This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of polyethylene blown film for packaging. This standard is applicable to films produced by blow molding with low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE) and blends of the above two resins as the main raw materials (additives may be added). GB/T 4456-1996 Polyethylene blown film for packaging GB/T4456-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Polyethylene blown film for packaging
Polyethylene blown film for packaging1Subject content and scope of application
GB/T 4456--1996
Replaces GB 4456-84
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of polyethylene blown film for packaging (hereinafter referred to as film).
This standard applies to films produced by blow molding with low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE) and blends of the above two resins as the main raw materials (additives may be added). 2 Reference standards
GB2828 Procedure and sampling table for batch inspection by counting (applicable to inspection of continuous batches) GB2918 Standard environment for conditioning and testing of plastic specimens GB/T5009.60 Method of analysis for hygienic standards of polyethylene, polystyrene and polypropylene products for food packaging Determination of thickness of plastic films and sheets Mechanical measurement method GB 6672
GB 6673
GB 9639
Determination of length and width of plastic films and sheets Test method for impact resistance of plastic films and sheets GB9687 Hygienic standards for polyethylene products for food packaging Test method for tensile properties of plastic films
GB 13022
3 Product classification
Divided into three categories: A, B and C according to the type of raw materials used, see Table 1. Table 1
4 Technical requirements
4.1 Specifications
4.1.1 Width and deviation should meet the requirements of Table 2. Approved by the State Bureau of Technical Supervision on April 10, 199624
Free falling dart method
Resin type
LDPE and LLDPE blending
Implementation on December 1, 1996
(folded diameter)
71～100
101～200
201~~300
301～400
401500
501~800
801～1000
Thickness and deviation shall conform to the requirements of Table 3.
Superior product
GB/T 4456—1996
Superior product
Thickness limit deviation, mm
First-class product
First-class product
Qualified product
Qualified product
Average thickness deviation, %
Superior product
Second-class product
Qualified product
GB/T 4456--1996
3The number of sections per roll and the length of each section shall comply with the requirements of Table 4. 4.1.3
Superior product
Number of sections per roll (section)
Length of each section (m)
Note: There should be a mark at the break.
4.2 Appearance
First-class products
There shall be no defects such as bubbles, perforations, water marks, stripes, ribs, poor plasticization, fish eyes and stiff blocks that may hinder use. 4.3 Physical and mechanical properties
The physical and mechanical properties shall meet the requirements of Table 5.
Thickness <0.05mm
Tensile strength
(longitudinal and transverse)
Elongation at break
(longitudinal and transverse)
Impact strength
Superior products
First-class products
Qualified products
Superior products
≥150 1≥130
≥200
Note: Impact strength is not tested for thickness <0.03mm. 4.4 Hygienic performance
First-class product
Qualified product
≥180
Superior product
≥250
First-class product
Qualified productWww.bzxZ.net
≥230
Thickness ≥0.05mm2
Superior product
First-class product
Qualified product
Superior product
Qualified product
Compliant Quality products
Superior products
Qualified products
≥250[≥200|
≥230
≥350
Number of samples without cracks ≥5 is qualified
Films used for food packaging and medical packaging should comply with the test methods specified in GB9687
5.1 Sampling
Cut a sufficient number of samples from the test film roll for testing. 5.2 Sample state adjustment and test environment
≥280
According to the standard environment and normal deviation range in GB2918, and test under this condition. State adjustment time is more than 4h. 5.3 Width and length
According to GB6673.
5.4 Thickness
According to GB6672.
The thickness limit deviation and thickness average deviation are calculated and expressed according to formula (1) and formula (2). N tmax (or tmin) -- to
Where: △t-
Thickness limit deviation, mm;
The maximum value of the measured thickness, mm;
.........( 1
-The minimum value of the measured thickness, mm;
to--Nominal thickness, mm.
Where: t—Average thickness deviation, %;
to Nominal thickness, mm;
Average thickness, mm.
