPa
Greater than 1.2MPa
Appendix C
Low temperature folding fastness
(reference)
Low temperature folding fastness test machine shall comply with GB4689.9 regulations. C2 Test steps
Based on the center line of the sample length, fold the coating inwards, and put one end of the folded sample into the upper clamp of the instrument so that the top is in contact with the screw and the fold line is flush with the bottom edge of the clamp. Then fold the other end of the sample inwards and insert it into the lower clamp. Then adjust the temperature in the box to -10±2℃. When the counter reaches 30,000 times, stop the test. Observe the changes in the folded part. If a sample surface is cracked, the low-temperature folding fastness of the sample is unqualified. Additional remarks:
This standard is proposed by the China Light Industry Federation.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Plastic Products. This standard was drafted by Beijing Plastic Factory No. 3. The main drafter of this standard is Tian Jingyan.
This standard mainly refers to Japanese Industrial Standard JISK6772--1976 (84) "Polyvinyl chloride artificial leather". 360
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