1、August 2016 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!%YZB“2545531www.din
2、.deDIN 55571-2Hot tack Part 2: Peel strength measuring devices,English translation of DIN 55571-2:2016-08Hot-Tack Teil 2: Kraftmessende Prfgerte,Englische bersetzung von DIN 55571-2:2016-08Hot-Tack Partie 2: Appareils de contrle pour mesurer la force,Traduction anglaise de DIN 55571-2:2016-08www.beu
3、th.deDocument comprises 10 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.08.16 DIN 55571-2:2016-08 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope 4 2 Terms and definitions 4 3 Measurand 6 4 Test a
4、ssembly 6 4.1 General 6 4.2 General test assembly and functional principle . 6 4.2.1 General 6 4.2.2 Method A . 6 4.2.3 Method B . 7 4.2.4 Method C . 8 5 Test preparation and test procedure . 8 6 Evaluation . 8 7 Test report . 9 Bibliography . 10 DIN 55571-2:2016-08 3 Foreword This document has been
5、 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 be the subject of p
6、atent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. DIN 55571, Hot-Tack, comprises the following parts: Part 1: Position measuring devices Part 2: Peel strength measuring devices DIN 55571-2:2016-08 4 1 Scope This standard specifies test methods
7、which can be used to determine the hot tack strength of a sealed seam within prescribed sealing parameters. By 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 dif
8、ferent hot seal media. The measurement results for methods A, B and C, with regard to the absolute value, cannot be compared directly, as the test assemblies and the sealing conditions differ greatly. Due to the positioning of the guide pulleys and the assessment of the strength of the sealed seams
9、by means of a peel test, the methods are primarily suitable for flexible packaging materials. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 hot tack hot tack strength strength of a sealed seam when hot, immediately after finishing the therm
10、al joining process (sealing) Note 1 to entry: The specification of a defined delay time is possible. SOURCE: DIN 55571-1:2014-03, 2.1, modified Note 1 to entry has been added 2.2 sealing temperature temperature on the surface of the sealing bars or contact surface of the sealing bars with the sample
11、 strips 2.3 sealing force force acting vertically from above via the sealing bars onto the contact surface of the sealing bars with the sample strips Note 1 to entry: The sealing force is given in N. 2.4 sealing pressure sealing force per contact surface area of the sealing bars with the sample stri
12、ps Note 1 to entry: The sealing pressure is given in N/mm2. 2.5 sealing time time during which the sealing pressure is applied SOURCE: DIN 55529:2012-09, 3.3 2.6 seam separating speed speed at which the sample strips are torn apart Note 1 to entry: The seam separating speed corresponds to the peel-o
13、ff speed if tension is applied to only one side of the sample strip. If tension is applied to both sides of the sample strip, the peel-off strength shall be halved in order to attain the seam separating speed. DIN 55571-2:2016-08 5 2.7 separating angle angle at which the sealed seam is separated dur
14、ing testing 2.8 separating force force required to separate the sealed seam 2.9 delay time minimum 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, depending on the device used 2.10 retention time adjustable tim
15、e between the opening of the sealing jaws and the start of seam separation, including the delay time 2.11 separating profile type of fracture of the sealed seam Note 1 to entry: In the case of multilayer materials, the separating profile describes where and how the separation occurs (adhesive, cohes
16、ive), or whether a tear or strain occurs at the sealing strips before the sealed seam is opened (determination of hot tack not possible). 2.12 adhesive fracture separation by detachment of a layer or, not visible, very close to the boundary between two layers 2.13 cohesive fracture separation by spl
17、itting within a layer 2.14 tear breaking of a sample strip before separation of the sealed seam 2.15 strain change in length of one or both sample strips before the sealed seam opens or a tear occurs 2.16 sealed seam width width of the sample strips used 2.17 sealed seam length width of the sealing
18、jaws used Note 1 to entry: The sealing process is carried out transversely, i.e. 90 to the longitudinal axis of the sample strip. DIN 55571-2:2016-08 6 2.18 sealed seam strength cold seam strength strength of a sealed seam when cold Note 1 to entry: See also DIN 55529. SOURCE: DIN 55571-1:2014-03, 2
19、.8 2.19 delay distance distance between the front edge of the sealing jaws and the point at which the seal begins to separate SOURCE: DIN 55571-1:2014-03, 2.5 3 Measurand The measurand shall be the separating force. This shall be represented as a force/path curve or force/time curve. The maximum sep
20、arating force that is required for complete separation of the sealed seam is derived from the recorded measuring curve. Results shall be given in N/mm sample strip width. 4 Test assembly 4.1 General The test assembly for determining the hot tack strength comprises a heat sealing device, to which the
21、 device for separating the heat sealed seam is directly connected. This device can be mobile so as to facilitate insertion of the sample strips and so that this can be performed outside the sealing jaws in order to prevent preheating. The method for separating the sealed seam differs among the devic
22、es available on the market, but is always carried out in the form of a 90 peel test. 4.2 General test assembly and functional principle 4.2.1 General Before testing, a sample strip comprising either two individual strips with the sealing sides facing each other or one sealing strip folded towards th
