DE10359964B4 - Method of displaying multicolored or patterned panels - Google Patents

Abstract

method for the production of elastic plastic molded skins (11), in which a Adhesive (2) in a mold container (1) in at least one partial area (3, 4) on the inside (6) of the cold mold container (1) is applied, then a first granular, flake or powdery Plastic material (8) is filled in said mold container (1), wherein the plastic material (8) only to the wetted Part areas (3, 4) with the adhesive (2) connects and under action of heat a thin, sticky porous Film (14) is formed, then a second granular, flake or powdery Plastic material (10) is filled in the hot mold container (1), and the mold container (1) is moved so that the entire inner side (6) of the mold container of at least one layer of plastic material (8, 10) completely covered which sinters to a closed plastic molded skin (11), which after cooling the mold container (1) in one piece can be removed.

Description

The The invention relates to a process for producing multicolored or Patterned panels and a device for carrying out the Process.

document EP1240990 A1 describes a mold reflow process for producing plastic moldings. Because of the mixing effect of the molten liquid in the mold container can be produced by this known as slush molding process melting only one-colored moldings, while for aesthetic reasons, but also to prevent bright interior paneling interior reflections annoying reflections of the interior trim on the windshield, often multicolored moldings, such as those with dark colored speckles on a light background, are required. The in the EP1240990 A1 proposed solution is based on the consideration that the unavoidable with the slush method, homogeneous coloration of the molding when using different color plastic particles can be prevented by at least one of the particle types is held during the Aufschmelzphase in a higher viscosity state. The differently colored plastic particles have a different depending on the color melting temperature and the mold container is heated only to the extent that the higher melting color particles remain below the low viscosity melt state, while the second variant material same plastic particles of different colors are used and the entire particle mixture in the Aufschmelzphase not on the is heated to a viscous molten state.

This On the one hand, the method requires a very precise temperature control for heating the surface of the mold container, Moreover, it is not disclosed in what way it is guaranteed that at an at least uniaxially movable form the two powdery materials do not mix.

In the further consequence will be accordingly also color or lighting effects described, which extend uniformly over the entire molded part.

The document DE 42 02 354 A1 shows the introduction of paints in portions of the mold prior to the introduction of a plastic material.

task The invention is to provide a method of the type mentioned, with which on production technology simple way multicolored moldings can be produced, in which individual areas of different coloring clearly separated from each other.

These The object is achieved by the in the claims described method solved. The powder is used to produce a surface of uniform thickness mixed by mechanical movement of the mold container and uniformly over the form surface of the cold mold container distributed, with the powder in the areas on the inside of the mold container adheres, in which an adhesive was applied. The granular, flaked or powdered Plastic material is subsequently sintered under the effect of heat in the mold vessel and at least on its surface melted. Then a second granular, flaking or powdery Plastic material in the hot mold container filled in and for producing a surface uniform thickness mixed by mechanical movement of the mold container and uniform at least over the form surface of the mold container which has not been wetted by the adhesive. By the heat effect is also the second granular, flake or powdered plastic material in the mold container sintered and at least melted on its surface. thereupon becomes the mold container chilled and the finished plastic molded skin removed.

One Such process takes place in the manufacture of plastic linings for interior parts in vehicles, such as the interior trim of an instrument panel of motor vehicles, use.

The Invention will now be described with reference to the method shown in the figures as well as on the basis of exemplary embodiments explained in more detail. These show in a highly schematic representation:

1a -E a process according to the invention in successive process steps

2 a view of a prepared according to the invention multicolor molding.

3 a view of another, prepared according to the invention multicolor molding.

According to 1 First, an adhesive is used to make a multicolor plastic panel 2 applied in a mold container. The adhesive is, for example, by means of a stamp 5 from a carrier material, which with the adhesive 2 is impregnated or has conveying means for the adhesive, such as by means of a tampon or a roller, in at least one defined area 3 . 4 the mold container is positioned, wherein the surface of the mold container within the boundary of each area 3 . 4 completely with adhesive 2 is covered. The temperature of the mold container 1 is on its inside 6 min at room temperature, in cyclic operation preferably between 20 ° C and 60 ° C. In this temperature range, the viscosity of the adhesive is 2 in a range which precludes bleeding of the adhesive at these temperatures. The adhesive properties of the adhesive correspond to those of a viscous oil. The adhesive used is a solvent, for example a plasticizer, which is also part of the plastic material described in more detail below or can mix with it in a homogeneous mixture or react with it. Areas ( 3 . 4 ) can be attached to any inclined parts of the inside 6 of the mold container.

