1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21901-7 SANS 929:2008Edition 2.7SOUTH AFRICAN NATIONAL STANDARD Plywood and composite board Published by SABS Standards Division 1 Dr Late
4、gan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 929:2008 Edition 2.7 Table of changes Change No. Date Scope Amdt 1 1989 Amended to change the requirements for 3 grades of surface veneers for rotary-cut SA pine boards, and to change
5、 a definition. Amdt 2 1991 Amended to change the requirement for minimum bond strength for decorative laminates bonded to a substrate and to change requirements and references for decorative boards. Amdt 3 1991 Amended to change the test method for transverse tensile (internal bond) strength of part
6、icle boards. Amdt 4 1992 Amended to add two definitions and to add three surface veneer grades, including their requirements, for rotary-cut SA pine boards. Amdt 5 2004 Amended to change the designation of SABS standards to SANS standards, to update the definition of “acceptable”, to include one-par
7、t polyurethane as an adhesive, to delete a reference to the standardization mark scheme and to update referenced standards. Amdt 6 2007 Amended to update referenced standards and to include a classification system based on bending properties. Amdt 7 2008 Amended to add a definition, to delete two ta
8、bles and to replace them with a new table to include requirements for rotary pine and eucalyptus surface veneer grades, to renumber the tables and to delete a footnote. Foreword This South African standard was approved by National Committee SABS SC 89C, Wood-based panel products Plywood and composit
9、e board, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in November 2008. This document supersedes SANS 929:2007 (edition 2.6). A vertical line in the margin shows where the text has been technically modi
10、fied by amendment No. 7. SANS 929:2008 Edition 2.7 1 Contents Page Foreword 1 Scope 3 2 Definitions . 3 3 Exposure class and type . 8 4 Materials 9 5 Constructional requirements and board properties 10 6 Physical and mechanical requirements . 16 7 Packing and marking . 19 8 Inspection and methods of
11、 test 20 8.1 Inspection 20 8.2 Visual determination of bleed-through area . 20 8.3 Moisture content of timber (oven-dry method) . 20 8.4 Diagonal difference (squareness of timber-based board products) 20 8.5 Flatness (flatness of timber-based board products) . 20 8.6 Edge straightness (edge straight
12、ness of timber board products) . 20 8.7 Surface bond strength of particle boards . 20 8.8 Transverse tensile (internal bond) strength of particle boards . 20 8.9 Accelerated degradation of adhesive bonds in wood . 21 8.10 Wood failure percentage in an adhesive joint 21 8.11 Knife test to determine b
13、ond quality of adhesive or glue lines . 21 8.12 Surface finish and appearance 21 Amdt 5 8.13 Surface laminae thickness . 21 8.14 Resistance to scratching 21 8.15 Resistance to wear 21 8.16 Resistance to high temperature . 21 8.17 Resistance to cigarette burns 21 8.18 Resistance to light, wool scale
14、. 21 8.19 Resistance to steam (water vapour) 21 8.20 Resistance to cracking . 21 8.21 Resistance to staining 21 Figures 1-4 22-24 Appendix A Applicable standards 25 Appendix B Notes to purchasers 26 Appendix C Quality evaluation of board produced to the requirements laid down in the specification .
