1、BRITISH STANDARD BS 5350-C5:2002 Methods of test for adhesives Determination of bond strength in longitudinal shear for rigid adherends ICS 83.180 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS 5350-C5:2002 This British Standard, having been prepared under the direction of
2、the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 31 January 2002 31 January 2002 The following BSI references relate to work on this British Standard: Committee reference PRI/52 Draft for comment 99/
3、124218 ISBN 0 580 38974 X Committees responsible for this British Standard The preparation of this British Standard was entrusted to PRI/52, Adhesives, upon which the following bodies were represented: BASA British Woodworking Federation Consumer Policy Committee of BSI Contract Flooring Association
4、 DETR represented by BRE European Resin Manufacturers Association National Physical Laboratory SATRA The Tile Association TRADA TWI UK Steel Association University of Bristol Amendments issued since publication Amd. No. Date CommentsBS 5350-C5:2002 BSI 31 January 2002 i Contents Page Committees resp
5、onsible Inside front cover Foreword ii 1S c o p e 1 2 Normative references 1 3 Principle 1 4A p p a r a t u s 2 5 Procedure 2 6 Test report 5 7 Expression of results 5 Annex A (informative) Method for determination of moisture content of wooden slips 11 Bibliography 12 Figure 1 Single overlap joint
6、5 Figure 2 Double overlap joint 6 Figure 3 Test adhered with locating hole 6 Figure 4 Preparation of specimen from large sheet adherends 7 Figure 5a) Test jig with locating hole 8 Figure 5b) Jig with lap shears assembled 9 Figure 6 Clamping device for holding five close-contact joints 10BS 5350-C5:2
7、002 ii BSI 31 January 2002 Foreword This part of BS 5350 has been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee. It supersedes BS 5350-C5:1990 which is withdrawn. The standard provides a method of assessing the strength of adhesives by determining t
8、he shear strength of overlap joints between rectangular adherends. This method is widely practised because the adherends are of simple form and the results are reasonably reproducible. However, since the stress applied to the adhesive is not a simple shear but contains other components, the breaking
9、 load is not a simple function of the width or the length of the overlap but is also influenced by the elastic properties and dimensions of the adherends, the bond-line thickness and the rate of change of stress. Hence it is necessary to standardize the procedure in order to obtain reproducibility.
10、The test does not necessarily reflect how the adhesive would perform in service. Such design data would normally be obtained using the construction materials and configuration used in the actual design. In this revision, the scope has been amended to exclude testing of wood-to-wood bonds for which o
11、ther standards exist, and several changes have been made to the procedure to align it with procedures in other recent parts of BS 5350. At the same time, the references to other British Standards have been brought up-to-date. Annex A is informative. A British Standard does not purport to include all
12、 necessary provision 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. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, p
13、ages 1 to 12, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 5350-C5:2002 BSI 31 January 2002 1 1 Scope This part of BS 5350 describes the method for testing adhesives using rigid adherends that can be produce
14、d to the required dimensional tolerances and that will withstand the forces applied to them. It is not normally applicable to the testing of joints between identical pieces of wood for which there are other, specific, standards, but may be used where wood is one adherend of an asymmetric assembly or
15、 where particular adhesives are not catered for by the specific standards. The method described in this part of BS 5350 is applicable to all types of adhesive. Although primarily intended for use in normal ambient conditions, the basic method is also applicable to testing under a wide range of tempe
16、rature and other environmental conditions. No account is taken of other mechanical properties of the adhesives or adherends that can affect the validity or usefulness of the test. The use of a particular adherend to test an adhesive does not necessarily imply that adhesive is the one most suitable f
17、or the adherend. This method of test is intended for ranking and quality control of adhesives and not for obtaining data for design purposes. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of this
18、British Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For undated references, the latest edition of the publication referred to applies. BS 3757, Specification for rigid PVC sheet. BS 5214-1, Specification for testing machines for
