DD206102A1 - METHOD FOR PRODUCING MOLDED PARTS FROM BEAMED MATERIALS - Google Patents

Abstract

THE OBJECTIVE OF THE INVENTION IS THE PRODUCTION OF COMPLICATED SHAPED SHAPED PARTS THROUGH EASY AND CHEAP PRESSING TECHNOLOGY AND HIGH PRODUCTIVITY. IN THE FACT, IN A FIRST WORKING STAGE, THE LAGENWERKSTOFF IS PRESCRIBED IN PREFERRED EBENDER FORM AND DEVELOPED IN A SECOND WORKING STAGE AND USE OF THE SHIPABILITY OF THE LAYERS ON THE BASIS OF THE INGREDIENT LIQUID OF THE ADHESIVE DURING THE FORMING OF THE SHAPE. THE USE OF THE SHAPED PARTS CAN BE CARRIED OUT IN MOEBEL, INDOOR, VEHICLE AND PACKAGING, TOYS AND SPORTS.

Description

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Title of the invention

Process for the production of standard parts from layer materials

Field of application of the invention

The invention relates to a method for the production of molded parts from layer materials such as laminated wood, laminated wood particle materials, composite materials and paper laminates, the application of which is possible in furniture construction, interior construction, vehicle construction as well as in the packaging, toy industry and sports equipment industry.

Characteristic of the known technical solutions

It is known to produce molded parts from glued layers, such as veneers and / or wood-based panels, by pressing these layers into one another at least two-part pressing tool in one of the intended shapes. Such a pressing tool is generally made of metal and is equipped with a heater. to be able to use hot-curing adhesives ·

For example, veneer bundles (1 to 2 mm beech veneers up to a maximum of 38 layers) are placed in a steel mold and then pressed using a pressure of 100 tons. * The heating takes place with superheated steam. · Depending on the laminate thickness, the pressing time including the post-curing time is 10 to 45 minutes.

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. Mese's ^ "Verfahren'hat the" D isadvantage $ that high pressures applied • be -Do j - that the press tool the shape of the molding is accordingly very bulky and expensive to produce, daßj to ensure an economic molding production _$ a number of identical parts must be produced, which can only be varied by the subsequent different cutting

A further process is concerned with the production of molded parts for chairs. There are 13 "to 19 pieces of veneer using binder solution in a 4 mm thick aluminum sheet lined plywood press mold using a hydraulic press at a pressure of 20 kp / cm 470 seconds pressed and heated by means of high frequency of 13 _S 8 Mis © Then the pressure of 20 kp / cm * is still maintained for about 110 seconds to cure the binder *

The disadvantage here again is the use of a molding press and an expensive Hochfrequenzgeneratorsβ

Furthermore, a method is known, are produced by the laminated blanks for round arch windows in a special frame press glued over interchangeable templates, about 2j5 mm thick veneer strips to moldings * The disadvantage of this method is that a special frame press © is required and that the blanks must remain clamped in doors for 4 weeks, so that they do not forgive themselves «

Furthermore, the postforming process «a method for coating rounded plate edges with flat laminates - known plate · Also for this method, in addition to the press system complex special Masohinen, such. Double end tenoner, edge banding machine, deformation mashine, required »

Process for the production of undercut or otherwise complicated shaped moldings require pressing tools with displaceable in different directions pressure elements

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provided segments are easily formed by the seams of the segments. In addition, these pressing tools require high construction costs.

All these methods have the disadvantage that the sealing tolerances of the layers to be pressed may only be small, since otherwise unacceptable geometric deviations of the molded part, in particular in the region of curvatures occur. The risk of incorrect bonding can only be compensated by excessively high densification of the layers.

Furthermore, it is disadvantageous in all these methods that the heating of the glued layers for the purpose of adhesive hardening or hardening takes place in the pressing tool. This is thereby blocked over a period of time dependent on the thickness of the molded part and is thus less productive.

In addition, in all the methods described so far, the reworking of the pressed moldings due to the more or less complicated shape consuming and difficult mechanisierbar.

The described "Postforming ⁿ method has also the disadvantage that the bending radius depends on the thickness of the layer material, so that only thin, not self-supporting and mechanically only limited claimable moldings or surface materials can be produced at the usual radii at table edges and the like.

