RU2344935C1 - Method of multi-layer basic part production - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method of multi-layer basic part manufacture consists in shaping of external and/or internal shell. After that shells are joined to each other, and space created between them is filled with adhesive mixture. Prior to molding of at least one shell made of transparent plastic with thickness of not more than 2 mm, mirror image is applied. Afterwards it is molded by double-stage vacuumising. At the first stage relief is shaped in accordance with applied image. At the second stage edge zones are vacuumised with high draft.

EFFECT: expansion of basic parts functional resources since they simultaneously perform heat-insulating, bearing and decorative functions.

5 cl

Description

The invention relates to the field of manufacturing parts and cases for refrigeration, commercial and household equipment, shelving and furniture with full-color images, relief, texture applied to them, which are used as advertising and / or information carriers.

A known method of manufacturing a hull multilayer parts, in which the outer shell is made of sheet metal processed in different ways. The inner shell is either processed sheet metal or processed sheet plastic. The space between the shells is filled with a filler, for example polyurethane foam. A good example is a household refrigerator. In this case, the body part performs the supporting and heat-insulating functions. This known method is implemented by the device according to patent RU No. 22252377, F25D 23/06, 2005.

The main disadvantage of this method is that even using thin metal sheet metal to shape the part, relatively expensive equipment and tools are needed. Bending and punching presses are usually used. On this equipment it is extremely difficult to make a part with a complex curved contour and convex or concave at the same time. It is possible to process sheet metal with a stamp, as in the manufacture of car body parts, but the cost of sets of stamps and stamping equipment will be very large.

And with any processing method, if the outer shell is made of metal, the part is painted outside. And the wear resistance of the coating is an important parameter of the trading equipment, near which customers walk with food trolleys, touch clothing, bags, etc. Known methods for applying a stable and high-quality full-color image to a metal require either very expensive equipment for painting large surfaces in an automatic (semi-automatic) mode, or the high cost of skilled manual labor (when painting with airbrush or using stencils) and, as a result, are not very productive.

Often, a film with a pre-printed image is glued onto the outer wall (patent RU No. 2263030, G21F 5/08, 2003). But at the same time, it is difficult to avoid wrinkles when gluing a complex surface. Therefore, the use of metal leads to a sharp restriction of the design of the entire product.

To expand design capabilities, plastic parts made by vacuum molding or injection molding are attached to the metal housing part from the outside. The use of these parts, performing, as a rule, a decorative and only sometimes different function (for example, protection against impact by a trolley), leads to the need to use expensive equipment (molds) and equipment (injection molding machine) for injection molding. At the same time, the cost of press equipment for metal processing does not decrease. Obviously, in this case, the cost of the hull product as a whole increases significantly.

There is also a known method of manufacturing a hull multilayer part, in which the outer and inner shells of the hull are made of sheet plastic, the sheets are molded, and the space between them is filled with filler. This known method is implemented by the device according to patent RU No. 2216059, class. G21F 5/08, 2003

In this case, the body part performs a decorative and heat-insulating function. To carry the load, an internal metal structure is usually made, to the power elements of which external body parts are attached.

The disadvantage of this constructive solution is the need to apply for at least one shell a relatively thick, more than 2 mm, sheet polymer material. This is necessary, since the end face of the product is visible and can be touched by the buyer or store employee when, for example, he takes or puts the goods, because thin plastic can break off or crack at the same time. Damage can be caused not only to commercial equipment, but also to a person. The use of thickened material leads to an increase in cost and a longer processing time, and sophisticated equipment is used for molding.

In addition, as a rule, plastic is taken not transparent and colored in bulk. The color and texture are determined by the manufacturer of the plastic sheet, and a full-color image can only be applied (glued) on the outside. As in the case of metal, this leads to serious limitations in form and overall design.

In addition to the above methods, body parts can be made from a solid billet - wood chipboard, plywood, fiberboard, etc. An example is kitchen and cabinet furniture.

The disadvantage of such parts is that in the manufacture of massive parts (1000 mm to 2000 mm) of complex shape, a workpiece is required, which is processed by cutting on a milling machine. The standard thickness of the plywood sheet is 18-40 mm, and if the part has a complex shape, a very large part of the material goes to waste, the processing time is large and the product design is extremely limited. You can manually assemble the workpiece, for example, glue or join with screws, increasing the thickness only in those places where it is necessary, but then the finishing of the product (puttying, polishing, etc.) will lead to a sharp decrease in productivity.

The disadvantage of such hull parts can be attributed to the fact that the part is painted or glued on the outside, while creating design restrictions.

The technical result of the claimed invention is:

- in expanding the functionality of hull parts due to the simultaneous performance of thermally insulating, supporting and decorative (advertising, information) functions;

- in the execution of body parts of complex shapes both along the outer contour (any curvilinearity) and along the entire front surface (convexity, concavity, except for deep undercutting);

- in the use of the full color gamut, including complex shades, through the use of digital, screen printing and other known methods of applying the image directly to plastic, allowing subsequent thermoforming;

- to increase the wear resistance of the image, since full color printing is under plastic;

- as well as to simplify and reduce the cost of production of hull parts, reduce costs and increase labor productivity.

The specified technical result is achieved due to the fact that with the manufacturing method of the case multilayer parts, the outer and / or inner shell is formed, then they are joined together and the space formed between the shells is filled with an adhesive filler, and before forming, a mirror image is applied to one of the surfaces of the transparent sheet , and also to improve color reproduction, a colorful background can be applied, after which this sheet is formed by two-stage evacuation: at the first stage, the volume is evacuated relief pattern applied, and the second stage is evacuated edge zones with high stretch, after which the outer and inner shells are connected.

