BS 771:1992

This standard BS 771:1992 Specification for phenolic moulding materials is classified in these ICS categories:

• 83.080.10 Thermosetting materials

1.1 General

This International Standard specifies requirements for the physical and chemical properties of phenolic moulding materials, classified by type and grade according to their use and properties.

1.2 Types

Four types of phenolic moulding material are specified, as follows:

• Type A: General purpose
• Type C: Heat resistant
• Type D: Impact resistant
• Type E: Electrical applications

1.3 Filler

The type of filler to be used in each type of phenolic moulding material is not specified but is usually as shown in the following examples:

Type of moulding material	Filler
A	Wood flour
C	Mineral filler
D	Cotton
E	Mica

1.4 Resin

Abbreviations are used to indicate the type of phenolic resin, as follows:

• One-step phenolic resin: PF 1
• Two-step phenolic resin: PF 2

1.5 Grades

The various types of material are further sub-divided into grades based on the property levels and requirements.

EXAMPLE

PF 2A1 is a phenolic moulding material made from two-step resin, intended for general applications. The last digit indicates a particular grade of one type of material.

1.6 Classification

Table 1 shows the types and the grades of phenolic moulding material covered by this International Standard, together with their applications and distinguishing properties.