WO2007116127A1

WO2007116127A1 - A method for manufacturing a wooden glue board and a glue board blank

Info

Publication number: WO2007116127A1
Application number: PCT/FI2007/050183
Authority: WO
Inventors: Matti Peltola
Original assignee: Upm-Kymmene Wood Oy
Priority date: 2006-04-07
Filing date: 2007-04-02
Publication date: 2007-10-18
Also published as: FI20065225A; RU2424112C2; FI20065225A0; EP2004370A4; EP2004370A1; RU2008144116A; FI122465B

Abstract

This invention relates to a method and blank for manufacturing a wooden glue board (3a-3d), in which method it is sawn off from the glue board blank (11, 12) a desired amount of glue boards (3a-3d) thinner than the blank (1, 12). In the manufacturing phase of the glue board blank, the blank (1.12) is assembled by gluing one upon the other a desired amount of sandwich planks, which sandwich planks are formed of at least two adjacent parts (2a,2aa - 2d,2dd), growth ring side of which is placed on the opposite sides with each other in a horizontal and/or vertical direction.

Description

A METHOD FOR MANUFACTURING AWOODEN GLUE BOARD AND AGLUE BOARD BLANK

This invention relates to a method presented in the preamble of claim 1 for manufacturing a wooden glue board and also to a glue board blank presented in the preamble of claim 6. According to the known technology wooden glue boards, i.e. glued timber slabs, are manufactured, for example, by gluing from the edges, i.e. from the narrower side, together a suitable amount of laths to obtain a sufficiently wide glue board. This way is suitable, for instance, for manufacturing single boards. In the industrial manufacturing of glue boards the thinner the boards to be manufactured are, the more ineffective this way is proved to be. In the industrial production, glue boards may be manufactured with a so-called "beam method' so that a reasonably thick glued timber beam is first manufactured to be a blank for instance, of a number of planks having a crosscut of 5d*100 mm. The planks will be glued together from longer sides or flanks so that in the planks which are placed one upon the other every other has a wood growth ring facing down and every other has a wood growth ring facing up. Thus deformations in the glued joints are prevented. After this, glued timber beam is sawn, for example, with a band saw into four parts as thin glue boards. A problem in this method is the adaptation of grain direction of the planks glued one upon the other to be such that also in outermost sawn glue boards the grain directions would be such that the outermost glue boards would not bend. This is practically impossible. In this case, compromises are needed due to cost motives because within the use of raw material and time it is not always possible to do a perfect adaptation of grain directions of planks. As a result, at least in part of the blanks, in the outermost glue boards to-be-sawn bending occurs frequently due to the wood tension. Figures 1 and 2 illustrate such a blank of a glued timber beam according to prior art and a sawn-off outermost glued timber beam. A detailed description of figures 1 and 2 is presented below. The target of this invention is to remove above-mentioned disadvantages and also to generate a simple, fast and preferred and also industrially applicable method to manufacture a glue board blank and glue board, and also a glue board preferably produced, in which all grain directions of lamellas have been adapted so that even the outermost boards sawn off from the blank do not bend substantially. A method in accordance with the invention is characterised by features presented in the characterising part of claim 1. Respectively, a glue board blank in accordance with the invention is characterised by features presented in the characterising part of claim 6. Other embodiments of the invention are characterised by features presented in other claims. An advantage of a new structure of the blank enabled by the method according to the invention is among other things the fact that it is possible to efficiently manufacture industrially with a so-called "beam method' wooden glue boards as inexpensively and of good quality as possible, in which the bending of glue boards sawn off from the edges of the blank is substantially small or nearly non-existing. In this case, also the adjacent grain direction of lamellas in the glue boards sawn off from the edges of the blank is such that in every other lamella the growth ring is on the other side of the glue board. A further advantage is a balanced-looking final product, in which it has been possible to remove esthetical faults. For instance, the final board product is not knotty in lines. In the following the invention is described in greater detail by means of an example applying a solution according to the invention by referring to the accompanying drawings, where

