EP3187320A1 - Method for fixing strips of fabrics, in particular edge tapes on the narrow sides of workpieces - Google Patents

Abstract

The invention relates to a method for fastening strip-like fabrics, in particular edgebands on narrow sides of workpieces, in particular furniture panels, by means of a band feeding device which transports the respective fabric from a storage container, in particular a supply roll, along a feed path to the workpiece. Furthermore, a heat source is used which brings an adhesion-promoting functional layer of the fabric to an activation temperature. In addition, a device for pressing or pressing the sheet on or to the respective workpiece narrow side is present. According to the invention, at least one first application device for a fluid medium is formed in the feed path of the sheet prior to the action of the heat source, which dispenses the fluid medium onto the side of the sheet opposite the functional layer such that a heat sink is produced for the required process of rapid cooling.

Description

The invention relates to a method for fastening strip-like fabrics, in particular edgebands on narrow sides of workpieces, in particular furniture panels, by means of a band feeding device which transports the respective fabric from a supply storage, in particular a supply roll along a Zuführweges to the workpiece, further using a heat source, in particular Laser light, hot air or infrared or plasma-based, which brings an adhesion-promoting functional layer of the sheet to an activation temperature, and with a device for pressing or pressing the sheet on the respective workpiece narrow side, according to claim 1.

From the DE 10 2012 007 281 A1 is a method for producing a furniture panel with plastic edge previously known.

The plastic edge is joined by partial melting to the panel body. In the method for producing the furniture panel, the plastic edge is melted on its side facing the panel body by means of laser light and / or plasma radiation and pressed with the molten surface against the panel body. When welding thermoplastic plastic edges, the use of thin edges is problematic, since a complete melting or excessive softening threatens. In this respect, it must be ensured that only part of the layer of the plastic edge is melted and the side of the edge facing away from the panel body remains sufficiently strong to preclude unwanted deformations of the edge when applying a pressing tool.

For this reason, multilayer plastic edges have been proposed, on the one hand have sufficient hardness of the outside and on the other hand have a functional layer that can be optimized for joining based on the respective furniture panel. In a further development of this basic idea, the DE 10 2012 007 281 A1 to add a viscosity reducer to the thermoplastic base material of a plastic edge as an additive to improve the melt flow and thereby build the plastic edge one layer with substantially homogeneous material composition over the entire plastic edge cross-section. As a result of the addition of the viscosity reducer, only a thin layer of the edge band melts when the plastic edge is welded by means of laser or plasma discharge and becomes sufficiently fluid while the opposite surface of the plastic edge remains in the solid state of aggregation.

Another advantage is that, overall, it is possible to work with smaller amounts of energy introduced into the plastic material and accordingly set a lesser temperature gradient over the cross section of the edge. Thus, the side opposite the panel body remains relatively cool.

However, the addition of a viscosity reducer must be done very precisely in the process of producing the corresponding edgebandings, with a reproducible and uniform distribution must be ensured even with different production batches and large production quantities. If, due to the desired lower energy input on the edge band, only an insufficient melting process occurs, the adhesive strength of the edge with respect to the furniture panel is reduced in an undesired manner. In other words, the problem in the attachment of edgebanding on furniture panels is shifted to the manufacturer of the edgebanding with the result of higher costs arising there.

In the apparatus and method for applying an edge band on a narrow side of a workpiece according to EP 2 952 307 A1 is used as a radiation source for activating an adhesive layer or adhesion-promoting layer, a radiation module with a plurality of laser radiation emitting individual radiation elements. Such a design of a laser source is intended to reduce the energy required for the activation of the layer and, overall, to achieve better efficiency. The individual elements emitting laser radiation are mounted relatively close to the respective plastic layer to be activated or in the vicinity thereof. Activating the adhesive layer or the adhesion-promoting layer of the plastic material produces emissions which can be precipitated on the surface in the form of particles. This leads to the problem that optical elements in the beam path of the laser generating device are contaminated, with the result of a reduction of the power and a deterioration of the operation. Thus, it is necessary in this regard protections for the optical elements. In addition, for safety reasons, the temperature of the edge band must be continuously measured in order to prevent a selective or temporally occurring undesirable increase in temperature and thus damage to the edge band by switching off the laser radiation source.

