FI86388B - FOERFARANDE FOER FRAMSTAELLNING AV EN FLERSKIKTSTRAESKIVA. - Google Patents

Description

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Method for producing a multilayer wood panel Förfarande för framställning av en flerskiktsträskiva 5

The invention relates to a method for producing multilayer wood panels according to the preamble of claim 1.

Similar multilayer wood panels are also called table tops, table tops, or plywood. The disadvantage of such multi-layer wood panels and possibly veneered plywood is that they either do not meet the frequent strength requirements or their manufacturing price is often too expensive for plywood due to the veneers used.

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It is further disadvantageous that either the surface layers have to be precisely pre-prepared by themselves or are made in conventional multilayer or single-layer heat presses, in which case the surface layers have seams at the butt points, because the surface layers cannot be precisely glued together. Coated or veneered mounting plates often do not meet the requirements of high strength properties. In addition, due to their formaldehyde content, they have recently had a bad reputation and are therefore opposed by many buyers. A further disadvantage of the fastening plates is that the bonded coatings 25 adhere only unsatisfactorily. The construction and furniture markets, on the other hand, want a technically complete, stable and environmentally friendly wood panel and a natural visible surface. The object of the invention is therefore to develop such a multilayer wood board and to provide a method and an apparatus for such, without the above-mentioned disadvantages. . 30.

According to the invention, this object is solved by a method for producing a multilayer plywood board through the process steps described in claim 1. Thanks to the structure and manufacturing method, it is thus possible to manufacture 35 multilayer wood panels industrially at high working speeds and with high quality.

2 86388 1 The load-bearing element is formed by a stable core layer of high-precision planed and sawn wood strips, which strips may be pre-glued together. The surface layers, which consist of strong solid wood boards, are seamlessly glued to both sides. Use one finished side and one unplaned back side or, if desired, two finished sides. The thicknesses of the core moldings and boards may vary from case to case depending on the operation and the required stability; the same equipment is used and the preparation time is very short.

10 In order to obtain high strength in a multilayer wood board, both surface layers are then made using a substantially greater thickness than would be possible for veneers by turning or planing techniques.

The corner joints of such a multilayer wood panel and the attachment of the coating have all the required and desirable positive properties of a solid wood panel without the harmful risks of warping and warping in the solid wood panel.

It is further preferred that all commercially available environmentally friendly adhesive grades can be used for gluing individual wooden slats, layers and boards.

. The invention will be described in more detail by way of example with reference to the drawing, in which: Fig. I shows a multilayer heat press with a first embodiment of a pressing device, Fig. 2 shows a horizontal projection of the multilayer press according to Fig. 1 in section AB, Fig. 1 Fig. 3 shows a multilayer press with a second and a third embodiment of a pressing device on the left, Fig. 4 shows the structure of a layer package, Fig. 5 shows the finished multilayer wood board according to Fig. 4, Fig. 6 shows the layer structure of a second multilayer wood board and Fig. 7 shows a third multilayer layer structure.

The multilayer heat press shown in Figures 1, 2 and 3 has a press body 17 with a press table 12 and a press bar 10 moved up and down by the pressure pistons 16. . The method for producing multilayer wood panels according to the invention and the mode of operation of the three pressing devices are described in more detail below.

According to Figure 1, the press device 20 designed per layer consists of press strips 15 IA of variable thickness and length and hydraulic cylinders 15. The press device 20 can be mounted on one side or both sides of the longitudinal side of the multilayer heat press on heating plates 11. a stop strip 18 is attached which receives the back pressure. When the filling step is completed and the layer pack-20 tit 1 is in the right position on the heating plate, the pressing cycle begins.

First, the heating plates 11 and the upper pressing beam 10 are placed on the boards 5 of the upper surface layer 3 so that the surface layer 3 and A

boards 5 can be moved horizontally. The baler is started ·. '··:: now started. In this case, the pressing strips IA press the boards 5 in both surface layers 3 and A seamlessly together. In this case, the lowered: heating plates 11 or the pressing beam 10 prevent the boards 5 from curving or warping and begin to form into layered plates 1 and the pressing and heating time for the adhesive to begin begins. Multilayer. . the wood board 25,26 or 27 is pre-pressed at full compression pressure ... 30 and with the planned heating energy. The process in which the pressing devices 21 and 22 are used is almost exactly the same, the only difference being that the multilayer pressing strips 23 or the pressing pieces 2A contact the boards 5 by dimension S outside the edge of the heating plate and: The pressing device 22 also has a mechanical or hydraulic compensating element 19 in each pressing piece 2A, so that a separately adjustable pressing pressure can be controlled in layers for each layer package.

4 8 6 3 δ 8 1 As shown in Fig. 3, the plate packs 1 are placed on the heating plates 11 in these working methods II and III so that the boards 5 of the surface layers 3 and 4 protrude by dimension S over the longitudinal edge of the heating plates.

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The pressing devices 21 and 22 shown in Fig. 3 can likewise be on one side or on both sides, or they may also co-operate with the stop strip 18 on the opposite side.

In order to increase the quality of the multilayer wood board 25, in particular its strength properties, it is proposed to use a thickness of the boards 5 of the surface layers 3 and 4 which is greater than the possible thickness of ordinary planed or turned veneers.

The strength properties of the multilayer wood board 25 can be further increased if the multilayer wood board 26 and 27 have several core layers 9 (according to Figs. 6 and 7) and / or several deck intermediate layers 8 (Fig. 6).

In order to produce multilayer wood panels 27, or if the core layer 2 of the three-layer wood board 25 20 has not been prefabricated, i.e. the wood strips 6 must be manufactured together and together with the boards 5 and 4 of the surface layers 3, presses 20,21 or 22 or abutment strips 18 are also necessary or necessary on the front of the heating plates 11.

'; · ·. · 25 In order not to impede the filling and emptying steps, it may be advantageous to arrange the pressing devices on the front sides of the multilayer heat press so that they can be turned inwards and outwards.

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Claims (2)

5,86388 1 Claims