GB/T 20202-2019Ethylene-vinyl acetate copolymer (EVA) blown covering film for agriculture (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 20202-2006 "Ethylene-vinyl acetate copolymer (EVA) blown film for agricultural use". This standard and Compared with GB/T 20202-2006, the main technical changes are as follows.

--- Increased astigmatism shed film terms and definitions (see 3.3);

--- Removed translucent shed film and opaque shed film (see 3.3, 3.4 of 2016 edition);

--- Increased astigmatism in the classification (see 4.1);

--- Increase the range of product recommended thickness (see 5.2);

--- Modified the width limit deviation (see 6.1, 5.1 of the 2006 edition);

--- Revised the thickness limit deviation and the average deviation index (see 6.2, 2006 edition 5.2);

--- Revised the mechanical performance index (see 6.5, 5.5 of the 2006 edition);

--- Revised the transmittance and haze performance indicators (see 6.7, 5.5 of the 2006 edition);

--- Revised tensile strength and fracture nominal strain test method (see 7.6, 2006 version 6.6);

--- Revised inspection rules (see Chapter 8, Chapter 7 of the 2006 edition).

1 Scope

This standard specifies the terminology and definition of agricultural ethylene-vinyl acetate copolymer (EVA) blown film (hereinafter referred to as EVA film).

Sense, classification and code, specifications and recommended thickness, requirements, test methods, inspection rules, marking, packaging, transportation and storage.

This standard is applicable to the internal addition type ethylene-vinyl acetate copolymer used in agricultural large, medium and small sheds and greenhouse transparent covering materials. The shed film of the object.

This standard does not apply to the shed film of ethylene-vinyl acetate copolymer produced by the T-type machine head.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

Determination of tensile properties of plastics - Part 3. Test conditions for films and sheets

GB/T 2035-2008 plastic terminology and its definition

GB/T 2410-2008 Determination of light transmittance and haze of transparent plastics

GB/T 2828.1-2012 Sampling procedures for counting sampling - Part 1. Quantitative inspection by batches plan

Standard environment for GB/T 2918 plastic sample conditioning and testing

GB/T 6040-2002 General rules for infrared spectroscopy

GB/T 6672-2001 Plastic film and sheet thickness measurement - Mechanical measurement

GB/T 6673-2001 Determination of length and width of plastic films and sheets

GB/T 16422.2-2014 exposure test methods for light source of plastics - Part 2: Xenon arc lamps

GB/T 30925-2014 Plastic ethylene-vinyl acetate copolymer (EVAC) thermoplastic vinyl acetate content Determination

QB/T 1130-1991 Test method for plastic right angle tearing performance

3 Terms and definitions

The following terms and definitions as defined in GB/T 2035-2008 apply to this document.