December 1991

\

1S16 ( Part 2 ) :1991

( TitTf?T ‘@hJT )

Indian Standard

SHELLAC – SPECIFICATIONPART 2 MACHINE-MADE SHELLAC

( Third Revision )

UDC 668°447”31

@ BIS 1991

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

Price Group 2

Lac and Lac Products Sectional Committee, CHD 22

FOREWORD

This Indian Standard ( Third Revision) was adopted by the Bureau of Indian Standards, after the draftfinalized by the Lac and Lac Products Sectional Committee had been approved by the Chemical DivisionCouncil.

Indian Standard for shellac covering hand-made shellac as well as machine-made shellac was firstpublished in 1949. It served as a basi; for initiating work at the level of the International Organizationfor Standardization (1S0) and culminated in the preparation of 1S0 Recommendation R 56 Shellac in

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1957. Simultaneously, It was revised to correspond with the ISO Recommendation. Later on, theTechnical Committee ISOITC 50 Lac reviewed the position in respect of adoption of ISO/R 56 Shellac

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by member countries of 1S0 and in the fourth meeting of ISO/TC 50 it was decided that specificproposals for changes in the 1S0 Recommendation be invited. On the basis of the proposals received

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it was seen that the adoption of ISO/R 56 was much more satisfactory in respect of machine-madeshellac than of hand-made shellac. Because the number of types and grades of machine-made shellac

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and hand-made shellac, taken together, was far too big and caused confusion in making reference to thestandard. Hence, two parts of the standards were printed. While, Part 2 covered machine-made shellac,

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hand-made shellac was covered in Part 1 of this standard, I

In the second revision of this standard for machine-made shellac, the requirement for non-volatilematter soluble in cold alchol had been dropped. The methods for quantitative determination of rosinhad also been dropped. I

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The requirement for colour index was given as essential. Though the colour index had been made anoptional requirement in ISO/R 560 the Sectional Committee had, however, decided that colour indexshould be made an essential requirement but the purchaser and the supplier may, by agreement, judgecolour by visual examination by comparison with an approved sample.

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During the last two decades, three amendments had been issued in view of the deterioration in quality ofshellac on storage and its usage in food and pharmaceutical industries. This third revision is beingundertaken to incorporate those amendments.

For the purpose of deciding whether a particular requirement of this standard is complied with, thefinal value, observed or calculated, expressing the result of a test or analysis, shall be rounded off inaccordance with IS 2: 1960 ‘Rules for rounding off numerical values ( revised )’. The number ofsignificant places retained in the rounded off value should be the same as that of the specified value inthis standard.

IS 16( Part 2 ) :1991

Indian Standard

SHELLAC – SPECIFICATIONPART 2 MACHINE-MADE SHELLAC

( Third Revision )1 SCOPE

1.1 This standard prescribes the requirementsand the methods of sampling and test formachine-made shellac.

1.2 The limits prescribed in this standard arelimits for rejection.

2 REFERENCES

The Indian Standards listed below ?re the neces-sary adjuncts to this standard;

IS No. Title

4908: 1968 Glossary of terms used in lacindustry

6921 : 1973 Methods of sampling and test forIac and Iac products

3 TERMINOLOGY

3.1 For the purpose of this standard, the defini-tions given in IS 4908: 1968 and the followingshall apply.

3.1.1 Approved Sample ‘ ‘

The sample agreed upon between the purchaserand the’ supplier as the standard for colour andgeneral appearance. ,..

4 FORM AND CONDITION

Machine-made shellac shall be in the form offlakes, sheets, - or buttons or any other formagreed to between the purchaser and the supplier.

5 TYPES AND GRADES

5.1 There shall be four types of machine-madeshellac as follows:

Type I — produced by heat process,

Type II — produced by hot solvent process,

Type III - de-waxed, and

Type IV — decolourized and de-waxed.

5.2 There shall be five grades in each of Types 1and 11 and four grades in each of Types HI andIv.

6 MANDATORY REQUIREMENTS

6.1 Matter Insoluble in Hot Alcohol

Machine-made shellac shall not contain matterinsoluble in hot alcohol, determined by either ofthe methods prescribed in 6 of IS 6921: 1973 asagreed to between the purchaser and the supplier,in excess of the limits given below:

Type MaximumPercent by Mass

0“75L 0“3111 0“2N 0“2

6.2 Colour Index or Colour and Appearance

6.2.1 The colour index of machine-made shellac,as determined by the method prescribed in 7 ofIS 6921 :1973, shall be not in excess of the limitsgiven below:

Colour Index, MaxfA~B 1:

Type I, Grades ~ C 22ID 35

Type H, Grades

Type III, Grades

Type IV, Grades

the appearance and colournot inferior to those of anwhen judged by visual

6.2.2 Alternatively,of shellac shall beapproved sampleexamination.

6.3 RosinMachine-made shellac shall not contain anvrosin, as tested by the method prescribed in 9 o~IS 6921:1973.

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IS 16( Part 2 ) :1991

6.4 Orpiment and Other Arsenical Impurities

6.4.1 Machine-made shellac shall not containany orpirnent, as tested by the methods prescri-bed in 14 of IS 6921 : 1973 except when aspecified percentage is agreed to between thepurchaser and the supplier, in which case thedetermination shall be carried out as prescribedin 20.1 of IS 6921 : 1973.

6.4.2 When the material is required for foodindustry or for drug preparations, the content ofarsenic shall not exceed 2 ppm ( as As ) whentested by the method prescribed in 20.2 ofIS 6921:1973.

6.5 Lead

When the material is required for food industryor for drug preparations, the content of leadshall not exceed 10 ppm ( as Pb ) when deter-mined by the method prescribed in 16 ofIS 6921:1973.

