EP1572434A1

EP1572434A1 - Device and method for moulding semi-finished pieces made from open-cell material

Info

Publication number: EP1572434A1
Application number: EP03767648A
Authority: EP
Inventors: Heinz BLÖMELING; Johannes Hysky
Original assignee: Carcoustics Tech Center GmbH
Current assignee: Carcoustics Techconsult GmbH
Priority date: 2002-12-18
Filing date: 2003-11-25
Publication date: 2005-09-14
Also published as: AU2003292108A1; WO2004054783A1; US20060076716A1; MXPA05003854A; JP2006510500A; DE10259641A1; DE10259641B4

Abstract

The invention relates to a method for the moulding of web- or sheet-like semi-finished pieces (7, 8), made from open-cell plastic, using a multi-component moulding tool (1), the tool pieces (2, 3) of which may be displaced relative to each other, towards and away from each other and which define a cavity (4) with at least one mould structure. The invention is essentially characterised in that at least one section of a web- or sheet-like semi-finished piece made from open-cell material is moulded in the cavity of the moulding tool (1) by inflation of a balloon or tube (18), made from an elastic material, provided in the cavity (4). Open-cell thermoplastic and open-cell duroplastic materials can thus be effectively and cheaply moulded. The invention in particular permits the production of open-cell moulded pieces with back-cuts (23, 24). The invention further relates to a device for carrying out said method.

Description

Device and method for forming semi-finished products made of open-pore material

The invention relates to a device and a method for forming sheet or plate-shaped semi-finished products made of open-pore plastic using a multi-part molding tool, the tool parts of which can be moved towards and away from one another define a cavity with at least one molding structure.

In automotive engineering in particular, insulation components are used which are made from foams and nonwovens and are used for sound and / or heat insulation. Such insulation components are usually designed as molded parts in order to adapt them to the space available at their installation location. In addition, the acoustic effectiveness of such insulation components can be influenced by their shape.

Various methods and devices for forming semi-finished products made of plastic are known in the prior art.

A known method for forming semi-finished products is, for example, deep drawing with positive and negative tools. It is also known in this connection to provide the upper tool with a cushion filled with water or a rubber membrane on the upper tool attached, which can be pressurized with pressurized water via a pump (see Saechtling, Kunststoff Taschenbuch, 28th edition, 2001, Carl Hanser Verlag, p. 343, fig. 3.128 and p. 348, fig. 3.135).

Furthermore, extrusion blow molding has been known for many years in the processing of thermoplastic or thermoelastic plastics. An extruder is used to manufacture tubular preforms. The preforms are squeezed between two movable halves of a blowing tool and pressed against the inner wall of the tool with compressed air. The compressed air is fed through a blow mandrel, which can also be used to calibrate a hollow body opening.

DE 40 06 729 AI describes a process for producing a hollow body from a permanently deformable foam by blow molding. According to this method, two sections of a closed-cell foam are first inserted into a multi-part mold after heating to a temperature above the softening temperature of the foam. By closing the multi-part shape, the sections are welded together along their edges, the gap between the sections being sealed. By introducing compressed air into the space between the sections, the sections are pressed against the walls of the multi-part mold and shaped. After the sections have cooled, the molded part is removed from the mold.

From DE 37 12 973 AI a method for producing molded hollow parts from foams is known, in which a substantially air-impermeable or at least one foam containing an essentially air-impermeable layer is used, tubular or hollow body-like preforms being initially formed from the foam. The preforms are heated to a temperature lying in the thermoelastic, possibly up to the beginning, thermoplastic state range and are then introduced into divided mold tools which have a cavity corresponding to the outer contour of a hollow body to be produced. Thereafter, heated air is blown into the hollow interior of the preforms, so that the preforms are inflated to the desired hollow body molded part. The hollow body molded parts are then solidified by cooling and finally demolded after sufficient solidification.

The object of the present invention is to provide a method and a device with which open-pore thermoplastic and open-pore thermosetting materials can be formed effectively and inexpensively. In particular, it should also be possible to produce undercuts in the molded parts in a simple manner.

With regard to the method, this object is achieved according to the invention with a method of the type mentioned at the outset in that at least a portion of a sheet-like or plate-shaped semi-finished product made of open-pore material is deformed in the cavity of the mold by inflating a balloon or tube made of elastic material and assigned to the cavity becomes.

