1、BRITISH STANDARD BS 5350-B9: 1984 Methods of test for Adhesives Part B9: Determination of resistance to sagging (flow after application) UDC 665.93:620.16:532.132.08BS5350-B9:1984 This British Standard, having been prepared under the directionof the Adhesives Standards Committee, was published under
2、 the authority ofthe Board of BSI and comes into effect on 29 February 1984 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference ADC/9 Draft for comment 82/51943 DC ISBN 0 580 13599 3 Foreword This Part of this British Standard has been prepared under the
3、 direction of the Adhesives Standards Committee. It is one of a series of methods for the assessment of physical properties of adhesives published as separate Parts of group B of this standard. WARNING NOTE. This British Standard calls for the use of substances and/or procedures that may be injuriou
4、s to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from the legal obligations relating to health and safety at any stage. A British Standard does not purport to include all the necessary provisions of a contract. Users of British
5、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, pages 1 to 10, an inside back cover and a back cover.
6、This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS5350-B9:1984 BSI 08-1999 i Contents Page Foreword Inside front c
7、over Section 1. General 0 Introduction 1 1 Scope 1 2 Definition 1 Section 2. Methods for the assessment of sagging on a vertical surface 3 Method A. Use of an applicator to apply a wet film 1 4 Method B. Use of plug former 2 Section 3. Methods for assessment of sagging from a restricted gap 5 Method
8、 C. Flow from a lap joint 3 6 Method D. Flow of adhesive through a hole 3 Figure 1 Applicator used for applying strips of adhesive 5 Figure 2 Diagram showing flow of adhesive strips 6 Figure 3 Illustration of flow test apparatus 7 Figure 4 Flow test 8 Figure 5 Test piece for method C 9 Publication r
9、eferred to Inside back coverii blankBS5350-B9:1984 BSI 08-1999 1 Section 1. General 0 Introduction When an adhesive joint is prepared it is important that the applied adhesive does not flow away from the area of the joint. Flow can occur before the joint has been assembled,e.g. before solvent or wat
10、er has evaporated, or after the joint has been closed but before the adhesive has set,e.g. during the curing, solidification or drying processes. The flow of an applied adhesive will be influenced by the stress applied and the duration and temperature of the bonding process. The extent of flow of an
11、 adhesive will also be influenced by the surface energies involved and the degree of roughness of the adherends. The occurence of flow under gravity is called sagging (see clause2). This Part of BS 5350 describes two types of test for the assessment of sagging. In the first type of test, which simul
12、ates the conditions before joint assembly (methods A and B), the extent of flow of an adhesive down a vertical surface is measured. In the second type of test, which simulates conditions after assembly (methods C and D), the flow of adhesive from a hole or slot is observed. The method appropriate to
13、 the type of adhesive and its consistency should be selected. 1 Scope This Part of this British Standard describes four methods for the assessment of flow-after-application characteristics of adhesives by the measurement of sag. Two methods are given for the assessment of sag on a vertical surface a
14、nd two methods are given for the assessment of flow from a restricted gap. The methods may be used both for specifying an adhesive or for quality control purposes. NOTEThe title of the publication referred to in this standard is given on the inside back cover. 2 Definition For the purposes of this P
15、art of this British Standard the following definition applies. sagging a downward movement of an adhesive film between the time of application and setting resulting in an uneven coating having a thick lower edge NOTEThe resulting sag is usually restricted to a local area of a vertical surface. Secti
16、on 2. Methods for the assessment of sagging on a vertical surface 3 Method A. Use of an applicator to apply a wet film 3.1 Principle. A wet film of the adhesive of defined thickness and shape is applied to a flat horizontal surface of a substrate using an applicator. After application the test panel
17、 is placed vertically in the test atmosphere for a specified time. The extent of sag of the applied adhesive is measured (using the top edge of the test panel as a reference). 3.2 Supplementary information. This method of test requires the following supplementary information which shall be specified
18、 when the method is called up. a) A description of the test substrate. b) The procedure for preparation of the test surface. c) Details of the conditioning atmosphere. d) Details of the test atmosphere. e) The method of application of the adhesive and applicator gap size. NOTEThe wet film thickness
