DE10133813A1 - Surface treatment of cut foam plastic panels comprises pressing glued paper sheets on to their surfaces - Google Patents

Abstract

Surface treatment of cut foam plastic panels (11) comprises pressing glued paper sheets (10) on to their surfaces.

Description

The The invention relates to a method for producing parts, in part consisting of plastic foam.

Plastic foam is a product with more variety Application.

One is a major problem in the production of plastic foam for some years the propellant. Plastic foam is created with a propellant. Propellants are sometimes also used as a blowing agent designated. This describes the effect of the propellant. The blowing agent forms bubbles in the molten plastic.

In front For some time, all manufacturers have been reliable and easy to use Propellants in the form of CFCs in various forms equally to Available. After the environmental damage the conventional one Propellant has shown, the manufacturers are to other propellants endeavor. The most popular Alternative propellant is carbon dioxide. However, this propellant is extremely problematic.

The shows, inter alia, that only at certain thicknesses a sufficient foaming result is reached. That has to the consideration guided, larger plate thicknesses to achieve by doubling and smaller plate thicknesses by division. The Division is also called peeling.

The Peel has long been the state of the art for particle foam parts. there will be a relatively large one Foam block of foam particles divided into webs. The single ones Tracks are peeled off the block. For peeling, e.g. Knife, Sawing and also heated cutting wires.

Particle foam parts are obtained from foam particles that come from different manufacturing processes disposal stand. In the main, foam particles are created by that initially granulated thin melt strands become. The melt strands are optionally unfoamed extruded and granulated. Subsequently, the particles in used an autoclave and under pressure and temperature with a propellant added. After sufficient propellant charge and softening The particles are suddenly released from the autoclave. The propellant leaves the particles lather up.

One other common ones The way to produce foam particles is also melt extrusion out. In contrast to the extrusion of unfoamed melt described above extruding a blowing agent-laden melt in the other way, so that one Foam strand is formed and in the subsequent granulation immediately foam particles attack.

The Foam particles become a molded part in a molding machine connected with each other. The molding machine contains a mold cavity with a exact picture of the desired Molding. The mold cavity is completely filled with the foam particles, preferably This happens under pressure Subsequently, the foam particles in the mold with superheated steam applied. The hot steam The task is to soften the foam particles on the outer surface. Under the existing pressure, it comes to a welding of Foam particles.

The proper softening requires a superheated steam temperature in the range the melting point of the plastic foam. In polystyrene lies the melting point slightly above 100 Centigrade. The necessary hot steam temperature is under increase reached the vapor pressure. Other plastics require a larger increase. polypropylene has a melting point between 150 and 170 degrees Celsius.

On the ways produces relatively thick blocks become.

With The new propellant can be less thick plates by pure Create extrusion.

Either the plates / blocks made of foam particles as well as the extruded sheets can be peeled. By peeling arise cut surfaces with open cells.

In the processing of skived foam products the open cells are a problem. The open cells are suitable not as a visible surface and are conducive to pollution, because the dirt collects in the cells. The same applies for pathogens.

Around such cut surfaces as visible surfaces use to be able to or to allow as touch surfaces is conventional a significant coating required. When laminating be Slides relatively large Thickness used. It is a melamine resin coating (thermoset) for peeled EPS foam sheets the cut surfaces known. The lamination is a Klebekaschierung.

The cut surfaces can not be painted directly. To generate a adequate painting quality have to the cut surfaces be filled until the open cells are closed / filled.

The object of the invention has been found to provide a simple and economical processing of plastic foam cut surfaces, in particular peeled plastic foam. The invention has recognized that the conventional lamination of plastic films has various problems:
The adhesive consumption is much higher than the consumption of comparable elsewhere. The coloring / decor design is complicated and difficult in the usual plastic films.

To The invention is achieved by applying paper to the cut surfaces. The paper is glued or laminated. advantageously, can with the paper layer according to the invention not only the problem of cut surfaces can be solved. The application of Paper layer is also for uncut molding surfaces Of particle foam moldings advantage. Normal molding surfaces are untreated areas (as a surface treatment thermoforming in the mold is also considered). Such surfaces show more or less an orange peel. Cause are the up facing surfaces between the boundaries of the foam particles. Usually there is sufficient Temperature of the molded part at the upwardly facing foam particle surfaces a curvature between the lateral boundaries of the foam particle surfaces, which are described in the Shape is emerging.

By Sticking or laminating paper, the surface is smoothed. at gluing paper is less adhesive than gluing required by slides.

paper has ideal conditions for this Imprinting of colors or decor.

The for the Surface treatment according to the invention provided paper preferably has a thickness determined by the weight measured in grams per square meter and 5 to 100 gr per square meter is.

The Paper is made regularly disordered, bonded together cellulose fibers. Such fiber structures can also be described as fleece. But it can also be knitted fabrics from ordered cellulose fibers find application.

To the Gluing the paper, many adhesives, e.g. Dispersion adhesive, Acrylic adhesive Pulyurethane adhesive. An amount of glue from 5 to 80 grams per Square meter is for a bond sufficient. As a rule, the amount of glue used 20 to 40 grams per square meter. The consumption of adhesive can over it be reduced by the fact that only a glue on the cut / peeled Plastic foam foam takes place. Only the cut surfaces of the cell walls wetted with glue.

