ISO 2930:2024 生の天然ゴム — 可塑性保持指数 (PRI) の測定 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.

This sixth edition cancels and replaces the fifth edition (ISO 2930:2017), which has been technically revised.

The main changes are as follows:

• subclause 5.4, “Laboratory mixing mill”, has been updated;
• subclause 5.7 has been updated, replacing “Tissue paper, as described in ISO 2007” by “Bleached, acid-free tissue paper, of approximately 27 g/m²”.

1 Scope

This document specifies a method to determine the plasticity retention index (PRI) of raw natural rubber.

The PRI is a measure of the resistance of raw natural rubber to thermal oxidation. A high resistance to thermal oxidation is shown as a high value of the index. PRI is not an absolute value and cannot give an absolute classification of plasticity number of different natural rubber after oxidation.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

Bibliography