S.I. No. 314/1952:

STANDARD SPECIFICATION (WRAPPING PAPER) ORDER, 1952.

STANDARD SPECIFICATION (WRAPPING PAPER) ORDER, 1952.

I, SEAN F. LEMASS, Minister for Industry and Commerce, in exercise of the power conferred on my by subsection (3) of section 20 of the Industrial Research and Standards Act, 1946 (No. 25 of 1946), hereby order as follows :

1. This Order may be cited as the Standard Specification (Wrapping Paper) Order, 1952.

2.--(1) The specification set forth in Part II of the Schedule to this Order is hereby declared to be the standard specification for the commodity described in Part I of the said Schedule.

(2) The said standard specification may be cited as Irish Standard 39 : 1952.

SCHEDULE.

PART I.

WRAPPING PAPER.

PART II.

SPECIFICATION.

SCOPE.

1. This specification covers the requirements of certain classes of paper for use in wrapping merchandise.

TYPES AND USES.

2. Wrapping paper covered by this specification shall be of one of the following types :

Pure Kraft Paper, for wrapping goods where strength is required ;

Sulphite Paper, for wrapping goods where attractive appearance and moderate strength are required ;

Imitation Kraft Paper, for general wrapping purposes where strength is less important.

FURNISH.

3. The furnish of wrapping paper shall be :

for pure kraft paper, sulphate pulp with not more than 10 per cent. of other fibres ;

for sulphite paper, sulphite pulp with not more than 20 per cent. of other fibrous material ;

for imitation kraft paper, sulphate fibre with not more than 80 per cent. of other material.

SIZES.

4. Wrapping paper shall be in the form of sheets or rolls. The sheets shall be of one of the following sizes :

The rolls shall be of one of the following widths :

12 in., 18 in., 24 in., 30 in., 36 in.

The rolls shall have a centre core of not less than 2¼ in. and shall be wound to a diameter of 9 in.

A tolerance of plus or minus 0·5 per cent. on the dimensions of sheets and rolls shall be permitted.

SUBSTANCE.

5. The substance of wrapping paper shall be taken as the weight in pounds of a ream of 500 sheets, of size 20 in. by 30 in. A tolerance of plus or minus 5 per cent. in the substance shall be permitted.

The substance of pure kraft paper shall be :

17, 20, 25, 30, 35, 40, or 50.

The substance of sulphite paper shall be :

17, 20, 25, 30, 35, 40, 45, 50, or 60.

The substance of imitation kraft paper shall be :

30, 40, 50, or 60.

The substance of wrapping paper shall be determined in the manner described in Appendix A.

BREAKING LENGTH.

6. The breaking length of wrapping paper shall be taken as the length of a strip of the paper which, if hanging freely from one end, would just support its own weight. The breaking length shall be. calculated from the formula :

Breaking length in metres =

The breaking load in pounds shall be determined, for the machine direction and for the cross direction of the paper, in the manner described in Appendix B.

The breaking length in the machine direction shall be not less than :

8,000 metres for pure kraft paper,

7,000 metres for sulphite paper, and

4,000 metres for imitation kraft paper.

The breaking length in the cross direction shall be not less than :

4,000 metres for pure kraft paper,

4,000 metres for sulphite paper, and

2,500 metres for imitation kraft paper.

For the purpose of this clause and of succeeding clauses the " machine direction " shall mean the direction of manufacture of the paper on the paper-making machine and the " cross direction " shall mean the direction perpendicular to the direction of manufacture of the paper.

STRETCH.

7. The stretch of wrapping paper, when determined as described in Appendix B, shall be not less than 1·5 per cent. for the machine direction and not less than 2·0 per cent. for the cross direction.

BURSTING STRENGTH.

8. The bursting strength in pounds per square inch, when determined in the manner described in Appendix C, shall be not less than :

1·2 lb. per square inch per unit of substance for pure kraft paper,

1 lb. per square inch per unit of substance for sulphite paper, and

0·6 lb. per square inch per unit of substance for imitation kraft paper.

