1、July 2011Translation by DIN-Sprachendienst.English price group 9No 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 83.
2、180!$sAz“1803087www.din.deDDIN EN 1238Adhesives Determination of the softening point of thermoplastic adhesives (ringand ball)English translation of DIN EN 1238:2011-07Klebstoffe Bestimmung des Erweichungspunktes von thermoplastischen Klebstoffen (Ring undKugel)Englische bersetzung von DIN EN 1238:2
3、011-07Adhsifs Dtermination du point de ramollissement des adhsifs thermoplastiques (mthode bille etanneau)Traduction anglaise de DIN EN 1238:2011-07SupersedesDIN EN 1238:1999-06www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1306.1
4、1 DIN EN 1238:2011-07 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 193 “Adhesives” (Secretariat: AENOR, Spain). The responsible German body involved in its preparation was the Normenausschuss Kunststoffe (Plastics Standards Co
5、mmittee), Working Committee NA 054-04-06 AA Klebstoffe Terminologie; physikalisch-chemische Prfungen. Amendments This standard differs from DIN EN 1238:1999-06 as follows: a) the title has been modified; b) the foreword now includes a “Safety Statement” and an “Environmental Statement”; c) Clause 2
6、“Normative references” has been updated: EN ISO 15605, Adhesives Sampling (ISO 15605:2000) has been added; EN 1066, Adhesives Sampling has been deleted; EN 923:2005+A1:2008 is now a dated reference; d) Clause 5 “Safety” has been deleted; e) the figures have been revised; f) the standard has been edi
7、torially revised. Previous editions DIN EN 1238: 1999-06 2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1238 April 2011 ICS 83.180 Supersedes EN 1238:1999English Version Adhesives - Determination of the softening point of thermoplastic adhesives (ring and ball) Adhsifs - Dtermination du poin
8、t de ramollissement des adhsifs thermoplastiques (mthode bille et anneau) Klebstoffe - Bestimmung des Erweichungspunktes von thermoplastischen Klebstoffen (Ring und Kugel) This European Standard was approved by CEN on 10 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regul
9、ations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN membe
10、r. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CE
11、N members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
12、Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nationa
13、l Members. Ref. No. EN 1238:2011: EEN 1238:2011 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and definitions .54 Principle 55 Apparatus .56 Sampling .87 Preparation of sample .88 Procedure .99 Expression of results . 1010 Test report . 10Annex A (normative) T
14、hermometer specification . 11DIN EN 1238:2011-07 EN 1238:2011 (E) 3 Foreword This document (EN 1238:2011) has been prepared by Technical Committee CEN/TC 193 “Adhesives”, the secretariat of which is held by AENOR. This European Standard shall be given the status of a national standard, either by pub
15、lication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELE
16、C shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 1238:1999. The main modifications regarding the previous version are in the Foreword, Normative References and Note in 5.8. This European Standard includes Annex A (normative) “Thermometer spec
17、ification“. SAFETY STATEMENT Persons using this document should be familiar with the normal laboratory practice, if applicable. This document does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety
18、and health practices and to ensure compliance with any regulatory conditions. ENVIRONMENTAL STATEMENT It is understood that some of the material permitted in this standard may have negative environmental impact. As technological advantages lead to acceptable alternatives for these materials, they wi
19、ll be eliminated from this standard to the extent possible. At the end of the test, the user of the standard should take care to carry out an appropriate disposal of the wastes, according to local regulation. According to the CEN/CENELEC Internal Regulations, the national standards organizations of
20、the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Roman
21、ia, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 1238:2011-07 EN 1238:2011 (E) 4 Introduction Thermoplastic adhesives do not change from the solid to the liquid state at a fixed temperature, but their viscosity decreases progressively as the temperature rises. For th
22、is reason, the determination of the softening point shall be carried out by defined methods to obtain comparable results. DIN EN 1238:2011-07 EN 1238:2011 (E) 5 1 Scope This European Standard specifies a method for the determination of the softening point of hot-melt adhesives. 2 Normative reference
23、s The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 923:2005+A1:2008, Adhesives Terms and defini
24、tions EN 1067, Adhesives Examination and preparation of samples for testing EN ISO 15605, Adhesives Sampling (ISO 15605:2000) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 923:2005+A1:2008 and the following apply. 3.1 softening point temperature at
25、which the adhesive under test attains a degree of softness under the specified conditions 4 Principle A steel ball of a specified mass is placed on a sample of adhesive contained on a metal ring of specified dimensions. The apparatus is heated at a constant defined rate. The temperature at which the
26、 sample is sufficiently soft to allow the ball to pass through the ring by a fixed distance is taken as the “softening point“. 5 Apparatus 5.1 Ball, two steel balls, (9,53 0,02) mm in diameter, each having a mass of (3,50 0,05) g. 5.2 Ring, tapered brass ring to the dimensions of Figure 1. NOTE As a
27、lternative the following can be used: a) shouldered brass ring to the dimensions of Figure 2; b) a straight-sided cylindrical ring with the following: 1) interior diameter (15,9 0,1) mm; 2) depth (6,4 0,1) mm. DIN EN 1238:2011-07 EN 1238:2011 (E) 6 Dimensions in millimetres Figure 1 Tapered brass ri
28、ng Dimensions in millimetres Figure 2 Shouldered brass ring To ensure the correct positions of the ring in its support, the exterior diameter shall be reduced at the lower part to (19,0 0,1) mm for a depth of 2 mm. If a shouldered or straight-sided ring is used, this shall be noted in the test repor
29、t. 5.3 Guide, to center the ball, the arrangement in Figure 3 is recommended to be used. DIN EN 1238:2011-07 EN 1238:2011 (E) 7 Dimensions in millimetres Figure 3 Ball centering guide 5.4 Ring supports The support described in Figure 4 shall be used. The distance between the two supports plates is (
30、25 1) mm. The same distance separates the ring holder from the bottom plate. Dimensions in millimetres Key 1 Ring holder 2 Base Figure 4 Ring holder and base DIN EN 1238:2011-07 EN 1238:2011 (E) 8 5.5 Thermometer, conforming to the specification of Annex A. 5.6 Bath, of heat resistant glass, to the
31、dimensions of Figure 5, with the rings supported horizontally as shown. The bottom of the bulb of the thermometer shall be level with the bottom of the rings and within 10 mm of them, but not touching them. 5.7 Stirrer, to ensure uniform heat distribution throughout the bath a mechanical stirrer whi
32、ch operates smoothly shall be used. It shall be so placed that the samples are not disturbed when it is in operation. 5.8 Bath liquid Water may be used to 80 C. Glycerol may be used up to 200 C. Above 200 C a liquid heat-transfer medium shall be chosen which is stable at the temperatures likely to b
33、e used; mineral or silicone oils are suitable. The liquid used shall not affect the specimen at the test temperature. NOTE Automatic apparatus for measuring the softening point of thermoplastics adhesives is commercially available. Differences in the softening point of some hot melt adhesives (e.g.
