1、BRITISH STANDARD BS 1088-1:2003 Marine plywood Part 1: Requirements ICS 79.060.10 BS 1088-1:2003 This British Standard was published under the authority of Standards Policy and Strategy Committee on 9 July 2003 BSI 9 July 2003 First published as BS 1088 Part 2: Determination of bonding quality using
2、 the knife test. Guidance on preservative treatment of plywood, which was previously included in BS 4079, is now dealt with by reference to DD ENV 1099. Unlike performance-based plywood standards, BS 1088 is unique in giving specific requirements for wood species, construction, lay-up and adhesives.
3、 These features have been maintained and where appropriate cross-referenced to current British and European Standards. Although the term “marine plywood” is widely used in commerce, there has not previously been a formal definition in British, European or International Standards. A definition is inc
4、luded in Clause 3 of this standard. Standard marine plywood as defined in and meeting the requirements of BS 1088 has outstanding resistance to both biodeterioration and loss of bond strength with time. Lightweight marine plywood as defined in and meeting the requirements of BS 1088 has outstanding
5、resistance to loss of bond strength with time. BS 1088 was originally developed to specify plywood meeting the exacting requirements of use in marine craft, but marine plywood is also suitable for use in extreme climates and in such applications as vehicle bodies and general building work where the
6、cost of replacement in the event of failure might be high. The scope of this edition reflects this wider range of use. The biological durability of marine plywood is expected to be greater than that of plywood of the same species that meets only the minimum requirements of BS EN 636-3. BS 1088:1966
7、and BS 4079:1966 were confirmed without amendment in 1992. The original text is no longer useable for a number of reasons: conformity to many requirements cannot be verified by tests on the finished product subsequent to manufacture, several references are now obsolete, there are no adequate verific
8、ation and labelling clauses and the language does not give the degree of precision and lack of ambiguity required by BS 0. The main technical changes in this edition are in the specification of the adhesive type to overcome the original unverifiable requirements for BS 1203 type WBP, and the use of
9、shear testing in place of the knife test for determining bonding quality. The knife test, described in Part 2 of this standard, may still be used for quality control in the mill. The mycological test has been deleted. The original edition gave no requirements for a statistical control of production
10、for the purpose of verifying conformity. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Assessed capability. Users of this British Standard are advised to consider the desirability of quality system assessme
11、nt and registration against the appropriate standard in the BS EN ISO 9000 series by an accredited third-party certification body. 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 cov
12、er, pages i and ii, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 1088-1:2003 BSI 9 July 2003 1 1 Scope This part of BS 1088 specifies requirements for marine plywood for use in the manufacture
13、 of marine craft and in other marine and waterway applications. It also applies to marine plywood that has been selected for use in building construction, in extreme climates and in such applications as vehicle bodies and general building work where a high standard of durability is required or where
14、 the cost of replacement in the event of failure might be high. This standard does not include strength data, which can be used to derive characteristic values or grade stresses for use in engineering design. NOTE 1 Where marine plywood is to be used in construction, attention is drawn to the requir
15、ements of the Construction Products Directive. Compliance with these requirements can be verified through demonstrating compliance with BS EN 13986. NOTE 2 Where marine plywood is to be used for load-bearing applications in building construction, it is necessary to substantiate the design or design
16、calculations. BS 5268-2 and DD ENV 1995-1-1 (Eurocode 5) provide suitable methods for achieving this. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the la