TEARING RESISTANCE.

9. The tearing resistance shall be taken as the force in grams required to tear the wrapping paper when the paper is tested in the manner described in Appendix D.

The tearing resistance of wrapping paper shall be not less than the value set out for its type and substance in Table 1.

TABLE 1

FOLDING ENDURANCE.

10. The folding endurance of wrapping paper, when determined as described in Appendix E, shall be not less than the value set out for its type and substance in Table 2.

TABLE 2

WATER RESISTANCE.

11. The water resistance of wrapping paper, when determined as described in Appendix F, shall be not less than 120 seconds.

FREEDOM FROM DEFECTS.

12. Wrapping paper shall be free from creases, holes, tears or slime spots.

TEST SAMPLES.

13. For the purpose of testing conformity of wrapping paper with the requirements of this specification samples shall be taken as follows :

(i) Sheets : For lots of 1 ton or under not less than 5 per cent. of the packages shall be sampled and for lots of more than 1 ton not less than 2 per cent. of the packages shall be sampled. Four successive sheets shall be taken from the centre of each package sampled.

(ii) Rolls: Not less than 10 per cent. of the total number of rolls comprising a lot of paper shall be sampled but in lots of over 50 rolls 5 per cent. shall be taken. Sample sheets shall be taken from the first unharmed layer of each roll.

Test samples shall be prepared from the samples taken and shall consist of sheets 10 in. by 10 in. in size. The test samples shall not include portions of sheets in which there are flaws.

Test samples shall be so cut that their edges are exactly parallel to the machine and cross directions of the paper. They shall be kept flat, free from wrinkles or folds and shall be protected from exposure to liquids, direct sunlight or other harmful influences.

CONDITIONS FOR TESTING.

14. Tests on wrapping paper shall be carried out in a room maintained at a temperature of 20°C.±0·5°C. and a relative humidity of 65±2·0 per cent. Arrangements shall be provided for circulating the air in the room so that its temperature and relative humidity shall be uniform.

The wrapping paper to be tested shall be dried at a temperature of 55°C. to 60°C. over a saturated solution of calcium chloride and then suspended so that the atmosphere of the room has access to all the surface of the paper. Before testing, the paper shall be weighed at intervals of one half hour until the weight is found to be constant.

The relative humidity of the atmosphere of the room shall be determined by means of wet-and-dry bulb thermometers placed in an air current having a velocity of at least three metres per second. The thermometers shall be graduated to the nearest 0·5°C. and shall be matched to within 0·25°C. throughout their range. They shall be compared with a certified thermometer before using and the necessary corrections applied.

Appendix A.

DETERMINATION OF SUBSTANCE.

Ten test samples shall be tested. Each test sample shall be weighed either on a beam scales or an automatic scales. The scales shall be sensitive to at least 0·25 per cent. of the load applied and shall be protected from air currents. If an automatic scales is used, it shall be checked before use both with increasing and decreasing loads made up of accurate weights.

The weight per ream for each test sample shall be determined and the average weight per ream of the ten test samples shall be calculated to two places of decimals. This average weight shall be taken as the substance of the paper.

Appendix B.

DETERMINATION OF BREAKING LOAD AND STRETCH.

Twenty test samples shall be tested. A strip 15 mm.±0·25 mm. wide and 200 mm. long shall be cut from each. The strips shall be cut with a guillotine having a fixed guide or with a knife using a rectangular template. Ten of the strips shall be cut with the longer dimension parallel to the machine direction of the paper and ten with the longer dimension parallel to the cross direction. The strips shall not be creased.

A pendulum type of instrument shall be used for carrying out this test. The instrument shall be levelled so that the pointer hangs freely at zero and does not touch the pendulum when the pawls are held up by a small wedge. The apparatus shall be calibrated by applying a vertical pull to the upper clamp by means of known weights and noting the reading of the quadrant corresponding to the applied weight, the pawls being held up and the arm swinging freely.

