GB/T 15568-2024Sheet molding compound (SMC) for general purposes (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part

1.Structure and drafting rules for standardization documents" Drafting is required. This document replaces GB/T 15568-2008 "General-purpose Sheet Molding Compounds (SMC)". Compared with GB/T 15568-2008, In addition to structural adjustments and editorial changes, the main technical changes are as follows: Changed the scope (see Chapter 1, Chapter 1 of the.2008 edition);

a) The definition of sheet molding compound (see

3.1 of the.2008 edition) has been deleted;

b) The definition of general-purpose sheet molding compound has been changed (see 3.1,

3.2 of the.2008 edition);

c) The classification and labeling have been changed (see Chapter 4, Chapter 4 of the.2008 edition);

d) The permissible deviation of mass per unit area has been changed (see 5.2,

5.3 of the.2008 edition);

e) Added tensile properties, load deflection temperature, density and vinyl ester resin SMC performance requirements (see 5.3.1);

f) The content of sampling method has been changed (see 6.1.1,

6.1 of the.2008 edition);

g) Added the preparation conditions and processing of the sample (see 6.1.2, 6.1.3);

h) Added sample state adjustment (see 6.2);

1 Scope

GB/T 15568-2024 is the Chinese national standard on sheet molding compound (smc) for general purposes, in the field of rubber and plastic industries. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 23 August 2024 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 March 2025. Classification: ICS 83.120, CCS Q23. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document specifies the classification and marking, requirements, test methods, inspection rules, as well as marking, packaging, transportation, and other aspects of general-purpose sheet molding compounds. Transport and storage requirements. This document is applicable to glass fiber as reinforcement material and unsaturated polyester resin (UP) or vinyl ester resin (VE) as matrix material. General-purpose sheet molding compound (hereinafter referred to as "general-purpose SMC").

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies. in this document.

GB/T 1446 General principles for test methods for properties of fiber reinforced plastics

GB/T 1447 Test method for tensile properties of fiber reinforced plastics

GB/T 1449 Test method for bending properties of fiber reinforced plastics

GB/T 1451 Test method for simply supported beam impact toughness of fiber reinforced plastics

GB/T 1463 Test method for density and relative density of fiber reinforced plastics

GB/T 1634.2-2019 Determination of deflection temperature of plastics under load Part

3 Terms and definitions

The terms and definitions defined in GB/T 3961 and the following apply to this document.

3.1 Sheet molding compound for general purposes Sheet molding compound with unsaturated polyester resin (or vinyl ester resin) and glass fiber as the main raw materials.

17 Test flame 500 W flame test method

GB/T 8924 Test method for combustion performance of fiber reinforced plastics - Oxygen index method

GB/T 27797.8-2011 Preparation of fiber reinforced plastic test panels Part 8: SMC and BMC molding

GB/T 32788.5-2016 Test methods for prepreg properties Part