FI85122C - Process for making plates - Google Patents

Description

85122

METHOD OF MANUFACTURING SHEETS

The present invention relates to a method of making sheets by laminating overlapping layers of paper, in which porous papers are impregnated with resin and stacked into a pellet which is laminated by compression at an elevated temperature, and in which an adhesive is applied to at least one point in the pellet. that one press results in at least two laminate sheets.

The amine stacks formed from overlapping paper layers and binder resin are known as high-pressure laminates, i.e. as a perpetual plate used for coating material 1 ina e.g. doors, walls and furniture. The main component of the sheets is the # # backing papers, which are porous paper such as kraftliner. The backing papers are impregnated with s ideharts i 11a, such as phenolic or 'me 1 am i i n i har t s i 11 a, dried and stacked so that. that a pile of sheets of paper corresponding to the size of the sheets to be produced is formed. The ladle, from which two laminate sheets are typically obtained, may comprise, in addition to the base paper sheets, surface or decorative papers on both sides thereof, which give the resulting sheets the desired appearance.

• · The slag is pressed into laminate sheets by means of two presses heated by two fireplaces. between the glossy plate.

The press may have tens of such plate gaps, whereby a corresponding number of deposits can be pressed at the same time. The pressing time varies between 7-30 min. and the compression temperature is about 140 ° C depending on the thickness of the pellet and the binder resin used. In compression, the surface papers of the ladle bodies are laminated into sheets in which the resin binds the overlapping layers of paper to each other.

Several solutions are known for splitting the ladel into two or more plates after compression. One of these is to provide the ladle with separate silicone head release papers that prevent the backing papers from sticking together. Another solution is to provide the ladel with a release or adhesive to be applied to the backing papers at the splitting point, in which e.g. alginite and crystalline polypropylene. However, there have been difficulties in using these known methods, and in addition, it may have been uncertain to achieve the desired result, cleavage of the compressed lamb.

FI patent publication 75758 further discloses a method based on the use of an adhesive, by which the problems related to the application of the substance and the formation of the pellet have been largely eliminated. According to this method, the adhesive is introduced into the pile by bonding the two paper layers together with an adhesive and placing them in the pile between overlapping paper layers, whereby cleavage takes place between said bonded paper layers while the layers are laminated into compression sheets. However, the problem with this method is also to find suitable adhesives. The polymers mentioned in the publication, isotactic and atactic polypropylene and ld-polyethylene, and waxes have not proved to be satisfactory.

The object of the present invention is to provide a new, more efficient adhesive for the production of high-pressure laminate sheets, which is particularly suitable for the manufacturing technique according to F1 patent publication 75758 but which can also be applied to the stack in the form of a coating applied to a single sheet of paper. The process according to the invention is characterized in that a mixture of a soap formed from a salt of a fatty or rosin acid and a mineral component is used as the adhesive.

»· 1

In the adhesive used according to the invention, the soap “1” forms a bonding material between the paper layers and the mineral component acts as a barrier to the adhesion of the resin 1 during the compression step. It is also essential that the adhesive * '1. does not react chemically with the resin. In addition to the invention

II

· 1 · • · 1 «· 3 85122 has the advantage of a good yield of the available sheets, i.e. the adhesive does not tend to stick to the sandpaper or the like used for its removal.

Particularly preferred adhesives for use according to the invention are mixtures in which the mineral component has a granular structure. Such a structure strongly promotes the splitting of the pellet into separate plates after compression, the splitting taking place along the surfaces of the mineral particles parallel to the plates. Useful shale minerals include kaolin, talc, mica or serpentine, of which kaolin has been found to be particularly preferred.

On the other hand, it should be noted that satisfactorily functioning adhesive mixtures have also been obtained with certain non-slate minerals. Such are e.g. Ti09 and CaCO.

* The soap component of the adhesive composition used according to the invention is preferably Ca, Cu, Mg, Pb or Zn stearate, especially the latter. An example of an excellent adhesive is a mixture of Zn stearate and slate kaolin.

The mixture ratio of the adhesive may suitably vary within the following limits: 40-95%, preferably 60-70% of the metal soap and * ... · 5-60%, preferably 30-40% of the mineral component.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawing, which schematically shows a sheet manufacturing process according to the invention.

