Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces QB/T 2707-2005 Leather - Physical and mechanical tests - Sample preparation and conditioning in whole.
In addition to a number of editorial changes, the following technical changes have been made with respect to QB/T 2707-2005 (the previous edition):
——the angle formed at the cutting edge in “5 Press knife” of former standard is changed from (20±1)° to 20°, which is consistent with the international standard;
——the condition control of "tropical standard atmosphere (optional)" and the explanatory "Note 2" are added in Table 1;
——in “7 Conditioning”, the conditioning time is changed from "at least 48h" to "at least 24h" and an explanatory note on sample conditioning is added, which is consistent with the international standard.
This standard has been redrafted and modified in relation to ISO 2419:2012 Leather - Physical and mechanical tests - Sample preparation and conditioning. The method adopted in ISO 2419:2012 is based on the method standards IUP 1 and IUP 3 of International Union of Leather Technologists and Chemists Societies (IULTCS).
According to the actual situation of China, the following technical modifications have been made in adoption of ISO 2419:2012:
——the clause of "Normative references" is added and the following clauses are postponed;
——in order to meet Chinese syntax and consistency, "2.1 atmosphere" in “2 Terms and definitions" is deleted and its relevant content is combined with “2.2 standard atmosphere”, which doesn't affect the normal use of terms and definitions;
——a description of standard atmosphere: “the atmosphere may circulate freely and environment consistency is ensured” is added in “3.1 standard atmosphere”;
——the contents of all clauses of "3 Standard atmosphere" in the former standard are merged into "Table 1 standard atmosphere and tolerance" in Clause 4, which is more concise and clear, and conforms to Chinese habit;
——according to the actual situation of China, the reference standard atmosphere condition in the former international standard is changed from 23/50 to 20/65;
——for the convenience of use in China, an explanatory "note 1" is added in Table 1;
——"5 Sampling and sample preparation" is subdivided into "6.1 sampling" and "6.2 sample preparation", and the requirements for sampling are added in 6.1.
The following editorial changes have also been made in this standard:
——foreword in ISO standard is deleted;
——"this international standard" is changed to "this standard";
——the comma "," used as the decimal point is replaced by ".".
This standard was proposed by China National Light Industry Council.
This standard is under the jurisdiction of National Technical Committee on Leather of Standardization Administration of China (SAC/TC 252).
This standard replaces the former professional standard QB/T 2707-2005 Leather - Physical and mechanical tests - Sample preparation and conditioning, which is abolished from the implementation date of this standard.
The previous editions of this standard are as follows:
——GB 4689.2-1984;
——QB/T 3812.2-1999;
——QB/T 2707-2005.
Leather - Physical and mechanical tests - Sample preparation and conditioning
1 Scope
This standard specifies the preparation of leather for physical and mechanical tests together with standard atmospheres for conditioning and test.
It is applicable to all types of dry leather.
2 Normative references
The following referenced documents are indispensable for the application 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.
QB/T 2706 Leather - Chemical, physical and mechanical and fastness tests - Sampling location (QB/T 2706-2005, ISO 2418:2002, MOD)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
standard atmosphere
atmospheric environment defined by temperature and relative humidity, in which a sample is kept for a given period of time before being subjected to test and the atmospheric environment is maintained within prescribed tolerance, and the atmosphere may circulate freely and environment consistency is ensured
3.2
conditioning
operation designed to bring a sample into a specified condition in relation to temperature and relative humidity by keeping it for a given period of time in the standard atmosphere (3.1) with free access of moving air to all surfaces
4 Standard atmosphere
Standard atmosphere and tolerance shall comply with the requirements of Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Standard atmosphere
5 Press knife
6 Sampling and sample preparation
7 Conditioning
8 Test
9 Test report