15、27 Appendix D Notes on the storage and handling of board . 29 SANS 929:2008 Edition 2.7 2 This page is intentionally left blank SANS 929:2008 Edition 2.7 3 Plywood and composite board 1 Scope 1.1 This specification covers requirements for materials, construction, preservative treatment, dimensions a
16、nd performance of plywood and composite board. 1.2 Specific requirements for decorative aminoplast-faced board are included. 1.3 Board of thickness not exceeding 3 mm is not included in this specification. NOTES a) The standards referred to in the specification are listed in appendix A. b) Requireme
17、nts that must be specified by the purchaser and one that must be agreed upon between the supplier and the purchaser are listed in appendix B. c) Information regarding the verification of the quality of plywood and composite board produced to this specification, and a sampling plan that could be used
18、 to assess compliance with this specification of a lot of plywood and composite board are given in appendix C. d) Notes on the storage and handling of plywood and composite board are given in appendix D. 2 Definitions1)2.1 For the purposes of this specification the following definitions shall apply:
19、 acceptable acceptable to the authority administering this standard, or to the parties concluding the purchase contract, as relevant Amdt 1; amdt 5 back the surface opposite to the face balanced construction a specific method of construction with specific materials, that gives a board the ability to
20、 withstand warpage during service NOTE Balancing is usually achieved by arranging similar laminae symmetrically around a core, as in figure 1(a). With present technology, balancing may still be achieved by using differing thicknesses of face and back veneers of different timber species cut by differ
21、ent methods, or by using specific backing materials for overlaid boards. 1) The definitions relevant to plywood are taken mainly from ISO 2074, in some cases with modifications. SANS 929:2008 Edition 2.7 4 battenboard a composite board the core of which consists of strips (battens) of solid wood of
22、width in the range 35-48 mm, and that may or may not be glued together (see figure 1(b) bleed-through adhesive that has seeped through the outer ply and shows up as a blemish on the surface blister local raising of the surface of board, resulting from a separation between or within laminae, and gene
23、rally not visible at the edge of the board (see figure 1(c) blockboard a composite board the core of which consists of strips of solid wood of width in the range 7-4 mm, and that may or may not be glued together (see figure 1(d) bluestain the most common form of sapstain producing a bluish discolora
24、tion Amdt 1 board a sheet of plywood or composite board bonding the process of uniting, by means of an adhesive, the components of board check separation of the fibres in an outer ply, that does not start at an edge, does not always extend through the whole thickness of the veneer, and does not allo
25、w the underlying ply to be visible (see figure 1(e) closed split a split (in a veneer) the edges of which are so close that only a hair-line crack remains visible on the surface or edge of the board coated board a board that has been given a coating of resin, paint, undercoat, sealant or other accep
26、table material by the manufacturer composite board a board that consists of laminae glued as cross-bands to a core core the central lamina(e) of a composite board NOTE The core is usually thicker than and of a different type from the other laminae. decorative aminoplast-faced board a composite board
27、 that consists of resin-impregnated layers of a fibrous material (such as paper) consolidated with a lignocellulosic substrate by means of heat and under a pressure of usually less than 5 MPa NOTE These boards are generally known as “low-pressure laminates“. dormant bud a pattern on the timber surfa
28、ce, caused by the beginning of a branch being formed, but not yet having the pattern of a knot SANS 929:2008 Edition 2.7 5 drying defects faults including warping, shrinking, checking or splitting, or collapse, in excess of the specified values, caused during drying of timber face the better surface
29、 of the board flight hole a hole made through the wood surface by an adult insect emerging after the completion of its larval and pupal stages grade of a board a measure of the quality of the face veneer and the back veneer of a board NOTE The face veneer and back veneer quality are given (in that o
30、rder) by classification letters according to the grades in tables 4-5 (inclusive), e.g. SB, AA, CD, etc. This is the board grade. Amdt 7 grade of a veneer a classification of a veneer according to the end use (see tables 4-5 inclusive) Amdt 7 high-pressure decorative laminate a sheet that consists o
31、f thin layers of a fibrous material (such as paper) impregnated with thermosetting resins and consolidated by means of heat and under a pressure of usually more than 5 MPa high-pressure decorative laminate board a composite board one or both surfaces of which are high-pressure decorative or non-deco
32、rative laminates of a specified type (see SANS 4586-1) Amdt 5 joint (see figure 1(g) butt-joint an end-joint between square-cut ends edge-joint a joint between the sides of two laminae in a longitudinal direction end-joint a joint between the ends of two laminae feather-joint an end-joint or edge-jo
