BS 5350-H2-1982 Methods of test for adhesives - Physical tests on hot-melt adhesives - Determination of low temperature flexibility or cold crack temperature《粘合剂试验方法 第H2部分 热熔粘合剂物理试.pdf

1、BRITISH STANDARD BS 5350-H2: 1982 Methods of test for Adhesives Part H2: Determination of low temperature flexibility or cold crack temperature UDC 665.93:620.173.2:620.176.2BS5350-H2:1982 This British Standard, having been prepared under the directionof the Adhesive Standards Committee, was publish

2、ed under the authority ofthe Board of BSI and comes intoeffect on 31 December 1982 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference ADC/9 Draft for comment 81/51113 DC ISBN 0 580 12631 5 Amendments issued since publication Amd. No. Date of issue Comme

3、ntsBS5350-H2:1982 BSI 07-1999 i Contents Page Foreword ii 1 Scope 1 2 Principle 1 3 Supplementary information 1 4 Apparatus 1 5 Test pieces 1 6 Conditioning and testing atmosphere 1 7 Procedure 1 8 Expression of results 2 9 Test report 2 Figure 1 Bend test apparatus 2 Figure 2 Bend test apparatus in

4、 use 2BS5350-H2:1982 ii BSI 07-1999 Foreword This method describes a procedure for determining the low temperature flexibility or cold crack temperature of an adhesive. The method can be used as a quality control test and also to compare the flexibility of adhesives at low temperatures. The test is

5、particularly applicable to hot-melt adhesives. The method is similar to that described in BS 3900 “Methods of test for paints” Part E1: “Bend test (cylindrical mandrel)”. WARNING NOTE. This British Standard method does not necessarily detail all precautions necessary to meet the requirements of the

6、Health and Safety at Worketc. Act 1974. Attention should be paid to any appropriate safety precautions and the method should be operated only by trained personnel. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible fo

7、r 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, pages1 and 2 and a back cover. This standard has been updated (see copyright date)

8、 and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5350-H2:1982 BSI 07-1999 1 1 Scope This Part describes a procedure for determining whether a film of adhesive of specified dimensions will craze, crack or fracture at a specified temp

9、erature. Alternatively the temperature at which the film will craze, crack or fracture is determined. The test is carried out either as a pass/fail test or at successively lower temperatures until failure occurs. 2 Principle An unsupported film of the adhesive, after conditioning, is bent through 18

10、0 over a cylindrical mandrel. The test piece is then examined for signs of fracture, crazing or cracking. 3 Supplementary information The following information shall be provided before the test is carried out: a) dimensions of the test piece; b) details of the conditioning of the test piece and test

11、ing atmosphere immediately before testing; c) whether a pass/fail test at a specified temperature is to be carried out or the cold crack temperature is to be determined and, if the former, the temperature concerned. 4 Apparatus 4.1 Bend test apparatus. The mandrel shall be made of rigid and suitable

12、 corrosion resistant material, e.g. stainless steel. The diameter of the mandrel shall be 6.0 mm and the gap between the surface of the mandrel and the plates of the hinge shall be0.55 0.05 mm. The other dimensions of the apparatus are not critical. The mandrel shall be free to rotate on its pin and

13、 the apparatus shall be provided with a stop to ensure that when the test piece is bent, the two plates of the hinge are parallel. NOTEA suitable apparatus is shown in Figure 1. 4.2 Controlled temperature chamber, capable of keeping a specified temperature to an accuracy of 2 C throughout the testin

14、g procedure. NOTEA suitable range of temperature for most purposes is 40 to + 20 C. 5 Test pieces 5.1 Dimensions. The thickness of the test piece shall be 0.4 0.1 mm but the other dimensions of the test piece are not critical provided that the test piece is rectangular and fits into the bend test ap

15、paratus. The test piece shall be without flaws when examined by normal corrected vision. 5.2 Preparation of film from hot-melt adhesive. Gently heat a quantity of adhesive until molten and remove any entrained air. Sandwich a small quantity of the molten adhesive between two layers of release paper,

16、 previously dried for 30 min at 70 10 C. Produce a film, e.g. by passing the composite through a pair of rollers, adjusted so as to obtain a uniform adhesive film0.4 0.1 mm thick. Allow the film to cool and then cut the test piece from the film of adhesive with a sharp knife to obtain clean edges. 6

17、 Conditioning and testing atmosphere 6.1 Preliminary conditioning. Condition the test pieces at a temperature of 23 2 C and 50 5 % r.h. for 24 h. NOTEThe flexibility of the adhesive can depend on its moisture content and the moisture sensitivity of the adhesive will depend on the chemical type. Spec

18、ial care on conditioning may, therefore, be necessary in some cases where the moisture content of the test piece alters during the period of preparation and testing. 6.2 Conditioning immediately before testing. Condition the test piece and test apparatus at the specified temperature for a minimum pe

19、riod of 4 h. 7 Procedure 7.1 Pass/fail test. Immediately after the conditioning period at the specified temperature, fully open the apparatus and insert a test piece under the mandrel so that one end is against the stop. Close the apparatus in not less than 1 s and not more than 2 s thus bending the

20、 test piece over the mandrel through 180 (see Figure 1 and Figure 2). NOTECare should be taken not to warm the test piece with the fingers. Tongs conditioned at the test temperature or cotton gloves should be used. Preferably carry out the test in the controlled temperature chamber, but in any case

21、ensure that warm air is excluded from the test piece and mandrel when the tests are being carried out. Carry out a series of five tests using different test pieces, conditioning the mandrel before each test for an appropriate time to restore it to the test temperature. Examine the test pieces visual

22、ly for signs of crazing, cracking or fracture. If any test piece shows signs of fracture, crazing or cracking, repeat the test. 7.2 Determination of cold crack temperature. Carry out the procedure described in 7.1 at a series of test temperatures at 5 C intervals using a fresh set of five test piece

23、s at each temperature. If necessary, carry out exploratory tests to determine the broad range in which the cold crack temperature lies.BS5350-H2:1982 2 BSI 07-1999 If any test piece shows signs of crazing, cracking or fracture, repeat the test. 8 Expression of results 8.1 Pass/fail test. Express the

24、 result as a failure at the specified temperature, if two or more of the test pieces show signs of crazing, cracking or fracture (this includes the results of the repeat test if any test piece in the first set fails). Otherwise, express the result as a pass at the specified temperature. 8.2 Determin

25、ation of cold crack temperature. Express the cold crack temperature as the highest temperature at which more than one test piece shows signs of crazing, cracking or fracture. 9 Test report The report shall state the following: a) a designation of the adhesive, giving all information required for com

26、plete identification of the sample; b) the items of supplementary information given in clause 3; c) the result of the pass/fail test at the specified temperature or the determined cold crack temperature; d) that the method of test complied with this standard, i.e. BS 5350-H2 or, if it did not, the r

27、espects in which it did not comply. Figure 1 Bend test apparatus Figure 2 Bend test apparatus in useblankBS 5350-H2: 1982 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view o

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