In 1b is shown that a powder box 7 is docked to the mold container. In this powder box 7 There is a first granular, flake or powdery plastic material 8th , The plastic material is distributed on the inside 6 of the mold container and stick in the areas ( 3 . 4 ) in which the adhesive has been applied.

In 1b The non-adhesive plastic material is returned to the powder box 7 tilted and the powder box then moved away from the mold container. The mold container 1 gets on its outside 15 heated by a heating medium. In 1c , is shown as another powder box 9 to the mold container 1 is docked. This powder box contains a second plastic material which differs in color and / or composition from the first plastic material. Then the mold container 1 heated so that it comes to a sintering process of the plastic particles. It forms a thin, sticky, porous film ( 14 ) in the subregions ( 3 . 4 ) on the inside of the mold container 1 out. The second plastic material is by means of a powder box 9 applied to the areas in which no adhesive 2 and therefore no first plastic material 8th available. Since the mold vessel is heated, the second plastic material adheres 10 directly on the inside 6 of the mold container. Due to the heating, the particles of the plastic material completely sinter together and subsequently gel on the surface of the plastic material, that of the inside 6 the mold container is opposite. If the plastic material is PVC containing a plasticizer, gelling causes the plasticizer to dissolve in the PVC matrix.

By This gelling process, it is very possible surfaces greater To obtain surface quality, which meets all requirements for surface quality in the vehicle interior Motor vehicle correspond.

During the heating process, an oscillating motion or a combination of a rotational and oscillatory movement of the mold container and the powder box is advantageous in order to ensure a uniform distribution of the plastic material over the entire surface of the mold container. Then the powder box 9 in 1e again from the mold container 1 separated and there is a cooling of the mold container. The cooling solidifies the plastic layer and a coherent plastic molded skin 11 can according to 1f be removed from the mold container.

In 1f Furthermore, a section of the plastic molded part is shown. The two plastic materials ( 8th . 10 ) directly adjoin one another in this embodiment. In the movie 14 it is the narrow area where both plastic materials are in close proximity to the inside 6 melt the mold container. This trained as a film layer 14 may also contain structures, so the mold container one or more different patterns, called graining, has.

2 is a view of such a plastic molded skin 11 after its removal with the surface, which the inside 6 of the mold container 1 located opposite. This surface 12 It is also referred to as the visible side because it represents the surface visible to the occupant of the vehicle. The two different plastic materials ( 8th . 10 ) are characterized by different hatchings.

In 2 are further openings 13 visible in the plastic molded skin. These openings are attached in a subsequent processing step in order to avoid that foam material can usually pass through the otherwise liquid-tight plastic molded skin in the foaming process which is usually directly adjacent to the production of the plastic molded skin.

In 3 is another plastic molded skin 11 shown in their installed state in the vehicle. Here is the first plastic material 8th only the areas ( 3 . 4 ) out. Selection and location of these areas is arbitrary, since for the method according to the invention no restrictions on the position of the said areas must be accepted.

In addition to PVC, other thermoplastic materials may be used, such as thermoplastic polyurethane elastomers (TPU), which in the melting phase ( 1d ) are usually heated to about 200 ° C with the mold container briefly on the Temperature of the melted state of the TPU is maintained, and then heated only to about 160 ° C, so that the two thermoplastic plastic materials ( 8th . 10 ) connect.

In a further embodiment become two plastic materials of different composition used. If the plastic material is polyvinyl chloride (PVC), is used as an adhesive plasticizer. Because plasticizer in the plastic material as additives usually to one anyway low percentage may be included, it is possible to the proportion of plasticizer in the first plastic material already at reduce its production. Since it too during the melting process a solution plasticizer comes in plastic material increases while the course of the process according to the invention the content of plasticizer in the first plastic material anyway.

The mold container itself can have either a smooth or a textured inside. For different areas ( 3 . 4 ) or for the subregions, which are each loaded with a different plastic material, different structures in the mold container, also referred to as Galvanoform, can be provided. Such structures can be separated from one another by grooves. If these grooves on the perimeter of the areas 3 . 4 come to rest, it is possible to produce by means of the method according to the invention a sharp dividing line between differently colored or patterned plastic parts.

