1、March 2014 English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 55.040; 55.080!%WY“2525459www.din.d
2、eDIN 55571-1Hot tack Part 1: Position measuring devices,English translation of DIN 55571-1:2014-03HotTack Teil 1: Wegmessende Prfgerte,Englische bersetzung von DIN 55571-1:2014-03HotTack Partie 1: Dispositifs de mesure de position,Traduction anglaise de DIN 55571-1:2014-03www.beuth.deDocument compri
3、ses 9 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.08.16 DIN 55571-1:2014-03 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope 4 2 Terms and definitions 4 3 Measurand 5 4 Test assembly 5 4.1 General
4、 5 4.2 Method A (functional principle) . 5 4.3 Method B (functional principle) . 6 5 Test preparation 6 5.1 Sealing parameters . 6 5.2 Drop weight . 6 5.3 Delay time . 7 6 Test procedure . 7 7 Evaluation . 7 8 Test report . 8 Bibliography . 9 DIN 55571-1:2014-03 3 Foreword This document (DIN 55571-1
5、:2014-03) has been prepared by Working Committee NA 115-02-01 AA Flexible Packmittel Laminate, Folien, Scke, Beutel, Tragetaschen of DIN-Normenausschuss Verpackungswesen (NAVp) (DIN Standards Committee Packaging). Attention is drawn to the possibility that some of the elements of this document may b
6、e the subject of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. DIN 55571-1:2014-03 4 1 Scope This standard specifies test methods which can be used to determine the hot tack strength of a sealed seam within prescribed sealing parameters. B
7、y varying the sealing parameters, this method can also be used to determine the conditions for achieving the optimal hot tack strength of such seams. The method can also be used to compare different hot seal media. The measurement results for methods A and B, with regard to the absolute value, canno
8、t be compared directly, as the test assemblies and the sealing conditions differ greatly. Both methods are suitable primarily for flexible packaging materials due to the positioning of the guide pulleys. 2 Terms and definitions For the purposes of this document, the following terms and definitions a
9、pply. 2.1 hot tack hot tack strength strength of a sealed seam when hot, immediately after finishing the thermal joining process (sealing) 2.2 wedge tool with which the seal is separated during testing (method A) 2.3 drop weight weight used to generate the force necessary to separate the seal 2.4 de
10、lay time time between the end of the sealing process (beginning with the opening of the sealing jaws) and the start of the separation of the seal 2.5 delay distance distance between the front edge of the sealing jaws and the point at which the seal begins to separate 2.6 split seam length length of
11、that part of the sealed seam that has been separated (split apart) during testing 2.7 residual seam length length of the seam that remains sealed after testing 2.8 sealed seam strength cold seam strength strength of a sealed seam when cold Note 1 to entry: See also DIN 55529. DIN 55571-1:2014-03 5 3
12、 Measurand The measurand shall be either the residual seam length or the split seam length. In either case, results shall be given in millimetres. 4 Test assembly 4.1 General The test assembly for determining the hot tack strength comprises a heat sealing device, to which the device for separating t
13、he heat sealed seam is directly connected. Seam separation can be achieved using either a wedge (method A) or suitably arranged guide pulleys (method B). 4.2 Method A (functional principle) The two sample trips are clamped together on one end and fixed to the device prior to testing (see Figure 1).
