BS-6162-1981.pdf

BRITISH STANDARD BS 6162:1981 Incorporating Amendment No. 1 Specification for Open-mouth sacks manufactured from woven polyolefin tape yarn UDC 621.798.151:677.494.742.074 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 This British Standard, having been prepared under the direction of the Packaging and Freight Containers Standards Committee, was published under the authority of the Board of BSI and comes into effect on 30 November 1981 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PKM/552 (formerly PKS/552) Draft for comment 77/64330 DC ISBN 0 580 12326 X Cooperating organizations The Packaging and Freight Containers Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of Drum Manufacturers British Bag Federation British Fibreboard Packaging Association British Food Manufacturing Industries Research Association British Paper and Board Industry Federation (PIF)* British Stationery and Office Products Federation Chemical Industries Association* Collapsible Tube Manufacturers Association Department of Trade (Paper, Printing, Publishing, Services and Distribution) Department of Transport Food Manufacturers Federation Incorporated* General Council of British Shipping Glass Manufacturers Federation Institute of Packaging Institute of Trading Standards Administration Institution of Production Engineers Metal Packaging Manufacturers Association Ministry of Defence* Oil Companies Materials Association Paintmakers Association of Great Britain Limited Pira (the Research Association for the Paper and Board, Printing and Packaging Industries)* Soap and Detergent Industry Association Timber Packaging and Pallet Confederation Timber Research and Development Association Coopted members The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: British Plastics Federation British Polyolefin Textiles Association Jute Sack and Bag Manufacturers Association National Coal Board National Association of British and Irish Millers Limited Packaging and Industrial Films Association Paper Sack Development Association Limited United Kingdom Sugar Industry Association United Kingdom Jute Goods Association Amendments issued since publication Amd. No.Date of issueComments 5788October 1988Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 © BSI 11-1999i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2Reference1 3Definitions1 4Materials1 5Dimensions1 6Construction2 7Liners3 8Performance requirements3 Appendix A Determination of the dimensions of a sack4 Appendix B Method of test for fabric strength and elongation at break4 Appendix C Method of test for strength of base closures and longitudinal seams5 Appendix D Guidance for users6 Figure 1 Open-mouth flat sack1 Figure 2 Open-mouth gusseted sack2 Figure 3 Stitched base closure or longitudinal seam2 Figure 4 Measurement of gusset width, method of folding4 Figure 5 Test specimen6 Table 1 Performance requirements for open-mouth sacks3 Publication referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 ii © BSI 11-1999 Foreword This British Standard has been prepared under the direction of the Packaging and Freight Containers Standards Committee at the request of the Chemical Industries Association. It had been the intention to include a performance requirement for resistance to degradation by ultraviolet (UV) light together with an appropriate method of test. However, methods of test currently available are not considered suitable. The position will be reviewed at a later date according to developments in this area. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 © BSI 11-19991 1 Scope This British Standard specifies requirements for the materials, dimensions and performance of open-mouth sacks manufactured from plain weave fabrics produced from polyolefin tape yarns. Methods of test are included in Appendix A to Appendix C. Notes for the guidance of users are included in Appendix D. 2 Reference The title of the publication referred to in this standard is given on the inside back cover. 3 Definitions For the purposes of this British Standard, the following definitions apply. 