As in the practical testing of the method according to the invention has shown, it has succeeded in this way, gradients between the to prevent different particle colors and thus multi-colored To obtain moldings with clear color boundaries. Both in laboratory tests as well as in a mold container, which has been charged with plastic materials for experimental purposes, could be made a multicolored plastic molded skin. It could also disguises for Instrument panels are represented by serial tools in two-color design become. Also in the pilot plants it was shown that a closed skin the cold introduced powdery Plastic material can be gelled and in the same heating phase a plastic material of a second color can be applied over it and seamlessly with the first plastic material in a double-flushing process can be connected. Then plastic skins were foamed and passed on to the laboratory test.

As In the laboratory tests, it shows that a groove is beneficial is when a sharp color separation is desired. Likewise, a Cover the second color range are considered, taking place in the "cold" state can be and technically much easier to solve than other methods, in which such covers must be made in the hot mold container. The embodiments were determined according to the procedure described below.

The method relates to the production of three-dimensional one-sided molded plastic molded skins, which are composed of several differently colored and / or patterned zones or areas with defined boundaries. These areas contain finely divided elastic plastic particles, such as microgranulate, Kryomahlgut or microcompound. To produce such plastic molded skins, a mold container is used, which is also referred to below as a tool. Parts of the tool surface are coated at a low temperature with a thin layer of a medium-viscosity solvent for the plastic particles and then by suitable rotational and optionally oscillatory movements of the tool unit, so with the plastic material - hereinafter limited to plastic powder to the exemplary embodiments described by experiments - brought into contact, that this superficially connects at the wetted sites with the solvent and forms a thin, sticky porous film to which in turn further powder adhered. After removal of the excess powder, defined areas of the tool surface are replaced by a fluid heating medium from the back or outside 15 of the mold container depending on the nature of the plastic powder heated to 180 to 250 ° C. During this period, this first plastic powder is brought into contact with further, differently colored plastic powder in order to form a closed powder layer in a matched on material properties and tool geometry 2-axis movement process, the one by the influence of temperature and time over the entire tool surface including the already In the first step, the surfaces produced are sintered to form a closed plastic film. After the subsequent cooling, the film solidifies to an elastic skin, which can be removed as a whole from the tool.

In the plastic material ( 8th . 10 ) in the first embodiment is a compound based on polyvinyl chloride (PVC). In this case, the solvent is a plasticizer, with the plasticizer content in the plastic material ranging from about 15 to 40%. The plasticizer composition comprises a 2 or 3 base aromatic acid and 1-3 saturated aliphatic monools.

In a second embodiment, the plastic material ( 8th . 10 ) to a polymer from the group of thermoplastic elastomers, such as aliphatic or aromatic linear or weakly branched thermoplastic polyurethane elastomers, aromatic ester-ether block elastomers or thermoplastic polyolefin elastomers.

Especially were in tests two-color plastic molded skins according to the inventive method manufactured, with a serial bus module with series rear wall and Serial galvano for an instrument panel was used. As plastic material were in the first powder box serial powder (color soul "black"), designation: TACZ 3 / TT, a compound based on polyvinyl chloride and in the second Powder box series powder (color platinum light "light gray"), with the designation: TA 509 / B6, likewise a compound based on polyvinyl chloride used. When Adhesive or primer was a repair plasticizer used. This plasticizer was applied by foam roller to the inside of the mold container, So applied to the Galvanos.

to execution of the experiment, the system is switched to "manual mode" The temperature of the heating medium for the mold container is 60 ° C. In the Oil is used as a heating medium in the present pilot plant.

Of the Apply the primer by means of foam roller in both wells of the electroplate in the area of the instrument panel, which in the installed state is arranged near the windscreen of the vehicle. This area should get a lighter shade, which are produced by serial powder "light gray" should. The duration of the contract of the adhesion agent is about 15 Minutes.

Then done the docking of the second powder box, the following sequence of movements the connected to the powder box Galvanos takes place: turning the Electroplating in + 145 ° position for one Duration of 5 minutes, then turning the electroplate to -145 ° position for one Duration of 5 minutes and finally turning in 0 ° position. Subsequently an oscillation process takes place, in this case a shaking movement with 150 strokes / min for a duration of 5 seconds.