Figure 1 Illustrates a glue board blank in accordance with the prior art in an end view for sawing glue boards, figure 2 illustrates a glue board sawn off from the blank in accordance with the prior art Figure 3 Illustrates a glue board blank in accordance with the invention in an end view for sawing glue boards,

Figure 4 Illustrates the outermost glue board sawn off from the blank in accordance with the invention and

Figure 5 Illustrates a glue board blank in accordance with a preferred embodiment of the invention in an end view for sawing glue boards. Figure 1 illustrates a glued timber beam functioning as a blank 11 for glued boards to-be- sawn in accordance with the prior art, which consists of a number of wooden planks 22a- 22d set on top of each other from their longer side or flank. Planks set on top of each other, crosscut of which is, for example, 50x100 mm have been adjusted with each other regarding wood grains so that every other plank 22a, 22c has a growth ring facing down and every other plank 22b, 22d has a growth ring facing up. It is sawn off from the blank 11, for example, with a band saw glue boards 33a-33d with a width equal to blank 11 along break lines 55 marked in Figure 1. It can be seen in Figure 1 that in every second lamella of middle glue boards 33b, 33c, i.e. The sawn part of the every second plank 22a, 22c has such a grain direction that the growth rings are facing down, while in the sawn part of every second plank 22b, 22d has growth rings facing substantially in opposite direction or up. For this reason middle glue boards 33b and 33c remain essentially straight and do not bend substantially. Instead, grain directions of the outermost glue boards 33a, 33d are poor in terms of bending. Grain direction of all lamellas of the glue board 33 is such that growth rings in the figure are facing right, while the grain direction of all lamellas of the glue board 33d is such that growth rings in the figure are facing left. Accordingly, growth rings in mutual lamellas of both of the outermost glue boards 33a, 33d are in all lamellas on the same side of the glue board.

Figure 2 illustrates an outermost glue board 33d sawn off from the blank 11, in which it clearly shows that grain direction 44 is such that in all lamellas the growth rings are on the same side of the glue board, i.e. On the side 55. Figures 3 and 4 illustrate a structure in accordance with the invention. The figure shows wooden glue board's glue board blank 1, which consists of a number of wooden sandwich planks glued on top of each other from their longer side or flank,

Each of which sandwich plank has been assembled by gluing at least two adjacent parts, at least one of which parts is a wider part 2a-2d and at least one part is a narrower part 2aa- 2dd. All sandwich planks are made substantially with a same principle, even though mutual size and mutual grain direction of the parts can vary. In the following only two uppermost sandwich planks will be described in detail. In the uppermost sandwich plank there is thus at least one wider part 2a on the left, in which the grain direction has been selected, for instance, so that the growth rings are facing down and substantially towards the centre of the sandwich plank, and one narrower part 2aa on the right, in which the growth rings are facing in a opposite direction to a wider part 2a, i.e. In the figure upwards and outwards of the sandwich plank, parts 2a and 2aa are glued side by side to one another to form a sandwich plank with a crosscut of a rectangle.

