GB/T 47391.2-2026Plastics - Unsaturated-polyester powder moulding compounds (UP-PMCs) - Part 2: Preparation of test specimens and determination of properties (English PDF)

1 Scope

This document describes the methods for preparation of test specimens and the test methods for properties of unsaturated-polyester powdered moulding compounds (UP-

PMCs), and specifies the requirements for handling test materials, as well as the requirements for conditioning the test materials before moulding and the test specimens before testing.

This document applies to the preparation of test specimens and tests of properties of unsaturated-polyester powdered moulding compounds (UP-PMCs), provides the procedures and conditions for the preparation of test specimens and the methods for using these test specimens for testing properties, and lists the applicable and necessary properties for characterizing PMCs and their test methods.

The properties are selected from the general test methods in GB/T 19467.1.Other widely used test methods or those particularly relevant to PMCs are also included in this document, such as the characteristic properties in GB/T 47391.1.

To obtain reproducible and comparable test results, it is crucial to adopt the test specimen preparation methods, conditioning methods, test specimen dimensions, and test procedures specified in this document. Test results obtained using different test specimen dimensions or different preparation methods may not be consistent.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 1033.1 Plastics - Methods for determining the density of non-cellular plastics

- Part 1.Immersion method, liquid pyknometer method and titration method (GB/T

1033.1-2008, ISO 1183-1.2004, IDT)

GB/T 1034 Plastics - Determination of water absorption (GB/T 1034-2008, ISO

62.2008, IDT)

GB/T 39818 Plastics - Thermosetting moulding materials - Determination of shrinkage (GB/T 39818-2021, ISO 2577.2007, MOD)

GB/T 46607.1 Plastics - Injection moulding of test specimens of thermosetting powder moulding compounds (PMCs) - Part 1.General principles and moulding of multipurpose test specimens (GB/T 46607.1-2025, ISO 10724-1.1998, MOD)

GB/T 46607.2 Plastics - Injection moulding of test specimens of thermosetting powder moulding compounds (PMCs) - Part 2.Small plates (GB/T 46607.2-2025,

ISO 10724-2.1998, MOD)

GB/T 47391.1 Plastics - Unsaturated-polyester powder moulding compounds (UP-

PMCs) - Part 1.Designation system and basis for specifications (GB/T 47391.1-

2026, ISO 14530-1.1999, MOD)

ISO 4614 Plastics - Melamine-formaldehyde mouldings - Determination extractable formaldehyde

ISO 6603-2 Plastics - Determination of puncture impact behaviour of rigid plastics

- Part 2.Instrumented impact testing

ISO 7808 Plastics - Thermosetting moulding materials - Determination of transfer flow

ISO 8256 Plastics - Determination of tensile-impact strength

3 Terms and definitions

For the purpose of this document, the terms and definitions defined in GB/T 2035 and

GB/T 47391.1, as well as the following apply.

3.1 thermal flow

A parameter that characterizes the flow behavior of thermosetting moulding compounds in the plasticized state.

NOTE. For example, the material’s property of filling a mould cavity is expressed as transfer flow determined by ISO 7808.

4 Preparation of test specimens

5 Conditioning of test specimens

Unless otherwise specified, test specimens shall be conditioned as follows before testing the properties listed in Tables 3 and 4.

- Method 1

The test specimens shall be kept in an environment with a temperature of (23 ± 2) °C and a relative humidity of (50 ± 10) % for at least 16 h, as specified in GB/T 2918.

This method is a general test method and is applicable to all cases where the use of method 2 is not specified. Method 1 is not further specified in Tables 3 and 4.

- Method 2

The test specimens shall first be placed in distilled water at room temperature for

24 h, then removed, dried, and kept in an environment with a temperature of (23 ±

2) °C and a relative humidity of (50 ± 10) % for 2 h, as specified in GB/T 2918.

6 Determination of properties

It shall use the standards, supplementary instructions, and notes given in GB/T 19467.1 for the determination of properties and the presentation of data.

Unless otherwise specified, all tests in Tables 3 and 4 shall be conducted in the standard laboratory environment with a temperature of (23 ± 2) °C and a relative humidity of (50

± 10) %.

Table 3 is prepared according to GB/T 19467.1, and the properties listed therein are applicable to UP-PMCs for compression moulding or injection moulding. These property data are used to compare different thermosetting and thermoplastic plastics.

The properties listed in Table 4, not specifically listed in Table 3, may also be meaningful for characterizing UP-PMCs. These properties may be limited to comparisons within the same category of thermosetting plastics.

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