DE1653188A1 - Process for the post-treatment of panels made of vegetable material and a suitable device for this - Google Patents

Description

. 62

Defibrator Aktiebolag, Sandhaumsgatan 81, Stockholm 27 /

Sweden.

Dec. 7, 1967

Process for the aftertreatment of panels made of plant-based material and a device suitable for this purpose

The wood pulp blanks are used in the manufacture of fibreboard a hot pressing at high temperature and under high pressure ur-be-i-throw, which gives them their final, coherent fiber structure obtain. It is known that the wood fiber boards produced in this way are a further heat treatment at high temperature, from about 150 - 210 G, and exposure for a long time, up to 1½ hours, in order to improve their properties in terms of breaking strength and water resistance to enhance. This further heat treatment of the plates was previously in closed chambers in which air is made to circulate at high speed and high temperature. The flat parts this process is high investment costs, cumbersome and expensive handling of the plates and the high risk of ignition, where eror; se values can be lost.

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lin. the surfaces of the panels have good painting properties give it is known the surface of the plates before pressing to cover with a layer of fine fibrous material in the hot press or the finished pressed board with so-called "sealers", oils or the like. To treat.

The invention relates to a method for treating wood fiber boards such that they have exceptionally good properties in one or more of the relationships mentioned above are obtained while avoiding the disadvantages inherent in the known methods. According to the invention, the aftertreatment should therefore be able to be carried out quickly without being dependent on special additives. Essentially the invention is characterized in that the wood fiber boards between two surfaces, such as the surfaces of rollers, are advanced at high temperature and under high pressure, namely at a speed that deviates from the at least one of the surfaces so that there is a sliding movement between them.

In the following, the invention will be shown schematically in cross section as an example with reference to an attached drawing The device shown for carrying out the method will be described in more detail, and here are also further characterizing the invention Properties to be specified.

In the drawing, 10 denotes a heat-insulating housing in which a number, in the exemplary embodiment 3, pairs of rollers 12, 14, 16, 18, and 20, 22 are accommodated. The ialzen are made of metal, such as cast steel, and expediently all have polished cylindrical surfaces. The rollers 16, 18 and expediently also the other rollers are provided with internal devices for heating them to a high temperature, such as 250-50O ⁰ G. The heating can be done electrically or by means of hot oil or another suitable heating medium.

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Wood fiber discs 24 are introduced into the chamber 25, which is enclosed by the housing, through a gap 26 and leave the chamber through a further gap 28, whereby seals 30 or 32 can be provided for closing the gaps on the side of the plates. Before they are introduced into the chamber, the plates can be placed on a or both sides are splashed with water, oil, resin, etc. These liquids are fed to mouthpieces 34 through lines 36.

The cooperating roller pairs are of Devices (not shown) operated so that the rollers under high pressure τοη both oeiton on the plate 24 press. This pressure the so called "linear uruck" in cm. in aer axial seal of the Orphan is charged, can be 50-200 kg and more. One of the pairs of rollers, or several of them, preferably the two outer ones Pairs 12, 14 and 20, 22 convey each plate through the chamber 25 the intended speed while applying the desired pressure. These pairs of rollers also preferably transfer heat to the Plate. Jines of the roller pairs or several of them, in the present case If the middle roller pair 16, 18, has a different peripheral speed than the feed speed for the fibreboard 24 This peripheral speed can thus be higher or lower than that of other pairs of orphans and is carried out in the same group. As a result, ax rollers 16, 18 grind or slide on the plates, and rian thus receives a kind of stirrup effect that is connected with the high pressure and the high temperature of the plate the desired Surface treatment granted so that the panels have good properties for paint application by closing the pores in their surfaces and at the same time closing the fiber ends pressed into the surface. You can also use pre-dried ones Press porous plates so that they become thinner and thus have a higher specific weight and increased strength, given

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if in coordination with improved properties for paint application

The chamber 25 may be provided with an outlet 38 in which a valve 40 is provided for regulating the temperature in the chamber is.

The surface treatment of the wood fiber boards 24 passing through the chamber 25 in rows one after the other can be one-sided or be two-sided, in the former case only one of the .valzen 16, 18 a different relative speed than the Yorsclub speed who needs to have records. 3ei double-sided surface treatment the plates 24. can in advance the on aeren one: -Jeite existing Sieve cloth markings are sanded away. So through this you can with exit from a one-sided smooth plate a two-sided smooth, Make the so-called S-2-S plate. This last-mentioned plate could be used so far only with the help of the so-called wet-dry process or the Manufacture dry process. The panels which are treated according to the invention can be hard, semi-hard and porous fiber panels be.

The rollers intended for the surface treatment, in the Embodiment either one of the rollers 16, 18 or both, can also stand still or rotate in the opposite direction to the feed direction of the plates, whereby the action on the Surface of the plates is particularly large. The number of drivers as drivers for the plates 24 serving rfalzenpaare is preferred greater than the number of pairs of rollers producing the sliding friction, especially if all rollers polished to the same degree have cylindrical surfaces.

The invention is of course not limited to the shown and described embodiment but can be modified in the broadest Sinna within the ^p frame means of the guiding principle underlying it. So they need the relative movement

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causing links not necessarily to be creased, but can be glass blocks, especially stationary ones, or also endless ribbons. The invention also includes treatment of chipboard and the like.

SAD

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Claims (6)

Claims (l.J method for the post-treatment of panels made of vegetable Material, characterized in that the plate is advanced between two surfaces at high temperature while this Surfaces exert a high pressure on the plate, the plate with an "relative velocity compared to at least one these surfaces is advanced in such a way that a sliding movement occurs between them. 2. The method according to claim 1, characterized in that the plate is supplied with the heat via the surface or surfaces will. 3 · The method according to claim 2, characterized in that the plate between at least two rollers pressing against one another is advanced, at least one of which has a different speed component at the point of contact with the plate has as the latter. 4. The method according to claim 3, characterized in that on the plate acts on a plurality of pairs of rollers, at least one of which is used to advance the plate. 5. The method according to claim A *, characterized in that the plate heat is supplied from all pairs of rollers. 6. Device for carrying out the method according to the preceding claims, characterized in that a plurality of heated roller pairs for exerting pressure against the plats from opposite ones Pages is provided, with at least one pair of rollers having a linfang- 10984Ö / 0305 3AD ORIGIN. *? speed has such that a sliding between the plate and the orphans are created. "AD 109848/0305 Blank page