19、given by an applicator is generally less than the depth of the gap. f) The duration of test. 3.3 Apparatus 3.3.1 Test panel(s), of glass or other specified material. Dimensions of 300mm 200mm are convenient. Sufficient panels to allow for three strips of adhesive of similar thickness are required. 3
20、.3.2 Applicator(s), of different gap sizes (or stencils and suitable applicators, if the nature of the adhesive requires this apparatus). 3.3.3 Enclosure(s), to provide the specified conditioning and/or test atmospheres. 3.4 Conditioning and pretreatment. Cut test panels as required. Thoroughly clea
21、n each panel (see BS 5350-A1) and carry out any specified pretreatment. Condition the adhesive and the prepared test panels (if required) in the specified conditioning atmosphere. NOTEIf not otherwise specified the recommended conditions are 23 2 C and 50 5 % r.h. 3.5 Procedure. Place a prepared tes
22、t panel in a horizontal position and apply strips of the adhesive parallel to the longer edge (see Figure 1). Mark one of the longer edges as the reference edge and as expeditiously as possible measure the distance in millimetres of the further edge of each strip from it.BS5350-B9:1984 2 BSI 08-1999
23、 Taking care to avoid vibration, mount the test panel within 2 of the vertical so that the strips are horizontal and the reference edge is at the top (seeFigure 2). Place the panel in the test atmosphere for the specified time and then determine the sag of the adhesive by measuring the maximum dista
24、nce of flow of each strip from the reference edge. NOTEThe test panel may be reused only if the surface condition in the actual bonding process can be reproduced in the test. Repeat the test for at least three strips at each applicator gap size. 3.6 Expression of results. For each strip calculate th
25、e sag as the difference in millimetres between the distance of the further edge of the strip from the reference edge before and after the test. Express the result as the mean sag in millimetres of the repeated tests at each specified applicator gap size. 3.7 Test report. The report shall state the f
26、ollowing: a) the designation of the adhesive giving all information required for complete identification of the sample; b) the items of supplementary information given in3.2; c) the result for each applicator gap depth; d) that the method of test complied with the requirements of this standard,i.e.
27、method A of BS 5350-B9, or if it did not, the respects in which it did not comply. 4 Method B. Use of a plug former 4.1 Principle. The adhesive is used to fill a cavity of known dimensions. The adhesive plug is then extruded and the apparatus is placed vertically in the test atmosphere for the speci
28、fied time and the degree of sag measured. 4.2 Supplementary information. This method of test requires the following supplementary information which shall be specified when the method is called up. a) Details of the test atmosphere. b) Details of the conditioning atmosphere. c) Duration of the test.
29、4.3 Apparatus and materials 4.3.1 Flow test apparatus. Block of metal,i.e. brass, light alloy or steel with a bright finish, overall dimensions not less than100mm 50mm. The upper part of the block is drilled to provide a cylindrical cavity of diameter38 0.05mm. The adhesive plug is extruded from the
30、 cavity by a solid plunger closely fitting the cavity and provided with means of positioning the face of the plunger flush with the face of the block and at a depth of9.5 0.05mm. A graduated scale shall be marked/engraved on the lower face of the block. The first line shall be tangential to the lowe
31、st point of the circumference of the cavity and subsequent lines shall be spaced at 1 0.1mm or 2 0.1mm intervals over a distance of 50mm. A suitable design is shown in Figure 3 with end plates fitted to support the block during filling. 4.3.2 Plastics scraper 4.3.3 Enclosure(s), to provide the speci
32、fied test and conditioning atmosphere(s). 4.3.4 Solvent(s) suitable for cleaning the apparatus before and after use and for removal of excess adhesive. 4.4 Conditioning and pretreatment. Thoroughly clean the test apparatus with the solvent. Then condition it and the test adhesive for at least 5 h in
33、 the conditioning atmosphere. NOTEIf not otherwise specified the recommended conditions are 23 2 C and 50 5 % r.h. 4.5 Procedure. Place the test apparatus on a level surface with the drilled face uppermost and depress the plunger until its face is 9.5mm below the face of the block. Thoroughly mix or
34、 stir the adhesive, as appropriate, and fill the cavity, ensuring that no air pockets are formed. Level the adhesive flush with the face of the block with the scraper (4.3.2), drawing it across the filled cavity so that the excess adhesive is carried away from the graduated scale,i.e. the part of th
