ISO 55:1977 pdf download.Seedlac-Specification.
0.1 The usual trade descriptions of seedlac are based on the Indian names of the host trees, the season of cropping the sticklac, visual differences or a combination of any of these. The use of these grade designations led to confusion and some marketing difficulties. When ISO/R 55 was prepared in 1957, it was decided to adopt only seven grades which were independent of the names of host trees or seasons. However, the expectation that the ISO grades for seedlac would be increasingly adopted in trade and ultimately replace the traditional grade designations has not come about. A new system has theiefore been adopted in ISO 55:1977 pdf download so that seedlac can now be completely identified by a combination of the ISO grade and the trade grade. In this revision, it has been found possible to reduce the number of ISO grades from seven to five.
0.2 For matter insoluble in hot alcohol, two limits are prescribed, in line with trade practice : a basic limit and a relaxed limit. The relaxed limit shall be the limit for rejection.
0.6 For the purpose of deciding whether a particular requirement of ISO 55:1977 pdf download is complied with, it is necessary for the final value, observed or calculated, expressing the result of test or analysis to be rounded off to the same number of places as that in the specified value, it being always understood that the analyst will carry out his determination to at least one place more than in the specified value.
1 SCOPE AND FIELD OF APPLICATION
1.1 ISO 55:1977 pdf download specifies requirements and methods of test for seedlac.
4 GRADES
Five grades of seedlac, namely Special, A, B, C and D are specified. Further, If required by the purchaser, the names of the grades as prevalent In trade shall be indicated In addition, In parentheses, as shown below:
— Grade Special (Golden Kusmi);
— Grade B (Kusmi No. 2).
The correspondence between ISO grades and trade grades Is shown In table 1.
6.4 Matter soluble in water
Seedlac shall not contain more than 1 % (rn/rn) of matter soluble in water, and the aqueous extract shall be neutral to methyl ied. Matter soluble in water shall be determined by the method described In annex D.
6.5 Ash
The limits and methods of test for ash content of seedlac shall be subject to agreement between the purchaser and the supplier.
6.6 Wax
Seedlac shall not contain more than 5,5 % (rn/rn) of wax when determined by the method described in annex E.ISO-55-1977