The known device and Werkstückzuführeinrichtung after DE 10 2013 002 920 A1 has a heat source with control. The controller uses signals from a temperature monitoring device to switch off a laser source when a predetermined threshold value is exceeded. In addition, the temperature monitoring device is provided with a cooling device, whereby it is achieved that the temperature rise in the temperature detection device triggering the deactivation of the heat source by the control is delayed or compensated.

The device for processing a plate made of wood or a wood material according to DE 200 14 953 U1 is also based on the idea to fix an edge band, which consists of plastic, to an edge of a workpiece by gluing, wherein a one or both sides projecting beyond the plate supernatant of the edge band is removed by means of an edgeband cutter.

A device is provided in front of the edge band mill with which a fluid agent which prevents electrostatic charging of the wetted regions and / or of the milling chips can be applied to the edge band and / or the plate. According to the local embodiment, corresponding spray nozzles are located both in front of the processing station of the edge band mill and in front of those of the format miller. The actual edge band, which is usually brought from a storage store, remains untreated in advance.

From various studies it has been shown that edge bands fed with dust and dirt particles, supplied in real operation to a furniture production or furniture board manufacturing company, are fed to a corresponding edge banding machine. A cleaning of the edge bands takes place so far with all the disadvantages associated with this, in particular a poorer appearance, a reduced liability and the expense of subsequent treatment does not take place. The processing speeds in modern edge banding machines, which accomplish the fixing of the edge bands on the respective furniture panel in a thermal manner, means that sufficient cooling of the adhesive or adhesive bond has not been achieved before subsequent processing steps, such as a milling or form milling, take place. If a mechanical milling head strikes an uncured, too soft material, the result of the milling step deteriorates, so that further post-processing becomes necessary or quality decreases occur.

Another problem with the use of different types of cooling and cleaning agents or so-called antistatic agents, which are used in edge banding machines, is the large number of these products with completely different properties. The consequence is that different storage containers and application devices for such fluid means are to be provided on the edge banding machines. This leads in addition to the increased technical effort to unnecessary storage and very high overall costs.

From the foregoing, it is therefore an object of the invention to provide a further developed method for attaching strip-like fabrics, in particular edge bands on narrow sides of workpieces, especially furniture panels, with the help of high processing speeds when fixing edge strips as preferred fabrics at high quality of the realized connection feasible are. Another object of the invention is to provide a universal fluid medium both for cleaning the edge bands or process-relevant surfaces and for their cooling. The corresponding appropriation is intended to ensure that maximum occupational exposure levels are not exceeded and that overall there is only a small, negligible health risk associated with the use of such fluid media. Ultimately, should by the be given to reducing fluid costs in the relevant relevant processing of furniture panels are achieved.

The object of the invention is achieved by a method according to the teaching of claim 1, a use of fluid means according to claim 6 and using a sprayable, non-corrosive surface function coating based on an alcoholic acetate solution according to claim 8, wherein the dependent claims at least useful embodiments and Represent further developments.

The proposed method makes use of a method known per se for attaching strip-type fabrics, in particular edgebands on narrow sides of workpieces, in particular furniture panels.

In this regard, a tape feeding device is used, which transports the respective sheet from a supply storage, in particular a supply roll, along a feed path to the workpiece. In addition, a heat source, in particular laser light, hot air, infrared or plasma energy is used, which brings an adhesion-promoting functional layer of the fabric to an activation temperature. The functional layer may be part of the actual fabric, but may also be an applied adhesive layer. Finally, a device for pressing or pressing the fabric onto the respective workpiece narrow side is used.

According to the invention, at least one first application device for a fluid medium is formed in the feed path of the sheet prior to the action of the heat source. This first application device applies the fluid medium to the functional layer opposite side of the fabric metered, in such a way that a defined heat sink is formed for the required process of rapid cooling after reaching the activation temperature and pressing the sheet.

A further, second application device according to the invention for a fluid medium is provided oriented on the functional layer side in order to prevent the Action of the energy of the heat source to accomplish a cleaning of the surface of the sheet.