3.1 woven polyolefin sack a flexible container, made from fabric manufactured from woven polyolefin tape yarn, with or without a liner 3.2 liner a single ply flexible container which may be loosely inserted or anchored in a sack 3.3 woven polyolefin fabric a sheet material woven from polyolefin tape yarn 3.4 polyolefin tape yarn flat yarn having a high ratio of width to thickness, composed of polyolefin polymer 3.5 weave 3.5.1 fabric weave the pattern of interlacing of the warp (the tapes running in the machine or longitudinal direction of the woven material) and the weft (the tapes in the transverse direction) 3.5.2 sack weave the number of tapes per 100 mm running in the longitudinal direction of the sack by the number of tapes per 100 mm running in the transverse direction NOTE 1The sack weave is expressed as, for example, 40 × 50. NOTE 2In the finished sack, the warp of the fabric may run along the length or across the width of the sack depending on the method of conversion. 3.6 coated fabric a fabric coated on one or both sides with a suitable polymer 4 Materials 4.1 Fabric. Fabric shall be woven from polyolefin tape yarns. The weave of the fabric shall be plain and its construction described as warp by weft in tapes per 100 mm, e.g. 50 × 40, i.e. warp 50 tapes/100 mm, weft 40 tapes/100 mm. The fabric shall be either uncoated or coated on one or both sides. 4.2 Stitching thread. The stitching thread shall be made from either: a) polypropylene, or b) other materials provided they are not adversely affected by the contents of the sack or by the expected climatic conditions in transit, storage and use. 5 Dimensions 5.1 Expression of dimensions. The stated dimensions of a sack shall be the internal dimensions and shall be expressed as: a) face width × length, in millimetres, for an open-mouth flat sack (see Figure 1); b) face width × width of gusset × length, in millimetres, for an open-mouth gussetted sack (see Figure 2); regardless of whether the length is greater or less than the face width. Figure 1 Open-mouth flat sack Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 2 © BSI 11-1999 5.2 Face width. The face width shall be within the range starting at 300 mm and increasing by increments of 25 mm to 750 mm. The method of measurement shall be as specified in Appendix A. 5.3 Sack length. The length shall be within the range starting at 300 mm and increasing by increments of 25 mm to 1 500 mm. The method of measurement shall be as specified in Appendix A. 5.4 Tolerances 5.4.1 Face width. The tolerance on sack face width shall be ± 12 mm. 5.4.2 Sack length. The tolerance on sack length shall be ± 12 mm. 5.4.3 Face width plus gusset. The tolerance on face width + gusset shall be ± 12 mm. 6 Construction 6.1 Sack. Sacks shall be produced either: a) from material woven as a tube, or b) from flat woven material. Either material may be coated prior to conversion. 6.2 Edge sealing. All raw edges shall be sealed to prevent fraying. 6.3 Base closure 6.3.1 General. The base closure shall be such as to ensure compliance with the performance requirements in clause 8. 6.3.2 Turned-over and stitched. Where the base closure is effected by a turned-over and stitched seam (see Figure 3) the turnover shall be 20 mm minimum, and the stitch line shall be 10 ± 3 mm from the base so formed and shall pass through all four thicknesses of material. 6.3.3 Woven. Where the base closure is woven, the woven portion shall extend for 20 mm minimum from the base of the sack and shall be such as to ensure compliance with the performance requirements specified in clause 8. 6.3.4 Bonded. Where the base closure is bonded, the seam shall be effected by applying capping tape over the ends of the sack and securing by means of an adhesive. The bond shall be such as to ensure compliance with the performance requirements specified in clause 8. 6.4 Longitudinal seams 6.4.1 General. Where longitudinal seams are used, they shall be either stitched, woven or bonded and shall be such as to ensure compliance with the performance requirements specified in clause 8. All longitudinal seams shall be along the edge fold except for bonded seams which shall be on the back face in the centre, unless required to be off-set to accommodate printing. 6.4.2 Stitched. Where the longitudinal seam is effected by a turned-over and stitched seam (see Figure 3) the turnover shall be 20 mm minimum, and the stitch line shall be 10 ± 3 mm from the outer edge of the seam so formed and shall pass through all four thicknesses of material. 6.4.3 Woven. Where the longitudinal seam is woven, the woven portion of the seam shall extend 15 mm minimum from the outer edge of the seam, and shall be such as to ensure compliance with the performance requirements specified in clause 8. 