For the production of molded parts from flat layer materials such as plywood, but also from other materials, methods are known in which the layer material is cut several times in the area of the intended curvatures, thereby making it elastically bendable · The resulting curvature must be made by gluing the incisions or be fixed by subsequent sticking of further layers © The disadvantages of this method consist in the low strength of such shaped parts in the region of curvature due to the extensive destruction of the material structure by the cuts and in the low productivity ·

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Object of the invention

The aim of the invention is a method ₉ which permits the production of different shaped parts from layer materials with high productivity and low manufacturing costs

Explanation of the essence of the invention

) © of the invention it _s proposing a method for the production of Forint hurry from ply materials that allows any deformation angle, undercuts, crossovers and Verarillungen "at a high strength and any thickness of the molded part." Furthermore, the method short residence pages of "moldings in the tool, ie a high productivity, low energy costs and large thickness tolerances of the layers to be glued »The mechanical processing of the moldings should be rational and automation-friendly« Pur the process should be used even for very large moldings simple and inexpensive to produce low-wear press tools ·

According to the invention, this object is achieved by completely or partially layering the layers of a layer material or of several layer materials with interlayers of an adhesive or several adhesives. The layers are then pressed. This pre-pressing can also be coupled with heating © The layer body thus obtained becomes thereafter by shifting the layers against each other without opening the mortar joints by applying bending * - * and / or torsion forces to a molded part © This molded part is fixed in the molded state until the adhesive interlayers have hardened or solidified ©

The pressing is preferably carried out in a planar manner. "Adhesives that can be reversibly fixed or irreversibly hardened! Adhesives have proven to be very effective. 2hermoplaat foils-preferably polythene foils of at least 0 _s 1 mm in thickness-have preserved themselves very well

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But also with thermoplastic powder and thermoplastic granules especially with polyacrylate with a grain size of 1 mm - good results were achieved ·

The known in the furniture industry hot melt adhesives can also be used for bonding the layers of the layer material »it is secondary ι whether the hot melt adhesive in granular or sheet form or in the already molten state, is used

As an irreversibly curing adhesive, either urea resin or an adhesive dispersion, preferably polyvinyl acetate, was used.

The use of reversibly setting adhesives is particularly favorable for the production of complicated molded parts. This makes it possible to carry out single or multiple repeated plastifications of the adhesive interlayers with subsequent complete or partial deformation and solidification.

If the method allows the deformation of the ski body to take place locally or over the entire surface.

Between the production of the layered body and its deformation, a mechanical treatment and / or surface treatment can be carried out in the case of hardened, partially cured or solidified, partially solidified or even plastic adhesive interlayers.

The heat is supplied to the layers of the layer material optionally to the layers, to individualized layers, to the loosely layered or to the adhesive-coated, strongly superposed layers.

For the production of molded parts, in particular of those which have planar and curved regions, it is advantageous to use the postformable layer material only in certain areas, such as the component curvatures, while in the remaining regions, preferably in the planar regions, comparatively cheap, non-deformable materials, such as ζ · Β. Fiber or particle boards are used. The cohesion of the molded part is ensured by partial and / or full-surface continuous layers.

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Ausführungsbeiepiele

Example 1s

10 layers of 1 _} 2 m thick veneer are layered with serving as an adhesive polyethylene films of 0.2 mm thickness and pressed hot in a flat press at a temperature of 180 C and a pressure of 1.2 MPa ·

After all the layers are soaked and the polyethylene films are melted, the resulting plywood board is removed from the press. The still viscous adhesive prevents the opening of the bond lines between the veneer layers and provides the manipulation and cutting or milling of the still hot plywood board After rapid onward transport or intermediate storage in wärmeisolie-generating or heated chambers such a strip is bent around by hand around the shape of the desired molding corresponding teaching or "laid around" expediently at the beginning and at the end of a curvature when changing the curvature direction or at the beginning and at the end of a rotation, a holding block or a holding fork is arranged · For accelerated solidification of the adhesive, the entire device, which consists of sheet metal, be blown with air · In this way, rounded parts for Sesselges made in the same way »

Example 2:

According to a second embodiment, 1.8 layers of the veneer, trookner coming from a veneer with a temperature of 180 C, sprinkled with powdered polyacrylate with a grain size of 1 mm layered and without further heat between a pair of rollers briefly with a pressure of 1.8 MPa pressed together, whereby the Lagenwerk fabric formation is already completed "The ply material plate is inserted into a bending device, which consists of the later molding on both sides enclosing fittings or multiple segments and ge by means of gravity is closed." Thus, the necessary for the deformation

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Bending forces as well as the holding forces required until the adhesive plague is applied mechanically · The device is made of wood · The format processing, such as trimming the edges and milling, takes place on the curved molded part · These molded parts are used as chair frames · · Β ^ν ·

Example 3:

According to a further exemplary embodiment, instead of the thermoplastic polyethylene or the polyacrylate, the hot melt adhesive known in the furniture industry is used, which by means of

rolled roller coating machines are rolled on 4 veneer layers at a temperature of 180 ° C. During the further transport of the veneer layers, the heat emission of the hot melt adhesive is prevented by the action of heat radiators.

