BS ISO 2426-1:2020 pdf free.Plywood一Classification by surface appearance.
BS ISO 2426-1 This document establishes general rules for the classification of plywood by its surface appearance.It concerns plywood made of hardwood including tropical and temperate hardwood, softwood and plywood derived from other lignocellulosic materials.It does not apply to overlaid plywood.The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2426-2, Plywood – – Classification by surface appearance一Part 2: Hardwood ISO 2426-3, Plywood一Classification by surface appearance一Part 3: Softwood.Classification of plywood by surface appearance is made according to the number and the extent of certain natural characteristics of wood and the defects that come from the manufacturing process.Five appearance classes are distinguished, identified with the following codes: E, I, II, II, IV.Determination of the appearance class, based on the appearance of the panel surfaces, shall take into account the categories of characteristics given in Table 1 and defects given in Table 2.The appearance class of plywood is determined by the classes of its surfaces.The class of the plywood first describes the class of the face followed by the class of the back.The permissible characteristics and defects for each of these appearance classes of this document are specified in ISO 2426-2 for hardwood and in ISO 2426-3 for softwood.Characteristics and defects which are limited in number, size, or extent are either enumerated or evaluated over the total surface of the panel. This number or extent is expressed par square metre of panel, with the exception of checks, splits and open joints which are related to one metre of panel width.In appearance classes I to IV, the number and the width of veneers which form the outer plies of a panel are not restricted, provided the joints are well made.The veneers forming the outer plies of class I shall be well matched for colour and have similar grain.The outer plies shall be laid with the joints approximately parallel to the edges of the panel.BS ISO 2426-1 pdf download.