DE102004023584A1 - Foaming plant for production of foam backed plastic components with grained surface for vehicles comprises film preforming station with grained tool, rotating table with lower tools and foaming station - Google Patents

Abstract

A film unwinding station(2) is followed by a film forming and foaming area(5) incorporating a film section preforming station(11) with a preforming punch(14) and a negative tool(15) with a grained surface. A rotating table(7) supports lower tools(8) incorporating negative tools with cover plates(10). A foaming station(16) meters foam onto a preformed film section in each lower tool. The film unwinding station(2) is followed by a film preheating station(3) and/or a heating station(4). Openings in the negative tool(15) are connected to a vacuum source to hold preformed film in place. Cover plates(10) for each lower tool have a second tool punch(19) on the underside for molding foam onto the rear of the film. The rotating table(7) is located at a foam curing station in which each lower tool is heated. Residual film left after cutting out film sections passes on to a film wind-up station(6). Opposite the rotating table there is a demolding station and a guide for returning tool cover plates to the foaming station extends between the demolding and foaming stations. An independent claim is included for a process for manufacturing a foamed plastic component with a grained surface which involves: a) forming a grained section of a plastic film(23) using a negative tool; b) coating the inner side of the film section with polymer foam.

Description

The The invention relates to a production device for producing a IMG thermoforming film with direct foam process of plastic parts and in particular of component parts, door panels, dashboards and covers, each without undercuts.

in the Prior art, such production methods in particular used for the production of dashboards for motor vehicles. In doing so, the surface becomes provided with a grain, which is also called "Graining". Especially inexpensive There are so-called "in-mold-graining" processes (IMG = in-mold-graining), in which the graining already during deep drawing the plastic part made in a special IMG mold becomes. Thus, processes are known in which an unnatural foam sheet Deformed grained in an IMG pressing tool and press-laminated with a prefabricated carrier becomes. With this procedure is disadvantageous that only little complex objects let produce.

From the EP 0 363 594 B2 is a method and a Vorrich device for the production of moldings or articles of thermoformable plastics according to the negative thermoforming known. In this case, a plastic sheet is heated introduced into a mold and shaped using a pressure difference. Furthermore, a production device is known in which an unnatural compact film is deformed in the IMG tool and thereby grained. Subsequently, the deformed and grained outer skin is backfoamed.

Finally is a method is known in which an unembossed foam sheet in an IMG die deformed, grained and pressed back with a natural fiber to a carrier and is laminated. Also in this process are only a little complex Components can be produced.

The The invention is based on the object, a method and thus produced objects to provide that in a simple way even with very complex Shapes are available.

These The object is solved by the subject matter of the independent patent claims. advantageous Formations are given by the subject-matter of the dependent claims.

In a very simple form has the foam plant for the production of plastic parts, in particular for motor vehicles, a film unwinding station and a molding and foaming area. there is a preforming station with a first forming punch and a Negative form for Foil sections provided by the Folienabwickelstation. The negative form is on its surface provided with a grain. Furthermore, a turntable is provided, arranged on the closable with a mold lid lower tools are. With a foaming station is ever one located in a lower tool Fo lienabschnitt applied with plastic foam.

there a film of plastic is provided, of which a foil section is transformed by means of a negative mold into a desired final shape. The film section is the same provided with a grain. Subsequently the film section is coated on its inside with plastic foam.

The Invention may be in plastic parts such as dashboards, door trim parts and general panels, which preferably no undercuts have to be used. With the invention do not need polyurethane spray skins or PVC skins be used more. The invention provides a very cost effective Preparation process ready. The invention enables high stacking capacities, thereby Transport costs are reduced. It does not need big investments at parking costs for storage areas more done become.

The Invention provides a negative deep drawing process or IMG process, at the over a film roll unhardened TPO film material (thermoplastic Olefin foil), ie a partially crystalline plastic which is amorphous, provided. This film is under the action of heat in a grained negative tool prestretched and by means of vacuum is the Skin form-fitting created on the shape contour. Thus, with relatively little effort a molded skin with more concise Scar and surface quality produced, which is visually equivalent to a PU or PVC outer skin. typical Film rolls have a length from about 150 meters.