14、On their other end, the strips are attached to a drop weight. The guide pulley converts the vertical force of the weight into a horizontal force. Before each series of measurements, ensure the pulley rolls smoothly. Place one strip to be sealed over the wedge and the other strip under the wedge. Imm
15、ediately after the sample strips are sealed, release them by opening the clamps and the sealing jaws. The drop weight will pull the freshly sealed seam first along the delay distance S and then against the wedge. The peel force generated at the wedge will then separate the hot sealed seam with more
16、or less strength. Key 1 drop weight 4 wedge S delay distance 2 sample 5 sealing jaws 3 guide pulley 6 clamps Figure 1 Schematic diagram showing a device for separating the sealed seam according to method A DIN 55571-1:2014-03 6 4.3 Method B (functional principle) With method B, the drop weight is at
17、tached to one end of both strips. The other end of the strips, laid together, is threaded over pulley 1 (see Figure 2). Before each series of measurements, ensure the pulleys roll smoothly. Take care that the measuring area covers the entire sealed area. After sealing, the sealed sample is pulled ba
18、ck by the weight to pulleys 2 and 3 and is separated there. The delay time is defined by the distance between these pulleys and the sealing jaws. The sample strips remain hanging in the device until the separation action has come to a stop. Key 1 guide pulley 1 5 sealing jaws 2 guide pulley 2 6 clam
19、ps 3 guide pulley 3 S delay distance 4 drop weight L gap between pulleys 2 and 3 Figure 2 Schematic diagram showing a device for separating the sealed seam according to method B 5 Test preparation 5.1 Sealing parameters The sealing temperature, pressure and time, as well as their variations shall be
20、 specified before the actual measurement. The basis can be derived from the values of a sealing curve comprising cold seam strengths. 5.2 Drop weight Trial runs, which should include all later variations of the sealing parameters used in practice, can be carried out to determine which drop weight is
21、 most suitable. Measurement results will be comparable if the same drop weight is used for a series of measurements. A drop weight is deemed suitable when the sealed seam is only slightly split under optimal sealing parameters, and is not yet fully split under unfavourable sealing parameters. As a r
22、ule, drop weights are selected in steps of 25 g. DIN 55571-1:2014-03 7 5.3 Delay time Measurements are only comparable if they are performed using the same delay time. The delay time can be modified by setting the delay distance S accordingly. A good approximation for the delay time can be achieved
23、using the gravitational acceleration formula. Typical delay times range from 30 ms to 100 ms. Preferably, the delay time should reflect those times found in practice, and can be agreed upon by the contract partners, where appropriate. In all cases, the delay distance and/or the delay time shall be r
24、ecorded in the test report. 6 Test procedure Samples shall be prepared using the material under test as follows: for method A, take 2 strips that are 15 mm wide and 250 mm long; for method B take two single strips that are 400 mm long and 30 mm wide and bond them. Alternatively, take one strip that
25、is 30 mm wide and 800 mm long. The sealing process is started as soon as the samples are placed in the test device. Take care that any preheating of the sample is kept to a minimum to ensure reproducible sealing parameters. The sample is released by opening the sealing jaws and the clamps, and the d
26、rop weight pulls the sample to the point where it is split. After the sample has run along the delay distance, separation takes place at the wedge, in the case of method A, and at the pulleys, in the case of method B. Once the separation process has stopped, the residual seam length or the split sea
27、m length is measured in millimetres. 7 Evaluation The test result shall be the residual seam length or the split seam length, given to an accuracy of at least one millimetre. The initial seam length shall also be stated. The measurement can be performed by the tester using a suitable gauge or callip
28、ers, or using a suitable measurement procedure at the test device itself. Test results (mean of all single measurements) shall be given in millimetres, and the variability (minimum and maximum split seam length or residual seam length) shall also be given. NOTE For quality control purposes it is rec
29、ommended that the mean value be taken from at least three single measurements. For statistical purposes, the number of single measurements should be increased. DIN 55571-1:2014-03 8 8 Test report The test report shall include the following information: a) reference to this standard; b) designation o
30、f the tested product; c) dimensions of the sample strips; d) pretreatment of the sample strips; e) sealing parameters (temperature, duration, pressure); f) type and dimensions of sealing jaws used; g) type of test assembly (method A or B); h) delay time and/or delay distance; i) drop weight used; j)
31、 type of wedge1)used (method A), or arrangement and dimensions of pulleys (method B); k) test results and type of measurand (residual seam length or the split seam length) in millimetres: single values; mean value (of at least three tests); variability; l) any deviation from the conditions specified
32、 in this standard; m) the test date. 1) For example, a wedge as is available from the company Brugger Feinmechanik GmbH. This information is given for the convenience of users of this national standard and does not constitute an endorsement by DIN of this product. Equivalent products may be used, in which case the material, dimensions and surface quality are to be specified. DIN 55571-1:2014-03 9 Bibliography DIN 55529, Packaging Determining the sealed-seam strength of sealings made of flexible packaging material
