DESCRIPTION

A METHOD OF PRODUCING OUTER PANELS OF WHITE GOODS

Technical Field

This invention is related to a thermoplastic material, which can be subjected to hot or cold forming process, especially used in doors and outer panels of coolers such as refrigerator, freezer or other white goods and a production method for this material.

Prior Art

There are solutions present for the use of a plastic material which can replace the metal sheet currently used in the front doors of white goods such as coolers and which is suitable for producers who would like to use various esthetic designs in white goods due to the easiness of forming with thermoform method. These solutions are the plastic plates which are produced through the co-extrusion of PMMA and ABS plastics. This structure which is produced multiple-layered where each layer provides different visual and functional property in order to be able to replace the metal sheet is very costly when compared to metal sheet.

The subject matter of invention of the material production technique for the outer panels of white goods provides the visual and functional properties with other materials and reduces the costs much more compared to the methods currently used. With the invention, the acrylic-based, PMMA (Polymethyl Methacrylate)- and ABS (Acrylonitrile Butadine Styrene)-composed, multiple-layered plastic plate is substituted by any thermoplastic and in order to provide the same visual impression, an additive composed of a special dye and varnish mixture is applied thereon and a moisture barrier is also laminated on the back surface of the plate. For example, in the prior art, the published patent applications WO2006005090, WO2005042248, WO9902339 mention multiple-layered composite materials which are generated with the use of above-mentioned materials. For the moisture solution, a HDPE (High Density Polyethylene)-based layer which is placed beneath the PMMA/ABS is used.

In the subject matter of the technique, the moisture transition is prevented with a film with low moisture permeability, which is laminated with hot combining or gluing method on the single-layered thermoplastic used in the present technique instead of HDPE but much more effective than HDPE.

Aim of the invention

This invention aims to develop a technique to solve the problems such as discoloration and moistening of thermoplastic material to be especially used in the outer panels of white goods, which can be subjected to hot or cold forming process.

Another aim of this invention is to develop a low-cost material as an alternative to the PMMA/ABS-based plastic plates which are currently subjected to forming in order to provide various esthetic factors in the cooler doors.

The other aim of this invention is to solve the moisture barrier to be generated on the material considered for the outer panels of white goods with a low-cost and easy-to-apply method.

Another aim of this invention is to ensure the production of a material which will be an alternative to the materials obtained with the methods used in the prior art and has the same visual impression but more functional.

Disclosure of Invention

The subject matter invention of material which is considered for the outer panels of white goods has a multi-layered structure and the production stages are performed as follows.

In the first stage, the powder or the wet dye is applied on one side of a thermoplastic plate and the plate is entirely dried through infrared light source, hot air blowing, furnacing, natural convection or other known methods apart from these.

In the second stage, a moisture barrier is generated by laminating a film layer, which does not permeate moisture to the uncoated lower side of the thermoplastic plate, with hot combining or gluing method.

The thermoplastic plate can be subjected to a forming process and converted into a desired form after or before any of said these two stages. As this forming process, hot or cold forming methods can be applied. It is also possible to apply both forming processes together.

The moisture barrier can be a film laminated with PA (Polyamide) - and PE (Polyethylene)-based hot combining method, an aluminum layer laminated with hot combining or gluing method, and another material with low moisture permeability.

In an alternative embodiment of the invention, after the first stage described above, as an optional intermediate stage, processes of coating varnish on the thermoplastic plate and curing varnish through the application of ultraviolet light with a wavelength less than 380 nm and a flux greater than 1 mW/cm ² for maximum 60 seconds can also be performed.

In another alternative embodiment of the invention, after the first stage described above, yet as an optional another intermediate stage, the thermoplastic plate can be coated with a titanium dioxide- or polyurethane-added polymer layer which is protective against fingerprints, scratches and bacteria, preventive against the contamination of the surface, gives hydrophobic or hydrophilic property based on the surface, actual area or request. By adhering the property of this coating, the surface is entirely dried with infrared light source, hot air blowing, furnacing, natural convection or similar methods. This intermediate stage is applied after the varnish coating stage if above-mentioned varnish coating stage is applied.

If above-mentioned intermediate stages are used in the present manufacturing method, the thermoplastic plate can be converted into the desired form by being subjected to a forming process before or after any of these intermediate stages. As this forming process, hot or cold forming methods can be applied. It is also possible to apply both forming processes together.