For pure kraft paper and sulphite paper of substance 17 or 20 and for imitation kraft paper of substance 30, 40 or 50, a quadrant scale with a maximum reading of 20 lb. shall be used and the rate of loading shall be uniform and from ½ lb. to 1 lb. per second. For wrapping paper of greater substance a quadrant scale with a maximum reading of 100 lb. shall be used and the rate of loading shall be uniform and from 1 lb. to 1½ lb. per second.

The strips shall be held in the clamps sufficiently firmly to prevent slip and in such a way that an even tension is applied. The length of the strip between the clamps shall be 180 mm.

Should cockles appear in the strip while being tested, or should the breaking take place at the clamp, or the strip slip in the clamp the reading shall be rejected and another strip tested.

If a reading differs by more than 25 per cent. from the mean of a set of ten readings the reading shall be rejected and another strip tested.

Readings of the breaking load shall be taken to the nearest 1/10 lb. Ten tests shall be carried out for both the machine direction and the cross direction. The arithmetic mean of the readings of the breaking load for the ten strips in each direction shall be taken as the breaking load.

The stretch of the wrapping paper shall be determined at the same time as the breaking load. For the purpose of determining the stretch a calibrated scale shall be used and the reading of the stretch indicator shall be taken at the end of each test. The arithmetic mean of the readings for the ten strips in each direction shall be taken as the stretch.

Appendix C.

DETERMINATION OF BURSTING STRENGTH.

Twenty test samples shall be tested.

The apparatus required for this test shall consist of an arrangement whereby pressure is applied by means of a rubber diaphragm to a circular area of paper. The periphery of the paper is held rigidly and the paper is allowed to bulge under the pressure until it bursts, the pressure at which it bursts being measured by a pressure gauge.

The diaphragm shall be such that it does not materially affect the bursting pressure. It shall be made of pure vulcanised rubber free from loading and shall be 0.4 mm. in thickness.

The surfaces of the clamps for clamping the test sample shall be parallel to each other and their apertures shall register when in contact. The diameter of the apertures shall be 1·2 in. ± 0·004 in. and the lower edge of the upper aperture shall be slightly radiused so that when bursting occurs the rupture is not peripheral due to shearing.

The diaphragm shall be arranged so that the portion of it which comes in contact with the test area of the paper is in the same plane. as the upper surface of the lower clamping ring.

Either of two pressure gauges, reading from 0 to 50 lb. per sq. in. or from 0 to 150 lb. per sq. in., shall be used depending on the bursting strength of the paper. The pressure gauge shall be calibrated before use so that its readings are accurate to within ±1 per cent. During calibration the pressure gauge shall be placed in a similar position to that in which it is fixed on the apparatus.

The application of pressure to the diaphragm shall be controlled so that the rate of increase of pressure is 10 lb. per sq. in. per second.

The test sample shall be clamped in position so that the full clamping area is utilised. The pressure of the clamps on the paper shall be firm enough to prevent slipping, but not so great as to damage the paper causing the burst to occur around the periphery of the test area. Slipping may be detected by the presence of creases after bursting and may be due either to insufficient clamping pressure or to non-uniform clamping pressure.

Immediately the paper has burst, the inlet valve shall be closed and the pressure indicated on the gauge shall then be read.

Twenty test samples shall be tested, half of them having the wire-side of the paper uppermost in the apparatus and the other half the top-side uppermost. If a reading differs by more than 25 per cent. from the mean or if the test sample shows creases due to slipping during testing, the reading shall be rejected and another sample tested. The arithmetic mean of the readings in lb. per sq. in. shall be calculated and shall be taken as the bursting strength of the paper.

Appendix D.

DETERMINATION OF TEARING RESISTANCE.

The apparatus to be used and the method of using it shall be as described in T 414 M-40 " Tearing Resistance of Paper " issued by the Technical Association of the Pulp and Paper Industry, 122 East 42nd Street, New York. A copy of this publication is available for reference in the library of the Institute for Industrial Research and Standards, Dublin.

