BS 4549-1-1997 Guide to quality control requirements for reinforced plastics mouldings - Guide to the preparation of a scheme to control the quality of glass reinforced polyester m.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 4549 : Part 1 : 1997 I

2、CS 83.120 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Quality control requirements for reinforced plastic mouldings Part 1. Guide to the preparation of a scheme to control the quality of glass reinforced polyester mouldingsBS 4549 : Part 1 : 1997 This British Standard, hav

3、ing been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 May 1997 BSI 1997 First published February 1970 Second edition May 1997 The following BSI references relate to the work on this

4、standard: Committee reference PRI/42 Draft for comment 94/342253 DC ISBN 0 580 26819 5 Amendments issued since publication Amd. No. Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PRI/42, Fibre reinforc

5、ed thermosetting plastics and prepregs, upon which the following bodies were represented: BEAMA Ltd. British Plastics Federation Chemical Industries Association Department of the Environment (Building Research Establishment) Department of Trade and Industry (National Physical Laboratory) European Re

6、sin Manufacturers Association Ministry of Defence Motor Industry Research Association RAPRA Technology Ltd. Society of Motor Manufacturers and Traders Ltd.BS 4549 : Part 1 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover Foreword ii Guide 1 Scope 1 2 References 1 3 Materials

7、 1 4 Selection of test specimens and frequency of sampling 1 5 Preliminary examination 2 6 Dimensions 2 7 Glass content 2 8 Cure of resin 3 9 Tensile strength and tensile modulus 3 10 Other requirements 3 Annexes A (normative) Determination of laminate thickness 4 B (informative) Process schedules 5

8、 C (informative) Methods of test for flammability 6 D (informative) Method of test for bolt bearing strength 6 E (informative) GRP laminate production record 7 Tables 1 Thickness tolerances 2 2 Suitable test methods 3 List of references 9ii BSI 1997 BS 4549 : Part 1 : 1997 Foreword This British Stan

9、dard was prepared by Technical Committee PRI/42. It supersedes BS 4549 : Part 1 : 1970 which is withdrawn and takes into account the revision of the standards for glass fibre reinforcement (BS 3396, BS 3691 and BS 3749) and polyester laminating resin (BS 3532) made since BS 4549 : Part 1 was first p

10、ublished. This revision presents the materials properties in a form consistent with current best design practice, as illustrated by BS 4994 : 1987 Specification for design and construction of vessels and tanks in reinforced plastics. The purpose of this standard is two fold: to facilitate the prepar

11、ation of adequate schemes for the quality control of the production of reinforced plastic mouldings, such as might be included in a certified quality scheme, e.g. BS 5750; to define all types of GRP laminates with clearly defined mechanical properties that designers can call up by code number thereb

12、y avoiding any potential problems arising from lack of clarity in the laminate specification. It is recognized that for the satisfactory performance of glass reinforced mouldings it is necessary to give consideration to the selection of the resin system, the reinforcement and the method of manufactu

13、re. Prior to the acceptance of a particular design it may be necessary to undertake a programme of type approval tests relevant to the specific application. This standard is intended as a guide to the test of a routine nature undertaken to ensure the continued supply of satisfactory mouldings, and d

14、oes not extend to type approval tests. It is intended that BS 4549 be composed of several Parts. Part 2 specifies the composition and mechanical properties of a number of standard laminates made from polyester resin, reinforced with either chopped strand mat or randomly deposited glass fibres. Compl

15、iance 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. BSI 1997 1 BS 4549 : Part 1 : 1997 Guide 1 Scope This Part of

16、BS 4549 gives guidance on the preparation of a scheme to control the quality of all types of glass reinforced polyester laminates and mouldings to enable conformity to the laminate specification. 2 References 2.1 Normative references This Part of BS 4549 incorporates, by reference, provisions from s

17、pecific editions of other publications. These normative references are cited at the appropriate points in the text and the publications are listed on page 9. Subsequent amendments to, or revisions of, any of these publications apply to this Part of BS 4549 only when incorporated in it by updating or

