JPH01308601A - Method and device for manufacturing fleece for manufacturing press molded form - Google Patents

Abstract

PURPOSE: To prevent a material to be pressed from sliding down the face part of a steep slope by compressing a molding material through giving a linear or a circular vibration at least, partially to a sieve-like bottom while or after filling a space between a die for a press molding and the sieve-like bottom with the molding material. CONSTITUTION: A sieve-like bottom 3 is structurally closed in a part where fleece has a significantly steep slope. In addition, the sieve-like bottom 3 makes a rotary motion with an amplitude such as to compress the fleece horizontally in the lateral wall part of a steep slope, as shown by an arrow, while or after filling a space 16 with a molding material. After this step, the fleece is still thick enough to be 2-4 times the thickness of the completed press molding. The horizontal movement of the sieve-like bottom 3 during compression is shown by a dotted line 18. Under this compression process, the fleece is maintained as a uniform layer even in the lateral wall part of the steep slope, after the sieve-like bottom 3 is removed. Further, the fleece is cured to such an extent that it can be formed in succession by a follow-up cold preliminary pressing work or a subsequent hot pressing work.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a chip-like or fibrous material for producing a press-molded product having a uniform wall thickness, which is composed of a horizontal plate-like surface and a side wall extending from the horizontal plate-like surface so as to form a depression at a steep slope. In order to produce a fleece made of a molding material to which a binder has been added, the molding material is applied to the surface of a press-forming die adapted to the shape of the molded body to be press-molded, and formed according to the shape of the molded body,
A method for producing a fleece for producing a press-formed body by automatically filling a required amount and thickness into a space between the sieve-shaped bottom of a container filled with molding material through the sieve-shaped bottom by vibration of the container. Regarding.

In the case of chip-like or fibrous molding materials, it may be a non-splatterable mixture of particles containing, for example, pulverized wood cellulose and admixed with a thermosetting binder having a thermosetting plastic matrix. . As is well known, shaped bodies, such as table boards, window sills, pallets, etc., can be made from such mixtures by applying a non-splatterable mixture to a layer or layers of as uniform a thickness as possible, depending on the shape or nature of the shaped body to be produced. It is manufactured by filling a press mold (or lower mold) with intentionally different layer thicknesses at certain locations. The thickness of the layer of the mixture in the mold is usually 4 to 7 times the thickness of the molded body to be produced. If the mold is a preforming mold, the mixture filled in the mold is preformed by the introduction of a press ram (or upper mold) and is compressed to almost its final dimensions. The strength of the pre-press molded body produced in this way is sufficient to prevent deformation or crushing during removal from the pre-forming mold. It is then introduced into a hot press tool, optionally protected at the same time with a covering layer, and brought from the preform into its final shape under the action of pressure and heat, in the course of hardening and optionally simultaneously coated with a covering layer. The mold may be a hot mold in which the molded body is produced directly from the molding material without preforming.

The quality of the pressed body generally depends on whether the body has the necessary density and/or fiber structure to obtain the desired mechanical properties. These properties are highly dependent on the thoroughness with which the work is undertaken when filling the mixture into the preforming mold. Filling traditionally involves charging a measured amount of the mixture into the preforming mold from a storage container using a meter or using an automatic dosing device when producing shaped bodies with modest dimensions. The coating may be distributed to a uniform or non-uniform thickness as required. It is clear that with such a distribution of the loading of the mixture, the desired properties are subject to large variations and possibly unintended consequences.

A device for producing mats of uniform thickness from wood chips or the like on a conveyor belt or on a supporting surface is known (DE 942 479 1). This device consists of a filled hopper-shaped container, which is arranged at a certain distance above the conveyor belt or the supporting surface of the device and whose bottom is configured as a vibrating screen. When the vibrating sieve is operating,
The chips freely fall through the screen of the sieve until the gap between the conveyor belt and the sieve is completely filled. Thereafter, the feeding of material to the belt stops even as the sieve continues to vibrate. When the conveyor belt passes under the sieve, a mat of uniform thickness forms on the conveyor belt, with the mesh of the sieve exerting a scouring effect.

Using this known device, mats of uniform thickness can be produced. However, the device fills a precisely dosed specific amount of fibrous molding material into a stationary press mold, and transfers the molding material from the horizontal flat surface of the press molding to the wall section. It is unsuitable for making it possible to press-form a molded body in which the molded body protrudes almost vertically. This shaping takes place, for example, in pallets or concrete forms that are press-molded in one piece from the material.

It has thus far not been possible to produce such pallets with a pot-shaped pallet bottom having a uniform wall thickness, which is produced as a press-molded body. This is because within the area of the bottom side walls of the pallet, which have a large slope, taking into account the angle of repose of the molding material, it is not possible to construct a fleece layer of uniform thickness from this material and to maintain it until press molding. It is. Rather, in known pallets produced in this way, the wall thickness of the pallet foot increases gradually from the pallet surface to the loading surface of the pallet foot.

Apart from the material waste and weight increase caused by this, the pallet base is thicker in those places where it has sufficient strength.

The problem underlying the invention is therefore to produce a non-flowing non-flowing press material with a uniform wall thickness for press workpieces with very steep surface areas. It is an object of the present invention to provide a method which can be constructed in such a way that after filling the mold, the material can no longer slide downwards on steep surface sections.

This problem is solved by the present invention in the method recited in the preamble of claim 1, during the filling of the molding material into the space between the mold for the press-formed body and the sieve-shaped bottom or After filling, or during and after filling, it is solved by compacting the cribriform base at least partially by means of linear or circular vibrations.