17、test edition of the referenced document (including any amendments) applies. BS 1203, Hot-setting phenolic and aminoplastic wood adhesives Classification and test method. BS EN 314-1, Plywood Bonding quality Part 1: Test methods. BS EN 314-2, Plywood Bonding quality Part 2: Requirements. BS EN 322, W
18、ood-based panels Determination of moisture content. BS EN 324-1, Wood-based panels Determination of dimensions of boards Part 1: Determination of thickness, width and length. BS EN 324-2, Wood-based panels Determination of dimensions of boards Part 2: Determination of squareness and edge straightnes
19、s. BS EN 326-1, Wood-based panels Sampling, cutting and inspection Part 1: Sampling and cutting of test pieces and expression of test results. BS EN 335-3, Durability of wood and wood-based products Definition of hazard classes of biological attack Part 3: Application to wood-based panels. BS EN 350
20、-2, Durability of wood and wood-based products Natural durability of solid wood Part 2: Guide to natural durability and treatability of selected wood species of importance in Europe. 3 Terms and definitions For the purposes of this British Standard, the following terms and definitions apply. 3.1 ami
21、no resin thermosetting synthetic resin derived from a condensation reaction of the NH groups of amines or amides with aldehydes NOTE “Ureaformaldehyde (UF)” and “melamineformaldehyde (MF)” resins are mainly of significance in the adhesives field. Adapted from BS EN 923:1998, definition 2.3.51 3.2 la
22、yer either one ply or two or more plies glued together with their grain direction parallel, or another material BS EN 313-2:2000, definition 2.11BS 1088-1:2003 2 BSI 9 July 2003 3.3 marine plywood 3.3.1 standard marine plywood veneer plywood possessing outstanding durability with respect to fungal d
23、ecay and bonding quality making it suitable for the construction of marine craft and certain applications in building construction 3.3.2 lightweight marine plywood veneer plywood made from timber species of lower density than those used in standard marine plywood (see 3.3.1) NOTE 1 Other than the re
24、quirement for density (see 4.3.2), all other requirements are the same as for standard marine plywood. Lightweight plywood is normally only specified where low weight is of critical importance to the design. An example of a lower density timber species is gaboon. NOTE 2 Lower density timber species
25、generally have lower durability than the species used in standard marine plywood. 3.4 phenolic resin thermosetting synthetic resin derived from a condensation reaction of a phenol with an aldehyde NOTE The main phenols used are: phenol, cresol, xylenol, butyl- and octyl-phenol, resorcinol and cashew
26、 nut shell liquid (from Anacardium occidentale), which consists mainly of substituted phenols. Mixtures of these phenols are used as well as mixtures of aldehydes like formaldehyde or furfuraldehyde for the manufacture of these resins; “lignin” a major constituent of wood obtained as a by-product of
27、 chemical pulping, has a phenol-like chemical composition and is usually used in combination with phenolformaldehyde (PF) resins as a phenol substitute; “condensed tannins” obtained from the bark of several species of trees have a phenol-like composition and are generally used in combination with PF
28、 resins. Adapted from BS EN 923:1998, definition 2.3.52 3.5 ply either one single veneer or two or more veneers joined edge to edge or end to end BS EN 313-2:2000, definition 2.17 3.6 tight side side of the veneer opposite the loose side BS 6100-4.3:1984, definition 430.2111 NOTE 1 In accordance wit
29、h BS 6100-4.3:1984, definition 430.2110, the loose side is the “side of a peeled or sliced veneer that is in contact with the knife as the veneer is being cut and which undergoes an elongation often producing lathe checks”. NOTE 2 This is sometimes referred to as slack side. 3.7 veneer thin sheet of
30、 wood not more than 7 mm in thickness BS EN 313-2:2000, definition 2.14BS 1088-1:2003 BSI 9 July 2003 3 4 Requirements for manufacture 4.1 Materials 4.1.1 Veneers Veneers shall be either sliced or rotary cut. Veneers prepared by either method shall have smooth surfaces. The outer plies of a panel sh
31、all be prepared by the same method, i.e. sliced or rotary cut, except for decorative face veneers (see 4.2.3). The permissible number of natural defects and edge joints shall not exceed the limits given in Table 1. Table 1 Permissible frequencies of defects and joints in veneer for outer and inner p
