ASTM D6116-18(2023)

Standard Test Method for Blocking

ABSTRACT
This test method establishes the standard procedure for determining the resistance of leather to blocking under specific conditions of temperature, humidity, and pressure. This method is not applicable to wet blue. This procedure requires the use of a forced circulating hot air oven, American Medical Museum jar with lid, Petri dish with cover, and weights.
SCOPE
1.1 This test method covers the determination of the resistance of leather to blocking under specific conditions of temperature, humidity, and pressure. This test method does not apply to wet blue.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2022
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.05 - Upholstery

Overview

ASTM D6116-18(2023) is the internationally recognized Standard Test Method for Blocking developed by ASTM International. This standard outlines a precise methodology for determining the resistance of leather materials to blocking under specific laboratory conditions including controlled temperature, humidity, and pressure. Blocking refers to the undesired sticking of leather surfaces, which can compromise leather's appearance and usability, particularly in upholstery and finished leather products. This test method is applicable to most leather types, but explicitly excludes wet blue leathers.

Conforming to SI units and international standardization principles, this test method supports manufacturers, quality assurance professionals, and testing laboratories in verifying leather quality and durability.

Key Topics

• Test Objectives: Measures the ability of leather to resist sticking or adhering when exposed to defined environmental stressors.
• Test Conditions: Specific conditions of temperature (80°C ± 3°C), humidity, and pressure form the basis of this assessment.
• Equipment Requirements: Includes a forced circulating hot air oven, American Medical Museum jar (with lid), petri dish with cover, weights, and a perspirometer.
• Specimen Preparation: Leather samples are cut into standard sizes and tested along both parallel and perpendicular axes to the backbone.
• Test Procedures:
  • Method 1 (Petri Dish): Leather specimens are folded and subjected to weighted pressure in a petri dish before examination.
  • Method 2 (Perspirometer): Alternative apparatus uses glass plates with controlled compression, simulating application of pressure over time.
• Assessment: After testing, specimens are visually examined for ease of separation, grain damage, and finish peeling. Results are reported as pass or fail based on blocking performance.
• Safety Guidelines: Users are responsible for meeting appropriate safety, health, and environmental protocols.

Applications

The ASTM D6116 test method is critically important for:

• Leather Manufacturers: Assures compliance with quality standards before finished leather moves to market or into production for consumer goods.
• Upholstery Producers: Verifies durability and workability of upholstery leathers, helping prevent product defects stemming from finish adhesion issues.
• Quality Control Laboratories: Provides a standardized, repeatable approach for evaluating batch-to-batch consistency and performance of leather.
• Research & Development: Assists in the development of new leather treatments or finishes with improved anti-blocking characteristics.
• Regulatory Compliance: Supports adherence to globally recognized standardization principles, facilitating international trade and acceptance of test results.

Related Standards

When conducting or referencing the ASTM D6116 test, it may be beneficial to consider other closely associated standards including:

• AATCC TM15 - Standard test method for colorfastness to perspiration, referenced as an alternative apparatus in the D6116 procedure.
• Other ASTM Leather Standards: Such as ASTM D1814 (resistance to cracking) and ASTM D2813 (finish adhesion), which address different aspects of leather quality.
• International Trade Standards: Developed under the WTO TBT Committee guidelines, ensuring relevance and acceptance in global markets.

By adhering to ASTM D6116-18(2023), organizations can demonstrate commitment to high-quality, reliable leather goods, ensuring customer satisfaction and facilitating compliance in both domestic and international supply chains.

Keywords: leather blocking, finish adhesion, ASTM D6116, leather quality testing, upholstery standards, anti-blocking, leather durability, international standards, ASTM International, AATCC TM15

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6116 − 18 (Reapproved 2023)
Standard Test Method for
Blocking
This standard is issued under the fixed designation D6116; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3.4 Weight, 2000 g.
1.1 This test method covers the determination of the resis- 3.5 Perspirometer, consisting of a number of glass plates
tance of leather to blocking under specific conditions of which can be kept in suitable compression loading frame. Any
temperature, humidity, and pressure. This test method does not other apparatus may be used, provided it gives the same
apply to wet blue. results; for example, the AATCC perspirometer tester as
described in AATCC TM15, which is commercially available.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4. Test Specimen
standard.
4.1 Test four specimens per sample with dimensions of
1.3 This standard does not purport to address all of the
2.5 cm by 10 cm. Two samples shall be parallel to the
safety concerns, if any, associated with its use. It is the
backbone, and two samples perpendicular to the backbone. If
responsibility of the user of this standard to establish appro-
material is limited, one specimen per direction is suitable.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
5. Procedure
1.4 This international standard was developed in accor-
5.1 The specimen shall be perforated 2 mm from one end
dance with internationally recognized principles on standard-
and hung on a standard size paper clip that has been opened to
ization established in the Decision on Principles for the
its full length. No more than five specimens shall be hung on
Development of International Standards, Guides and Recom-
one clip. The clip holding the specimen shall be set into the
mendations issued by the World Trade Organization Technical
indentations of the jar. No more than three clips shall be placed
Barriers to Trade (TBT) Committee.
in a jar. The jar shall be filled with distilled/deionized water at
23 °C 6 2 °C to a level no higher than 1.25 cm from the
2. Referenced Documents
bottom of the hanging specimen. The lid shall then be placed
2.1 AATCC Standard:
on the jar and the specimen allowed to condition for 4 h.
AATCC TM15 Colorfastness to Perspiration
5.2 After conditioning, the 2.5 cm by 10 cm specimen shall
3. Apparatus
be removed from the jar and immediately folded finish to finish
to form a 2.5 by 5 cm rectangle. If the leather is unable to be
3.1 Forced Circulating Hot Air Oven, capable of maintain-
folded upon itself (too thick or stiff), it may be cut to 2.5 by 5
ing 80 °C 6 3 °C.
cm sections and placed finish to finish. Follow Method 1 or
3.2 American Medical Museum Jar (with Lid), having inner 3
Method 2 from this section forward.
dimensions of 16 cm high, 10 cm long, and 8 cm wide. There
5.3 Method 1 (Petri Dish Method):
shall be three indentations at the top of each 8 cm side. Other
5.3.1 The folded specimen shall then be placed in an
glass containers similar in size may be used, provided they give
inverted (rim up) petri dish cover. The bottom plate of the dish
the same result.
shall then be placed concentrically within the inverted cover
3.3 Petri Dish, 100 mm by 15 mm, with cover.
plate so as to cover the specimen evenly.
5.3.2 A2000 g weight shall be placed on top of the inverted
1 bottom plate. The whole assembly shall then be placed in an
This test method is under the jurisdiction ofASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.05 on Upholstery. oven at 80 °C 6 3 °C for 2 h and then removed. The weight
Current edition approved Jan. 1, 2023. Published January 2023. Originally
and cover plate shall be removed from the ass
...