National standard plywood term definition
this standard refers to the international standard iso2047-1972 plywood vocabulary
1 subject content and scope of application this standard specifies the definitions of main terms of plywood. This standard is applicable to all kinds of plywood classified by gb9846.1
2 reference standard GB 9846.1 classification of plywood cars
3 composition and preparation
3.1 veneer veneer mountain rotary cutting, semi-circular rotary cutting, planing or sawing method to produce thin-walled wood
3.2 loose side in the process of rotary cutting or planing, the side of the veneer in contact with the knife, which often produces rotary cutting or planing cracks due to reverse stretching
3.3 ply each layer of plywood
3.3.1 surface ply refers to the surface veneer of plywood
3.3.1.1 the surface plate with good appearance quality of the whole panel face glue
3.3.1.2 the back is relative to the surface plate on the other side of the panel
3.3.2 central ply the central ply of plywood, and other layers are symmetrically configured on both sides of the export heat in the plastic machine industry
3.3.3 core board cross band, lateral ply inner unit whose texture direction is perpendicular to the surface board texture
3.3.4 long and medium plate centres, longitudinal ply inner veneer with texture direction parallel to surface plate texture
3.3.5 the central layer of core sandwich plywood or composite plywood. Generally, its thickness is greater than other layers
3.4 splice the connection of adjacent single strips in the same layer
3.4.1 longitudinal edge joint two pieces of edge aligned veneers are spliced along the longitudinal edge, and the direction of the seam is the same as that of the veneer texture
3.4.2 end joint two flush veneers are spliced along the extreme, and the seam is perpendicular to the direction of veneer texture
3.4.3 miter scarf joint two veneers are spliced along the end or edge of the inclined panel
3.4.4 finger joint the ends of two veneers are processed into finger tenons, which are staggered and spliced on the plane
3.5 glue, adhesive is used for substances with two surfaces glued to each other
3.5.1 glue bond with adhesive
3.5.2 glue Linc glue the thin layer of adhesive on two adjacent surfaces
4 grain
4.1 grain grain the texture formed by the arrangement direction of Chinese fibers in wood
4.1.1 straight grain wood grain is straight and parallel or nearly parallel to one of the two main directions (long direction or wide direction) of the veneer
4.1.2 the twill angle grain grain is not perpendicular to the edge of the veneer
4.1.3 the lower regular grain wood grain is straight due to the abnormal structure of wood
5 all kinds of plywood
5.1 plywood plywood a group of veneers are usually glued together vertically according to the grain direction of adjacent layers. Usually, its surface plate and inner plate are symmetrically arranged on both sides of the central layer or core
5.1.1 plywood with grain parallel to or nearly parallel to the long side of the board
5.1.2 the cross grained plywood veneer has wood grains that are parallel to the short side of the board, led by zirconium/titanate, fluorosurfactant and silica sol
5.1.3 ordinary plywood for general use
5.1.4 special plywood special plywood can meet the requirements of plywood for special purposes
5.1.5 outdoor plywood eltetior plywood has a plastic pallet that is resistant to climate, water and high humidity
5.1.5.1 type L plywood weather resistant plywood of class 1 corrugated board has the properties of durability, boiling resistance or steam treatment, and can be used outdoors
5.1.6 interior plywood is a glued rice that does not have the gluing property of long-term water immersion or excessive temperature
5.1.6.1 type 2 plywood water-resistant plywood, which can be soaked in cold water or hot water for a short time, but is not resistant to boiling
5.1.6.2 Plywood Type 3 plywood moisture resistant plywood, which can withstand short-term cold water immersion and is suitable for indoor use
5.1.6.3 type 4 plywood non moisture resistant plywood, which is used under normal indoor conditions and has a certain bonding strength
5.1.7 structural plywood plywood with limited mechanical property requirements
5.1.8 star shaped composite plywood star plywood veneer texture is made of plywood assembled according to star arrangement
5.2 sandwich plywood core plywood plywood with plate core
5.2.1 Blockboard core is composed of wood strips, which can be glued or not
5.2.2 the honeycomb board core is composed of a honeycomb structure, and there are usually at least two layers of veneers with wood grains vertically arranged on both sides of the core
5.3 composite plywood board core (or some layers) is composed of materials other than solid wood or veneer, and there are usually at least two layers of veneers with wood grains vertically arranged on both sides of the board core
5.4 decorative plywood two surface veneers or one of them is decorative veneer
5.5 molded plywood a non planar plywood formed by pressing in a die
5.6 mitered plywood scarfed plywood uses an inclined plane to glue two or more plywood to increase its size
5.7 finger joined plywood consists of two or more plywood, which are glued together by the method of finger cross combination of board edges to increase the size of plywood
5.3 length of panel dimension along the grain direction of the surface board
5.9 width of panel is perpendicular to the extremely long dimension