6.4.4 Bonded. Where the longitudinal seam is bonded, the edges of the material shall be overlapped 30 mm minimum and bonded with a width of bond of 15 mm minimum. The bond shall be such as to ensure compliance with the performance requirements specified in clause 8. Figure 2 Open-mouth gusseted sack Figure 3 Stitched base closure or longitudinal seam Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 © BSI 11-19993 6.5 Mouth. The mouth of the sack shall be either: a) plain, formed from a selvedge or from a sealed raw edge (see 6.2); or b) hemmed, with a single or double foldover stitched continuously round the mouth of the sack. 7 Liners Where liners are used, they shall be either: a) loosely inserted; or b) anchored with adhesive (or other suitable medium); or c) stitched at the base closure; or d) stitched at the mouth. Where a stitched anchorage is used, the stitch line shall only perforate the liner below the bottom seal or within 15 mm of the mouth of the sack. The width of the liner shall be at least equal to that of the woven sack. 8 Performance requirements 8.1 Sack grades. Sacks shall be manufactured in five grades. The minimum fabric strength and elongation at break of each grade shall be as detailed in Table 1 when tested as described in Appendix B. 8.2 Base closure. The base closure strength shall be not less than that detailed in Table 1 when tested as described in Appendix C. 8.3 Longitudinal seams. The longitudinal seam strength shall be not less than that detailed in Table 1 when tested as described in Appendix C. Table 1 Performance requirements for open-mouth sacks Grade Minimum mean strength of fabrica Elongation at break of fabrica Minimum mean longitudinal seam strength Minimum mean base closure strength Min.Max. N/50 mm%N/50 mmN/50 mm 5505501325440330 6506501325520390 7507501325600450 8508501325680510 9509501325760570 a In either direction. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 4 © BSI 11-1999 Appendix A Determination of the dimensions of a sack A.1 General All measurements relate to the internal width and length of the sack. Where the sack has been turned after sewing (see Appendix D), for measuring purposes it shall be turned back to the position as sewn so that the stitch line(s) are visible. A.2 Open-mouth flat sack A.2.1 Face width. Fold the sack in half placing mouth to base, and measure the distance along the fold so formed, between the longitudinal edge(s), stitch line(s) or seam(s) of the sack, whichever is applicable. A.2.2 Length. Fold the sack in half along its length (see Figure 1) and measure the distance along the fold so formed between the mouth and the seam, stitch line or sealed edge at the base, whichever is applicable. A.3 Open-mouth gusseted sack A.3.1 Face width. Measure face width as for the open-mouth flat sack specified in A.2.1. A.3.2 Width of gusset. Open and fold back one gusset (see Figure 4) retaining the outer folds for more than half the length of the sack. Fold the sack in half placing mouth to base, such that the flattened gusset is outside, and measure the width of the gusset along the fold so formed. Repeat the procedure with the other gusset. A.3.3 Length. Proceed as for open-mouth flat sacks, specified in A.2.2. Appendix B Method of test for fabric strength and elongation at break B.1 Principle A 50 mm wide specimen is extended at a constant rate of 200 ± 10 mm/min until it breaks. B.2 Apparatus The apparatus shall be in accordance with that described in BS 2576 with the exception that the rate of separation of the pulling jaw from the fixed jaw shall be 200 ± 10 mm/min. B.3 Test specimens B.3.1 Dimensions. The width of each test specimen shall be 50 mm (excluding any fringe). The length of each test specimen shall be greater than the required gauge length of 200 mm by an amount necessary to ensure adequate clamping at each end. B.3.2 Number of specimens. Five longitudinal specimens and five transverse specimens shall be tested. The sample from which the specimens are cut shall be as representative of the consignment as possible. B.3.3 Preparation of specimens B.3.3.1 General. Each test specimen shall be cut with its length parallel to the longitudinal or transverse direction, and no specimen shall contain selvedge ends. Figure 4 Measurement of gusset width, method of folding Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 12:49:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6162:1981 © BSI 11-19995 B.3.3.2 Uncoated fabric. The width of the test specimen shall be sufficient to allow for fringes of sufficient width such that during the process of testing no longitudinal tapes escape from the fringe. For the m