With the method according to the invention, both semi-finished products made of open-pore thermoplastic materials, such as open-cell, thermoplastic foams or thermoplastic nonwovens, and semi-finished products can be made Economically transform open-pore thermosetting materials such as melamine resin foams into molded parts with complex contours. In particular, the method according to the invention enables the production of open-pore molded parts with undercuts.

In contrast to the prior art, the method according to the invention does not produce a preform and thus saves at least one work step. In particular, in the method according to the invention, there is neither coating of the open-pore material with an air-impermeable layer, nor foaming of the material. When forming sheet-like or plate-shaped semi-finished products from open-pore foam according to the invention, it is also not necessary to crosslink the foam.

Furthermore, the above-mentioned object with regard to the device is achieved by a device with the features specified in claim 9. The device according to the invention thus comprises a multi-part molding tool, the tool parts of which can be moved relatively towards and away from one another define a cavity with at least one molding structure, and at least one blowing mandrel assigned to the cavity, which is provided with a balloon or tube made of elastic material, which is located within the cavity of the mold for deforming at least a portion of a sheet or plate-shaped semi-finished product made of open-pore material.

The device according to the invention is thus prepared for the forming of sheet or plate-shaped semi-finished products made of open-pore plastic material. An advantageous embodiment of the invention consists in that a plurality of sheet-like or plate-shaped semi-finished products made of open-pore material are simultaneously formed in the cavity by inflating the balloon or tube. In this way, the performance of a device according to the invention can be increased accordingly.

With regard to the forming of sheet or plate-shaped semi-finished products made of open-pore thermoplastic material, it is advantageous if a heating device for heating the semi-finished product is connected upstream of the molding tool. As a result, the thermoplastic semifinished product can be heated to an optimum forming temperature before being arranged in the mold, the heating preferably taking place parallel to the forming of an upstream semifinished product or semifinished product section, so that the total processing time required for the shaping is minimized.

The heating device can preferably consist of movable heating plates. Alternatively or additionally, radiant heaters can also be used as the heating device.

Further preferred and advantageous embodiments of the invention are specified in the subclaims.

The invention is explained in more detail below on the basis of a drawing showing several exemplary embodiments. In a schematic representation:

Fig. 1 shows a first embodiment of an inventive device for forming two sheet-shaped semi-finished products made of open-pore thermoplastic material while the material is being fed into the opened mold,

2 shows the device according to FIG. 1 with the mold closed during the forming of two sections of the web-shaped semi-finished products made of open-pore material,

3 shows a second exemplary embodiment of a device according to the invention for forming two web-shaped semifinished products made of open-pore thermosetting material while the material is being fed into the opened mold, and

FIG. 4 shows the device according to FIG. 3 with the mold closed during the shaping of two sections of the web-shaped semi-finished products made of open-pore, thermoset material.

The device shown in FIGS. 1 and 2 has a molding tool 1 formed from two halves. The two tool halves (tool parts) 2, 3 can be moved relative to one another and define a cavity 4. Each of the two tool halves has a shape structure on its inside, in this case a negative shape.

As shown in FIG. 1, the molding tool 1 can be opened by moving the two tool halves (tool parts) 2, 3 apart. Two material webs 7, 8 are fed from above between the two tool halves 2, 3 that have moved apart. The essentially flat material webs 7, 8 are each unrolled from a roll 9, 10 and guided to the mold 1 via a deflection roller 11, 12. The supply of the material webs 7, 8 and the opening and closing of the molding tool 1 are coordinated with one another in time and take place in cycles.

In this embodiment, the material webs 7, 8 each consist of an open-pore, thermoplastic material. The material can be, for example, open-celled thermoplastic foam, thermoplastic nonwoven or a multi-layer web of such open-pore materials.

A heating device 13 is connected upstream of the molding tool 1. The heating device 13 forms a preheating station. In this exemplary embodiment, it has three heating plates 14, 15, 16 for section-by-section contact heating of the material webs 7, 8. While the middle heating plate 15 is fixed, the two outer heating plates 14, 16 can be moved in the direction of the double arrows by means of a drive device (not shown). As an alternative or in addition to the heating plates 14, 15, 16, radiant heaters (not shown) can also be used to heat the material webs 7, 8 in sections.