Respectively, in second uppermost sandwich plank there is at least one narrower part 2bb on the left, in which the grain direction has been selected, for instance, so that the growth rings are upwards and outwards, and one wider part 2b on the right, in which growth rings in the figure are upwards and substantially towards the centre of the sandwich plank 1. Parts 2bb and 2b are also glued side by side to one another to form a sandwich plank with a crosscut of a rectangle. When the uppermost sandwich plank is glued to the next sandwich plank under it, narrower parts 2aa and 2bb of the sandwich planks remain with each other and respectively wider parts 2a and 2b with each other in the opposite sides of the vertical middle line of the blank 1. Onto the lower surface of the second uppermost sandwich plank the next sandwich plank 2c, 2cc substantially corresponding to the sandwich plank 2a, 2aa is glued into the corresponding position with the sandwich plank 2a, 2aa and further in turns every sandwich plank so that in every other sandwich plank narrower parts of sandwich planks with each other and respectively wider parts with each other are on the opposite sides of the vertical middle line of the blank 1. it is sawn, for example, with a band saw out of the finished glue board blank 1 glue boards 3a-3d with a width equal to blank 1 along break lines 6 marked in Figure 3. Glued joint 7 between the wider part and narrower part of the sandwich plank could be at saw cut line, but it can as well be also located on some other place, such as it can be seen in saw cut line on the left- hand side. Figure 4 illustrates an outermost glue board 3d sawn off from the glue board blank 1, in which it clearly shows that grain direction 4 is such that every other lamella 5a, 5c has growth rings in the figure on the right and every other lamella 5b, 5d has growth rings in the figure on the left. In this case, every second lamella growth rings are thus on the opposite sides with each other. Figure 3 illustrates two structurally slightly different sandwich plank types 2a, 2aa and 2b, 2bb, the like of which are glued in turns on top of each other to form a glue board blank 1. Just as good final result is reached, with only one type of sandwich planks, for example sandwich planks of type 2a, 2aa, every second of which is turned upside down in the blank. Figure 5 illustrates a blank 12 formed with such sandwich planks. As a difference from the solution in accordance with Figure 3 is now that narrower parts 2bb and 2dd are upside down in regard to the corresponding parts of Figure 2. It is essential that in the sawn-off outermost glue boards 3a and 3d growth rings of every second lamella are on the opposite side of the glue board, in which case there is no substantial occurence of bending. A glue board in accordance with the invention is manufactured in accordance with a method of the invention as follows: glue board blank 1, 12 is initially manufactured by forming substantially sandwich planks in the form of rectangle, which consist of at least one wider part 2a-2d and one narrower part 2aa-2dd with each other, which wider and narrower parts are glued with each other side by side together by selecting the mutual grain direction of the parts so that the growth rings remain either in the vertical direction or horizontal direction in the opposite sides of said parts of the sandwich plank. The sandwich plank of type 2a,2aa growth rings are in the vertical direction in the opposite side of said parts 2a and 2aa of the sandwich plank, while in the sandwich plank of type 2b,2bb the growth rings are sidewardly or in the horizontal direction in the opposite side of said parts 2b, 2bb of the sandwich plank. The sandwich planks manufactured in such a way are glued with each other one upon the other together from the longer sides so that every other sandwich plank at least growth rings of wider part 2a-2d are on the opposite side of the adjacent sandwich plank. In this case, the growth rings of every second wider part 2a-2d of the sandwich plank are, for example, facing up and of every second down. Grain directions on sandwich planks are selected so that when the finished blank 1 is sawn with a band saw to a number of narrower parts 3a-3d of glue boards, all adjacent grain directions of lamellas 5a-5d of the sawn glue boards are different from each other and hence arranged so that every second or adjacent lamellas have growth rings on the opposite sides.

As for a balanced and esthetical final result sandwich planks and a glue board assembled of them is manufactured of planks sawn off from different trees for instance, so that all lamellas 5a-5d of a finished glue board originate from different trees. In this case, the finished glue board is as a whole balanced-looking, and, for example, there is no occurence of knots in lines.

For those skilled in the art it is apparent that the invention is not limited to exclusively before-mentioned examples, but it can vary as presented in the patent claims below. Thus, for example, depending on a desired glue board width the blank may have on top of each other a different number of sandwich planks as presented before. The number may be, for example, any desired number between 2-n, where n is an integer.