35、e face down which flow will subsequently occur. Advance the plunger to the limit of its travel so that its face is level with the surface of the block thus leaving a test portion of adhesive in the form of a cylindrical plug, 38mm in diameter on the face of the block. Taking care to avoid vibration
36、immediately mount the apparatus vertically with the adhesive plug at the top see Figure 4(a) and leave in the test atmosphere for the specified time. At the end of the test period, read to the nearest millimetre the lowest point of the flowed adhesive see Figure 4(b).BS5350-B9:1984 BSI 08-1999 3 Imm
37、ediately clean the apparatus and repeat the test with a further test portion of adhesive. Carry out at least three tests. 4.6 Expression of results. Express the sag as the mean of the distance in millimetres travelled by the adhesive for the repeated test results. 4.7 Test report. The report shall s
38、tate the following: a) a designation of the adhesive giving all information necessary for complete identification of the sample; b) the items of supplementary information given in4.2; c) the result of each individual test and the mean; d) that the method of test complied with the requirements of thi
39、s standard,i.e. method B of BS 5350-9, or if it did not, the respects in which it did not comply. Section 3. Methods for assessment of sagging from a restricted gap 5 Method C. Flow from a lap joint 5.1 Principle. The liquid adhesive fills an open slot between two panels of the test substrate. The t
40、est assembly is placed vertically in the test atmosphere for the specified time. Any flow from the slot is noted. 5.2 Supplementary information. This method of test requires the following supplementary information which shall be specified when this method is called up. a) Description of the test sub
41、strate and its surface condition. b) Thickness of adhesive layer to be tested. c) Details of the test atmosphere. d) Details of the conditioning atmosphere. e) Duration of the test. 5.3 Apparatus and materials 5.3.1 Panels of the specified substrate and specified surface condition 50mm 100mm and 50m
42、m 25mm. 5.3.2 Spacers, 5mm 25mm of different thicknesses,e.g. 0.5, 1, 1.5, 2mm, etc. to provide the specified thickness of adhesive layer in the test assembly. 5.3.3 Securing device, to hold the test assembly together. 5.3.4 Enclosure(s), to provide the specified conditioning and/or test atmosphere(
43、s). 5.3.5 Plastics scraper 5.4 Conditioning. Condition the adhesive and the test panels in the specified conditioning atmosphere. NOTEIf not otherwise specified the recommended conditions are 23 2 C and 50 5 % r.h. 5.5 Procedure. Take one large panel (5.3.1) and one small panel and a pair of spacers
44、 (5.3.2) of specified thickness and form a lap joint assembly as shown in Figure 5. Fill the slot between the two panels with adhesive holding the assembly together with the securing device if necessary. Lay the assembly on a horizontal surface with the smaller panel uppermost and level off the adhe
45、sive in the slot flush with the edges of the smaller panel using the scraper (5.3.5). Taking care to avoid vibration, immediately mount the assembly with the slot uppermost within 2 of the vertical and maintain it in this position in the test atmosphere for the specified time. At the end of the test
46、 period, examine the lower edge of the slot and note whether the adhesive has sagged below the plane of the lower slot edge. 5.6 Expression of results. Express the result as sagging or no sagging of the adhesive in the specified time in the specified test atmosphere. 5.7 Test report. The report shal
47、l state the following: a) a designation of the adhesive giving all information required for complete identification of the sample; b) the items of supplementary information given in5.2; c) the result of the test; d) that the method of test complied with the requirements of this standard,i.e. method
48、C of BS 5350-B9, or if it did not the respects in which it did not comply. 6 Method D. Flow of adhesive through a hole 6.1 Principle. The liquid adhesive is placed to a specified depth in a shallow tray provided with holes of specified diameters. The tray is mounted in the test atmosphere for a spec
49、ified time and the holes from which dripping of the adhesive occurs are noted. 6.2 Supplementary information. This method of test requires the following supplementary information which shall be specified when this method is called up. a) The diameters of the holes to be used. b) Details of the test atmosphere and conditioning period.BS5350-B9:1984 4 BSI 08-1999 c) Duration of the test. 6.3 Apparatus 6.3.1 Tray(s), of aluminium,e.g. dish or cap of stamped foil having a depth of at least 5mm, provided with circular holes of different specifi