The process according to the drawing produces, on the other hand, surface-treated high-pressure laminate sheets from kraft-liner backing papers, surface papers on top of them and papers from a bonding phenolic resin. The production takes place by pressing a pile of overlapping sheets of paper so that one press results in two laminate sheets.

According to the drawing, the molten mixture of zinc stearate and slate-like kaolin in the tank 3, which acts as an adhesive in the process, is applied to the body paper web 1 impregnated and dried with the phenolic resin by means of a rotating roll 2. The adhesive remains on the Dough 1 in a thin layer, against which a second body-paper web 4 treated with phenolic resin, respectively, is passed. The rolls 5 press the webs 1 and 4 against each other, and the solidifying adhesive binds them together. After the rollers 5, the webs are cut by a cutter 6 into sheets 7, the size of which corresponds to the laminate sheets produced by the process. Against each of said sheets 7, phenolic resin-treated and dried run paper sheets 8 of equal size are brought on both sides thereof, so that said sheet 7 remains between the body paper sheets 8. The sheets 7,8 thus form a layer 9, in which a sheet of surface paper 10 forming the surface of the laminate sheet, which has been treated with phenolic resin or melamine resin, is placed on the outermost side on both sides. In the lamination step, which takes place in the drawing in the heating chamber indicated by reference numeral 11, the ladle 9 is pressed against two heated press plates 12, the so-called between the glossy plate. The heating temperature, which can be achieved by means of the heating liquid passed through the press plates 12 or the electrical resistors in the plates, is in the range of 120-180 ° C, preferably in the range of about 130-150 ° C. At this temperature, the phenolic resin laminates the overlapping papers to each other and the adhesive mixture melts. After the pressing step, the press sheets 12 are pulled out of the pressed pile 9, which immediately splits between the innermost sheets 7 cut from the pastes 1 and 4 into two separate laminate sheets 13. Said inner body paper sheets 7 are integrally laminated into these sheets.

It will be clear to a person skilled in the art that the various embodiments of the invention are not limited to the above example but may vary within the scope of the appended claims.

5 85122

Thus, the production of high-pressure laminate sheets according to the invention can be carried out as a continuous process, in which the paper-forming paper layers pass through the process as continuous webs and in which the laminates obtained in web form are cut into sheets of the desired size only after compression. It is also possible for the adhesive to be applied at two or more different points in the pellet so that the pellet splits into three or more laminate sheets after compression. It is further possible that the adhesive is applied directly to the individual paperboard sheet to be placed in the stack, whereby the bonding of the two paper layers 1.4 described above is omitted.

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Claims (9)

A method of making sheets (13) by laminating paper layers (1, 4, 8, 10) of one another together, in which process porous paper is impregnated with resin and stacked as a batch (9) so as to laminate it by pressing it in an elevated temperature, and in which method at least one place in the kit causes an adhesive substance which causes the kit to fall after pressing in pieces, so that as a result of a pressing one obtains the edible mint tone two laminate sheets, characterized in that the adhesive substance is used. the mixture of a double consisting of a metal salt of a fatty or resin acid and a mineral component. Process according to claim 1, characterized in that said mineral component is shale-shaped in its structure. Method according to claim 2, characterized in that the mineral component consists of shale-like kaolin, talc, mica or serpentine. 4. Process according to claim 3, characterized in that the mineral component consists of shale kaolin. Process according to any one of the preceding claims 1-4, characterized in that the soap containing the adhesive is Ca, Cu, Mg, Pb or Zn stearate. Process according to claims 4 and 5, characterized in that the adhesive substance consists of the mixture of zinc stearate and shale kaolin. Process according to any one of the preceding claims 1-6, characterized in that the adhesive substance contains 40 - 95% metal well and 5 - 60% mineral component. Process according to claim 7, characterized in that the adhesive substance contains 60 - 70% metal as well as zinc stearate, and 30 - 40% mineral component, such as slate kaolin 9 85122. Method according to any one of the preceding claims 1-8, characterized in that the adhesive blank is brought to the kit (9) by bonding two layers of paper (1, 4) together by the adhesive blank and placing them in the kit between adjacent paper layers (8). ), wherein the splitting takes place between said paper layers bonded together, while the adjacent layers are laminated at the pressing as part of emerging sheets (13).