5.10 plate thickness ihickness of panei is perpendicular to the size of the plate surface
6 groups of billets
6.1 groups of billets the configuration of veneers in each layer of 1ay up slab according to the direction and thickness of wood grain
6.1.1 vertical configuration of wood grain of two adjacent veneers of orthogonal composite cross banded plies
6.1.2 star formation two adjacent single-phase wood grain calibration star arrangement configuration
6.1.3 parallel grain plies the wood grains of two adjacent veneers are configured in the same direction
7 use of friction and wear testing machine for various defects
7.1 material defects
7.1.1 knots are the branches wrapped in wood
7.1.1.1 pin knuckles PLN Knuts sound knuckles with a diameter of no more than 3mm
7.1.1.2 the intergrown knots are formed by the living skill strips of trees. The knot is closely connected with the surrounding wood or the part connected with the surrounding wood is greater than 3/4 of the peripheral length of its cross section, with hard texture and normal structure
7.1.1.3 dead knots are formed by the dead branches of trees. The knots are continuous with the surrounding wood around, or the continuous part is only 1/4 or less than 1/4 of the peripheral length of its cross section. The texture is hard or soft, and sometimes falls off to form holes
7.1.1.4 semi articulated partially intergown knowns the contiguous part around the knot and the surrounding wood is more than 1/4 to 3/4 of the peripheral length of its cross section, and the texture is hard
7.1, 1.5 sound knots no decayed knots
7.1.1.6 unsound knots the rotten part on the knot section is not more than 1/3 of the knot
7.1.1.7 rotten knots more than 1/3 of the rotten knots on the cross section of rotten knots
7.1.1.8 knot holes holes caused by knot shedding
7.1.2 abnormal structure defects caused by abnormal wood structure, such as wrinkles. Wavy veins. Crisscross pattern, spiral pattern, etc
7.1.3 resin capsule resin pocket is a lentil shaped cavity in wood, which contains or once contained resin substances
7.1.4 bark bark pocket because of the growth of trees, all or part of the bark is wrapped in wood
7.1.5 resin leakage (resin strip) after local injury of resin streak trees, a large number of resins gather and penetrate into the surrounding wood, forming a deeper color than the surrounding normal wood
7.1.6 wormholes wormholes.borer holes holes holes and wormholes formed by borers or their larvae in wood
7.1.7 marks of parasitic plants groups of small ditches formed by parasitic plants or rotten host plants penetrating into wood
7.1.3 discoloration discoloration where the normal color of wood changes, it is called discoloration, which can be divided into chemical discoloration and fungal discoloration
7.1.8.1 false heartwood the color of the central part of sound wood is different from that of normal wood, often dark brown or reddish brown, and usually its density and hardness are relatively large
7.1.8.2 chemical stain the discoloration of wood caused by the chemical reaction between wood components and some foreign substances
7.1.8.3 mold layer mold hyphae and spores on the surface of wood
7.1.8.4 blue stain, also known as blue stain, sapwood color turns gray, slightly blue or light green
7.1.8.5 pith flecks the healing tissue formed by insect invasion of the cambium before felling. The tissue of medullary plaque is fragile
7. l. 8.6 flecks streams are formed at the initial stage of wood rot fungi invading the wood, and Brown can often be seen. Tan or purplish red spots
7.1.9 decay rot due to the invasion of wood rot fungi, the cell wall materials are decomposed, resulting in the softness of wood, the decline of strength and density, and the change of wood tissue and color
7.1.9.1 initial rot incipient decay wood is eroded by fungal growth, causing slight changes in its chemical composition (generally before drying), showing slight changes in hardness and discoloration, resulting in changes in wood properties
7.1.10 row nail holes dog holes holes holes caused by hooks and tools of mining and transportation workers during log shipping
7.1.11 crack split, end split fibers are separated along the grain direction, usually starting from one end, and extending through the thickness of the early plate
7.1.12 crack check surface fiber flame retardant reinforced PBT stability is good, and the widely used is still the separation of short dimension of bromine antimony system, which usually does not start from the edge of the board, and does not extend through the thickness of the veneer
7.2 processing defects
7.2.1 open joint the splicing between two adjacent veneers in the same layer is not tight
7.2.1.1 core plate off seam core gap plywood core plate or seam in the core
7.2.1.2 the seam separation of long and medium plywood
7.2.2 laminated overlay two adjacent veneers (or two parts of a cracked veneer) in the same layer of veneer overlap each other
7.2.3 bubbling blister local separation caused by gluing failure between adjacent veneers
7.2.4 delamination separation of two adjacent veneers due to lack of glue or poor bonding
7.2.5 local depression on hollow surface plate
7.2.6 indentation local dent on the surface plate
7.2.7 bump bump the local super thickness on the surface plate
7.2.8 rotate check cutting check tiny cracks that can appear when the loose surface of the surface plate is configured outward
7.2.9 burr groove mark torn grain due to fiber
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