Strips of paper 100 mm. by 50 mm. shall be cut from the test samples. The tests shall be carried out on enough strips to ensure that when torn together the scale readings on the apparatus are about 30 to 40. The number of strips required for a test is given in Table 3.

TABLE 3

Five tests shall be carried out on the strips with the longer dimension parallel to the machine direction of the paper and five on strips with the longer dimension parallel to the cross direction.

The wire sides of the strips forming a test bundle shall all face in the same direction. In each alternate test the test bundle shall be reversed, i.e., placed in the apparatus with the wire sides of the strips facing in the direction opposite to that of the previous test.

If the mean value of the lowest and highest readings differs from the average of all the readings by more than 10 per cent., further tests shall be carried out until there is agreement between these limits. Readings obtained in which the tear deviates by more than 10 mm. from the line of the initial slit shall be rejected.

The average of five readings for the machine direction of the paper and the average of five readings for the cross direction shall be calculated. The lower of these averages, corrected if necessary for calibration error, shall be multiplied by 16 and divided by the number of sheets torn at a time. The result shall be taken as the force in grams required to tear the paper.

Appendix E.

DETERMINATION OF FOLDING ENDURANCE.

The apparatus to be used and the method of using it shall be as described in PT 5 : sm 1950 " Folding Test " issued by the Technical Section of the British Paper and Board Makers' Association (Incorporated), St. Winifred's, Welcomes Road, Kenley, Surrey. A copy of this publication is available for reference in the library of the Institute for Industrial Research and Standards, Dublin.

Strips shall be cut from twenty test samples to a uniform width of 15 mm. ± 0·25 mm. and to a length of 97 mm. The strips shall not be creased. Ten of them shall be prepared for the machine direction of the paper and ten for the cross direction.

The apparatus shall be operated at such a speed that 90 to 120 double-folds per minute are produced.

The average number of double-folds which the paper sustains before rupturing shall be calculated for the ten test samples in the machine direction and similarly the average number of double-folds for the ten test samples in the cross direction. The lesser of the two values obtained shall be taken as the folding endurance of the paper.

Appendix F.

DETERMINATION OF WATER RESISTANCE.

This determination is based on the use of a galvanic sizing tester. A suitable apparatus for the purpose is manufactured by Messrs. Kelvin and Hughes Limited, Kelvin Avenue, Hillington, Glasgow, S.W.2, Scotland.

The apparatus shall consist of two electrodes connected to a high resistance microammeter, the paper to be tested being placed between the electrodes. The lower electrode shall consist of a plate 8·6 cm. in diameter made from zinc of not less than 99 per cent. purity and its upper surface shall be machined and polished. The upper electrode shall consist of a porous metallic wetting pad 7·6 cm. in diameter made of sintered bronze the porosity of which shall be not less than 35 per cent. and shall be capable of yielding at least 1 ml. of water when placed on a piece of absorbent paper. The upper electrode shall be filled with distilled water by sucking the water through it or by placing it on a pack of discs of blotting paper contained in a vessel filled with water to the level of the surface of the upper sheet. The lower electrode shall be wiped clean with a dry cloth. The pointer of the microammeter shall be adjusted to zero if necessary.

The apparatus shall be kept in the testing room for at least one hour before carrying out determinations.

Ten test samples shall be tested. A test sample shall be laid on the lower electrode and the upper electrode shall be placed on top of the paper and a stop-watch started at the same instant. The stop-watch shall be stopped at the instant that the instrument indicates a reading of 80 microamperes. The upper electrode shall then be returned to the reservoir containing the soaked blotting paper and the lower electrode shall be wiped dry. Five samples shall be tested with the wire-side of the paper in contact with the lower electrode and five with the top side in contact with the lower electrode. The average time taken for the ten test samples shall be calculated to the nearest second and shall be taken as the water resistance of the paper.

GIVEN under my Official Seal this 27th day of October, 1952.

(Signed) SEÁN F. LEMASS,

Minister for Industry and Commerce.