The Laminating paper can be done by ironing. When ironing is heats the paper on the side facing away from the plastic. The Temperature must be there be chosen so high that on the contact surface of the Paper with the plastic foam a minimum temperature and a maximum temperature should not be exceeded. The minimum temperature is at most 20 degrees, preferably at most 10 degrees Celsius, below the melting point of the plastic in question. The maximum temperature is at most 20 degrees, preferably at most 10 degrees Celsius, over the melting point of the plastic in question. The paper is at the temperatures required here are relatively insensitive.

To the Iron are conventional Iron. Such irons are operated by hand. A robot could replace manual operation.

in the Meaning of the invention counts to the ironing too a warming with a heating roller. Preferably, the ironing is done with a hot press. The press has the advantage of being with appropriate design at the same time apply their pressure on the entire paper surface can.

Optional the lamination is facilitated with a bonding agent. When Adhesion promoters come with coatings / primers and / or additional surface treatments into consideration. It can too Papers find application, the plastic foam side with a plastic coated, which forms a connection with the plastic foam. The coating may e.g. be prepared by that fine-grained particles made of the same plastic as the plastic foam spread on the paper and subsequently be melted.

One Adhesive can also by an interposed plastic film be formed.

Cheap is it, when the plastic foam to be coated with paper on two opposite To coat pages. This will be a uniform expansion / contraction at temperature changes guaranteed.

A Press is especially for a coating on several sides suitable. In addition, with a press simultaneously several coating operations done become.

The coating operations can also be repeated several times. Advantageously eig Paper is very good for printing. Any decor can be printed.

With the method according to the invention can be e.g. economically produce very cheap decorative surfaces. One field of application is wall cladding, e.g. the imitation of wood paneling or the imitation of stone surfaces, e.g. Marble surfaces. Across from real wood imitations of the invention are not crack / moisture vulnerable. Similarly the weight is very cheap. light Bonding secure inventive panels in every desired Position.

Preferably is applied according to the invention Paper or decorative paper provided with a protective coating, colored or colorless, as needed.

In The drawing is an embodiment of a Invention shown.

The drawing shows a multiple press, consisting of a lower crossbar 1 , an upper crossbar 2 , Guide and tie rods 3 and 4 , sliding on it press parts 6 and 7 and a hydraulic power piston 5 ,

The parts 1 . 6 and 7 are heated. The heating is done electrically with a variety of uniformly distributed heating cartridges that can be easily controlled or controlled, because they have integrated temperature sensor.

In the embodiment, peeled webs 11 made of polypropylene foam with a density of 150 kg per cubic meter on both sides with decorative paper 10 coated.

In each case there is a train 11 with two decor papers 10 between the press parts 6 and 7 respectively. 1 and 7 ,

By actuating the hydraulic power piston 5 All parts are pressed against each other. At the same time the plastic foam on the surface undergoes heating up to melting temperature. The heating temperature is set to 200 degrees Celsius. The exposure time is selected by some experiments so that exactly the melting temperature is reached on the plastic foam surface and a small melting takes place, so that the paper adheres to the plastic foam.

To sufficient cooling can the coated plates are removed from the press again.

After that a protective coating with colorless varnish.

Claims (15)

Process for the surface treatment of plastic foam parts, in particular plastic foam cut surfaces, characterized in that paper is glued or laminated, in particular ironed. Method according to claim 1, characterized in that that for plastic foam cut surfaces with open Cells an adhesive at a rate of 5 to 80 grams per square meter, preferably 20 to 40 grams per square meter is applied. A method according to claim 1 or 2, characterized by dispersion adhesive, acrylic adhesive or polyurethane adhesive. Method according to claim 1, characterized in that that at iron on a temperature is generated at the plastic foam surface, the maximum Preferably 10 degrees Celsius below the melting point of the plastic lies and / or at most 20, preferably 10 degrees Celsius above the melting point of the plastic lies. Method according to claim 4, characterized by use a paper with a basis weight from 5 to 100 grams per square meter. Method according to one of Claims 1, 4, 5, characterized that the Ironing heat at the applied to the plastic foam side facing away from the paper becomes. Method according to claim 6, characterized by Use of an iron and / or a heating roller and / or a heated press. Method according to claim 7, characterized by Using a multiple press. A method according to claim 7 or 8, characterized through the use of electric heating cartridges, in particular with integrated temperature sensor. Method according to one of claims 7 to 9, characterized by cooling after the coating. Method according to one of claims 7 to 10, characterized by simultaneously coating several surfaces in a heating press Method according to one of claims 1 to 11, characterized by a Mehrfachbeschich tung. Method according to one of claims 1 to 12, characterized through the use of a decorative paper. Method according to one of claims 1 to 13, characterized by a protective coating after coating. Method according to one of claims 1 to 14, characterized by application to extruded foams as well as to particle foam moldings, also peeled Plastic foam parts, in particular webs and plates.