FI97959C - Method and apparatus for joining at least two pieces of wood into one piece - Google Patents

Description

97959

METHOD AND APPARATUS FOR JOINING AT LEAST TWO PIECES OF TIMBER

The invention relates to a method according to the preamble of claim 1 for joining pieces of wood into one piece. The invention also relates to an apparatus according to claim 5 for joining pieces of wood into one piece.

10 In the manufacture of pieces of wood, in particular in the manufacture of glulam beams, adhesive has traditionally been applied to at least one of the opposing surfaces, the pieces to be joined being pressed and held in presses until the adhesive has sufficiently dried. Due to the long drying time of the Pit-15, large presses have been required which can accommodate a large number of pieces to be pressed at one time. The temperature has a significant effect on the drying time of the adhesive, in which case solutions have been developed in which the body to be glued is heated from the outside. Heating the body from the outside 20 has been difficult because wood is an insulating material. In addition, directing heat to the gluing point has been cumbersome and the solutions used have been complicated.

The object of the present invention is to provide a completely new method and apparatus by means of which the disadvantages of the prior art are avoided.

The method and apparatus according to the invention are characterized by what is stated in the claims.

30

The solution according to the invention has numerous significant advantages. The method according to the invention has made it possible to accelerate the drying of the adhesive substantially. In this case, a significantly higher capacity is achieved than with conventional methods.

35 97959 2

The invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a simplified side view of a device applying the method according to the invention,

Figure 2 shows a top view of an apparatus applying the method according to the invention, Figure 3a shows the pieces to be joined before pressing, and Figure 3b shows the piece to be joined.

In the method according to the invention, at least two wood pieces 1, 2, 3 are joined into one piece 8 by means of an adhesive L and a press 10. Typically, the method can be used, for example, in the production of glulam beams, lamellar logs or multilayer boards. According to the method, an adhesive L is introduced into at least one of the joint surfaces 4, 5, 6, 7, at least one of the pieces 1, 2 to be joined together at each joint; 2, 3 are heated before the surfaces to be joined are placed opposite each other, after which the pieces are placed on the joint surfaces 4, 5; 6, 7 aligned and pressed together. Preferably, at least one of the pieces to be joined at each joint is heated by radiation. Usually, an adhesive L is introduced into one of the joint surfaces 5, 7 of each joint and the other joint surface 4, 6 is heated by means of radiation, in particular infrared radiation.

In a preferred embodiment of the method, in which the final product body 8 consists of more than two pieces of wood 1, 2, 3, the adhesive L is applied to one surface 5 of the body 2, the body 2 is heated on the opposite side 6, the bodies 1, 2, 3 are stacked. the adhesive surface 7 of the pieces 2, 3 and the heated surface 3 97959 are placed opposite each other and pressed together by a press 10. Only the adhesive L is introduced into the body 3 forming the lower surface and the body 1 forming the upper surface is only heated. Both treatments are performed on the pieces 5 between these pieces 1, 3.

The apparatus according to the invention operates as follows in the manufacture of glulam beams. The planed pieces 2 coming through the glue 9 by the longitudinal conveyor 12 are turned by the turning device 10 13 the glue side 5 downwards onto the transverse conveyor 14 on the knuckles or the like, thus avoiding staining of the glue. The body 2 preferably moves in the transverse direction under the IR radiator 11, whereby the non-glued surface 6 is heated to the desired temperature. The IR radiator 11 is preferably substantially at least the length of the body to be heated. The piece 2 is turned and placed on the conveyor 15, preferably on the comb conveyor, on the combs 20 acting as separating means, whereby there is an air gap between the pieces 2, whereby the adhesive does not yet react. The pieces placed on the comb conveyor 15 form a stack 20, which, when desired, is transferred to the press 10.

In the case according to Figure 3, in the joint surfaces the adhesive surface 5, 7 is placed upwards and the heated surface 4, 6 is placed downwards.

The pieces 1, 2, 3 are pressed together for the desired time. With the help of efficient heating acting directly on the joint, the pressing times can be substantially shortened. In a conventional case, the pressing time is reduced from 8 to 11 hours to less than an hour. In this case, a temperature in the range of 40 to 90 ° C is usually used as the heating temperature. The pressing time is substantially affected by the adhesive used and the temperature in the joint.

35 4 97959

It will be clear to a person skilled in the art that the invention is not limited to the exemplary embodiments presented above, but can be varied within the scope of the appended claims.

Il

Claims (7)

A method of joining at least two pieces of wood (1.2.3) to one piece (8), in which method glue (L) is applied to at least one of the joint surfaces (4,5; 6.7), the pieces (1.2.3). ) are placed with the joint surfaces (4,5; 6.7) against each other and pressed together, in which at least one of the pieces of wood (1,2; 2,3) soin forms the respective joint is heated before the joint surfaces (4,5; 6, 7) is placed opposite each other, characterized in that glue (L) is applied to one joint surface (5.7) in each joint and the other joint surface (4.6) is heated by irradiation, especially with infrared radiation. , and that the pieces are arranged in the press so that the upper surface (4.6) of each joint is heated and pk the lower surface (5.7) is applied glue (L). 15 Method according to claim 1, characterized in that at least one piece (2) is located between the surface bits (1.3) and glue (L) is applied on one side (5) of this bit (2), the opposite side (2) of the piece (2). 6) heated, the pieces (1,2,3) are stacked so that adjacent pieces (1,2; 2,3) of adhesive surfaces (L) are stacked against one another and the heated surfaces are placed against each other and pressed together. 3. A method according to claim 1 or 2, characterized in that the pieces (2) after the application of the glue with a turning device (13) are turned so that the adhesive surface (5) comes down and is placed on a conveyor (14). the bits (2) are passed to an IR irradiator (1 1) by which the non-adhesive surface (6) of each bit (2) is heated to the desired temperature, that the bits (2) are turned and placed in a conveyor (after the heating phase). 15), preferably a cam conveyor, where they rest against separating means (20) and that of the bits (2) placed in the cam conveyor (15) forms a stack which is moved to the press (10) bit by bit or hay and hob. 35 8 97959 4. A device for joining at least two pieces of wood (1,2,3) to a piece (8), which device is provided with means (9) for applying glue (L) to at least one of the pieces (1,2). 3) being treated, a radiator heater (11) with which at least one of the surfaces (4,5; 6.7) to be joined is heated before being placed against each other and means (10) for compressing the pieces (1,2 , 3), characterized by a turning device (13) placed between the adhesive coating device (9) and the radiator heater and a device (15) positioned after the radiator heater which turns the bits (2) and places them in the press (10), after which the press the sow presses them to a stack. Device according to claim 4, characterized in that the device which turns the bits (2) and places them in the press comprises a conveyor (15), preferably a cam conveyor, in which the pieces (2) are placed resting on cams (20) which function as separating means such that air gaps are formed between the pieces (2). 20 Apparatus according to claim 4 or 5, characterized in that handling means (15) are provided in connection with the cam conveyor which in the press (10) one by one or as a bundle pushes the pieces resting against the conveyor cams (20) which are to be stacked. 1