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Pine plywood is classified into two main types:
Interior-INT
INT type plywood is bonded with adhesive for interior use. The plywood manufacturer recommends do not use this type of plywood in direct contact with water and moisture. Normally formaldehyde resin based adhesives are used.
Exterior-EXT
EX type plywood is bonded with adhesive for exterior use. This plywood manufactured for in exterior works where contact with moisture and water occurs. Normally phenol resin based adhesives are used, but it is also possible to use adhesives made on the basis of other resins.
Plywood sizes:
Standard size - 2440x1220, plywood in other sizes is manufactured on orders.
Number of plies and tolerances:
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Thickness, mm
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Minimum number of plies
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Tolerance
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Thickness, (%)
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Length, mm
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Width, mm
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9
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5
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12
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5
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15
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5
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18
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7
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+/-5
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+0.0/-2.0
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+0.0/-2.0
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21
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7
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22
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9
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25
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11
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Plywood quality depending on types
Depending on the quality and processing of veneer face plywood is classified into grades provided in the table :
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Defects
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Face veneer grade
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A
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B
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C+
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C
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Knots
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Not allowed
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Allowed less than 10 mm in diameter and maximum 10 knots in one layer
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Unlimited
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Open knots, cracks
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Not allowed
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Open knots and cracks in the process of manufacture shall not be bigger than 6x12.5 mm and they have to be patched.
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Open knots and cracks unlimited. But sizes cannot be bigger than 65 mm in diameter and 50 mm. They have to be patched.
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Unlimited
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Split of knot heartwood
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Splits up to 20 mm
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Splits up to 50 mm
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Open joints
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Not allowed
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Open joints not bigger than 2 mm, patched.
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Open joints not bigger than 5 m, patched.
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Splits
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Not allowed
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Splits allowed in width of maximum 5 mm and length of 300 mm and patched.
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Splits are allowed in width of maximum 10 mm and length of 600 mm and patched.
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Splits allowed in width of maximum 15 mm and length of 700 mm and patched.
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Number of face joints
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No
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Only one
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Maximum two
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Stains
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Not allowed
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Max 10% in face layer.
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Max 20% in face layer.
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Plywood application:
Plywood is widely used in furniture industry, for interior and exterior decoration, construction works, in the production of railway wagons, packing containers and pallets, in the production and repair of motor vans, in shipbuilding industry and many other industries.
Country of origin : Brazil
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