5.5 Appearance inspection
Visual inspection under natural light.
5.6 Physical and mechanical properties
5.6.1 Tensile strength and elongation at break
GB/T 4456—1996
t = (t.-to)/to × 100
Perform according to GB13022, the sample is type 1, and the test speed (no load) is 500±50mm/min. 5.6.2 Impact test
Perform according to GB9639A. Number of samples: 10 pieces. Perform the test according to the dart drop mass specified in Table 6. Table 6
Sanitary properties
Superior products
Perform according to GB/T5009.60.
Inspection rules
6.1 Batch
Dart drop mass + g
Qualified products
Superior products
Class B and C
First-class products
Qualified products
Products are inspected in batches. Products with the same brand of raw materials, the same specifications and the same formula are continuously produced in batches of no more than 8 tons.
6.2 Inspection classification
6.2.1 Factory inspection
The factory inspection items are the tensile strength and elongation at break in Table 5 of 4.1, 4.2 and 4.3. 27
6.2.2 Type inspection
GB/T 4456--1996
Type inspection items are all items in the technical requirements. Type inspection is required in any of the following situations: a.
When new products or old products are transferred to other factories for production;
When there are major changes in raw materials, formulas, and processes that may affect product performance; when there is continuous production for 6 months;
When the product is resumed after a long period of suspension,
When the factory inspection results are significantly different from the last type inspection; when the national quality supervision agency makes a request. 6.3 Sampling
6.3.1 Specifications and appearance are sampled according to the secondary normal sampling plan specified in GB2828. The general inspection level 1 is adopted, and the acceptable quality level (AQL) is 6.5, see Table 7. Each roll of film is a sample Unit. 6.3.2
Physical and mechanical properties and hygienic properties are tested on any roll from the sample. Table 7
51~~90
91~150
151~280
281~500
501~1200
1201~3200
6.4 Judgment rules
6.4.1 Judgment of qualified items
Sample size
Cumulative sample size
Number of qualified judgments
Number of unqualified judgments
6.4.1.1 The judgment of the specification and appearance sample units shall be carried out in accordance with the provisions of 4.1.1, 4.1.2, 4.1.3 and 4.2 respectively. If the test results of the sample units meet the requirements of Table 7, the specifications and appearance are considered qualified. If there are unqualified items in the physical and mechanical properties test results of 6.4.1.2, double samples should be taken from the original batch to re-test the unqualified items. If all the re-test results are qualified, the physical and mechanical properties are considered qualified. 6.4.1.3 If any of the hygienic properties are unqualified, it will be judged as unqualified. 6.4.2 Determination of qualified batches
If the specifications, appearance, physical and mechanical properties, and hygienic performance test results are all qualified, the batch is judged to be qualified. The product quality grade is determined by the lowest grade among all the test results. 7 Marking, packaging, transportation, storage
7.1 Marking
Each roll of film should be accompanied by a certificate of conformity, which should indicate: product name, trademark, manufacturer name, factory address, specifications, weight, batch number, quality grade, standard number, production date, shift, operator seal, inspector seal, etc. The main content of the mark should also be on the outside of the packaging. 7.2 Packaging
GB/T4456—1996
Film is generally packaged with kraft paper or plastic film. It must be tied firmly. The packaging must be reinforced for long-distance transportation. 7.3 Transportation
The film should be covered with a bitter cloth during transportation to prevent mechanical collision and sun and rain. The outer packaging should be kept intact during transportation. Rough loading and unloading is strictly prohibited.
7.4 Storage
The film should be stored in a clean, dry and cool warehouse, stacked neatly, at least 1m away from heat sources, and the storage period should not exceed one year from the date of production.
Additional instructions:
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 Huadun Plastic Packaging Equipment Co., Ltd. The main drafters of this standard are: Zhang Dasheng, Niu Suju, Qin Lijie. This standard is not equivalent to the Japanese Industrial Standard JISZ1702-1986 "Polyethylene Film for Packaging". 29
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