Colored Compreg
Wood can be densiied and its properties modiied not only by illing its void volume with polymers, molten sulfur, or molten metals but also by compressing it under conditions such that the structure is not damaged.
Compressed solid wood has been made in Germany since the early nineteen thirties and marketed under the trade name of Lignostone. These densiied materials are used for textile shuttles, bobbins and picker sticks,
for mallet heads, for forming jigs and for various tool handles. Commonly, a synthetic resin treatment, phenol formaldehyde resin has been used with a high compression in order to improve the physical and mechanical properties of wood or
wood-based materials.
The plasticizing effect of phenol formaldehyde resin forming mixes on wood has been taken advantage of in making a resin treated compressed wood with speciic gravities ranging from 1.2 to 1.35 at pressure of 1,000 psi or less at 125 to 150oC. Compreg
is much more dimensionally stable than the best untreated compressed wood.
Compreg is a phenol formaldehyde resin impregnated woodveneer laminate; compressed under high heat and pressure to a high speciic gravity, thus the properties of wood and a synthetic resin polymer network are combined. These products
normally have mechanical properties higher than untreated wood due to their higher speciic gravity. Generally, compreg has been used for special purposes, such as concrete shuttering, deck, electrical insulation, fan blades, silent gears and aircraft
parts.
The inal products are more expensive than normal wood or wood-based panels because of high production costs of the chemicals and the special processing. Various methods are known for the production of artiicial
wood veneer whereby sheets of natural wood, obtained by rotary cutting from a log are dyed or coloured, superimposed and glued together by compressing them in a mould to form a block of sheets in a press provided with moulds having surfaces
of a suitable coniguration for shaping the sheets of the block according to a predeined pattern.
