BS-6225-2-1982 ISO-3783-1980.pdf

BRITISH STANDARD BS 6225-2: 1982 ISO 3783:1980 Method for Determining the resistance to picking of paper and board: accelerating speed method using the IGT tester Part 2: Electric model ISO title: Paper and board Determination of resistance to picking Accelerating speed method using the IGT tester (electric model) UDC 676.017.435.2:62 83 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 This British Standard, having been prepared under the direction of the Paper Standards Committee, was published under the authority of the Board of BSI and comes into effect on 26 February 1982 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PAS/11 Draft for comment 75/61962 DC ISBN 0 580 12601 3 Cooperating organizations The Paper Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: British Paper and Board Industry Federation (PIF)* British Printing Industries Federation* Envelope Makers and Manufacturing Stationers Association* HM Customs and Excise Her Majestys Stationery Office* Institute of Trading Standards Administration National Association of Paper Merchants National Economic Development Office Pira (The Research Association for the Paper and Board, Printing and Packaging Industries)* Royal Institute of Public Health and Hygiene 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 Fibreboard Packaging Association British Wood Pulp Association Chemical Industries Association Man-made Fibres Producers Committee Ministry of Defence Paper Sack Development Association Ltd. Post Office Society of British Printing Ink Manufacturers University of Manchester Institute of Science and Technology Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 © BSI 11-1999i Contents Page Cooperating organizationsInside front cover National forewordii 0Introduction1 1Scope1 2Field of application1 3References1 4Definitions1 5Principle1 6Apparatus and materials1 7Sampling2 8Conditioning2 9Preparation of test pieces2 10Preparing the tester2 11Procedure3 12Determination of picking3 13Steps for subsequent tests3 14Test report4 15Bibliography4 Annex A Diagram of IGT printability tester (electric model) in common use5 Annex B 1977 version of IGT tester (electric model)6 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 ii © BSI 11-1999 National foreword This Part 2 of this British Standard has been prepared under the direction of the Paper Standards Committee and is identical with ISO 3783:1980 “Paper and board Determination of resistance to picking Accelerating speed method using the IGT tester (Electric model)” published by the International Organization for Standardization (ISO). Part 1 of this standard is identical with ISO 3782:1980 “Paper and board Determination of resistance to picking Accelerating speed method using the IGT tester (Pendulum or spring model)”. Together these two Parts supersede BS 4885-2:1974 which is therefore withdrawn. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard.” 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. Cross references International StandardCorresponding British Standard ISO 186:1977BS 3430:1980 Method for sampling for testing paper and board (Identical) ISO 187:1977BS 3431:1973 Method for the conditioning of paper and board for testing (Technically equivalent) 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 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 © BSI 11-19991 0 Introduction A number of methods for assessing the picking resistance of paper, i.e. the ability of paper to withstand the forces involved in splitting of ink films in printing processes, have been developed and accepted in different countries. However, it has not been possible to achieve reproducibility between the results obtained by the different methods; nevertheless several of the methods do rank particular papers in the same order and to this extent enable comparisons to be made. It is hoped that it will eventually be possible to achieve genuine reproducibility, but meanwhile it is considered necessary to provide internationally agreed guidance on the use of instruments that are employed in many countries. One of the most widely used pick testers is the IGT1) instrument. This International Standard deals with the electric model of that tester. ISO 3782 deals with other IGT instruments (pendulum or spring model), and the preparation of further methods is being considered. 1 Scope This International Standard specifies a method of operating the electric model of the IGT printability tester in order to provide a measure of the picking resistance of paper and board. 2 Field of application This International Standard applies to the testing of any kind of paper and board likely to be used for printing, mainly by lithographic or letterpress processes. 3 References ISO 186, Paper and board Sampling for testing. ISO 187, Paper and board Conditioning of samples. 4 Definitions 4.1 picking the rupture of the surface of a paper or board during printing, which occurs when an external tensile force applied to the surface is greater than the cohesion of the paper or board NOTEIn the case of coated papers, the rupture may take the form of particles of coating or fibres wholly or partly detached from the sheet, “blistering” of the surface or gross stripping of the surface. In the case of board, “blistering” is called delamination and this is often reported separately from picking. In the case of uncoated papers the rupture normally takes the form of the removal of fibre aggregates. 4.2 picking velocity the velocity of printing at which the picking of the surface of the printed paper begins 5 Principle A strip of paper or board is printed at constant force and increasing velocity with a standard oil. The minimum velocity at which picking occurs is a measure of the picking resistance of the paper or board. 6 Apparatus and materials 6.1 IGT tester The tester comprises two separate units: an oil applicator which enables an oil film of known (controlled) thickness to be placed on a printing disc, and a printing unit on which the drive is electric. Printing force is controlled by variable spring loading. Slightly different versions of the electric model of the IGT tester are in existence, the differences being of detail and affecting mainly the positions of certain controls. The description of the IGT tester given in 6.1, together with the detailed instructions given in clauses 10 and 11, apply to a version of the electric model in common use and a diagram of the printing unit is given in Annex A.2) Annex B gives the amendments required to the text of 6.1.1 and 11.4 when using the version of IGT tester (electric model) available from the manufacturer during 19772). A diagram of the electric model printing unit, in this version, is included in Annex B. NOTEIf there is any doubt concerning which version of IGT tester is being used, the instrument manufacturer should be consulted. 