34、poly(ethylene-vinylacetate) based adhesives) measured by automatic or manual equipment can occur. In such case comparative tests should be carried out to determine whether it is necessary to apply a correction factor. 6 Sampling A significant sample of the adhesive shall be taken in accordance with
35、EN ISO 15605 and prepared for testing as described in EN 1067. 7 Preparation of sample 7.1 Preparation of test specimens in duplicate Heat a portion of the sample in air or a liquid bath, to obtain an approximate value of the softening point. When this is noted continue until the temperature of the
36、sample is between 25 C and 50 C above the softening point noted. Stir the sample during heating until it is completely fluid, homogeneous, and free from air bubbles. If necessary, pour the fluid sample through a 315 m sieve, to remove solid impurities. Heat the ring to the same temperature as the sa
37、mple under test on a metal, porcelain or heat resistant glass plate, coating lightly with oil or silicone grease to prevent adhesive sticking. Fill the ring with an adequate amount of fluid adhesive, so that a slight excess remains after cooling. Cool in air for 30 min removing excess adhesive with
38、a heated knife. 7.2 For heat sensitive adhesives Carry out the above method in an inert atmosphere, or by another method agreed by the parties concerned. NOTE If guides (see Figure 3) are not being used, a mark for the balls should be made in the middle of the prepared specimens, just deep enough to
39、 ensure that they cannot move and are centred in the rings. DIN EN 1238:2011-07 EN 1238:2011 (E) 9 8 Procedure 8.1 Prepare the apparatus as indicated in Figure 5, ensuring the rings are horizontal. Dimensions in millimetres Key 1 Liquid level 4 Shouldering ring, see Figure 2 2 Thermometer 5 Ring hol
40、der, see Figure 4 3 Steel ball 6 Base, see Figure 4 Figure 5 Complete test assembly 8.2 Sample softening points expected to be below 80 C. a) Start from a temperature at least 10 C below the expected softening point, using the liquid maintained at that temperature in a thermostat bath for at least 1
41、5 min. Using forceps, place the balls, previously kept at the same temperature in the same thermostat, into the guides. b) Heat the apparatus and stir the liquid so that the temperature rises at a uniform rate of (5 1) C/min until the balls fall through the rings. Do not average the rate of temperat
42、ure rise over the test period. Reject any determination in which the rate of temperature rise does not fall within the specified limits after the first 3 min. Record for each ring and ball the temperature shown by the thermometer at the instant the sample surrounding the ball touches the bottom plat
43、e. DIN EN 1238:2011-07 EN 1238:2011 (E) 10 8.3 Sample softening points to be above 80 C. Fill the bath with glycerol or oil as indicated in 5.8. Maintain the bath at 35 C for 15 min and using forceps, place the balls, previously brought to 35 C, in each ball guide. Follow the procedure of 8.2, b). 9
44、 Expression of results As softening point report the mean of the temperatures recorded in duplicate determinations, without correction of the emergent stem of the thermometer, rounded to the nearest 0,5 C if the recorded temperature is 100 C or below; 1 C if the recorded temperature is between 100 C
45、 and 260 C, and 2 C if the recorded temperature is above 260 C. 10 Test report The test report shall include: a) reference to this European Standard, i.e EN 1238; b) type and designation of the adhesive tested; c) type of ring used, if the tapered one (see Figure 1) is not used; d) type of ring heat
46、ing fluid used; e) use or not of inert atmosphere; f) test temperature; g) result of the test expressed in accordance with Clause 9; h) any circumstances which may have affected the result; i) date of the test. DIN EN 1238:2011-07 EN 1238:2011 (E) 11 Annex A (normative) Thermometer specification Tab
47、le A.1 Thermometer specification Characteristics Low range Medium range High range Immersion Partial Partial Partial Temperature scale - 1 C to 101 C - 10 C to 260 C - 10 C to 400 C Subdivisions 0,1 C 1 C 2 C Max. error (at all points of the scale) 1 C 1 C to 100 C 1,5 C above 100 C 2,5 C to 300 C 5 C above 300 C Min. scale (mm length) 500 250 250 Diameter (mm) 5,5 to 8 5,5 to 8 5,5 to 8 DIN EN 1238:2011-07