23、e sealing side is to be made from the material to be tested and fixed in the device. The fixing is preferably not to be carried out in the area where the sealing jaws can have an influence, in order to avoid preheating of the sample strips. The sealing and measuring processes are started automatical
24、ly and performed corresponding to the device presetting. The peel strength force measurement is output by recording and displaying the force/time curve or the force/path curve and the maximum value for the required separating force. 4.2.2 Method A The sealing strips are placed in the measuring devic
25、e outside the sealing jaws and fastened to the peeling and fixing rollers using clamps (see Figure 1). Sealing and measurement are automated. After the sample strips are fed between the sealing jaws and after sealing, the measuring procedure is started immediately after the sealing jaws have been op
26、ened, by rolling up one of the sample strips. The peel strength force is measured via the force transmitted to the other sample strip. DIN 55571-2:2016-08 7 Key 1 Sealing jaw 2 Clamp 3 Measuring element 4 Winding device Figure 1 Schematic diagram showing a device for separating the sealed seam accor
27、ding to method A 4.2.3 Method B A sample strip is clamped at both ends in the measuring device before the sealing device. A loop is formed from this using a bayonet. This loop is guided between the sealing jaws and fixed on the opposite side (see Figure 2). After withdrawing the bayonet the sealing
28、is carried out, the fixing is released upon opening of the jaws, and the measuring process is conducted by tearing off the sample strip facing downwards followed by measurement of the force transmitted to the upper end via the sealed seam. Key 1 Fixing 2 Measuring element 3 Bayonet 4 Sample 5 Baffle
29、 plate Figure 2 Schematic diagram showing a device for separating the sealed seam according to method B DIN 55571-2:2016-08 8 4.2.4 Method C Two sample strips with the sealing sides facing each other are placed in the guide pulleys in the test device, fixed with the clamp behind the sealing zone and
30、 clamped in the tension station (see Figure 3). The sealing jaws move to the sealing strips for sealing. Upon opening of the sealing jaws, the fixing is released and the tension station draws the sample strips through the guide pulleys. The seam is separated by the forces applied to the sealed seam
31、at both sample strips. The resultant force transmitted to the sample strip facing upwards is measured. Key 1 Fixing 2 Sealing jaw 3 Measuring element 4 Sample Figure 3 Schematic diagram showing a device for separating the sealed seam according to method C 5 Test preparation and test procedure The se
32、aling temperature, force and time, and the retention time, delay time and seam separating speed, as well as their variations shall be specified before the actual measurement. The basis can be derived from the values of a sealing curve comprising cold seam strengths. Sample strips of 15 mm to 60 mm w
33、idth and of a length adapted to the requirements of the individual devices shall be used for all methods. After having placed the sample strips in the test device, the sealing process is started. The device settings and sample preparation shall be selected so that preheating of the sample strips is
34、kept to a minimum to ensure reproducible sealing conditions. The procedure shall be continued as specified in 4.2.2, 4.2.3 or 4.2.4. 6 Evaluation The separating force profile is recorded in the form of a force/time curve or force/path curve. The maximum separating force is indicated as a test result
35、. The separating force (mean value of the individual measurements) is indicated in N/mm sample strip width, whereby the fluctuation range shall be indicated additionally. DIN 55571-2:2016-08 9 For quality control purposes it is recommended that the mean value be taken from at least three single meas
36、urements. For statistical purposes, the number of individual measurements should be increased. 7 Test report The test report shall contain the following information: a) reference to this standard (DIN 55571-2:2016-08); b) designation of the tested product; c) dimensions of the sample strips; d) pret
37、reatment of the sample strips; e) sealing parameters (sealing temperature, sealing duration and sealing pressure); f) type and dimensions of sealing jaws used (material, coating, dimensions, profiling) g) type of test assembly (method A, B or C) and device type; h) retention time; i) seam separating
38、 speed; j) separating angle; k) test results and type of measurand (maximum separating force in N/mm sample strip width): single values; mean value (of at least three tests); variability; l) type of separation: adhesive fracture/cohesive fracture/tear/strain. Breaking point, in the case of multilaye
39、r composites; m) any deviation from the conditions specified in this standard; n) tester and test date. DIN 55571-2:2016-08 10 Bibliography DIN 55529, Packaging Determining the sealed-seam strength of sealings made of flexible packaging material DIN 55571-1, Hot tack Part 1: Position measuring devic
40、es ASTM F 1921-98, Standard Test Methods for Hot Seal Strength (Hot Tack) of Thermoplastic Polymers and Blends Comprising the Sealing Surfaces of Flexible Webs IVLV-Merkblatt No. 101/2010, Hinweise fr die Hot-Tack-Prfung mit unterschiedlichen trennkraft- und trennwegmessenden Prfgerten (Information for Hot Tack Testing with Different Test Devices Measuring Peel Strength and Separating Position)1)1) Obtainable from: IVLV Industrievereinigung fr Lebensmitteltechnologie und Verpackung e. V., http:/www.ivlv.org/ueber-uns/veroeffentlichungen/merkblaetter/
