GB/T 31479-2015 in English

《GB/T 31479-2015与食品接触染色纸和纸板色牢度的测定》由607（中国轻工业联合会）归口，主管部门为中国轻工业联合会。
本标准规定了两种测定与食品接触染色纸和纸板色牢度的方法。
本标准的方法 A 适用于与食品长时间接触(接触时间≥24h)的染色纸和纸板色牢度的测定(如:食品包装纸),方法 B适用于与食品短时间接触(接触时间<24h)的染色纸和纸板色牢度的测定(如:餐巾纸、厨房用纸)。

1 Scope

This standard specifies the two methods for determination on colour fastness of dyed papers and boards intended to come into contact with foodstuffs.

In this standard, Method A is applicable to determination on colour fastness of the dyed papers and boards (like food wrap paper) in long contact with foodstuffs (contact time ≥ 24h) while Method B is applicable to determination on colour fastness of the dyed ones (like paper napkin and kitchen paper) in short contact with foodstuffs (contact time < 24h).

2 Normative references

The following referenced documents are indispensable for the application of this document. For the dated normative references, only the dated editions are applicable to this document. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 251 Textiles - Tests for colour fastness - Gray scale for assessing staining
GB/T 450 Sampling of paper and cardboard specimens and determination of vertical and horizontal, front and back of specimens
GB/T 461.1 Paper and board - Determination of capillary rise (Klemm method)

3 Principle

Contact the specimen with the glass fiber paper which has been completely soaked in the test solution for 10 min. After being placed under a certain pressure for a period of time, compare the stained glass fiber paper (the test sample) with the blank sample, and assess the grayness level with a gray scale. Choose the test solution according to the use of the paper; the test solution may be distilled water or deionized water, acid acetic dilute, simulated saliva fluid, isooctane or olive oil.

Foreword i
1 Scope
2 Normative references
3 Principle
4 Materials and apparatus
5 Reagents
6 Sampling
7 Specimen preparation
8 Test methods
9 Assessment
10 Test report
Annex A (Normative) Composition and preparation method of simulated saliva fluid