It comes so only a cleaned surface with the actual workpiece in contact, which improves both the adhesive properties of the fabric, in particular the edge band relative to the workpiece as well as provided for an advantageous appearance.

In a further development of the invention, a third application device for a fluid medium is present, which is oriented both to the functional layer and to the opposite back side of the planar structure. The third application device is formed at or in the vicinity of the edge band store in order to effect intensive surface cleaning of the fabric and, if appropriate, sensitization to the subsequent process steps. In this aspect, an activator, in particular an activator for an already applied or still to be applied adhesive can be added to the fluid medium used.

The application devices comprise, according to the invention, a pressure-generating device and at least one application nozzle which is matched to the fabric.

The amount of fluid applied by the first applicator is determined by considering the feed rate of the supplied sheet and the desired evaporative cooling, i. the desired effect of the resulting heat sink determined.

According to the invention, furthermore, the use of one and the same fluid agent both for cleaning and for cooling the edge band for the first to third application device. When using the principle according to the invention, it has surprisingly been found that further cooling and cleaning devices can be dispensed with immediately before mechanical aftertreatments, in particular the use of edge band cutters. In particular, the complex application of so-called antistatic fluids can be completely eliminated.

The fluid agent according to the invention is a temporary acting, sprayable, non-corrosive surface functional coating based on an anhydrous alcoholic acetate solution.

In particular, this is a surface-functional coating, wherein at least one function-determining substance present in powder form is added to a melt in order to embed the powder particles and subsequently the thus enriched melt is converted into a solution by addition of a glycol. This is caused by introducing, in particular instillation of the solution in demineralized water as a carrier agent association colloids which envelop the embedded powder particles, wherein the thus pretreated function-determining substance of the alcoholic acetate solution is added.

As a function determining substance come e.g. Polytetrafluoräthylen nanoparticles, metallic powders, inorganic pigments and / or germ reducing agents used.

The aforementioned melt is provided on the basis of nonionic, low-foaming surfactants, in particular on the basis of block copolymers.

The enriched melt is added according to an embodiment of the invention hexylene glycol. The total mixture can then be added to salt for ion formation.

The method-side approach of the invention is thus based on attaching an application device, in particular a nozzle directly to or in the vicinity of the action of the heat source so that at least the side of the edge band facing away from the heat source, i. the back is wetted. The fluid agent, which contains constituents that readily evaporate, results in a heat sink that provides the desired rapid cooling after heating and contacting the edge band with the workpiece.

The additionally provided intensive cleaning with the help of the applicators, which are primarily on the edge band before Heat treatment and contacting with the workpiece extends, ensures an optimal work result.

The surface function coating which is preferably used according to the invention and which is based on an alcoholic acetate solution has such properties that, in addition to a cleaning action, it is ensured that the respectively treated surfaces have an increased degree of gloss, improved feel, but also a temporary protective film.

The non-corrosive surface-active coating medium based on an alcoholic acetate solution used initially relies on a powder-form, function-determining substance which is added to a melt in order to embed the powder particles of the function-determining substance.

Subsequently, the thus enriched melt is transferred by the addition of a glycol in a solution. By introducing, in particular instillation of the solution in a small amount of demineralized water as a carrier, association colloids are formed, which envelop the embedded powder particles.

The functional agent so pretreated, which is otherwise insoluble, becomes the starting solution, i. added to the alcoholic acetate solution.

As function determining substances, e.g. Polytetrafluoräthylen nanoparticles, metallic powders, inorganic pigments and / or substances are used, which are particularly suitable for improving the properties of the surface of the materials to be treated.

Regardless of the solubility of the function-determining substances, consideration must be given to the fluid used, since it is possible for the particles to be embedded and enveloped, so that they are evenly distributed in the sprayable surface-coating material that is contained. The surface coating retains its clear, translucent, transparent structure. The desired particles are not visible to the naked eye in the sprayable functional coating.

The melt is provided on the basis of nonionic, low-foaming surfactants, in particular on the basis of block copolymers.

In particular, hexylene glycol is added to the enriched melt. In addition, salt can be added to the overall mixture for ion formation.

