Surface improving process

Details Surface improving process Surface improving process

1999-02-19

2002-08-13

Kuhns, Allan R. (Department: 1732)

Adhesive bonding and miscellaneous chemical manufacture

Methods

Surface bonding and/or assembly therefor

C156S247000, C264S046400, C264S046500, C427S373000

Reexamination Certificate

active

06432237

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to a process and an assembly for improving surfaces, preferably uneven narrow surfaces, of wood-based materials.
BACKGROUND OF THE INVENTION
Surface treatment processes of the type in question are widely used in the furniture industry. This is because the wood-based materials used in the furniture industry are not left in their original state, but are given an improving surface coating, mostly a melamine coating. The coating materials used also include veneers, decorative laminates or decorative films.
A special edge material is often used for coating sides, edges or, generally, narrow surfaces. This special edge material may be, for example, an edge veneer or a so-called narrow-surface band which is applied to the narrow surfaces by means of an adhesive. This process is known generally as edge banding.
However, it is often desirable to round off the narrow surfaces or edges on aesthetic grounds or to provide profiled surfaces for functional reasons. Other coating techniques besides edge banding, which is also known as soft forming, are used in the coating of such “soft” contours.
One of the reasons for wanting to improve surfaces is that the surfaces to be coated are often very uneven, full of voids, etc. This applies in particular to chipboards.
When coated by one of the processes mentioned above, surfaces such as these become noticeably uneven, “bumpy” or undulating which spoils the appearance of subsequent pieces of furniture for example. To obtain an improvement, thicker edge or coating materials are often used because they are able sufficiently to level out any unevenness in the surface and to avoid so-called telegraphing of the substrate. However, any increase in the thickness of the material is accompanied by an increase in the resilience of the bent coating material. This in turn means that a longer contact pressure zone is required for bonding the stiffer coating material. Moreover, thicker coating materials are generally more expensive.
The process and assembly described in DE 44 42 397 for treating surfaces, more especially narrow surfaces, are better. Here, a formable coating material is applied and smoothed by means of a smoothing band. However, the surfaces obtained are again not smooth enough for all applications.
SUMMARY OF THE INVENTION
Accordingly, the problem addressed by the invention was to provide a possibility by which the disadvantages mentioned above could be eliminated and which would enable surfaces to be smoothed in a simple manner.
The present invention provides a process comprising the steps of applying a formable coating material to a wood-based material, forming the applied formable coating material by smoothing, modelling or both smoothing and modelling to achieve a smoothed surface on the wood-based material, and heating the applied formable coating to form closed pores while maintaining said smoothed surface intact.
In embodiment of the invention, the process comprises the steps of applying a formable coating material to decorative layer, pressing the decorative layer with the formable coating material applied thereto against a wood-based material to achieve a smoothed surface on said wood-based material, and heating the applied formable coating material to form closed pores while maintaining said smoothed surface intact.
The present process may in another embodiment comprise the steps of applying a formable coating material to a flexible layer having and adhesive-repellent coating, pressing the flexible layer with the formable coating material applied thereto against a wood-based material to achieve a smoothed surface on said wood-based material, heating the applied formable coating material to form closed pores while maintaining said smoothed surface intact, and removing the flexible layer from said smoothed surface.
DETAILED DESCRIPTION OF THE INVENTION
The coating material is applied, for example, by a roller, an adjustable slot die or a transfer tape, preferably to the edge band (edge veneer). However, it may also be applied to the wood-based material. It is preferably applied to the surface by means of a transfer tape. This has the advantage that there is no need for an applicator roller adapted to the profile to be coated in order to apply the material. The manufacture of such profile-adapted applicator rollers or even specially adapted application nozzles is time-consuming and extremely expensive, especially where large numbers of different edge profiles are involved. In addition, different profiles cannot be coated in a short time.
The coating material is preferably applied to the surface to be treated by pressure. A suitable pressure element applies a force to the band on its uncoated side so that the coated side of the transfer tape is pressed onto the surface to be coated.
Application of the coating material is improved by additional heat treatment of the coating material or wood-based material. Infrared heaters, hot air fans, high-frequency heaters or the like are preferably used for this purpose.
In one preferred embodiment of the process/assembly according to the invention, the coating material is applied to the transfer tape immediately before application to the surface to be coated. This is preferably done using a suitable applicator roller or an application nozzle which applies the material to the transfer tape in an adjustable thickness. In determining the material thickness, it is of advantage to increase it in the middle part of the transfer tape. As mentioned above, surface unevenness is at its greatest in particular in this region of the surface to be coated with the result that more material has to be used there.
In another advantageous embodiment of the invention, the transfer tape is removed from the surface to be treated, the material having previously penetrated into and set or hardened in the pores of the surface to be treated so that it does not stick to the transfer tape when it is removed.
Another advantageous embodiment of the invention is characterized in that, after removal, the transfer tape is returned to the application system so that an endless tape can be used.
The transfer tape is preferably also used as a smoothing tape so that there is no need for smoothing rollers or smoothing blocks.
However, smoothing or modelling can also be carried out by other known methods, for example by rollers and coating knives or by sanding after spray application.
Further information on application and smoothing can be found in the relevant literature, cf. in particular DE 44 42 397 to which reference is expressly made.
The coating materials used may be both solid and non-solid, for example thixotropic, paste-like or highly viscous, at room temperature.
Where importance is attached to simple processing and not to the particular performance properties of a thermoset material, thermoplastic materials are preferably used for coating. On the one hand, they combine well with the surface and, on the other hand, they are readily formable or smoothable.
In order to enable commercially available hot melt applicators to be used to apply the thermoplastic coating material, the thermoplastic material should be sufficiently free-flowing during application. Good free flow of the material is important insofar as it is thus able better to wet the transfer tape, can be better applied to the narrow surface to be coated and, in addition, can penetrate better into the pores of the chipboard. To avoid excessive penetration, that side of the coating or the transport tape remote from the narrow side is cooled, for example by means of a cold air blower or a cooling roller. That part of the coating material in contact with the transport tape thus hardens very quickly so that it “sinks” less into the surface. This effect can be increased by foaming.
In addition, reactive non-thermoplastic materials can be used for coating. Specific examples of such materials include one-component or two-component systems based on polyurethanes, polyesters, poly(meth)acrylates and epoxides. They may contain additives

Affiliated with

Also associated with

Rating

Surface improving process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Surface improving process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface improving process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2975486