Present processes are known for the manufacturing of both fine-thickness, i.e. fine and normal thickness particle board of fine and/or normal sized chips. A first known type of process relates to a continuous-flow production of particle board using calenders and the like, for example "Mendes" process. The second known type of process relates to a continuous production of particle board using a conveyer-belt, which moves first from under a filling machine, where the mat is made and then carries the mat under the press, where the final pressing operation occurs. This type of operation which is somewhat similar to the type of the present invention may be carried out in two different manners.
A first and better-known process essentially employs a movable filling machine and a fixed press. A conveyor-belt, either formed of a plastic-covered canvas and/or similar material, or formed of a steel-belt, moves between the filling machine and the fixed press and carries the mat from the former to the latter. To obtain the finished particle board, the mat is compressed while it lies on the belt at the press stage.
If a steel belt is used in this process, a number of difficulties are encountered due to the considerable expansion of the belt during the pressing operation. Furthermore, another disadvantage with the use of a metallic belt is the fact that it becomes impossible for the superheated vapor, generated within the pressed material, to be released satisfactorily.
On the other hand, if a fabric or similar belt is employed to eliminate these defects which are encountered with the use of a metallic belt, the produced particle board is often insufficiently flat, the thickness is inconsistent and the surface finish is not smooth and even. When this occurs, it is necessary to further finish the particle board, which results in increased manufacturing labor and costs. Also, this type of belt is considerably less durable than metallic belts, thereby entailing high maintenance costs.
A second process employs a belt system shuttling between the filling machine and the press, the belt depositing the mat directly on the press plate so as to obtain a good tolerance and surface finish quality of the final product and to eliminate subsequent surface finishing. Furthermore, this system obtains also a superior quality product. However, the system is extremely complicated and it contains the defects mentioned above and, futhermore, cannot be used to obtain fine thicknesses. In this case great difficulties are encountered in depositing the material in the plane of the press for producing thin products.
Processes with a movable filling machine and a movable press, while suggested, have not been in use in view of the difficulties in shifting these machines.