As a result, the press material deposited on the steeply sloped surface portion is sufficiently compressed, and sliding down of the press material on this portion is sufficiently avoided. Since the movement of the sieve bottom is partially linear or circular, other surface areas not located in the main vibration plane are also compressed, which is completely desirable.

An apparatus suitable for carrying out the method of the invention consists of a box-shaped container for the molding material which can be mounted on a mold for the press-formed body having the cross-sectional shape of the molded body, the sieve-shaped bottom of the container being is inserted in a mold configured according to the shape of the mold and having the same cross-sectional shape of the molded body to limit the filling capacity, at least part of the sieve-shaped bottom to compress the steep side wall portions. It is characterized by comprising a vibration device that performs linear or circular vibration. This device is distinguished by the fact that the cribriform base has a closed wall in the area of the recess when the recess is narrow, and the side wall section has a closed wall when the recess is configured wide.

Having closed walls in the area of the depression facilitates and/or improves the compaction of the press material in this area. It is also not necessary for the sieve base to have a mesh structure within this range. This is because at these locations, due to the slope of the filling cavity and due to the narrow design of the recesses, the press material has sufficient access to the press mold.

In the case of a wide design of the recess, the side wall parts have closed walls, so that the pressing material between the protrusions or the side parts of the recess can sufficiently reach into the lower part of the pressing tool, and compaction of the pressing material in the side parts is achieved. will not be harmed.

The invention will now be explained in detail with reference to the drawings.

FIG. 1 shows a press molding die 13 in which a fleece of uniform thickness is formed. The shape of the molded body to be press-molded from the fleece is formed in a mold 13.

Similarly, the cribriform base 3 has the shape of a shaped body. cribriform base 3
are arranged at a distance from the mold 13 that corresponds to the thickness of the fleece to be manufactured. As is well known, the thickness of the fleece is 4 to 7 times the thickness of the resulting press-formed body.

Before producing the fleece, ie before filling the cavity 16 between the mold 13 and the sieve sole 3, the cavity above the linear base is filled with molding compound. Due to the vibration of the horizontally flexibly suspended sieve base 3, the molding material falls through the sieve base and fills the cavity 16.

As can be seen in FIG. 1, the sieve bottom 3 is designed in such a way that the fleece closes in areas with a particularly large slope, ie later on the sides and bottom of the pallet foot. Furthermore, the cribriform bottom is rotated horizontally during and/or after filling the void I6, as shown by the arrow, with an amplitude such that the fleece is already compressed to some extent, at least in the steep side wall sections. Do exercise. After this step, the fleece still has a thickness 2 to 4 times that of the finished pressed body. The horizontal movement that the cribriform bed undergoes during compression is indicated by the dotted line 18.

Due to this compaction by the sieve sole 3, the fleece remains as a homogeneous layer even on its steep sidewalls after the sieve base has been removed, and can be further processed by subsequent cold pre-pressing or rather directly subsequent hot pressing. Hardens to the extent that it can be processed.

The device shown in FIG. 2 is different from the device described above in connection with FIG. They only differ because of what they have. Blank space 1
In order to ensure that 6 is filled with molding material in a time interval that is not unnecessarily large, in this embodiment the sieve bottom 3 is configured in such a way that it closes only on the sides and passes through again at the bottom of the recess. There is. Furthermore, this cribriform base performs horizontal linear movements as indicated by the arrows.

However, otherwise the same effect as the device of FIG. 1 is obtained.

Therefore, using the method described, mats are produced from molding material in the form of chips or fibers with the addition of a binder, which can be further processed to provide uniform walls even on steep, almost vertical sidewall sections. It is possible to obtain a press-molded body having a large thickness.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the device according to the invention.
The figure is a longitudinal sectional view of an apparatus for producing fleece for pallets at the pallet base leg portion, and FIG. 2 is a longitudinal sectional view of an apparatus for producing fleece for concrete temporary frames within an area having a wide recess.

Claims (1)

[Claims] 1. A bonding agent in the form of chips or fibers for producing a press-formed body having a uniform wall thickness consisting of a horizontal plate-like surface and a side wall extending from the side wall at a steep slope to form a depression. In order to produce a fleece made of the added molding material, the molding material is applied to the surface of a press molding die that is adapted to the shape of the molded object to be press-molded, and the molding material is In this method, the molding material is automatically filled in the required amount and thickness into the space between the sieve-shaped bottom of a filled container through the sieve-shaped bottom by vibration of the container, and the molding material is placed in a mold for a press-formed body. and the sieve bottom, or during or after filling the space between the sieve bottom and the sieve bottom. Method of manufacturing fleece for manufacturing. 2. The method according to claim 1, in which a flat portion extending in a plane different from the vibration plane is compressed. 3. Consisting of a molding material in the form of chips or fibers with a binder added, for the manufacture of press-formed bodies with a uniform wall thickness, consisting of a horizontal plate-like surface and a side wall extending from the side wall at a steep slope to form a depression. A fleece manufacturing apparatus consists of a box-shaped container for a molding material that can be mounted on a mold for a press-formed body having the cross-sectional shape of a molded body, and the sieve-shaped bottom (3) of the container corresponds to the shape of the press-formed body. and inserted into a mold having the same cross-sectional shape of the compact to limit the filling capacity, and at least partially linear or circular vibrations of the sieve bottom to compress the steep side wall sections. 1. A fleece manufacturing device for manufacturing a press-formed body, comprising a vibrating device. 4. The cribriform bottom (3) has a closed wall in the area of the recess when the recess is narrow, and the side wall portion has a closed wall when the recess is configured wide. The device according to item 1.