Subsequently, will decoupled the powder box and moved back to the basic position. The Galvano is now in the removal position for the plastic molded skin, so that a control of the adhering powder can be done and at the same time by gently blowing off the others, not from the Wet series powder "light gray" Areas were ensured that no slush powder in the not located by adhesion promoter wetted areas.

Afterwards the module is switched to "automatic mode" and the series injection program is started, but with the first powder box In the series program the slush powder of the color "soul" is used as second color layer over the first color layer and above all on the areas of the first color layer not covered Galvanos applied and molded by a conventional slush method to a coherent plastic molded skin. The side of the powder facing the inside of the electroplating sinters and gels, so that a surface of higher quality can be produced. Subsequently, the galvano is moved to the removal position and the instrument panel double skin can be removed after a short cooling cycle. This plastic molded skin is then foamed with a carrier material in a conventional series foaming tool. As a result, four double skins of an instrument panel were produced in a slush process and foamed in a subsequent process step. The suitability of the plastic molded skin for paneling an instrument panel could thus be demonstrated in the experiment. The arrangement of the two differently colored portions of the panel are in 2 in the plan view of the instrument panel approximately reproduced. Of the four foamed instrument panels, two were passed to laboratory tests. By means of the experiments, a clear color separation could be generated, whereby the overlapping area of the two colors is limited to a few millimeters. At a distance of 50 cm, the color separation is perceived by the eye as a line.

1

mold container

2

adhesives

3

Area

4

Area

5

stamp

6

inside

7

powder box

8th

first Plastic material

9

powder box

10

second Plastic material

11

Plastic molded skin

12

surface

13

opening

14

Movie

15

outside of the mold container

Claims (12)

Process for producing elastic plastic molded skins ( 11 ), in which a Haftmit tel ( 2 ) in a mold container ( 1 ) in at least one subarea ( 3 . 4 ) on the inside ( 6 ) of the cold mold container ( 1 ), then a first granular, flake or powdered plastic material ( 8th ) in said mold container ( 1 ), the plastic material ( 8th ) only at the wetted subregions ( 3 . 4 ) with the adhesive ( 2 ) connects and, under the action of heat, a thin, sticky porous film ( 14 ), then a second granular, flake or powdered plastic material ( 10 ) in the hot mold container ( 1 ), and the mold container ( 1 ) is moved such that the entire inner side ( 6 ) of the molding container of at least one layer of plastic material ( 8th . 10 ), which forms a closed plastic molded skin ( 11 ) sintered, which after cooling of the mold container ( 1 ) can be removed in one piece. Method according to claim 1, characterized in that the adhesive ( 2 ) a solvent for the plastic material ( 8th . 10 ). Method according to claim 1, characterized in that the plastic material ( 8th . 10 ) is thermoplastic and soluble in solvents. Method according to claim 3, characterized in that the plastic material ( 8th . 10 ) is a compound based on polyvinyl chloride (PVC). Process according to claims 3 or 4, characterized in that the solvent a plasticizer. Process according to claims 4 or 5, characterized in that the plastic material ( 8th . 10 ) comprises a plasticizer content of 15 to 40%, wherein the plasticizer comprises a 2 or 3 base aromatic acid and comprises 1-3 saturated aliphatic monools. Method according to claim 3, characterized in that the plastic material ( 8th . 10 ) comprises the group of thermoplastic elastomers such as aliphatic or aromatic linear or weakly branched thermoplastic polyurethane elastomers, aromatic ester-ether block elastomers or thermoplastic polyolefin elastomers. Method according to claim 3, characterized in that the plastic material ( 8th ) against the plastic material ( 10 ) has a reduced content of solvent. Method according to claim 1, characterized in that the molding container ( 1 ) after each entry of plastic material ( 8th . 10 ) Performs oscillatory movements or rotational movements or combinations thereof. Method according to claim 1, characterized in that that the plastic material of micro granules, Kryomahlgut or Microcompound or the like exists. Method according to claim 1, characterized in that that the mold container on its outside is heated. Method according to claim 11, characterized in that that the heating temperature is in the range between 180 ° C and 250 ° C.