JPS61237602A - Manufacture of molded shape worked by press - Google Patents

Abstract

The process is for producing highly structured sectional bodies, for example of a latticed ceiling element, from a non-rising mixture, such as a mixture of fibres containing lignocellulose and of a heat-setting synthetic resin. The mixture is introduced into a press-die bottom part equipped with a least one step narrowing the filling space and is pressed to completion by a press-die top part having the contour of the sectional body. <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the press forming process in a press tool from a fluid but dust-free mixture of fibers and a thermosetting binder. The present invention relates to a method of manufacturing a molded body by.

PRIOR ART Such a method is known (German Patent No. 2,548,739). With this known method, a large number of different moldings are produced, for example exterior moldings for producing internal and external claddings of gate structures, balcony claddings, table boards, etc.

Dust-free mixtures usually consist of lignocellulose-containing fibrous materials, such as crushed and dried chips, bagasse fibers, etc., which are combined with thermosetting synthetic resins, such as melamine-urea formaldehyde resins or Mixed with phenol formaldehyde resin. However, instead of crushed and dried wood or bass fibers, other fiber materials such as glass fibers, asbestos or Aspes fibers, alone or mixed with each other, may also be used. A suitable, preferably organic binder is added to the fiber material.

If the shaped body has a homogeneous and low-structured shape, it can be easily pressed in a press tool consisting of a lower press tool part and a press tool upper part. The surfaces of the upper press tool and the lower press tool facing the volume of the press tool that accommodates the mixed material are shaped according to the shape of the compact.

Pressing of the molded body is first carried out by uniformly filling the lower part of the press tool with a specified amount of the mixed material up to a specified height. The filling height is approximately 2 to the thickness of the molded body.
It is 7 times more. In the case of molded bodies which do not need to have a decorated surface, they are pressed in one stage and hardened by supplying heat. If the shaped body is provided with a decorated surface, first of all a pre-pressed part is produced from the mixture in a first pressing step, which sub-pressed part already has almost the final volume of the shaped body. has been compressed to. This child pressing is then removed from the pre-pressing machine and inserted with the decorated surface coating into another pressing machine for final pressing.

As already emphasized, the use of the method described above is only possible if the shaped body to be pressed has a low-structured shape. However, it is also possible to press compacts with strongly structured shapes from dust-free mixtures, but this requires a pressing tool consisting of two or more parts, and it is not possible to simply It is necessary to apply pressing force not only in the vertical direction but also in the horizontal direction.

However, there are also shaped bodies which have a strongly structured shape and which cannot be pressed from a dust-free mixture. This is because either the press tools for producing the compacts are too expensive and therefore too expensive, or the compacts themselves are so structured that multi-part tools cannot be applied. It is from.

Such shaped bodies are, for example, square or rectangular grid-like lattice-cover parts, which cover parts have shaped strips arranged cross-shaped and transitioning into one another; The strip has a highly structured cross section, which cross section consists of a homogeneous substrate, for example square, rectangular or trapezoidal, and one or more webs attached to the sides of the substrate. There is.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method capable of press working a molded body having the above-mentioned cross section.

Means for Solving the Problem The means of the present invention for solving the problem described above is characterized in that the lower part of the press tool is provided with at least one step at the bottom constricting the filling chamber and is filled to a defined filling height. The upper part of the integral press tool with the contour of the compact is vertically lowered into the lower part of the press tool to compress the compact to its final dimensions and at the same time harden it under the action of heat.

Example The invention will now be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows, in the simplest possible form, a cross section of a molded body to be pressed from the initially mentioned mixture. This (yellow cross-section) has a rectangular base body 1 which transitions into a sea urchin f2 laterally on the upper surface.

When such a compact is to be pressed in a known manner using a press tool consisting of a press tool lower part 3 and a press tool upper part 4 shown in FIG. It is necessary to fill the lower part of the press tool with a thickness of 5-7 times the body. FIG. 2 shows a mixed filling material 5, which corresponds to five times the thickness of the finished molding. As is clear from FIG. 2, it is not always easy to carry out such a filling in the lower part of the press tool.

Rather, from such a mixed filler 5, the press tool lower part 4
It is even more difficult to press a molded product by lowering it vertically. In this case, the part 6 of the mixed filling material which is to form the nib 2 in the molded body sinks inward. As a result, the web 2 has an excessively low density in the final pressed body. The web therefore does not have the required amount of material and its strength is insufficient.

According to the invention, this disadvantage is eliminated in that the shaped body is pressed in the lower part 3 of the press tool shown in FIG. The press tool lower part 3 shown in FIG. 6 differs from the press tool lower part 3 shown in FIG. 2 in that a step 7 is disposed at the bottom to narrow the filling chamber in this range. The step 7 has a similar shape to the web 2. Due to the arrangement of the step 1 in the press tool lower part 3, the press tool lower part 3 can have a mixed filler 5 with a uniform height, as is clear from FIG.

The step or steps T in the lower part of the pressing tool have the effect of ensuring a sufficient amount of the mixture in the area of the web 2 to be pressed, so that the finished web 2 has an excellent density. have. This is the sixth
It is clear from the figure, in which the upper final dimension 10 of the finished molded body is indicated by a dashed line.

When the molded body is now pressed by lowering the press tool lower part 4 from the mixed filler 5, a molded body having the cross section shown in FIG. 4 is produced. This molding has, as desired, a protruding, square web 2, so that exclusively the base body 1 has two undercuts 8, but this in no way detracts from the molding. Rather, the sea urchin f2 now has the same density and mechanical properties as the substrate 1. It is also possible to provide the underside of the base body 1 of the molded body with recesses, for example groove-like recesses.

5 and 6 show examples of applications for molded bodies produced according to the invention. FIG. 5 shows a longitudinal sectional view of a half portion of the lattice-cover member. The grid-like lattice is made up of a plurality of molded materials 9 arranged in a cross shape.
In the cover part, the cross section of the molding 9 has a block-shaped base body 1 and at least one web 2 . In the embodiment shown in FIGS. 5 and 6, the shaped body has sharp edges. However, according to the present invention, the same molded body can also be produced with rounded edges.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a molded body to be pressed, FIG. 2 is a schematic cross-sectional view of a known press tool, and FIG. 3 is a schematic cross-sectional view of a press tool according to the present invention. , FIG. 4 is a schematic cross-sectional view of a molded body press-formed using the press tool shown in FIG. 6, and FIG. 5 is a half-section of a lattice-shaped cover member press-formed according to the present invention. FIG. 6 is a partially enlarged view of FIG. 5.

Claims (1)

[Claims] A method for producing a molded article by pressing in a press tool from a fluid but dust-free mixture of fibers and a thermosetting binder. , at least one step (7) constricting the filling chamber;
in the lower part of the press tool, which is provided at the bottom and is filled to a defined filling height, the integral upper part of the press tool with the contour of the compact is vertically lowered into the lower part of the press tool to form the compact. A process for producing a pressed molded body, characterized in that it is compressed to its final dimensions and simultaneously hardened under the action of heat.