32、lies Defect/joint type Veneer for outer plies Veneer for inner plies Pin knots Up to 6 per square metre of panel surface No limit Closed splits A maximum of 2 per metre width of panel area with a total length of 200 mm No limit Open splits Not permitted A maximum of 1 split of up to 0.5 mm wide on a
33、ny panel edge Small worm holes, k 1.5 mm diameter Up to 2 per square metre Holes in plane of veneer not permitted Greater number permitted including some in plane of veneer, provided they do not produce voids Variation in colour Low contrast variation in colour is permitted if free from fungal decay
34、 Permitted, if free from fungal decay Edge joints For peeled face veneers: the minimum distance between edge joints shall be 300 mm For sliced face veneers: the minimum distance between edge joints shall be 100 mm No limit End joints Not permitted Not permitted Compression failure Not permitted Not
35、permitted Others: Not permitted Not permitted Knots other than pin knots Worm holes 1.5 mm diameter Fungal decay Repairs Not permitted Properly made and tightly fitted glued patches with their grain aligned with the grain of the veneer and having a maximum dimension of 60 mm permitted up to 3 per sq
36、uare metreBS 1088-1:2003 4 BSI 9 July 2003 4.1.2 Adhesive for bonding the plies The adhesive shall be based on either: a) a phenolic resin; or b) a melamineformaldehyde (amino) resin containing sufficient resorcinol (or other phenol) to ensure that the requirements of 5.6 are met. Additives shall be
37、 included only with the manufacturers written approval. 4.2 Lay-up and panel structure NOTE The requirements of 4.2.3 and 4.2.4 aim to ensure that the marine plywood has the balanced construction essential to most applications. For some applications, however, marine plywood with an unbalanced constr
38、uction is advantageous. Such material may be supplied provided that it conforms in all other respects to the requirements of this standard. 4.2.1 Number of plies Panels having a thickness of 6.5 mm or less shall have three or more plies. Panels having a thickness greater than 6.5 mm shall have five
39、or more plies. 4.2.2 Edge joints Glued edge joints shall be made using either a thermosetting phenolic or an aminoplastic adhesive. In the case of the latter, the moisture resistance shall be type MR, or better, in accordance with BS 1203. Thermoplastic adhesives shall not be used. Inner plies shall
40、 not be edge joined with metal fastenings, tapes or stitching. NOTE Veneers for outer plies may be taped or stitched to repair splits. Where outer plies have been taped or stitched, such material shall be removed after pressing. 4.2.3 Lay-up Adjacent plies shall be laid up with their grains at right
41、 angles to each other. NOTE 1 Cores (centres) may comprise two veneers of equal thickness with their grains parallel, provided that the panel conforms to the requirements of 4.2.1. The veneers forming any one layer and the corresponding layer on the opposite side of the central plane of the panel sh
42、all be of the same thickness and species, or of species known to be similar to one another in physical characteristics. These veneers shall be cut by the same method. NOTE 2 Decorative outer veneers (face veneers) may be cut by different methods but the physical characteristics and thickness of the
43、veneers should be selected to avoid distortion of the panel in service. Outer plies shall be laid up with the tight side of the veneer outermost. 4.2.4 Panel structure 4.2.4.1 General Panels shall conform to the requirements of 4.2.4.2 or 4.2.4.3 after sanding, when conditioned to a moisture content
44、 between 6 % and 14 %. 4.2.4.2 Three-ply panels The combined thickness of the two outer plies after sanding shall be not less than 40 % and not more than 65 % of the nominal, unsanded thickness of the panel. 4.2.4.3 Multi-ply panels After sanding, the thickness of each of the two outer plies, combin
45、ed with those of the core and other inner plies with their grain direction parallel to the outer plies, shall be not less than 40 % and not more than 65 % of the nominal, unsanded, thickness of the panel. In addition, for panels with a nominal thickness of greater than 3.8 mm, each outer ply shall be not less than 1.0 mm thick after sanding and each inner and core ply shall be not more than 4.8 mm thick.