18、 revision. 2.2 Informative references This Part of BS 4549 refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on page 10, but reference should be made to the latest editions. 3 Materials 3.1 Gener

19、al For adequate quality control, the particular resin and reinforcement to be used should be specified and of a consistent quality. Glass fibre reinforcements should conform to BS 3496 for chopped strand mat or BS 3691 for chopping roving. Polyester resin, filled or unfilled, should conform to BS 35

20、32. All laminating materials, including catalyst and accelerator, if required, should be obtained from manufacturers registered under a recognized quality certification scheme. 3.2 Laminates The laminate composition and the required mechanical properties should be clearly defined in the laminate spe

21、cification. Laminates should be specified in accordance with BS 4549 : Part 2. 3.3 Moulding procedures The moulding procedures should be clearly defined and include sufficient written records to allow full traceability of the materials used in the laminate, the moulding and workshop conditions and t

22、he laminators involved. Laminator training and certification to a nationally recognized procedure is recommended. The information on the moulding procedure should include the items listed in annex B, but not necessarily limited to this list. Further information may also be given in other reference d

23、ocumentation and on the component drawing. A suggestion for a simple laminate production record sheet suitable for hand laminating is given in annex E. 3.4 Certification of the moulded laminate properties The dimensional and physical properties of the moulded products should be determined by the tes

24、t methods listed in this standard, together with such other tests as may be necessary to ensure conformity to other specified properties to meet specific needs. The sampling plan and testing frequency should be in accordance with a recognized statistical sampling plan standard. NOTE. BS 6000, BS 600

25、1 and BS 6002 provide a comprehensive guide to sampling prodedures for production runs of identical items. For small production batches 100 % inspection may be necessary or some other simple plan may be acceptable. 4 Selection of test specimens and frequency of sampling 4.1 Selection of test specime

26、ns For the determination of dimensions, Barcol hardness and loss on ignition, the test specimen should be taken from the moulding. The number of test specimens and their location in the moulding will depend on the size, shape and complexity of the individual moulding. For some other tests it may be

27、necessary for the test specimens to be taken from a special flat moulding, made from the same materials and under the same fabrication conditions. In this case it is essential that the method of preparation of this test moulding should be specified in detail and should follow as closely as is reason

28、able the method used in the manufacture of the moulding. Test specimens intended for the determination of mechanical properties should be taken from laminates or mouldings that have either been post cured to the specified schedule or which have been kept under defined conditions for a minimum period

29、. BS 4549 : Part 2 defines a set of controlled cure conditions. Other conditions may be defined in individual product specifications where these are more appropriate. NOTE. It is the manufacturers responsibility to ensure that the test moulding is representative of the whole production batch. 4.2 Fr

30、equency or level of sampling The frequency of sampling should be a function of the expected variability of the tested parameter of the moulding, combined with the past history obtained from the statistical sampling described in BS 6001 and BS 6002. Although the production batch of a particular mould

31、ing may not be sufficiently large to generate statistical quality data, the total production of similar items by the same production unit may be used to define the sampling frequency. Each individual test method will define the number of measurements required to provide one reported property determi

32、nation.2 BSI 1997 BS 4549 : Part 1 : 1997 5 Preliminary examination 5.1 Visual examination Each moulding should be examined to ensure that it is substantially free from protruding fibres, voids, pits, bubbles, cracks, blisters, resin rich or resin starved areas, or foreign matter. Adequate levels of

33、 surface appearance are important in many applications. The individual product specification should define specific critical properties where necessary. NOTE 1. It is good practice in any laminate to avoid excessive resin drainage. If evidence exists of excessive drainage the moulding procedures sho

34、uld be changed to correct the fault. NOTE 2. Suitable methods of test may be found in BS 3900 : Group D and in BS 2782 : Part 5. 5.2 Tackiness Each moulding should be examined to ensure it has no surface tackiness. 5.3 Mass The determination that the mass of a moulding is outside some defined limit

35、may be used as a rapid method of identifying those mouldings likely to be out of specification for dimension (particularly thickness). Depending on the nature of the moulding the determination of mass can be by 100 % sampling or by statistical sampling of a batch. If mass is used as a control parame

