摘要:
Press racking, or lateral movement of the movable portions of a press, occurs in certain particleboard processes during heating and pressing of the panels. It is attributed to shingling of wood particles during the formation of a mat. To eliminate or reduce the movement of the press, the mat is subjected to rolling engagement by a relatively small diameter roll located between the forming apparatus and the press. The roll subjects the mat to a downward rolling pressure. The peripheral roll surface is in contact with the newly formed upper surface of the mat and has a linear speed and direction of movement identical to the speed and direction of movement of the mat support. A resulting wave action within the mat is caused by shear and displacement forces applied to the wood particles, such that the shingled nature of the mat is modified to reduce or eliminate resulting lateral movement of the press components.
摘要:
A layer-forming apparatus for making particle-board mats comprises a spreading head adapted to deposit particulate matter upon a mat-forming surface. The distributing head comprises an array of mutually parallel interdigitated disk rollers with the interfitting disks defining progressively increasing interstitial spaces as the particles move from one side of the roller array to the other side thereof.
摘要:
Resin treated lignocellulosic fibers are conveyed by a stream of air downwardly to a separator containing one or more doffing rolls, which rotate adjacent a perforated scroll assembly. At the side opposite the doffers the assembly is connected to a vacuum supply which draws dust and foreign particles out of the fibers as they fall downwardly through the separator and into a hopper located in the rear of a feeder assembly housing. From here the fibers are fed by endless belts or aprons to an expansion chamber formed in the rear of a condenser housing containing one above the other a pair of endless condensers or screens. The fibers cascade downwardly in the expansion chamber to a generally wedge-shaped air bridge formed at the inlet end of the space formed between the confronting runs of the condensers. This space is connected to a pair of suction fans so that the fibers are slightly compacted as they are sucked by the fans through the throat of the air bridge and deposited on the confronting runs of the screen condensers. These two runs travel continuously toward the discharge end of the housing to produce an endless mat of fibers at the output. The upper belt is also mounted for vertical adjustment to vary the thickness of the mat.
摘要:
A transprinting, bonding or fusing machine having a drum, a pressure roller arranged in contact with the surface thereof, an endless belt passing between the pressure roller and the drum and extending a part way around the surface of the drum, the drum being driven through the pressure roller. Electric heating elements are arranged exterior to the drum surface to direct heat on that part of the endless belt which is in contact with the drum surface, the material to be printed, bonded or fused passing between the endless belt and the surface of the drum.
摘要:
Apparatus for the continuous production of chipboard, fibreboard or like panels, comprising a tensioned endless steel belt guided over a plurality of rollers and partially around a heated revolvable press drum such that said rollers press the belt against said drum, sprinkler apparatus disposed over a portion of the belt which extends horizontally before said drum in the direction of movement of the belt such that material to form said panels sprinkled onto said portion of the belt is pressed between the belt and the drum to form a web of material, wherein at least one of said plurality of rollers has over its width a convexly ground surface, whereby panels produced on the apparatus can have substantially uniform thickness and weight.The apparatus may include heating and/or cooling means for regulating the temperature of longitudinally extending zones of the belt and/or peripherally extending zones of said drum and/or said rollers thereby, due to thermal expansion or contraction, to regulate the tension in said longitudinally extending zones of said belt or to change the contour of the peripheral faces of said drum and said rollers to assist production of panels of uniform density and thickness across their width.
摘要:
Apparatus for spreading or scattering fiber or chip fleeces made up of a mixture of cuttings of extremely fine or superfine, fine, and coarser glue-covered chips for the subsequent press forming into fiberboards and the like. A mixture of chips is supplied to a fleece or particle carrier by gravity feed between sets of air emitting classifying registers. The upper portion of the classifying registers include oppositely facing air outlet openings which face the stream of chips and effect an initial classification by spreading some of the fine and superfine particles outwardly of the central stream. The lower part of the registers include openings facing oppositely to one another and away from the center line of the stream of particles and spaced from one another to permit passage therebetween of a central portion of the mixture without further modification. Baffle plates are also provided in preferred embodiments to assist in preventing further classification of the central stream in the lower regions of the registers. The baffle plates are vertically adjustable so as to accommodate varying conditions for desired varying thickness boards to be formed by the layers of particles passed through the distributing chamber containing the air classifying registers.
摘要:
A process of producing fire retardant particleboard comprising forming courses of particleboard furnish and dry fire retardant chemical immediately under courses of fine furnish particles which form outer courses of the particleboard, consolidating the assembled particles under heat and pressure, and sanding off particles of the outer courses to expose the inner courses as faces of the board.
摘要:
Apparatus and method for forming deckle-free edges and windows in molded fiber products such as cartons, trays and the like, said apparatus comprising a forming mold equipped with non-porous block-out ridge and/or patch members to define the periphery and/or windows in the finished product. The apparatus includes a mating press mold for cooperation with the forming mold with passageways therein through which jets of fluid such as air and/or steam may be supplied from a high pressure source to control deckle accumulated on the forming mold. The method of forming deckle-free windows and/or edges in molded fiber products by applying a fiber pulp slurry on the face of a forming mold and removing deckle from block-out portions of said forming mold by directing high pressure jets of fluid at said mold to blast deckle into upstanding position and away from adjacent portions of said mold and pressing the upstanding deckle down into pulp therebelow thereby concentrating fiber in the vicinity of edges and windows in the finsihed product.
摘要:
Heatable single or multilevel platen press for manufacturing wood and fiber composition panels or the like includes a stationary base structure and a displaceable structure, each of the structures being composed of a plurality of individual bridge members and rib members interconnecting the bridge members and forming conjointly therewith a grid extending over the entire width of the press, press platens loosely mounted on the grid at the workpiece-side therof, the rib members having fluid circulation passages therein for equalizing longitudinal thermal stresses, and the bridge members having fluid circulation passages therein for equalizing transverse thermal tensions, the passages of both the rib and the bridge members being connected into at least one close circulatory loop, and at least one pump connected in the circulatory loop for circulating fluid medium therethrough.
摘要:
A resin-fiber glass mixture is sprayed-up and partially cured to a flexible, non-tacky sheet molding compound for second stage curing to a solid, infusible resin in a heated mold. The mixture is sprayed-up into a relatively flat sheet of one layer or two or more separable layers or with a variable thickness, if desired, to conform to the profile of the part to be molded. The resin comprises a polyanhydride, such as the copolymer of maleic anhydride and an alpha-olefin, an olefinically unsaturated monooxirane compound such as glyeidyl methacrylate, and an olefin such as styrene.