A blow mandrel 17 is assigned to the cavity 4 of the molding tool 1 and is connected to a compressed air source or a compressed air generator via a compressed air line (not shown). The blow mandrel 17 is provided with an inflatable tube 18 made of elastic material. The hose 18 is hermetically connected at one end to the blow mandrel 17 with a sleeve 19 and is hermetically closed at its other end with a releasable closure 20. The cuff 19 and the closure 20 are arranged at a fixed distance from one another. This can be realized, for example, by means of a tube (not shown) or a corresponding rod (not shown) arranged inside the tube 18, the tube or the rod being firmly connected or connectable to the sleeve 19 and the closure 20. The tube can represent an extension of the blow mandrel 17 and can have a plurality of passage openings. The distance from the sleeve 19 to the closure 20 is dimensioned such that when the molding tool 1 is closed, the sleeve 19 ^' and the closure 20 are clamped together with smaller sections of the material webs 7, 8 in recesses (not shown) which face each other Edge sections 21, 22 of the tool halves 2, 3 are formed.

When the mold 1 is closed, the two sections of the material webs 7, 8 are pressed together at the edge sections 21, 22 of the tool halves 2, 3. The pressure force is dimensioned such that when the elastic hose 18 is inflated, some web material can slide into the cavity 4. For this purpose, the tool halves 2, 3 can also be provided with a clamping frame (not ^" shown).

The sections of the material webs 7, 8 located within the cavity 4 of the molding tool 1 are pressed against the inside of the tool halves 2, 3 by the inflation of the elastic hose 18 and corresponding to the shape structure 5, 6 of the tool halves 2, 3 reshaped. The shape structure can in particular also have undercuts 23, 24 (cf. FIG. 4). After the formed material sections have cooled, the compressed air is released from the hose 18 and the hose is relaxed. For this purpose, a multi-way valve (not shown) arranged in the compressed air line is actuated; to which a blow-off branch is connected. The molded parts produced are then removed from the mold. The molding tool 1 is relatively cold. To shorten the cooling time, the tool halves 2, 3 can also be equipped with a cooling device (not shown) with which forced cooling is effected.

It can be seen in FIG. 2 that during the forming of the material sections in the molding tool 1, the subsequent, not yet formed material sections are heated in the heating device 13.

A cutting device (not shown) can also be assigned to the molding tool 1 in order to separate the molded parts produced in the material web 7, 8 from the latter. It is also possible to feed material sections which have already been cut to the molding tool 1.

The shape of the elastic tube 18 can be adapted to the shape of the tool cavity 4, so that it has, for example, a pillow-like shape or a complex balloon shape. It is also within the scope of the invention to assign several inflatable elastic hoses or the like to the tool cavity 4.

The device shown in FIGS. 3 and 4 is for the shaping of open-pore thermosetting material certainly. This material can be, for example, an open-pore melamine resin foam which is impregnated with a thermosetting binder such as melamine resin or phenolic resin.

In this exemplary embodiment, the open-pore thermosetting material is also present as a wound material web 7, 8, which is fed to the molding tool 1 via deflection rollers 11, 12. The molding tool 1 again consists of two tool parts or halves 2, 3. The two tool halves 2, 3 can be moved relative to one another in the direction of the double arrows. They each have a heating device. The heating device is implemented here by one or more heating channels 25 formed in the tool halves 2, 3, through which hot water or another heating fluid circulates. Instead of heating channels 25, electrical heating wires (not shown) can also be integrated in the tool halves 2, 3.

As in the exemplary embodiment described above, a blow mandrel 17 is assigned to the tool halves 2, 3 and is arranged between the tool halves 2, 3 and is provided with an elastic hose 18 or the like. The design of the hose 18 and its attachment to the blow mandrel 17 correspond to the exemplary embodiment shown in FIGS. 1 and 2. Before the elastic hose 18 is inflated, the molding tool 1 is closed, so that the sleeve 19 and the releasable closure 20, together with smaller sections of the material webs 7, 8, are clamped into recesses (not shown) which are in the edge sections 21, 22 of the tool halves 2, 3 are formed. As indicated in FIGS. 3 and 4, the shape structure 5, 6 of the tool halves 2, 3 can have one or more undercuts 23, 24. The use of the inflatable elastic tube 18 enables the open-pore material to be pressed into the region of the undercuts 23, 24 and to be shaped accordingly. In addition, the use of an inflatable elastic tube 18 or balloons enables the simultaneous shaping of several open-pore semi-finished products. The molded parts produced in this way can be removed from the molding tool 1 without problems after their thermosetting binder has hardened, since they are still sufficiently elastic after hardening.