The veneer layers are layered while still hot melt adhesive and briefly pressed together in a cold flat press · By Färmeausgleich between the veneer layers and the adhesive and by heat dissipation of the pressed plywood solidifies the hot melt adhesive, whereby the plate thus formed is arbitrary storable and sawed by conventional methods, milled or · To be drilled · For deformation, the machined plate is heated to a total temperature of 130 ° C, using a heat plate, a radiator panel, a hot air operated heat channel or a heated flat press · After heating, the bending of the plywood plate in the described manner · These molded parts are used as handles on furniture ·

Example 4:

As further adhesive variant heat-curing urea resin is used which is condensed with the appropriate hardener at a temperature of 100 ⁹ C in a few minutes x 6 wood fiber boards of a thickness of each 1.6 mm are brought to a tempering rate of 120 ⁰ C, provided in a roll coater with urea resin and immediately to a layer material history

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wherein paper laminates are applied as outer layers. Immediately after the layering, the pressing takes place in a pair of rolls and then the sheet material sheet is bent in the manner described. The bending must be completed before the urea resin has reached the final solid state. The bending device must suppress the heat release of the molded part in order to prevent the bending complete and rapid curing of the resin, eg by lining the contact surfaces with heat-insulating material, such as mushroom · The molded parts are used as curved seat and backrest surfaces «

Example 5:

According to a further embodiment, an adhesive dispersion - polyvinyl acetate - is used. This adhesive is cast on 3 mm thick chipboard in the cold state by means of casting machines. Next, the layers of the 4 chipboard and the compression between a pair of rollers with a low pressure, whereby only a complete contact the liquid adhesive surface with the adjacent chipboard must be achieved. Now, the sheet material thus formed is bent with a radius of 300 mm and fixed in this position in the specified manner until the adhesive is solid by releasing its moisture to the chipboard and to the environment

 The molded parts are used for round table frames ·

Example 6;

It is possible for another example, inexpensive, irreversibly curing adhesives with reversible adhesives, such as. To combine hot melt adhesive. If a molded part consists of a larger flat surface and a curved edge, the veneer layers in the area of the later flat surface of the molded part can be provided with urea resin and the remaining areas with hot melt adhesive. * Hot-pressed layers in flat presses are coated with urea resin

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Fixed areas and irreversibly glued, while the edge areas can be bent and fixed either immediately after removal from the press or after a later rewarming in the manner described ·

This method is suitable for furniture floors with shaped curves.

Advantageous in the method shown in Example 1 is the rational production of sheet material in productive flat presses, the easy to automate mechanical processing of the strip in a flat form, the simple construction of the bending device, the short residence time of the molded part in the bending device and in particular the possibility of intricately shaped, For example, it is possible to make a chair or armchair frame out of a few, in extreme cases from a single component, undercut, intersecting, running in twisting in all three spatial directions molding parts without any extra effort.

Compared to the first example of application, in the example a low energy consumption results from the use of the drying energy and the possibility of mechanization of the deformation process.

In Example 3, the higher bond strength that is achieved by the more expensive melt adhesive is advantageous over Examples 1 and 2. The arbitrary temporal separation of the production of the laminated wood board from its deformation to form a central Sohichtholzherstellung, the shipping of semi-finished products and processing in User companies possible ·

The advantage of using an irreversibly curing adhesive in example 4 is the very favorable price with good bond strength.

It is advantageous in Example 5 that a heating of the adhesives or the layers to be bonded is eliminated and thus energy is saved.

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The advantage of the solution shown in example 6 is the possibility of processing parts of parts in stages. In extreme cases, great differences in time may exist between the individual processing stages and the production sites may be territorially separated for the individual processing stages.

Example 7:

Three layers of a known thermoformable, thermoformed wood fiber material of a thickness of 4 mm in each case are laminated together with 0.2 mm diök Polyäthylenfolien · The outer layers are covered with interposing the same polyethylene film, each with a 0.8 mm thick beech veneer layer or a paper laminate layer · This layer stack is compressed at a temperature of 180 ⁰ C in a flat press and subsequently bent in a bending apparatus according to exemplary embodiment 2 to a quarter-circular shape portion with an inner radius of 30 mm x This molding is used as the component transition to a Behältnismöbpl ·

In contrast to a reformable, thermoplastically bonded fiberboard, the thickness of which is equal to the thickness of the described five-layered molded part, a much smaller radius of curvature without cracking in the material is achieved here. The risk of cracking is additionally increased by the outer, more rigid and more rigidly veneered veneer. Paper laminate insulated ·

Example 8:

