Patent DE-10061072-A1 (DE)
Title: To coat dry fibers with glue, for the production of fiberboards, they are carried through a shaft against the shaft wall by the centrifugal action from a rotating roller with surface pins, to be sprayed and ejected from the shaft outlet
Inventor: SCHNEIDER FRITZ
IPC: B27N1/02
Filed: 2000-12-08
Abstract: To apply a glue to fibers, for the production of fiberboards, the dry fibers (14) are fed by a dosing unit through a feed shaft (10) under an underpressure to a fiber roller (17). The surface of the roller has a number of pins (18), so that the roller rotation moves the fibers between a section (20) of the roller surface and a part-wall section (21) of the shaft and the shaft section (22) defining the glue application unit. The fibers are accelerated to the surface speed of the roller by the pins and the generated air stream, with a centrifugal action to hold the fibers at the wall without contact with the pins. The glued fibers are coated at the wall section or near its end, to emerge from the shaft outlet opening (23).  To glue fibers, for use in fiberboards, a guide plate ramp at the shaft wall can deflect the fibers back to the roller pins, before separating to the shaft wall again. The shaft wall or its leading section, to carry the fibers, starts after about \4 of the fiber roller circumference. The fibers are coated by slit glue applicator jets (26) or spray jets. The fibers lie on a gluing board at the slit jets or after the spray jets. The gluing board has a profiled surface e.g. with fins, needles or steps, and is pitched at an angle to the fiber flow to deflect the fibers and press them against the board to be caught again by the roller pins. At the slit applicator jets, the fibers strike the gluing roller (45) at a tangent to the fiber flow direction, or they strike the gluing roller in the flow direction when using spray jets. On striking the gluing roller, the fibers are deflected to be caught by the roller pins. The surface of the gluing roller is smooth, or it is profiled e.g. with fins, needles or steps, radial or axial grooves or hemispherical depressions.. The gluing roller is cleaned continuously by a rotating brush (48) with water. The used water is returned to the glue preparation station, to be used as glue diluting water for application to the fibers. The fibers can be coated with a glue by a roller, where a part of its mantle surface defines a shaft section, where the glue is transferred by friction to the fibers. The gluing roller can be next to a glue bath, where the glue is transferred on to the mantle surface as a glue film by immersion. The application of glue to the fibers can be set by a belt weighing scales at the fiber dosing unit feed, which gives the rotary speed required by the gluing roller. The glued fibers are fed separately to an accelerator. The fibers leave the shaft outlet opening on a horizontal movement path, and are then deflected downwards by suction, and they can be coated with glue at the deflection point by spray jets which deliver glue and air. The fiber flow can be deflected in a channel by a pneumatic carrier system, with two facing rows of spray jets for the fibers to travel between them. The speed of the fiber movement, on striking the gluing roller, is set by the level of the underpressure in the feed shaft. The fibers can be divided into two symmetrical flow streams, to be coated with glue, and then beat against each other after they emerge from the shaft outlet opening. The fibers are sifted directly after gluing. An Independent claim is included for an assembly to coat fibers with glue, for fiberboards, with a feed shaft for a dosed delivery of fibers to a fiber roller fitted with surface pins. The fibers are carried through, with centrifugal force to hold them against the shaft wall, to be coated with a glue application before passing out through the shaft outlet opening.