ASTM D640-44 PDF

Full title and description

ASTM D640-44 — Specification and Methods of Test for Concentrated Ammonia Preserved, Creamed, and Centrifuged Natural Rubber Latex. A short (historical) specification that defined basic definitions and test procedures for concentrated natural rubber latex preserved with ammonia, including creamed and centrifuged forms.

Abstract

ASTM D640-44 is an early ASTM specification (designated with the year 1944) that set out requirements and simple test methods for concentrated natural rubber latex stabilized with ammonia, in creamed and centrifuged forms. The document was brief (only a few pages) and was withdrawn in the early 1950s as more comprehensive and modern specifications and test methods were developed and consolidated into later ASTM standards covering concentrated and stabilized natural latex.

General information

• Status: Withdrawn (withdrew in 1951).
• Publication date: 1944 (designation D640-44).
• Publisher: ASTM (American Society for Testing and Materials, now ASTM International).
• ICS / categories: 83.040.10 (Latex and raw rubber / raw materials for rubber and plastics).
• Edition / version: D640-44 (1944 edition).
• Number of pages: 2 (short specification).

Scope

This specification covered first-order requirements and basic test methods for concentrated natural rubber latex that was preserved with ammonia — explicitly covering creamed and centrifuged latex preparations. It applied to concentrated (non‑compounded) natural latex intended for commercial handling and quality classification; it did not address compounded latex products or later analytical advances introduced in subsequent standards.

Key topics and requirements

• Definitions and classification of concentrated natural rubber latex (ammonia preserved, creamed, centrifuged).
• Basic test methods and acceptance criteria relevant in the 1940s for quality control of concentrated latex.
• Requirements intended to assure reasonable dry rubber content and stability for handling and storage.
• Procedural notes for sampling and simple laboratory checks used at the time.
• Short, prescriptive format — intended as an industry practice / specification rather than a full modern test-method compendium.

Typical use and users

Originally intended for rubber producers, latex processors, quality control laboratories and buyers of concentrated natural latex in mid-20th century commerce. Today it is mainly of historical interest to standards librarians, industry historians, and organizations researching the evolution of latex quality standards; practitioners use later ASTM standards that consolidate and extend the scope and test methods for concentrated, ammonia-stabilized latex.

Related standards

Later and more comprehensive ASTM standards cover concentrated and stabilized natural latex (for example, the D1076 series and subsequent revisions), as well as a range of test methods and specifications that replaced or superseded early, brief specifications like D640-44. Modern standards provide expanded analytical methods (dry rubber content, protein testing, mechanical stability, pH/KOH number, metal contaminants, etc.) and clearer category definitions.

Keywords

ASTM D640-44, natural rubber latex, concentrated latex, ammonia preserved, creamed latex, centrifuged latex, latex specification, latex test methods, rubber standards, historical standard.

FAQ

Q: What is this standard?

A: ASTM D640-44 is an early (1944-designated) ASTM specification that established requirements and simple test methods for concentrated natural rubber latex preserved with ammonia, including creamed and centrifuged forms.

Q: What does it cover?

A: It covered classification and short prescriptive test procedures for concentrated ammonia-preserved natural latex (creamed and centrifuged), intended for production control and commercial acceptance in the period when it was active.

Q: Who typically uses it?

A: At the time of publication it was used by latex producers, processors, QC laboratories and buyers. Today it is primarily referenced for historical research; current users rely on later ASTM standards (for example, the D1076 series) for practical testing and specification.

Q: Is it current or superseded?

A: It is withdrawn (withdrawn in 1951) and is not current. Its subject matter has been incorporated into and superseded by later, more comprehensive ASTM specifications and test-method standards for concentrated and stabilized natural rubber latex.

Q: Is it part of a series?

A: D640-44 is a standalone, early designation; the technical topics it addressed have been absorbed into the later ASTM D10x–series standards for rubber and latex (notably the D1076 family for concentrated, ammonia-stabilized, creamed and centrifuged natural latex).

Q: What are the key keywords?

A: natural rubber latex, concentrated latex, ammonia preserved, creamed latex, centrifuged latex, specification, test methods, ASTM, historical standard.