According to another example, each two intersecting veneer layers of 0.8 mm thickness are used as cover layers of a layer material, as the middle layer are non-malleable, conventional chipboard of H mm thickness for later flat areas and 8 layers of 1.8 mm thick veneers for used the later bent areas. All layers are layered by means of 0.2 mm thick polyethylene film. The pressing and bending is carried out analogously to Embodiment 2, wherein the molding is box-shaped or frame-shaped. The 4 bending edges, in

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the area of which the veneer layers are arranged as the center layer have an inner radius of 10 mm. The molded part is used as a furniture body

As a variant, instead of the chipboard, a medium density fiberboard and, instead of the 8 ply layers in the area of curvature, one or more layers of postformable, thermoplastically bonded pastern plates may be used. As a result, a uniform appearance over the circumference is achieved at the laterally machined cut surface of the molded part, so that a subsequent coating of the cut surface with solid coating materials may possibly be omitted.

It is advantageous in the use of non-malleable, flat middle layers, such as chip or Paserplatten for the later flat areas of the molding of low compared to the moldable materials material cost ·

Example 9:

A layer of known deformable, thermoplastically bonded wood material of a thickness of 3 mm is covered on both sides with 0.7 mm thick beech veneer and pressed at a temperature of 160 C in a flat press. The thermoplastic binder of the wood material is so dimensioned that it is unnecessary to interpose, for example, a polyethylene film acting as an adhesive. After the hot pressing, the flat plate is cooled in a pressing device with flat press plates so far that a plastic deformation is no longer possible. Then, if necessary, in another production facility and after prolonged storage, the plate is processed by sawing, milling, drilling and grinding. Then the processed plate is brought to a temperature of 160 ° C. and bent in the manner already described Thermoplastic bonded wood material at the joint between veneer and wood material allows the inventive displacement of the layers · The resulting molded part is used as part of a container furniture door, possibly in combination with a support structure.

Claims (4)

239 94 7 2 invention claim 1. A process for the production of Pormteilen of ply materials, characterized in that the layers of a layer material or more layer materials with layers of an adhesive or more adhesives completely or partially layered, pressed or heated and pressed, that the laminate thus obtained by moving the layers against each other without opening the glued joints by applying bending and / or torsional forces to form a molded part, and that the molded part is fixed in the molded state until the adhesive interlayers have hardened or solidified. 2. The method according to item 1, characterized in that the pressing takes place in planar form · 3 · Method according to item 1, characterized in that a reversibly or / and an irreversibly solidifying or hardening adhesive is used as the adhesive interlayer. 4 · Method according to items 1 and 3> characterized in that thermoplastic films, preferably polyethylene film at least 0.1 mm thick, are used as the reversibly adhesive. 5o method according to item 1 and 3 », characterized in that is used as a reversibly fixed adhesive thermoplastic powder or granules, preferably polyacrylate with a grain size of 1 mm, 6 * Method according to item 1 and 31, characterized in that a hot-melt adhesive is used as the reversibly adhesive. Method according to items 1, 3 and 6, characterized in that a hot melt adhesive in granular or film form is used 8, process according to point 1 and 3 », characterized in that a urea resin is used as irreversibly curing adhesive · 239947 2 ¹³ 9 »method according to item 1 and 3», characterized in that an adhesive dispersion, preferably polyvinyl acetate, is used as the irreversibly curing adhesive · 10. The method according to item 1 and 3 to 6, characterized in that after solidification of the adhesive is a one or more times repeated complete or partial plasticization of the adhesive liners and then complete or partial deformation and solidification. 11 »method according to item 1 and 2, characterized in that the deformation of the composite body takes place locally or over the entire surface. 12. The method according to item 1 to 10, characterized in that between the production of the composite and its deformation in cured, partially cured or solidified, partially solidified or still plastisol adhesive interlayers, a mechanical processing and / or surface finish takes place » 13th method according to item 1, characterized in that the heat is supplied to the isolated, to the loosely layered or to the adhesive layered, strongly superposed layers · Method according to points 1 to 13, characterized in that, in the case of molded parts, in particular those which have planar and curved regions, the nanoformable layer material is used only partially for the curved regions, while the remaining regions, in particular the planar regions, are not deformable Layer materials are constructed, wherein in each molding partially and / or over the entire surface continuous layers are included · 15 · Method according to items 1 to 14 »characterized in that the layers to be bonded consist of elastically formable material types. 239 94 7 2 16 »method according to item 1 to 15» characterized in that are used as elastically moldable materials purns, cardboard, paper and / or thin wood particle boards · 17 · Method according to item 1 to 16, characterized in that as plastic moldable materials corresponding wood fiber boards or chipboard are used.