The The invention combines a negative thermoforming process indirectly with the foam backing of support parts.

The Paneling according to the invention, etc. do not need any longer made by special manufacturing companies and then be packed in special racks. It is no longer necessary, this with a truck to a subcontractor or automobile manufacturer to transport where they are for a later one Backfolded component become.

The invention provides a solution that results in low manufacturing costs, and process-related by the applied manufacturing method. There is no need for high investment in manufacturing equipment such as electroforming or Foaming plants are provided more. There is no need for a high investment for racks. This results in low transport costs, because the dashboards or panels are made where they are needed. There is no longer a large storage requirement for any racks longer necessary and a high in-house transport traffic is avoided. In addition, parts production is very cost effective due to the feeds used.

The The invention provides a negative thermoforming process in which a IMG process (in-mold-graining) is made possible. Immediately afterwards a foam process set, whereby the parts production costs at similar lasting quality reduce considerably.

Of the Inventive machine transports the preheated TPO film in a preforming station of the thermoforming unit. After that a tenter is closed. The heated to about 200 ° C TPO film will over a preform stamp in the IMG tool pre-stretched and by vacuum the TPO film is in an IMG lower tool created. about a trimming unit integrated into the preform stamp will be of use separated from the waste. The IMG film remains in the lower tool. The Bottom tool is with both a trimming edge as well provided a lower clamping frame. Afterwards, the preforming punch moves out the lower tool up and the tenter is automatically open.

In the next Clock sequence rotates a rotary table, with, for example, 4 IMG tools stocked is one position or 90 degrees farther to the foaming station. The mold skin in the tool is then over a given entry line foamed with a PU component. After that will over a backdrop tour that Form upper tool supplied to the lower tool and locked together. After that drives the empty backdrop clockwise past a curing station in a waiting position for the removal or to an insertion station.

During this foaming At the same time, the new deformation process is initiated. With the retraction of the heated TPO foil into the deformation station At the same time the waste is about Pulleys further to the opposite Folieaufwickelstation transported.

In a third station on the rotary table was done actual curing process of the PU foam system with closed tool.

While above as mentioned the foaming process takes place, at a partial withdrawal station the closed Foam tool over the slide tour open and the mold cover with the power supply is automatically connected to the empty backdrop coupled. The mold lid is opened. The finished foamy Part is manually removed by the worker from the foam mold.

After that The tool is cleaned and a new carrier part is on the mold cover placed. Subsequently she drives second backdrop with the mold cover clockwise past the Deformation station waiting for the foaming station.

The inventive plant can for a cycle time of 51 seconds are designed. In a three-shift operation is the gross annual volume above 230 days per year at about 350,000 units.

The According foamed plastic parts according to the invention can produced locally by the consumer or subcontractor, and with low transport costs and storage costs, because the Goods in the form of film rolls is delivered.

For outer skins are Thus, no special racks necessary, resulting in a considerable Reduction of transport costs for molded skins, including the storage areas results. By eliminating electroforming and corresponding Facilities result in significant reductions in investment costs.

The Foaming are structurally similar to today's tool design, but with some additional versions, designed. This process involves four negative IMG tools needed in the underfoaming tools are integrated. The material properties of the TPO film with respect to Aging and lightfastness are excellent. The foil material is by the way recyclable. The resulting waste can for producing the TPO lower film be processed again. The invention enables a clock-bound and therefore very economical Process flow. Furthermore can installations used or their components for modified model facilities to be used again. Typical heating temperatures for the IMG film used are 80 ° C in the preheating station or 210 ° C in the heating station.

The present invention makes it possible to save both investment and product costs, since the method according to the invention can be highly automated and is very efficient. Only four IMG lower tools and three mold covers are required in this process. Another advantage is that the TPO film can be positioned exactly in the lower tool thanks to the negative thermoforming process niert, since the film remains until the foaming process in the lower tool without a manual correction of the sub-position must be made. This makes it possible to produce component part with very tight tolerances, or with "zero gap".

