ASTM D8042-18 (2023) PDF

Full title and description

ASTM D8042-18 (reapproved 2023) — Test Method for Shrinkage Temperature of Wet Blue and Wet White. This standard specifies a laboratory procedure to determine the temperature at which wet-blue or wet-white leather specimens exhibit shrinkage caused by hydrothermal denaturation of collagen. The test uses an aqueous heating medium (water or glycerine–water) and a shrinkage meter (shrinkometer) to record the temperature at which noticeable shrinkage occurs.

Abstract

This test method provides a repeatable procedure to measure the shrinkage temperature of all types of Wet Blue and Wet White leather. Shrinkage temperature is commonly used as an indicator of tannage type and degree of tannage (for example, chrome tanning vs. vegetable tannage) and as a quality-control and specification parameter within leather processing and laboratory testing. The method covers specimen preparation, immersion media, apparatus, heating and observation, and reporting of results.

General information

• Status: Active (reapproved).
• Publication date: Original approval Sept 1, 2018; published October 2018; reapproved September 1, 2023 (designated D8042-18(2023)).
• Publisher: ASTM International.
• ICS / categories: 59.140.30 — Leather and furs; Committee D31 (Leather), Subcommittee D31.02 (Wet Blue).
• Edition / version: D8042-18, reapproved 2023 (sometimes shown as D8042-18R23 or D8042-18(2023)).
• Number of pages: 3 pages (concise test method).

Scope

The standard covers the determination of shrinkage temperature for all types of Wet Blue and Wet White leather. For shrinkage temperatures at or below 98 °C the heating medium is water; for temperatures above 98 °C a glycerine–water solution is used. The method is intended for laboratory, quality-control, and specification use and does not address workplace safety practices, which remain the responsibility of the user.

Key topics and requirements

• Definition and significance of shrinkage temperature as an indicator of type and degree of tannage.
• Specimen preparation and conditioning procedures for Wet Blue and Wet White samples.
• Required apparatus: shrinkage meter (shrinkometer), clamps, immersion heater, stirring device, and appropriate temperature-measuring instruments.
• Selection of heating medium: water for ≤98 °C, glycerine–water solution for >98 °C.
• Stepwise heating procedure and observation criteria for detecting the temperature of noticeable shrinkage.
• Reporting requirements including test temperature, specimen identification, and any deviations from the method.

Typical use and users

This method is used by leather laboratories, tanneries, quality-control personnel, material specifiers, research organizations, and standards bodies concerned with leather processing and characterization. Typical applications include process control, batch acceptance testing, research into tannage chemistry, and verification of leather thermal stability for downstream processing.

Related standards

Commonly referenced documents include ASTM D1517 (Terminology Relating to Leather) and ASTM D6076 (Standard Test Method for Shrinkage Temperature of Leather). The method is issued under the jurisdiction of ASTM Committee D31 (Leather) and is related to other leather-testing standards addressing physical and chemical properties used in material specification and quality assurance.

Keywords

Shrinkage temperature; Wet Blue; Wet White; leather; tannage; boil test; shrinkometer; degree of tannage; thermal stability; leather testing; D8042-18; D8042-18(2023).

FAQ

Q: What is this standard?

A: ASTM D8042-18 (reapproved 2023) is a concise test method that defines how to determine the shrinkage temperature of Wet Blue and Wet White leather specimens using an aqueous heating medium and a shrinkage meter.

Q: What does it cover?

A: It covers specimen preparation, apparatus requirements, choice of heating medium (water or glycerine–water), the heating and observation procedure to identify the temperature of shrinkage, and reporting of results for Wet Blue and Wet White leather.

Q: Who typically uses it?

A: Leather testing laboratories, tanneries, quality-control and R&D personnel, material specifiers, and standards organizations involved in leather manufacturing and testing.

Q: Is it current or superseded?

A: The method was originally approved Sept 1, 2018 and published October 2018; it was reapproved in 2023 and is presented as D8042-18(2023) or D8042-18R23. Users should confirm with ASTM International for the very latest status or any subsequent revisions.

Q: Is it part of a series?

A: It is part of ASTM Committee D31’s leather testing suite and references other ASTM leather standards (for example D1517 terminology and D6076 related shrinkage-temperature methods). It complements other physical and chemical test methods used to characterize leather.

Q: What are the key keywords?

A: Shrinkage temperature, Wet Blue, Wet White, tannage, shrinkometer, boil test, leather testing, D8042-18.