LIST OF REFERENCE NUMBERS

1 mold

2 tool halves

3 tool halves

4 cavity

5 shape structure

6 shape structure

7 material web (semi-finished product)

8 material web (semi-finished product)

9 wraps

10 wraps

11 pulley

12 pulley

13 heating device

14 heating plate

15 heating plate Hot plate blow mandrel elastic tube sealing sleeve releasable closure edge section of one tool half edge section of the other tool half undercut undercut heating channel

Claims

PATENT CLAIMS

1. A method for reshaping sheet-like or plate-shaped semi-finished products (7, 8) from open-pore plastic using a multi-part molding tool (1), the tool parts (2, 3) of which can be moved towards and away from each other, a cavity (4) with at least one Define the mold structure (5, 6), characterized in that at least a section of a sheet or plate-shaped semi-finished product made of open-pore material in the cavity (4) of the mold (1) by inflating a balloon or formed from elastic material and associated with the cavity (4) Hose (18) is formed.

2. The method according to claim 1, so that several web or plate-shaped semi-finished products (7, 8) made of open-pore material are simultaneously formed in the cavity (4) by inflating the balloon or tube (18).

3. The method according to claim 1 or 2, characterized in that when reshaping a portion of a sheet or plate-shaped, made of thermosetting plastic open-pore semi-finished product, the semi-finished product (7, 8) is heated within the mold (1).

4. The method of claim 1 or 2, d a d u r c h g e k e n e z e i c h n e t that when a portion of a sheet or plate-shaped, made of thermoplastic plastic open-pored semi-finished product is formed, the semi-finished product (7, 8) is heated before being fed into the mold (1).

5. The method according to claim 4, that the semi-finished product (7, 8) is heated by contact heating or by thermal radiation.

6. The method according to any one of claims 1 to 5, so that the molded part formed from the semifinished product (7, 8) is cooled in the mold (1).

7. The method according to any one of claims 1 to 6, so that a molding tool (1) is used, the at least one molding structure (5, 6) of which has at least one undercut (23, 24).

8. The method according to any one of claims 1 to 6, that the open-pored semi-finished product (7, 8) is fed to the molding tool (1) from a winding (9, 10) as a unwound web product.

9. Device for forming sheet or plate-shaped, open-pore semi-finished plastic products (2, 3), with a multi-part molding tool (1), the relative Tool parts (2, 3) that can be moved towards and away from each other define a cavity (4) with at least one shape structure, and at least one blow mandrel (17) assigned to the cavity (4), characterized in that the blow mandrel (17) with a balloon or tube (18) 'is made of elastic material which is inflatable within the cavity (4) of the molding tool (1) for shaping at least a portion of a sheet or plate-shaped semi-finished product (7, 8) made of open-pore material.

• 10th Apparatus according to claim 9, so that at least one of the tool parts (2, 3) of the molding tool (1) is provided with a heating device (25).

11. The apparatus of claim 9 or 10, d a d u r c h g e k e n e z e i c h n e t that the molding tool is preceded by a heating device (13) for heating the open-pore semi-finished product (7, 8).

12. The device according to claim 11, so that the heating device (13) is formed from heating plates (14, 15, 16) which can be moved towards and away from one another.

13. The apparatus according to claim 11, characterized in that the heating device is formed by at least one radiant heater.

14. Device according to one of claims 9 to 13, so that the molding tool (1) has at least one molding structure (5, 6) with at least one undercut (23, 24).

15. Device according to one of claims 9 to 14, characterized in that the molding tool (1) is designed such that a plurality of sheet or plate-shaped semi-finished products (7, 8) made of open-pore material simultaneously in the cavity (4) by inflating the balloon or Tube (18) are formed, each tool part (2, 3) being assigned to a semi-finished product (7, 8) to be formed.

16. The device according to any one of claims 9 to 15, d a d u r c h g e k e n n e e c h n e t that the hose at one end with a cuff (19) on the blow mandrel (17) attached airtight and at the other end with a releasable closure (20) is airtight.