1) Stichting Instituut voor Grafische Techniek TNO, Postbus 4150, 1009 AD Amsterdam. 2) See also Bibliography. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 2 © BSI 11-1999 6.1.1 Printing apparatus The printing apparatus consists of a semi-circular sector (8), having a radius of 85 mm, which is covered with standard packing against which the test piece is secured. The part of the sector used for the pick test is approximately 150°. This sector rotates with an increasing velocity against a smooth metal printing disc. The disc, which is 65 mm in diameter and 10 mm wide, presses against the test piece with a force that is adjustable to 345 ± 10 N (35 kgf) 3). NOTESpecial attention is drawn to the importance of ensuring correct adjustment of the distance between the sector and the shaft (12) that carries the printing disc during printing, preferably in consultation with the instrument manufacturer. The increasing velocity setting (14) that is required for the test is selected on the instrument only when the sector is in the starting position. The selector switch (3) is initially turned to the low velocity position. Maximum velocities up to 4 m/s may be selected by adjustment of the velocity control knob (5). For each point on the test strip, the corresponding velocity should be known. NOTEDiagrams are supplied with the apparatus showing velocity versus distance on the strip (see 12.3 and 12.4). The printing force is adjusted (9). The test piece is placed on the packing and secured. The printing disc on shaft (12) is in contact with the strip. NOTESpecial attention is drawn to the importance of ensuring accurate calibration of the apparatus, preferably in consultation with the instrument manufacturer. 6.1.2 Oil application system The distribution roller used for oil application shall be of polyurethane. The printing disc shall be provided with an even layer of oil 7,6 ± 0,6 4m in thickness. This will normally be produced by the application of 1 ml of oil to the distribution system. NOTEThe oil film thickness on the printing disc is checked by weighing the printing disc before and after inking, using a knowledge of the density of the oil. 6.2 Standard picking oils 6.3 Standard card packing material The packing shall be 1,5 ± 0,1 mm thick. NOTEThe Nederlands Normalisatie-Instituut (NNI), Postbus 5810, 2280 HV, Rijswijk (ZH) Netherlands, is willing to provide information as to the source of supply of appropriate oils and cards. 6.4 Oil-measuring devices A balance capable of weighing a mass of approximately 60 g to an accuracy of ± 0,1 mg. A graduated ink pipette to dispense a volume to an accuracy of ± 0,01 ml. 7 Sampling Sample in accordance with ISO 186. 8 Conditioning Condition the sample in accordance with ISO 187. 9 Preparation of test pieces Cut 10 test pieces each for each side of the test material (for example, top side and wire side respectively) and also in the machine and cross directions, or as appropriate. Each test piece shall measure 350 mm × 35 mm. Mark the sides, and the machine and cross direction, on the test pieces. This marking shall be carried out in such a manner that it is possible, after the test pieces have been cut, both to identify each side of the test material and the machine direction and cross direction, and to test half the machine direction test pieces in one direction and half in the other. 10 Preparing the tester 10.1 Mounting and tensioning of packing Turn the two small milled screws on the sector counter-clockwise as far as possible. Press open the packing clamp (18) on the left-hand side of the sector and insert the glued edge of the packing as far as possible. Ensure that the packing is positioned exactly straight on the sector and clamp the glued end by means of the large milled nut. Press open the packing clamp (7) on the right-hand side of the sector and insert the other end of the packing as far as possible between the two jaws. Clamp by tightening the large milled nut. Stretch packing by turning clockwise, alternately, the small milled screws of the sector. Renew the packing if it becomes damaged or shows obvious signs of wear. 10.2 Adjustment of printing force Verify that the distance between the sector and the shaft (12) that carries the printing disc during printing has been correctly adjusted. Mount the test piece on the sector so that it lies flat against the packing. 3) In view of the ISO decision to use SI units and their preferred multiples and sub-multiples, these have been adopted in this International Standard; metric technical units are given in parentheses as many existing instruments use these units for their scale readings. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:28:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6225-2:1982 © BSI 11-19993 Turn the top printing-disc lifter (11) clockwise as far as it will go. Place an unoiled printing disc on the shaft. Turn the sector to its starting position. Turn the top printing disc lifter (11) counter-clockwise as far as it will go. Turn the tension adjuster (9) at the top of the right-hand side of the tester until the top printing force scale (13) reads 345 ± 10 N (35 kgf). 11 Procedure 11.1 Test conditions Carry out all tests in the atmospheric condition at which the paper or board has been conditioned. Ensure that the tester and the test material are at the test temperature. 11.2 Inserting test pieces Press open the paper clamp (18) on the left-hand side of the sector and insert the test piece between the jaws. Guide the test piece over the sector, keeping it in line with the sector. Press open the right-hand clamp and insert the folded end of the test piece under the clamp, it is unnecessary to stretch the strip over the sector. 11.3 Preparation of printing disc Apply the appropriate quantity of oil to the oil application system and distribute it on the system for a minimum time of 8 min. Then place the printing disc on the appropriate shaft to receive the oil for a minimum time of 90 s. NOTEThe use of the back rollers supplied with the IGT tester is optional. 11.4 Making a test Set the selector pin (14) to the increasing velocity setting. Set the selector switch (3) to the low velocity position. Turn the top printing-disc lifter (11) clockwise as far as possible and place the oiled printing disc on the shaft (12) until it