As the filler, any material is used that has sufficient adhesion to the inner surface of the finished shells, for example, polyurethane foam of any density, foamed epoxy, expanded polystyrene, and waste paper.

If necessary, power inserts are installed in the volume between the outer and inner shells, and a flexible decorative profile is installed at the junction of the shells on the outer surface of the finished multilayer case, which is also a connecting and sealing structural element.

A method of manufacturing a hull multilayer parts is as follows.

For the manufacture of at least one shell of a multilayer case part, a full-color mirror image is applied to a thin, not more than 2 mm thick, transparent sheet of polymer (polyethylene terephthalate copolymer PET g, PET (ARET, CPET), PMMA, SAN), for example, an advertisement drawing on one from surfaces. If necessary, a background is also applied. The image is applied by any known methods that allow subsequent thermoforming, for example, by screen printing or digital printing, which allows the use of the full color gamut.

Another shell can be made of thin polymer plastic with an image, relief and / or texture, or flat, for example, of plywood, fiberglass or paper-laminated plastic (BSP). In this case, at least one shell is made volumetric.

From plywood or fiberglass, a matrix is prepared with the shape and surface necessary for the design.

After applying the image, they begin the process of forming a sheet of plastic, necessary for the relief design and texture, using the 2-stage evacuation method. To do this, put a sheet of plastic on the matrix so that the image is inside, on the inside of the shell. At the same time, at the first stage, important relief details are formed to keep them from sliding, and thus a shell shape corresponding to the applied image is created.

At the second stage, edge zones with a high hood are formed. Such a 2-stage vacuum molding makes it possible, firstly, to achieve high accuracy in combining the image with the relief, and secondly, to create the front surface of the body part without defects in the form of folds, pinches, bubbles.

After cooling on the matrix, the plastic completely takes its shape, the technological fields are cut off.

If necessary, other shells of the body part are formed in the same way.

Prepared at least two shells, at least one of which is a transparent plastic with a pattern applied on its inner surface and created shape, relief, texture, are interconnected by a flexible profile of the original sections.

The inner cavity between the outer and inner shells is filled with any filler having good adhesion simultaneously to the paint layer and to the material of the inner shell through a small hole. In this case, the filler acts as a binder and a heat insulator.

As filler, polyurethane foam of any density, foam epoxide, polystyrene foam or waste paper is usually used.

Filling takes place in molds using a press.

If necessary, power inserts are used to strengthen the body part, which are installed in the volume between the shells, which can be made of metal, wood, plywood, etc.

An example of a specific implementation.

For the manufacture of the outer shell of a multilayer case for a refrigerator, a transparent, colorless sheet of polyethylene terephthalate copolymer (PET) 1 mm thick is taken. A full-color mirror image of an advertisement is applied to one of its surfaces by screen printing. The same method is applied to the background. A matrix is prepared from fiberglass with the shape and relief corresponding to the advertisement drawing. Next, a plastic sheet is placed on the matrix so that the image is inside, on the inner side of the shell and begin the process of forming this sheet by 2-stage evacuation. At the first stage, a relief is formed in accordance with the image, and at the second stage, edge zones with a high hood are formed.

After cooling on the matrix, when the plastic completely takes its shape, the technological fields are cut off.

The inner shell is made of paper-laminated plastic 1 mm thick.

Prepared shells are interconnected using a flexible profile of a certain cross section made by extrusion of PVC, while leaving a small hole in the invisible place of the body part, a size sufficient for further filling, for example 15 mm In the volume between the panels to strengthen the body part, power inserts of plywood are installed.

The internal cavity is filled with low density polyurethane foam through the hole left. During polymerization, polyurethane foam adheres firmly to the paint layer of the outer shell and to the inner surface of the paper-laminate of which the inner shell is made. Filling takes place in a mold using a press.

Using the claimed method allows to obtain the following advantages over known methods.

Bearing body parts of the equipment themselves become design, advertising elements. The manufacturer has the opportunity to significantly save on equipment, materials, additional operations, production facilities while dramatically expanding the design (decorative) capabilities of products.

The use of transparent plastic as a material with a sheet thickness of less than 2 mm can reduce weight and reduce the cost of hull parts and the structure as a whole, and most importantly reduce the cost of tooling and equipment.

Thin material allows, in addition, to change the texture of the shell over a wide range (The texture is set by the texture of the matrix on which the product is molded).

Full-color printing of the entire product from the inside allows you to increase the durability of the body part and expand the design capabilities and, as a result, opens up new areas of application (in particular, the advertising capabilities of equipment).

The design has high bearing capacity.

The possibilities are expanded in form and texture, allowing non-planar external and internal contours of parts. It becomes possible to design voids in detail and versatility for load-bearing and non-load-bearing structures.

The proposed method makes it possible without losing the fundamental characteristics (thermal insulation, strength, wear resistance) to provide designers with space in the choice of form, texture and complete freedom in color solutions, which meets the current state of the market.

Claims (5)

1. A method of manufacturing a body multilayer part, in which the outer and / or inner shells are formed, then they are joined together and the space formed between them is filled with adhesive filler, characterized in that on the inner surface of the shell made of transparent plastic with a thickness of not more than 2 mm, a mirror image is applied, formed by two-stage evacuation, and at the first stage, a relief is formed in accordance with the applied image, and at the second stage, edge zones are formed. 2. The method according to claim 1, characterized in that the background is applied to the inner surface of the shell. 3. The method according to claim 1, characterized in that for the manufacture of the shell can be used and colored in the mass of plastic. 4. The method according to claim 1, characterized in that power inserts are installed in the volume between the outer and inner shells. 5. The method according to claim 1, characterized in that at the junction of the shells of the shell multilayer parts establish a flexible decorative profile.