33、int with a groove cut into the matching ends or edges and with a timber strip fitted to increase the glue surface and strength of the joint finger-joint an end-joint made up of several meshing fingers and slots glued together scarfed-end joint an end-joint or edge-joint between ends or edges cut at
34、an angle to increase the glue surface tongue-and-groove joint a joint formed by a projection at the end of one member of lesser cross-section than the member, and fitting into a corresponding slot in the member to which it is to be joined SANS 929:2008 Edition 2.7 6 lamina one of the layers (which m
35、ay be of metal, solid timber, veneers, built-up timber, particle board, a form of lignocellulose fibre, resin-impregnated bonded paper, high-pressure decorative laminate, fibreboard or other acceptable material) forming the board laminboard a composite board the core of which consists of strips of s
36、olid wood or veneer that are of width less than 7 mm, and are placed on edge and glued together (see figure 1(h) laminveneer veneer made of strips of wood of width less than 7 mm (see figure 1(i) laminveneer board a board one or both surfaces of which consist of laminveneers long grain plywood plywo
37、od in which the grain of the outer plies in the plane of the board is parallel or nearly parallel to the long side (see figure 1(j) marine plywood an exposure class 1 plywood, bonded with a phenolic adhesive, having specified surface veneer grades, and intended to be constantly or periodically in co
38、ntact with estuarine or sea water and directly exposed to salt water wood-destroying agencies such as the Teredo worm and the Gribble isopod metallic inclusions a metal object (e.g. a staple) present in board (see figure 1(l) natural whole sheet NWS a sheet of veneer that has no joint (see figure 1(
39、r) open defect an opening, cavity or separation of the wood fibres on a face veneer caused by a resin pocket, open bark inclusion, knot hole, split, sand through, press mark and mechanical damage that can be filled to its full extent with a non-shrinkable synthetic filler Amdt 7 overlaid board a com
40、posite board that has bonded surface laminae consisting of acceptable a) resinated paper foil, decorative or non-decorative, b) thermoplastic foil, c) metal, or d) any other lamina(e) overlap an overlapping of two adjacent veneers (or two sections of a split veneer) in a ply, resulting in local exce
41、ss thickness or in a change in the appearance of the surface of the board (see figure 1(m) pencil knot a knot formed in timber by a branch approximately the thickness of a pencil SANS 929:2008 Edition 2.7 7 pin hole damage to timber by a member of certain genera of the families Platipodidae or Scoly
42、tidae (usually Lyctus brunneus), leaving tunnels of diameter approximately 1 mm pleat the result of a veneer being folded, forming several thicknesses of the veneer locally (see figure 1(n) ply a timber lamina plywood board consisting of an assembly of plies bonded together with the direction of the
43、 grain in alternate laminae usually at right angles NOTE In the case of timber boards, these laminae are also referred to as plies. resin defect flecks, streaks or pockets of resin (see figure 1(o) sand-through local absence of outer veneer resulting from excessive sanding which reveals some of the
44、glue line or of the substrate (see figure 1(p) short a defect in a board, where one or more laminae do not fully extend to the end or edge of the board (see figure 1(s) short grain plywood plywood in which the grain of the outer plies in the plane of the board is parallel or nearly parallel to the s
45、hort side (see figure 1(f) shutterboard a type of structural board (used in formwork) which may be coated with a release agent such as resin, oil, bitumen or other acceptable material split separation of the fibres along the grain, extending through the whole thickness of the veneer, and generally s
46、tarting at an end (see figure 1(q) structural board board used in load-bearing applications, permanent structures or residential constructions, and being of an exposure class and type that ensures a certain performance for a specific application substrate the lamina below the surface lamina tape a s
47、trip of paper (or equivalent material) with an adhesive backing, used to hold the free edges of a joint or split during the manufacture of board telegraphing the projection of imperfections from the substrate to the surface of the board SANS 929:2008 Edition 2.7 8 torn grain the surface condition of
48、 a veneer where a cutting blade has torn out strips of fibres instead of making a clean cut through them (see figure 2) veneer a thin sheet of wood rotary cut veneer veneer produced by rotary cutting (peeling) centred on the axis of a log sliced veneer veneer produced by slicing woodstain discolorat
49、ion or variation from the natural colour of the wood Amdt 4 3 Exposure class and type 3.1 Exposure class Board shall be of one of the exposure classes given in column 1 of table 1, as required. Table 1 Exposure classes2)for board products 1 2 Exposure class and application Conditions of exposure Class 1 (Exterior) Exposed (intermittently or constantly) to water, or constantly to open air. Class 2 (Semi-exterior) At infrequent intervals exposed (partly or as a whole) to unprotected open air conditions. Class 3 (Humid interior) Constantly protected fro