For one skilled in the art it is also apparent that the grain directions can be selected differently as presented above. It is essential that grain directions of the sandwich planks have been selected so that in all sawn-off glue boards every other lamella has growth rings on the opposite side. In addition, to those skilled in the art it is apparent that the sandwich planks may have also parts of different width of an amount different from two. For instance, there can be three or four parts or in some planks even only one. For those skilled in the art it is furthermore apparent that the sandwich planks may have two parts of substantially equal width, in which the growth rings are on the other side of each other either in the horizontal or vertical direction.

Claims

1. A method for manufacturing a wooden glue board (3a-3d), in which method it is sawn off from a glue board blank (1, 12) formed with gluing of planks a desired amount of glue boards (3a-3d) substantially thinner than the blank (1, 12), characterised in that the planks of the glue board blank (1, 12) are formed to be a sandwich plank by gluing together at least two mutually adjacent parts (2a, 2aa - 2d, 2dd), growth ring side of which parts is placed to an opposite side of each other in a horizontal and/or vertical direction, and sandwich planks formed in this way are glued a desired amount one upon the other.

2. A method as claimed in claim 1, characterised in that a grain direction of different parts of the sandwich planks in the sandwich plank internally and between the sandwich planks set one upon the other is selected so that growth rings of mutually adjacent lamellas (5a-5d) of substainally all glue boards (3a-3d) to-be-sawn-off are on the opposite side of the glue board (3a-3d).

3. A method according to claim 1 or 2, characterised in that the sandwich plank is formed of two adjacent parts of different sizes with each other (2a,2aa - 2d,2dd), which are glued to each other.

4. A method according to claim 1, 2 or 3, characterised in that parts of different sizes (2a, 2aa - 2d, 2dd) of the sandwich planks mutually one upon the other are placed mutually criss-cross and the grain directions between the sandwich planks one upon the other are selected so that at least in the wider parts (2a- 2d) the growth rings of two sandwich planks one upon the other are on the opposite side of the sandwich plank with each other.

5. A method in accordance with any above claim, characterised in that all sandwich planks are assembled of two parts of a different size (2a,2aa - 2d,2dd) to be substantially similar and that all sandwich planks are arranged in the blank (12) by gluing them mutually one upon the other so that every other sandwich plank is upside down.

6. A glue board blank (1.12) for manufacturing glue boards (3a-3d) to-be-sawn-off from a blank substantially thinner than the blank, which blank (1, 12) comprises a number of planks glued one upon the other being substantially thicker than finished glue boards (3 a- 3d), characterised in that at least a part of planks are sandwich planks, which sandwich planks have been formed of at least two mutually adjacent parts (2a,2aa - 2d,2dd), a growth ring sides of which have been placed on the opposite sides with each other in a horizontal and/or vertical direction.

7. The glue board blank according to claim 6 (1.12), characterised in that all planks are sandwich planks, and that the grain direction of different parts of sandwich planks (2a,2aa - 2d,2dd) in the sandwich plank internally and between the sandwich planks set one upon the other has been selected so that growth rings of mutually adjacent lamellas (5a-5d) of substainally all glue boards (3a-3d) to-be-sawn-off are on the opposite side of the glue board (3a-3d).

8. The glue board blank (1,12) according to claim 6 or 7 characterised in that the sandwich planks have been formed of two adjacent parts of different sizes with each other (2a,2aa -

2d,2dd), which have been glued to each other.

9. The glue board blank (1, 12) according to claim 6, 7 or 8, characterised in that parts of different sizes (2a, 2aa - 2d, 2dd) of the sandwich planks mutually one upon the other have been adjusted with each other criss-cross and the grain directions between the sandwich planks one upon the other have been selected so that at least in the wider parts (2a-2d) the growth rings of two sandwich planks one upon the other are on the opposite side of the sandwich plank with each other.

10. The glue board blank (12) in accordance with any claim 6-9 above, characterised in that all sandwich planks are assembled of two parts of a different size (2a,2aa - 2d,2dd) to be substantially similar and that the sandwich planks have been adjusted to the blank (12) by gluing them mutually one upon the other so that every other sandwich plank is upside down.