Forintek Canada Corporation

Other

Michael R Clarke

Gary Ellis Troughton

Donald C Walser

Paul R Steiner

Axel W Anderson

A system of drying veneer sheets for manufacturing wood products such as plywood, measures the moisture content of the sheets and controls drying to a predetermined moisture content. By drying veneer sheets to the predetermined moisture content, avoids excessive drying to ensure all sheets are below the 11% moisture content level. A process of drying comprises incising a veneer sheet, sensing the moisture content of the incised veneer sheet, steam drying the sheet under pressure and controlling the drying based on the sensed moisture content of the veneer sheet, to dry the sheet to the predetermined moisture content.

Controlled steam drying of veneer sheets

An improved phenol formaldehyde resin not requiring fillers or extenders and capable of bonding wafers or veneers having a moisture content of 10% or above is disclosed. The adhesive composition is prepared by mixing together a caustic solution of a high molecular weight PF resin, a dispersion of PF resin which is characterized in that it can swell in aqueous caustic medium but not go into solution, and alkylene carbonates or phenol resorcinol formaldehyde resins. Optionally, borax is utilized. The disperse phase is made by converting a solution of PF resin into a fine particle size particulate form by precipitation, spray drying or freeze drying, and partially cross-linking the resin during or subsequent to the formation of the fine particle size dispersion. The PF resin is partially cross-linked by (a) heat, by (b) acid catalysis, or by (c) a reaction with cross-linking chemicals. Also disclosed is a wood product produced from veneers having moisture contents of 10% or above and incised to improve their permeability to gases and liquids.

Phenol formaldehyde adhesive for bonding wood pieces of high moisture

Disclosed is an improved phenol formaldehyde (PF) resin that does not require fillers or extenders and is capable of bonding wafers or veneers having a moisture content of 10% or above. In the case of veneers exceptional results are obtained when the permeability of the veneer is increased by incising. The adhesive composition is prepared by mixing together a caustic solution of a high molecular weight PF resin, a dispersion of PF resin which is characterized in that it can swell in aqueous caustic medium but not go into solution, and a chemical which is capable of reacting with resins in both the continuous and the disperse phase, such as alkylene carbonates or phenol resorcinol formaldehyde (PRF) resins. Optionally, a component may be used such as borax which is capable of complexing with resins in the continuous and the disperse phase. The disperse phase is made by converting a solution of a PF resin into a fine particle size particulate form by precipitation, spray drying or freeze drying and partially cross-linking the resin during or subsequent to the formation of the fine particle size dispersion. The PF resin is partially cross-linked by (a) heat, by (b) acid catalysis, or by (c) a reaction with cross-linking chemicals such as cyclic carbonates or epoxy compounds or by a combination of (a) (b) and (c). The disperse phase may be made from a PF resin or from a resin in which some of the phenol has been replaced by other phenolic chemicals such as resorcinol, catechol, or kraft lignin. The chemical capable of reacting with resins in the continuous and the disperse phase may be a cyclic carbonate or a phenol resorcinol resin. Also disclosed is a wood product produced from veneers having moisture contents at 10% or above and incised to improve their permeability to gases and liquids.

A wood veneer lathe that includes a sensor carried by the nose bar and co-acting with the peeling knife to detect and provide an output signal in response to and proportioned to deviations from a predetermined spacing of the nose bar and knife relative to one another. The sensor is located downstream from the point of contact of the nose bar with the block at a position opposite a flate face of the knife and adjacent the latters cutting edge. A particular veneer lathe is disclosed that includes electrohydraulic linear actuators with feedback control means for adjustably positioning the peeling knife. Signals from the sensor, detecting deviations of the peeling knife from its fixed setting, are analyzed by a computer and the latter controls actuators to make suitable knife position adjustments to control the veneer thickness.

Veneer lathes having veneer thickness sensor and thickness control

A wood incising roller where the teeth are formed by grooves in the roller surface and where some of such grooves cross others. Each cutting tooth has a knife-like cutting edge of finite length that is in one instance perpendicular to the axis of rotation of the roller and in another instance parallel to such axis. The grooves can be formed by machine cutting, either turning or grinding or by being molded in the surface and then shaped by a grinding operation. At least some grooves preferrably spiral about the roller. The pattern of cutting teeth and shape are determined by such variable parameters as pitch, number of thread starts, angle of cutter, depth of cut and lead angle. An incisor for lumber or veneer consists of two rollers at least one of which is as described in the forgoing. The grooves can be filled or partially filled with an elastic compressible material. The incising roller of the foregoing also is used in combination with a veneer lathe.

Wood tenderizing apparatus and method

A method and apparatus for rapidly determining the moisture content of a substance. An area of one surface only of the substance is subjected to a predetermined intensity of radiant energy for a selected period of time and the temperature rise is measured. The rise in the surface temperature of the substance such as pieces of wood, is approximately inversely proportional to the moisture content of the wood and thus is easily determined. This is obtainable by transporting the substance on a fixed speed conveyor past a heat source, variations in the rise and fall in the surface temperature readings immediately following the application of heat are representative of its moisture content; low readings indicating high moisture content while high readings being indicative of low moisture content.

Growing community of inventors

Vancouver, Canada

Michael R Clarke