An embodiment for providing the fluid agent is as follows.

First, a melt of poloxamer is formed, in which respect the melting temperature is about 120 ° C. This melt is then added as an exemplary function-determining substance, a PTFE nanoparticle powder. As a result, a melt embedding of these nanoparticles takes place. The addition of the nanoparticles takes place successively and with stirring of the melt.

The thus-prepared starting material is crosslinked with hexylene glycol and goes into solution. The resulting solution is placed in demineralised water. After that, micelles form. A concentration would of course be possible. The optionally concentrated mixture is then added to the alcoholic acetate solution and is available as a sprayable, non-corrosive functional coating for the application relevant here.

When applying the surface function coating e.g. On an edgeband material, the PTFE nanoparticles close pores in the plastic surface, resulting in a noticeable surface smoothness and improved feel. Subsequent polishing with the use of polishing agents, in particular waxing of such treated surfaces can be omitted. It should be noted that the demineralized water is used only as a carrier. The total water content of the mixture is nearly zero so that the fluid medium is not corrosive. The use of corrosion inhibitors can be dispensed with.

The fluid composition according to the invention is free of gasoline, which is the problem of the use of the coating and the maximum permissible workplace concentration relaxed by pollutants. The functional coating may be added a polyhydric alcohol, for example isopropanol, which acts as a release agent. As a result, isopropanol can advantageously replace commonly used silicones as release agents. In fact, silicones must be removed again for subsequent processing steps in elaborate purification steps.

Claims (10)

Method for fastening strip-shaped fabrics, in particular edgebands on narrow sides of workpieces, in particular furniture panels, by means of a band feeding device, which transports the respective fabric from a supply storage, in particular a supply roll along a Zuführweges to the workpiece, further using a heat source, in particular laser light, hot air or based on infrared or plasma, which brings an adhesion-promoting functional layer of the fabric to an activation temperature, as well as with a device for pressing or pressing the fabric onto the respective workpiece narrow side,
characterized in that
at least one first application device for a fluid medium is formed in the feed path of the sheet prior to the action of the heat source, which doses the fluid medium to the side of the sheet opposite the functional layer such that a heat sink is formed for the required process of rapid cooling. Method according to claim 1,
characterized in that
a further, second application device for a fluid medium, oriented on the functional layer side, is provided to achieve a cleaning of the surface of the sheet before the action of the heat source. Method according to claim 1 or 2,
characterized in that
a third application device for a fluid medium, oriented to both the functional layer and the opposite back side of the fabric, is provided, wherein the third application device is formed on or in the vicinity of the storage reservoir, to intensively clean the surface of the fabric and to sensitize the fabric to effect subsequent process steps. Method according to one of the preceding claims,
characterized in that
the applicator devices have a pressure-generating device and at least one application nozzle matched to the fabric. Method according to claim 1,
characterized in that
the amount of fluid applied with the first applicator is determined in consideration of the feed rate of the supplied sheet and the desired evaporative cooling. Method according to one of the preceding claims,
marked by
the use of one and the same fluid agent for both cleaning and cooling. Method according to claim 6,
characterized in that
the fluid means a temporary acting. sprayable, non-corrosive surface function coating based on an anhydrous alcoholic acetate solution. Sprayable, non-corrosive surface function coating based on an alcoholic acetate solution, wherein at least one, present in a powdered function-determining substance is added to a melt to embed the powder particles, then the thus enriched melt is transferred by the addition of a glycol in a solution and thereafter by Incorporation, in particular instillation of the solution in demineralized water as carrier agent. Colloids of association are formed enveloping the embedded powder particles, the pretreated function-determining substance being added to the alcoholic acetate solution for use according to one of Claims 1 to 6. Sprayable surface function coating according to claim 8,
characterized in that
polytetrafluoroethylene nanoparticles, metallic powders, inorganic pigments and / or germ-reducing agents are used as the function-determining substance. Sprayable surface function coating according to claim 8 or 9,
characterized in that
the melt is provided on the basis of non-ionic, low-foaming surfactants, in particular based on block copolymers, and hexylene glycol is added to the enriched melt, salt being added to the overall mixture for ion formation if necessary.