The Invention allows it, today's design requirements in terms of resistance, feel, to meet tight radii. The invention is in the drawing based on an embodiment illustrated.

1 shows a Hinterschäumungsanlage invention in cross section from the side,

2 shows the foam plant 1 in plan view and

3 shows a table in which the timing of the inventive method is illustrated.

1 shows a Schäumungsanlage invention 1 in the view from the side, partially cut. The foam plant 1 is divided into a film unwinding station 2 , in a subsequent Folienvorwärmstation 3 , in a subsequent heating station 4 into a molding and foaming area 5 as well as in a Folienaufwickelstation 6 ,

The molding and foaming area 5 is divided into a turntable 7 to the or on the other components of the foam-making plant according to the invention 1 are arranged. So are a total of four lower tools 8th in a 90 ° division on the turntable 7 placed. In 2 are the four lower tools 8th each of a mold cover 10 locked.

How to best in 1 sees is in the molding and foaming area 5 on the left a preforming station 11 arranged. The preforming station 11 has a press facility 12 with a guide stamp 13 which has a preform stamp on the bottom 14 wearing. The preform stamp 14 is designed so that it contour to the provision of a distance with a negative mold 15 in the lower tool 8th interacts. The negative form 15 is provided on its surface with a not shown here grain. In addition, small vacuum openings are in the negative mold 15 attached and connected to a non-visible in this view vacuum generating device. From the preforming station 11 are in 2 for the sake of clarity, most of the components have been omitted.

The foaming area 5 also has a foaming station 16 with a mobile mixing head, the polyurethane components polyol and isocyanate linear in the open foaming tool 8th enters.

The foaming station 16 opposite is a removal station 20 where an operator is standing. Between the removal station 20 and the foaming station 16 extends circumferentially a slide guide 21 that have two rails 22 having. In that this area are circulating are two scenes, each with a guide plate 17 and a guide stamp 18 designed. With the two sets, the mold covers 10 , depending on the corresponding forming station, the lower tool 8th added or the lower tool 8th taken. Between the removal station 20 and the foaming station 16 becomes the mold lid 10 transported across the mobile backdrop. The energy supply for the mold cover also takes place via the slotted guide 21 ,

The operator of the foam plant 1 always sets a mold lid 10 with second shape stamp 19 at the removal station 20 into the slide tour 21 one, whereupon this to the foaming station 16 emotional.

For film transport, a number of guide rollers is provided, over which a film 23 across the foam plant 1 to be led. Here is the slide 23 starting from the film unwinding station 2 through the preheating station 3 and through the heating station 4 guided. The foil 23 then leads across the preforming station 11 , is then deflected obliquely downwards, through a recessed middle part of the turntable 7 downward. The foil 23 gets diagonally below the right area of the turntable 7 led through how best in 1 sees. After that, the film becomes 23 guided back up and in the Folienaufwickelstation 6 wound.

In the use of the foam plant according to the invention, the procedure is as follows. In an initial state, the film is 23 across the foam plant 1 led, as in 1 and 2 you can see. There are a total of four lower tools 8th on the turntable 7 , The heating station 4 is actuated so that the film therein 23 is heated. After heating the film 23 becomes the film unwinding station 2 and the film winding station 6 so pressed that in the heating station 4 heated area of the film 23 in the preforming station 11 moves, via the lower tool located therein 8th and 15 , Then the guide stamp becomes 13 so pressed that the forming punch 14 moved down. This is the film 23 in the negative form 15 protruded. By applying a vacuum, the heated film section settles against the negative mold 15 at. At the same time, a cutting device, not shown here, has the advantage that results in the negative form 15 from the rest of the slide 23 separated, leaving a cutout 24 in the slide 23 arises.

Then the guide stamp moves 13 back from the lower tool 8th out. The turntable 7 turns the lower tool 8th with the benefit in it in a clockwise direction, below the foaming station 16 , this is the scharmant on the already station 16 into the open foaming tool. The mold cover located on the backdrop 10 with the carrier insert is in the lower tool 10 retracted. The complete tool, which comes from the lower tool 8th and the mold lid 10 is closed and locked. Thereafter, the area between the inner contour of the mold cover 19 and foams the benefits with PU foam. The empty scenery moves in a clockwise direction past the PU hardening station in waiting for the partial removal station 20 ,

The turntable 7 continues to rotate 90 ° clockwise, leaving the lower tool 8th and 15 with the benefit contained therein, the plastic foam between benefits and the forming die 19 is heated by a heater, so that the plastic foam hardens.

