Foreword
This document is drafted in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents".
This document is part 1 of GB/T 41877 "Plastics Ethylene vinyl alcohol (EVOH) copolymer molding and extrusion materials".
GB/T 41877 has been published in the following parts:
---Part 1:Naming system and classification basis;
---Part 2:Specimen preparation and property determination.
This document is modified to adopt ISO 21309-1:2019 "Plastics Ethylene vinyl alcohol (EVOH) copolymer molding and extrusion materials Part 1: Naming system and basis of classification".
The technical differences between this document and ISO 21309-1:2019 and the reasons for them are as follows:
--- replaced ISO 1043-1 (see 4.1) with the normative reference GB/T 1844.1, to adapt to our technical conditions and increase operability operability;
ISO 21309-2:2019 (see 4.2) was replaced by the normative reference GB/T 41877.2 to adapt to China's technical conditions and increase operability; --- ISO 21309-2:2019 was replaced by the normative reference GB/T 41877.2 (see 4.2) to adapt to China's technical conditions and increase operability. To adapt to our technical conditions and increase operability;
--- replaced ISO 1133-1 (see 4.5) with normative reference GB/T 3682.1 to adapt to China's technical conditions and increase operability; --- replaced ISO 1133-1 (see 4.5) with normative reference GB/T 3682.1 to adapt to China's technical conditions and increase operability The ISO 1133-1 (see 4.5) was replaced by the normative reference GB/T 3682.1 (see 4.5) to adapt to the technical conditions in China and increase operability;
--- Regarding character group 4, a test condition M (see 4.5) has been added to make the standard provisions more complete;
--- Regarding the naming example, the reference of the standard number in the example "ISO 21309" is changed to "GB/T 41877.1", which is consistent with the naming system of other plastic resins.
The naming system of other national standards is consistent (see Chapter 5).
The following editorial changes have been made to this document:
--- The ethylene content of the numerical code 32 in character group 1 is amended from ">30~34" to ">31~34" (see 4.2);
--- Amend "character group 2" to "character group 3" in Table 2, "letter designators used in character group 2" (see 4.4); Table 4 "Character group 3 The "character group 3" in Table 4 "Numerical designation of melt mass flow rate in character group 3" is amended to "character group 4" (see 4.5);
--- Amended melt mass flow rate into "11 ranges" to "12 ranges" (see 4.5);
--- Removed references.
Please note that some of the contents of this document may be patent related. The issuer of this document does not assume responsibility for identifying patents.
This document is presented by the China Petroleum and Chemical Industry Federation.
This document is attributed to the National Technical Committee for Standardization of Plastics (SAC/TC15).
Introduction
GB/T 41877 is the basic standard for the classification and naming, sample preparation and performance determination of ethylene vinyl alcohol copolymer resins, which provides support for the evaluation and application of ethylene vinyl alcohol products and the development of product standards. As ISO 21309 consists of two parts, the national standard is in the process of transformation, the structure remains consistent with ISO 21309.
GB/T 41877 consists of two parts:
--- Part 1: Naming system and classification basis;
--- Part 2: Specimen preparation and performance determination.
This document is based on ISO 21309-1:2019, according to the characteristics of ethylene vinyl alcohol (EVOH) molding and extrusion materials, with the specified
Characteristic performance values as well as recommended uses and/or processing methods, important properties, additives, colorants, fillers and reinforcing materials are used to distinguish between different types of ethylene vinyl alcohol (EVOH) molding and extrusion materials.
Plastics Ethylene vinyl alcohol (EVOH) Copolymer molding and extrusion materials Part 1: Naming system and classification basis
1 Scope
This document specifies the naming system for ethylene vinyl alcohol (EVOH) copolymer thermoplastic materials, which can be used as a basis for classification.
Different types of ethylene vinyl alcohol (EVOH) copolymer thermoplastic materials with the following specified values of characteristic properties, such as melt mass flow rate, as well as recommended uses and/or processing methods, important properties, additives, colorants, fillers and reinforcing materials based on a classification system to distinguish.
This document applies to copolymers of ethylene and vinyl alcohol with ethylene content (molar fraction) in the range of 15% to 60%. This document applies to materials that are conventionally in the form of powder, granules or pellets, unmodified or modified by colorants, additives, fillers, etc.
This document does not mean that naming the same material must have the same properties. This document does not provide the engineering data, performance data or processing conditions data required to describe the special use of the material and (or) processing methods. If required, the test methods specified in GB/T 41877.2 are used to determine this additional information.
In order to illustrate the special use of thermoplastic materials or to ensure reproducible processing, additional information can be given in character group 4 and character group 5 (see Chapter 4).
2 Normative references
The contents of the following documents constitute essential provisions of this document through the normative references in the text. Among them, note the date of the reference document, only the date corresponds to the version applicable to this document; do not note the date of the reference document, its latest version (including all the change orders) applicable to this document.
GB/T 1844.1 Symbols and abbreviations for plastics Part 1: Base polymers and their characteristic properties (GB/T 1844.1-2008, ISO 1043-1:2001, IDT)
GB/T 3682.1 Plastics Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics Part 1: Standard method (GB/T 3682.1-2018, ISO 1133-1:2011, MOD)
GB/T 41877.2 Plastics ethylene vinyl alcohol (EVOH) copolymer molding and extrusion materials Part 2: Specimen preparation and property determination (GB/T 41877.2-2022, ISO 21309-2:2019, MOD)
3 Terminology and definitions
There are no terms and definitions that need to be defined in this document.
4 Naming and classification system
4.2 Character group 1
This character group in accordance with the provisions of GB/T 1844.1, hyphenated with "EVOH" after the ethylene - vinyl alcohol copolymer, EVOH after the empty space, and then use the two digit code specified in Table 1 to indicate its ethylene content.
4.3 Character group 2
This character group indicates the type of filler and (or) reinforcing material and its content, EVOH is not involved.
4.4 Character group 3
In this character group, position 1 gives a description of the recommended use and (or) processing methods, position 2 to position 8 gives a description of the important properties, additives and colors. The letter codes used are specified in Table 2.
If the description is given in position 2 to position 8, and no description is given in position 1, the letter X should be inserted in position 1.
4.5 Character Group 4
In this character group, the melt mass flow rate (MFR) is indicated by a code consisting of a letter (indicating the test condition) and three numbers (indicating the range in which the value falls).
If the characteristics of the value falls in or close to the boundaries of a block, the producer should state that the material is named according to a block. If later due to the production process tolerance limits so that the individual test value falls on the boundary value or the other side of the boundary, the naming is not affected.
Melt mass flow rate according to GB / T 3682.1 to determine the test conditions for X. If the melting point of ethylene - vinyl alcohol copolymer is lower than 190 ℃, the test conditions can be D, for comparison with polyethylene (PE), ethylene - vinyl acetate (EVAC) or other polymers. If the melting point of ethylene vinyl alcohol copolymer is higher than 210°C, the test condition is M. See Table 3.
4.6 Character Group 5
This optional character set indicates additional information and is a method of converting the designation of a material into a specification for a specific application. For example, for products with defined specifications, reference can be made to appropriate national standards or similar standards.
5 Naming examples
5.1 A certain ethylene vinyl alcohol (EVOH) copolymer with an ethylene content (molar fraction) of 38% (38), for extrusion (E), without additives, with a melt mass flow rate (MFR 190/2.16) of 1.6 g/10 min (Do15).
Foreword
Introduction
1 Scope
2 Normative references
3 Terminology and definitions
4 Naming and classification system
5 Naming examples
