ISO 2557-1:1989
Plastics — Amorphous thermoplastics — Preparation of test specimens with a specified maximum reversion — Part 1: Bars

Standard No.

ISO 2557-1:1989

Release Date

1989

Published By

International Organization for Standardization (ISO)

Latest

ISO 2557-1:1989

Scope

This part of ISO 2557 specifies procedures for the preparation of test specimens of amorphous thermoplastic materials in the form of bars with a specified level of uniaxial molecular orien- tation which is characterized by determination of the maximum reversion R, in accordance with ISO 8328. It is not applicable to fibre reinforced thermoplastics or cellular plastics. specimens of amorphous thermoplastic materials in the form of plates with a specified level of uniaxial molecular orientation. The conditions required to produce a specified state of the material need to be determined for each type of moulding material. The recommended procedure will depend on the re- quired or specified maximum reversion. To produce test specimens in the basic state, having almost no molecular orien- tation and a maximum reversion of nearly zero, compression moulding and thermal relaxation are the recommended pro- cedures. Test specimens with uniaxial molecular orientation and a maximum reversion greater than that of the basic state can be obtained by injection moulding. Preparation of test specimens with a specified reversion - Part 2: Plates. machining. ing materials - Determination of reversion. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 state of a specimen: The condition of a specimen as characterized by its maximum longitudinal reversion. 3.2 basic state of a specimen: The state in which a specimen is nearly free of internal stresses and molecular orien- tation. A specimen is considered to be in its basic state if, after the heat treatment specified in ISO 8328,

ISO 2557-1:1989 history

• 1989 ISO 2557-1:1989 Plastics — Amorphous thermoplastics — Preparation of test specimens with a specified maximum reversion — Part 1: Bars
• 1976 ISO 2557-1:1976 Plastics — Amorphous thermoplastic moulding materials — Preparation of test specimens with a defined level of shrinkage — Part 1: Test specimens in the form of parallelepipedic bars (Injection mouldin