After curing, the lower tool 8th by a rotation of the forming table 7 90 ° clockwise to the removal station 20 emotional. Here, over the second link guide the mold cover 10 automatically opened. The mold lid 10 remains at the scenery. The operator removes the finished foil / foam part, cleans the negative mold 15 and places a new carrier part on the mold lid 10 ,

In mass operation, the backfoaming system 1 operated at a predetermined clock, at the same time the preforming station 11 , the foaming station 16 , the heater and the withdrawal station 20 operate. The film is thereby moved discontinuously.

3 illustrates the cyclic operation of the foam plant according to the invention 1 along with estimated cycle times.

1.

Hinterschäumanlage

Second

Folienabwickelstation

Third

Folienvorwärmstation

4th

heating station

5th

Shape- and foaming area

6th

Folienaufwickelstation

7th

turntable

8th.

lower tool with clamping frame and trimming edge

9th

adjustment mechanism

10th

mold cover

11th

preforming

12th

presser

13th

guide die

14th

preform temple

15th

negative form (IMG tool integrated in lower tool 8)

16th

foaming station

17th

guide plate the slide tour

18th

guide die the slide tour

19th

inner contour forming punch

20th

removal station and insertion station

21st

link guide

22nd

rail

23rd

foil

24th

neckline

Claims (10)

Backfoaming plant ( 1 ) for the production of plastic parts, in particular for motor vehicles, the backfoaming plant having the following features: a film unwinding station ( 2 ), - a molding and foaming area ( 5 ), with a preforming station ( 11 ), which have a shape stamp ( 14 ) and a negative form ( 15 ) for film sections from the film unwinding station ( 2 ), wherein the negative mold ( 15 ) is provided on its surface with a grain, with a turntable ( 7 ), on which with a mold cover ( 10 ) closable sub-tools ( 8th ) are arranged, and with a foaming station ( 16 ) for each one located in a lower tool film section with plastic foam. Foaming machine according to claim 1, characterized in that a to the Folienabwickelstation ( 2 ) subsequent Folienvorwärmstation ( 3 ) and / or in one of the at the Folienabwickelstation ( 2 ) or to the Folienvorwärmstation ( 3 ) subsequent heating station ( 4 ) is provided. Foaming system according to claim 1 or claim 2, characterized in that the negative mold ( 15 ) Has vacuum ports connected to a vacuum generator. Foaming system according to one of the preceding claims, characterized in that for the lower tools ( 8th ) at the foaming station ( 16 ) each a mold cover ( 10 ) is provided, on its underside a second forming punch ( 19 ) having. Foaming plant according to one of the preceding claims, characterized that on the turntable ( 7 ) a curing station is provided, each having a lower tool ( 8th ) applied with heat. Foaming installation according to one of the preceding claims, characterized in that a film receiving station ( 6 ) for receiving film residues from the molding and foaming area ( 5 ) intended. is. Foaming plant according to one of the preceding claims, characterized in that on the turntable ( 7 ) of the foaming station ( 16 ) opposite a removal station ( 20 ) is provided, wherein between the removal station ( 20 ) and the foaming station ( 16 ) a slide guide ( 21 ) for mold covers ( 10 ). A method of manufacturing a grained surface plastic foam part, the method comprising the steps of: providing a film ( 23 ) made of plastic, forming a film section of the film ( 23 ) using a negative form ( 15 ) into a desired final shape, wherein the film portion is provided with a grain, coating the film portion on its inside with plastic foam. A method according to claim 8, characterized in that for forming the film section, the film ( 23 ) in the negative form ( 15 ) is pressed, wherein the film section by means of vacuum to the negative mold ( 15 ) is created. Method according to claim 8th or claim 9, characterized in that the film ( 23 ) is heated before forming.