GB652508A - Method for treating wood surfaces - Google Patents

Abstract

652,508. Wire-brushing wood to accentuate grain; rotary brushes. DEHN, S. G. (Davidson Plywood & Lumber Co.). Oct. 14, 1948, No. 26781. [Classes 19 and 60] A method of treating a flat wood surface, such as a panel surface and the like, to produce a raised grain thereon in sharp relief includes the step of scouring said surface with a plurality of wire brushes impinging on said surface at a variety of angles each being oblique to the grain of said surface. Slabs or panels 13, Fig. 2, of wood or plywood are carried by a conveyer 18 under banks of vertically adjustable brushes 19, rotated by individual motors, having their axes of rotation inclined to the direction of travel of the conveyer; succeeding banks are oppositely inclined. In each bank, the brushes on one side of the centre line of the conveyer rotate oppositely from those on the other side of the centre line; the brushes in the second bank rotate oppositely to the corresponding brushes in the first bank, the brushes in the third bank rotate in the same direction as the corresponding brushes in the second bank, the brushes in the fourth bank rotate oppositely to the corresponding brushes in the third bank, the brushes in the fifth bank rotate in the same direction as the corresponding brushes in the fourth bank, and the brushes in the sixth bank rotate oppositely to the corresponding brushes in the fifth bank. The first four banks of brushes effect the scouring out of the soft fibres; the brushes have wire bristles of about seventy-five ten-thousandths of an inch thickness and which are crinkled, Fig. 3; in operation, the brushes are rotated at high speed e.g. 2,500 R.P.M. and centrifugal force causes the bristles to elongate by straightening their crinkles, Fig. 4, thus exerting the desired pressure on the wood surface. The last two banks of brushes effect polishing of the hard fibres; the brushes may be set closer to the wood surface than the preceding banks, or may have longer bristles or may be rotated at higher speeds so as to accentuate the elongation of the crinkled bristles; the desired effect is to cause the bristles to flex under the pressure of contact with the wood surface to a degree at which they drag across the wood surface with a sweeping rather than a scouring action, making contact with the sides of their tips rather than with the points of their tips, thus polishing the hard fibres. Specification 652,507 is referred to.