GB/T 39365-2020 PDF in English
GB/T 39365-2020 (GB/T39365-2020, GBT 39365-2020, GBT39365-2020)
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Leather - Physical and mechanical tests - Determination of dry heat resistance
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GB/T 39365-2020: PDF in English (GBT 39365-2020) GB/T 39365-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.140.30
Y 46
Leather - Physical and mechanical tests -
Determination of dry heat resistance
(ISO 17227:2002, Leather - Physical and mechanical tests -
Determination of dry heat resistance of leather, MOD)
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: JUNE 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Principle ... 5
4 Instruments and apparatuses ... 5
5 Sampling and sample preparation ... 6
6 Test conditions ... 7
7 Test method ... 7
8 Result calculation and expression ... 8
9 Test report ... 8
Foreword
This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This Standard uses the redrafting method to modify and adopt ISO 17227:2002
“Leather - Physical and mechanical tests - Determination of dry heat resistance
of leather”.
Compared with ISO 17227:2002, the structural adjustments of this Standard
are as follows:
-- Adjust 7.4 of ISO 17227:2002 to the note of 7.3; merge 7.5 of ISO
17227:2002 into 7.3, and move the following chapters forward;
-- Merge 8.3 of ISO 17227:2002 into 8.2.
The technical differences between this Standard and ISO 17227:2002 and the
reasons are as follows:
-- With regard to the normative references, this Standard makes technical
adjustments to adapt to the technical conditions of China. The
adjustments are concentrated in Chapter 2 “Normative references”. The
specific adjustments are as follows:
● Use GB/T 39364 which modifies and adopts international standards to
replace ISO 2418 (see 5.1);
● Use QB/T 2707 which modifies and adopts international standards to
replace ISO 2419 (see 4.5, 5.3 and 7.3);
-- Modify the description of the principle (see Chapter 3; Chapter 3 of ISO
17227:2002);
-- Modify the accuracy requirements of the vernier caliper (see 4.2; 4.2 of
ISO 17227:2002);
-- Delete the example of glazed-pottery tripod (see 4.3 of ISO 17227:2002);
-- Add provisions for sampling of non-standard parts (see 5.1);
-- Add regulations on the placement mode of the sample in the oven (see
7.2);
-- Modify the adjustment time of the sample after the test (see 7.3; 7.5 of ISO
17227:2002);
Leather - Physical and mechanical tests -
Determination of dry heat resistance
1 Scope
This Standard specifies the test method of dry heat resistance of leather.
This Standard applies to the determination of dry heat resistance of various
types of leather.
2 Normative references
The following documents are indispensable for the application of this document.
For dated references, only the dated version applies to this document. For
undated references, the latest edition (including all amendments) applies to this
document.
GB/T 39364, Leather - Chemical, physical, mechanical and fastness tests -
Sampling location (GB/T 39364-2020, ISO 2418:2017, MOD)
QB/T 2707, Leather - Physical and mechanical tests - Sample preparation
and conditioning (QB/T 2707-2018, ISO 2419:2012, MOD);
3 Principle
Place the air-conditioned sample in an oven for heating; then, test the area
shrinkage of the sample; record other changes of the sample.
4 Instruments and apparatuses
4.1 Oven, of which the temperature at the center can be controlled at (150±5) °C,
(200±5) °C and (250±5) °C respectively.
4.2 Vernier caliper whose accuracy is 0.01 mm.
4.3 Bracket, which is used to support the sample when it is heated in the oven,
so as to minimize the contact between the sample and the oven, such as a grid.
4.4 Stopwatch whose accuracy is 1 s.
6 Test conditions
6.1 Oven temperature
Select the oven temperature from the following three temperatures: (150±5) °C,
(200±5) °C and (250±5) °C.
6.2 Test time
Select the test time from the following three times: (15±0.5) min, (30±0.5) min,
(60±0.5) min.
7 Test method
7.1 Use a vernier caliper (4.2) to respectively measure the distance between
AB and CD on each sample; then, calculate the arithmetic average value, to
the nearest 0.1 mm. Measure the distance between AC and BD in the same
way; calculate the arithmetic average.
7.2 Preheat the oven (4.1) to a certain temperature that is specified in 6.1; place
the sample grain face up on the bracket (4.3) at the center of the oven.
7.3 After heating to a certain time that is specified in 6.2, take out the sample;
readjust the sample for 24 h in accordance with the provisions of QB/T 2707.
Note: According to the needs, select another oven temperature in 6.1 and
another test times in 6.2; use the newly prepared sample to repeat the
operations of 7.2 and 7.3 for the test.
7.4 Use the vernier caliper (4.2) to measure the distances of AB, CD, AC and
BD again; respectively calculate their arithmetic averages according to the
provisions of 7.1.
Note 1: The dry heat resistance test at 250°C is an extremely strict test for
leather. It should be noted that the leather (especially the leather with
higher oil content) may be burned during the test.
Note 2: The leather can volatilize and release gas under the test conditions that
are specified in 6.1 and 6.2. In order to avoid damage to the operator,
which is caused by the released gas, the test should be carried out in
a well-ventilated place.
7.5 Record any other obvious changes of the sample, such as sample distortion,
sample carbonization, changes in softness.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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