19、rubbers and plastics Part 1: Tensile, flexural and compression types (constant rate of traverse). BS 5214-2, Specification for testing machines for rubbers and plastics Part 2: Constant rate of force application machines. BS 5350-A1, Methods of test for adhesives Adherends Part A1: Adherend preparat
20、ion. BS 5350-A2, Methods of test for adhesives Adherends Part A2: Guide to the selection of adherent materials. BS 5350-E1, Methods of test for adhesives Sampling and analysis of test data Part E1: Guide to statistical analysis. BS EN 438-1, Decorative high-pressure laminates (HPL) sheets based on t
21、hermosetting resins Specifications. BS EN 10365:1995, Adhesives Designation of main failure patterns. BS L 165, Specification for sheet and strip of aluminium-coated aluminium-copper-magnesium-silicon-manganese alloy (solution treated and artificially aged) (Cu 4.4, Mg 0.5, Si 0.8, Mn 0.8). 3 Princi
22、ple A single or double overlap joint (see Figure 1 and Figure 2) between rectangular adherends is strained to rupture by a longitudinal tensile force, i.e. a force that is parallel to the major dimensions of the adherends and in the same plane as the bond-plane (bond-line). The reported result is th
23、e observed force at rupture.BS 5350-C5:2002 2 BSI 31 January 2002 4 Apparatus 4.1 Testing machine The testing machine shall comply with the requirements for machines of grade B of either BS 5214-1 or BS 5214-2 as appropriate. In addition, the response time of the machine shall be short enough not to
24、 affect the accuracy with which the breaking load can be measured. The range of the machine shall be such that the specimens break at loads between 15 % and 85 % of the full-scale reading. 4.2 Grips The grips shall be free to swivel about axes in the mean plane of the bond plane. They shall grip the
25、 adherends sufficiently firmly to avoid slipping but not so firmly as to cause excessive crushing. Grips that operate by bolting through the adherend are acceptable unless ductile materials are involved, where distortion during test may give rise to misleading results. 5 Procedure 5.1 Adherends 5.1.
26、1 Selection The two adherends in a single overlap joint shall be identical unless the test is being carried out to verify compliance with a specification that requires the adherends to be of different materials. In a double overlap joint involving two adherend materials, the two outer adherends shal
27、l be of identical material and dimensions. The adherend or adherends shall be fully described in the test report. If practicable, select the materials for the adherends from the list given in BS 5350-A2. The most commonly used materials are as follows. a) Wood 1) Beechwood (European beech). One face
28、 of the wood shall be planed and the other planed or smoothly sawn. The wood shall be flat and free from splits, knots, whorls and dotes. The angle of inclination of the grain across the face of each test specimen shall not be greater than 1 in 9, and the grain shall not be obviously inclined to the
29、 face. NOTE 1 The angle of the growth rings relative to the face is not critical. 2) Plywood. Birch plywood, 3 ply, all layers birch, weather-proof and boil-proof (WBP) grade. The test piece shall be cut with the grain (outer layers) in the long direction, shall be flat and shall have no defects. NO
30、TE 2 Defects in plywood are defined in BS 1203. NOTE 3 Specific test methods for wood adhesives are detailed in BS 1204 (relating to structural adhesives) and BS 3544 and BS 4071 (relating to non-structural adhesives). b) Metals 1) Mild steel (cold rolled) type CR 1E shall be as defined in BS 1449-1
31、. 2) Aluminium-coated aluminium alloy shall be as specified in BS L 165. 3) Any substrate as agreed by both parties. c) Plastics 1) Phenolic laminated sheet of a type shall be specified in BS EN 438-1:1991. 2) Rigid pressed PVC sheeting of type Ai shall be as specified in BS 3757. BS 5350-C5:2002 BS
32、I 31 January 2002 3 5.1.2 Dimensions The adherends shall be rectangular and of the following dimensions (see also Figure 3): The thickness of the adherends shall be such that they are able to withstand the forces that are required for the test, and shall be stated in the test report. NOTE The choice
33、 of thickness of the adherends depends on the adherend materials, the adhesive and on the particular application and should be agreed between the purchaser and the supplier of the adhesive. For general use the following thicknesses are recommended: If the central adherend in a double overlap joint i
34、s of the same material as the two outer adherends, it shall have a thickness of twice that of one of the outer adherends. 5.1.3 Preparation Before bonding, prepare the surfaces of the adherends in accordance with the recommendations in the instructions supplied by the manufacturer of the adhesive. I
