QB/T 2712-2005Leather. Physical and mechanical tests. Determination of distension and strength of grain. Ball burst test (English PDF)

Foreword

This standard is a revision of QB/T 3812.7-1999 Leather-Determination of distension

and strength of grain-Ball burst test.

This standard is modified in relation to ISO 3379.1976 Leather - Determination of

distension and strength of grain - Ball burst test, which is based on the standard IUP 9

of the International Union of Leather Technologists and Chemists Societies (IULTCS).

Based on the Chinese actual situation, the following technical modifications were made

to this standard when it was modified in relation to ISO 3379.1976.

-- The descriptive "NOTE" in the scope has been removed.

-- The original ISO standards cited in the section "Normative references" have been

replaced by the relevant Chinese standards, and necessary reference standards

have been added.

-- In accordance with Chinese practice, the section "5 Test pieces" has been further

refined into 5.1, 5.2, and 5.3 for ease of use.

-- The requirements for the calculation results have been added to the section

"Expression of results" to make it easier to use.

The following editorial changes were also made to this standard.

-- The foreword to the ISO standard has been removed.

-- The phrase "this international standard" has been changed to "this standard".

-- The comma "," used as a decimal point has been replaced with a decimal point

".".

Compared with QB/T 3812.7-1999, the main changes in this standard are as follows.

-- Chapter 2 "Normative references" has been added.

-- Chapter 5 "Sampling and sample preparation" has been added.

This standard was proposed by the China National Light Industry Council.

This standard is under the jurisdiction of the National Technical Committee on Leather

Industry of Standardization Administration of China (SAC/TC252).

This standard was drafted by the China Leather and Footwear Industry Research

Institute.

Leather - Physical and mechanical tests - Determination of

distension and strength of grain - Ball burst test

1 Scope

This standard specifies the methods for determining the strength and distension of the

grain side of leather.

This standard applies to all types of leather (light leather).

2 Normative references

The provisions in the following documents become the provisions of this standard

through reference in this text. For the dated references, the subsequent amendments

(excluding corrections) or revisions do not apply to this standard; however, parties who

reach an agreement based on this standard are encouraged to study if the latest versions

of these documents are applicable. For undated references, the latest editions of the

referenced documents apply to this standard.

QB/T 2706-2005 Leather - Chemical, physical and mechanical and fastness tests -

Sampling location (ISO 2418.2002, MOD)

QB/T 2707-2005 Leather - Physical and mechanical tests - Sample preparation and

conditioning (ISO 2419.2002, MOD)

3 Principles

A steel ball is pressed against the center of the flesh side of a circular leather sample,

which is secured around its perimeter with clamps. The pressure and distension are

recorded when cracks and fractures occur on the grain side.

4 Apparatus

The apparatus for burst testing shall include the following parts (see Figure 1, Figure 2,

and 7.2).

5 Sampling and sample preparation

2005 and Figure 3.

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