36、ter the allowable tolerance about a norm should be defined as a function of both the production process and the requirements of the finished moulded product. 6 Dimensions 6.1 Shrinkage and distortion Variations in catalyst, accelerator, workshop ambient conditions and laminate construction locally w

37、ithin a moulding can all affect the shrinkage during cure and any subsequent distortion on de-moulding. Where such overall dimensional variations are likely to be critical, for example when a moulding is part of an assembly, then tolerances should be defined on the overall dimensions and sampling pl

38、ans defined to ensure control. 6.2 Tolerances The tolerances of all essential dimensions should be defined. The admissible tolerances on the overall dimensions of an individual moulding are a function of the shape and moulding, the materials used, the moulding conditions and the ambient conditions.

39、Consequently, fixed parameters (e.g. percentage of the overall dimension) can not be defined in this standard. The thickness of the moulding is a function only of the materials used. Therefore tolerances for thickness can be defined which are applicable to most mouldings. Table 1 lists normal tolera

40、nces for the thickness of a moulding. 6.3 Measurement For overall dimensions depending on the size and shape of the moulding, a calibrated ruler or measurement tape can be used or a dimensionally stable jig. The thickness of laminates and moulding should be determined in accordance with annex A. The

41、 thickness tolerances should be within the ranges defined in table 1. Table 1. Thickness tolerances Nominal thickness Moulding from open mould Moulding from closed mould Matched metal mouldings mm mm mm mm x 1,5 +0.50,20.5 0.0 0.8 1,5# x 3 0.5 0.0 0.0 3# x 6 1.1 0.0 0.0 6# x1 2 1.5 0.5 0.0 12# x 2 5

42、 2.0 1.4 0.0 25# x 3.0 1.9 0.5 7 Glass content 7.1 Specification The nominal glass content and limits of its variation within a moulding should be defined. In general for a nominal glass content of n % the permissible range should not be greater than (n2 2.5) % to (n + 7.5) %. 7.2 Test procedures Fo

43、r unfilled compounds, a loss on ignition test may be used to determine the glass content, but with mouldings containing inert fillers it may be necessary to agree on a more elaborate test procedure. NOTE 1. If a loss on ignition test is used on mouldings containing inert fillers it should be noted t

44、hat the residue will not necessarily represent the combined glass and filler content since some fillers (e.g. aluminium tri-hydrate) are unstable at the ignition temperature. NOTE 2. BS 2782 : Method 1002 defines a method of test for laminates without inert filler. ISO 1172 defines methods for lamin

45、ates with and without fillers, except for those cases where thermally unstable fillers are used. BSI 1997 3 BS 4549 : Part 1 : 1997 8 Cure of resin To ensure that the resin system is adequately cured, a minimum value for the Barcol hardness (see BS 2782 : Method 1001) of the moulding should be defin

46、ed. The value specified should be calculated as 90 % of the minimum hardness specified for the cured system by the resin supplier. The positions on the moulding where measurements are to be made should be defined in the individual product specification. In some cases it may be desirable to measure t

47、he hardness of the gel-coat as well as the laminate. NOTE 1. The hardness value is temperature dependent, and it may be necessary either to quote a test temperature with a tolerance of 2 C or minimum values for a range of temperatures. NOTE 2. The hardness value can increase sharply if the indentor

48、strikes a glass fibre strand. The test area selected should have no obvious glass fibre strands close to the surface. 9 Tensile trength and tensile modulus 9.1 Specification The minimum tensile strength and tensile modulus of the moulding should be specified. For laminates and mouldings made from ch

49、opped strand mat (CSM) by the hand lay-up process, or randomly deposited glass fibres by the spray-up process, it is recommended that one of the standard laminates defined in BS 4549 : Part 2 be specified if possible. If the design constraints require a specification different from one of the standard laminates then care should be exercised in defining the properties and the tolerances to ensure that they are achievable in regular production. 9.2 Test procedure The test for the determination of tensile strength and modulus should be made in