7 OPTIONAL REQUIREMENTS

7.0 The optional requirements given below shallbe subject to agreement between the purchaserand the supplier.

7.1 Volatile Matter

Machine-made shellac shall contain not morethan 2’0 percent by mass of volatile matter( moisture), as determined by the method pres-cribed in 5 of IS 6921: 1973.

7.2 Wax

Machine-made shellac of Type I and Type IIshall not contain more than 5.5 precent by massof wax, and that of Type HI and Type IV notmore than 0“2 percent by mass of wax whentested in accordance with Method I and MethodH respectively prescribed in 11 of IS 6921:1973.

7.3 Ash

Machine-made shellac shall contain not morethan 0“3 percent by mass of ash when determinedby the method prescribed in 12 of IS 6921: 1973.

7.4 Matter Soluble in Water

Machine-made shellac shall contain not morethan 0“5 percent by mass of matter soluble inwater and the aqueous extract shall not be acidicto methyl red or alkaline to bromothymol blue.The test shall be carried out according to themethod prescribed in 13 of IS 6921 : 1973.

7.5 Flow Test

Machine-made shellac shall have a flow withinthe range agreed to between the purchaser andthe supplier, when tested bY the me~o~ Pres-cribed in 21 of IS 6921: 1973.

7.6 Heat Polymerization Test

Machine-made shellac shall satisfy a heat polym-erization test within the range of time as agreedto between the purchaser and the supplier. Themethod shall be that prescribed in 22 of IS 6921 :1973 and unless otherwise agreed, the temper-ature of test shall be 150 “C.

7.7 Acid Value

The acid value of machine-made shellac shall befixed, if desired, by agreement between thepurchaser and thesupplier. It shall be determinedby the method prescribed in 15 of IS 6921:1973.

7.8 Lead Content

The limit of lead content shall be subject toagreement between the purchaser and the sup-plier and the percentage of lead shall be deter:mined by the method prescribed in 16 of1S 6921:1973.

NOTE - Shellac is, not expected’ to contain any lead,but to guard against inadvertent. contammat]on,when lead-free shellac is required, lt shall not con-tain more then 0“03 percent by mass of lead calcu-lated as lead ( see also 6.5 ).

7.9 Grit

The maximum limit for grit content in shellacshall be as agreed to between the purchaser andthe supplier. When required, it shall be deter-mined by the method prescribed in 23 of1S 6921:1973.

7.10 Iodine Value

The maximum limit for iodine value of shellacshall be as agreed to between the purchaser andthe supplier. When required, it shall be deter-mined by any one of the two methods presc-ribed in 24 of IS 6921:1973.

7.11 Clarity of Solution

This requirement is applicable to Type 111 andType lV shellac and shall be subject to agree-ment between the purchaser and the supplier.The shellac shall show no turbidity when testedby the method prescribed in 25 of IS 6921:1973.

8 PACKING AND MARKING

8.1 Packing

The material shall be packed as agreed to be-tween the purchaser and the supplier.

8.1.1 It n recommended that the material beconsumed as early as possible after purchase;till the time it is consumed, the containers shallbe stored at low temperatures. preferably 4 to5 “c.

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IS 16 ( Part 2 ) :1991

.8.2 Markhg

The material shall be marked with the followinginformation:

a) Name, standard grade and trade ( see 4.1and 4.1.1 ) of the material;

b) Net mass of the material;c) Indication of the source of manufacture;d) Month and year of manufacture; and

e) Lot number or Code number to trace thelot of manufacture.

9 SAMPLING

9.1 Samples shall be prepared in the mannerprescribed in 3 of IS 6921:1973.

9.2 Samples shall be prepared separately foreach grade of the material.

9.2.1 Samples shall be stored in air-tight con-tainers at temperature not more than 20 “C forperiods upto three months; if it is intended tokeep the samples for longer periods, they shallbe kept in a refrigerator.

9.3 Number of Tests

9.3.1 Tests for matter insoluble in hot alcohol,co lour index, rosin, orpiment and arsenic shallbe done on two independent samples.

9.3.2 Test for all other characteristics shall bedone on a single sample only.

9.4 Criteria for Conformity

The lot shall be considered as conforming tothe specification if no failure occurs in any test.

I II Standard Mark 1

The use of the Standard Mark is governed by the provisions of the Bweau of IndianStanalwds Act, 1986 and the Rules and Regulations made thereunder. The Standard Mark onproducts covered by an Indian Standard conveys the assurance that they have beenproduced to comply with the requirements of that standard under a well defined system ofinspection, tosting and quality control which is devised and supervised by BIS and operatedby the producer. Standard marked products are also continuously checked by BIS for Con-

formity to that standard as a further safeguard. Details of conditions under which a licencefor the use oft he Standard Mark may be granted to manufacturers or producers may beobtained from the Bureau of Indian Standards.

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goodsand attending to connected matters in the country,

Copyright

BIS has the copyright of all its publications. No part of these publications may be reproduced in anyform without the prior permission in writing of BIS. This does not preclude the free use, in the course ofimplementing the standard, of necessary details, such as symbols and sizes, type or grade designations.Enquiries relating to copyright be addressed to the Director ( Publications ), BIS.

Revision of Indian Standards

Indian Standards are reviewed periodlpally and revised, when necessary and amendments, if any, areissued from time to time. Users of Indian Standards should ascertain that they are in possession of thelatest amendments or edition. Comments on this Indian Standard may be sent to BIS giving thefollowing reference

Doc : No. CHD 22 ( 0097)

Amendments Issued Since Publication

Amend No. Date of Issue Text Aifected

BUREAU OF INDIAN STANDARDS

Headquarters:

Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002Telephones :3310131, 3311375

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Printed at New Indie Printing Rcrr. Khuria, India