35、n the absence of such recommendations, select the appropriate procedure from those given in BS 5350-A1. NOTE 1 It is recognized that in some circumstances it might be necessary to test contaminated surfaces. Prepare the specimens individually, or cut them from a large sheet (see 5.3 and Figure 4). N
36、OTE 2 It is recommended that adherends cut from large sheets should, because of the flatness requirement (see 5.1.2), be sawn rather than sheared. 5.2 Bonding Apply the adhesive and make the bond by the methods recommended by the manufacturer of the adhesive. In the absence of such recommendations,
37、the procedure shall be such as to minimize variations (e.g. thickness of adhesive, open and closed assembly lime, pressing time). The adhesive layer shall cover completely the areas to be bonded and shall be of a uniform thickness. Methods of achieving a uniform thickness in the finished joints incl
38、ude the application of a predetermined quantity of adhesive (mass or volume), or by use of an applicator. The use of thin wire shims, which remain outside the joint that is to be tested (i.e. in the waste material that is discarded after the specimens are cut out) should be considered when operating
39、 as indicated in 5.3. NOTE 1 It is recommended that an overlap of (12.5 0.5) mm be used unless there are overriding practical or technical considerations for using a different size. NOTE 2 With very strong adhesives, the adherends can yield or even break before the bond ruptures. In this case the ov
40、erlap may be reduced or the adherend thickness increased; the latter is preferable. NOTE 3 Since different adhesives and different applications might require different thicknesses of adhesive, the thickness of the adhesive layer should be agreed between the purchaser and supplier of the adhesive. Ap
41、ply sufficient adhesive to avoid starvation (incomplete coverage of the bonded area) and to provide a slight surplus including fillets at the overlap. Plastics film may be used to protect jigs and specimens from contamination by excess adhesive. Excess spew shall be removed. NOTE 4 It is preferable
42、to remove the surplus adhesive from the edges before it is set and whilst the specimen is still in the clamp but, if this is not possible, it is permissible to remove the surplus after the adhesive has set. Excess spew should be removed with great care to avoid damaging the integrity of specimens, f
43、or example by using a wooden dowel of appropriate dimensions. Assemble the test pieces either in a press or in a jig see Figure 5a) and Figure 5b) or by clamping. The screw clamping jig (see Figure 6) shall only be used for joints involving wood as one or both adherends. NOTE 5 If clamps are used, a
44、 jig to ensure correct overlap and accurate alignment of the adherends is recommended. If the jig is similar to the one shown in Figure 5a) and Figure 5b), a hole should be drilled in each adherend as shown in Figure 3. The tolerances on the figure show the need to maintain accuracy in drilling the
45、holes to prevent misalignment during loading. Length: (100 1.5) mm; Width: (25 0.25) mm; Flatness: Within 0.5 mm over the length and width of the area of the specimen to be bonded and within 1.0 mm over the length of the specimen. Metals: (1.5 0.15) mm; Non-metals (other than wood): (3 0.15) mm; Woo
46、d: (5 0.15) mm.BS 5350-C5:2002 4 BSI 31 January 2002 General purpose jigs that allow the application of a pressure of 35 kPa are shown in Figure 5a), Figure 5b) and Figure 6. The jig shown in Figure 6 is used by screwing down until finger tight. This will give a force of approximately 0.2 kN, which
47、on a 25 mm wide test piece with a 12.5 mm overlap will give a suitable pressure. NOTE 6 A rubber pad with a shore A hardness of 60 Shore as determined by the method in BS 903-A26 has been found suitable for this type of clamp. Allow the assembly to set in the jig and then to condition without applie
48、d pressure for the times recommended by the manufacturer of the adhesive. NOTE 7 Contact time is not critical for contact adhesives since the bond is formed as soon as the surfaces touch. For test purpose, an assembly time of 30 s under pressure is sufficient. 5.3 Preparation of specimens from large
49、 sheets of adherend materials NOTE Under some circumstances, for example when assessing the affect of storage time or other parameters on bond strength, a relatively large number of nominally identical test specimens might be required. It might then be more economical and effective to prepare the specimens by cutting them from larger sheets previously bonded together. Use material complying with 5.1.1, with a thickness and flatness complying with 5.1.2 and having a width of (100 1.5) mm and a length an integral multiple of 25
