EP0911128A1 - Laminated wooden beam - Google Patents

Abstract

The laminated wood beam has a number of wood layers glued together. In cross section, the outer layers (5a,5d) have a semi-orientation of their grain, with an angle of 30-60 degrees between the grain and the width of the wood. In the inner layers (5b,5c), the grain runs tangentially. This configuration ensures that as little of the grain surface as possible is exposed on the laminate surface.

Description

The invention relates to the construction of a laminated Wooden beams for various structural and non-structural Applications. In particular, this is according to the invention Wooden beams for the production of wooden facade elements, especially for the production of windows, revolving windows and doors, but also for conservatories with a wooden frame intended.

It is known to be laminated for facade joinery work Use wood or finger-jointed laminated wood, especially softwood, such as spruce, Larch and hemlock wood, but also hardwood. In a The standard version has a laminated wooden beam from which a window is made a width of 120 millimeters and a height of 72 millimeters, the window beam preferably three, four, five or more, adjacent slats is built. In The slats are seen in the longitudinal direction of the bar mostly from lamella parts connected by finger jointing.

Seen in cross section, the slats of the known laminated wooden beams for the manufacture of windows a tree ring course that is considered completely tangential or completely rift / semi-rift is marked.

• Rift: Bezeichnung für aufrechtstehende oder fast aufrechtstehende Jahrringe, wenn der Winkel zwischen dem Jahrring und der Breite des Holzteils etwa zwischen 90° und 60° liegt,
• Halbrift: Bezeichnung wenn der Winkel zwischen dem Jahrring und der Breite des Holzteils etwa zwischen 60° und 30° liegt,
• Tangential: Bezeichnung für liegende Jahrringe, wenn der Winkel zwischen dem Jahrring und der Breite des Holzteils etwa zwischen 30° und 0° liegt.

As is generally known, annual rings can be seen on the cut surface, the front side, of a wooden part. The following generally accepted terms are used to describe the course of the tree rings:

• Rift: term for upright or almost upright tree rings if the angle between the tree ring and the width of the wooden part is between 90 ° and 60 °,
• Semi-rift: Description if the angle between the tree ring and the width of the wooden part is between 60 ° and 30 °,
• Tangential: Description for horizontal growth rings if the angle between the growth ring and the width of the wooden part is between 30 ° and 0 °.

Furthermore, it is generally known that softwood and some Hardwood species due to their lower natural resistance less resistant to rot, weathering and are like tropical wood. Therefore it is necessary the wood of one of such laminated beams manufactured facade element, in particular a window, always by means of a good layer of paint of sufficient thickness protect. In practice, however, it turns out that the Resistance of a layer of paint to such a layer laminated wooden facade element is applied, is disappointing, which makes the paint undesirably common must be repeated to the required quality and To ensure layer thickness.

The present invention is based on the object Abolish the above disadvantage.

The invention solves this problem by creating one Wooden beams according to the generic term, which thereby is marked that, seen in cross section of the bar, the outer slats semi-lift and the ones in between Slats are tangential.

As is known in the surface of the broad top a grain of a wooden beam recognizable when the wood is sawn tangentially. This grain is from the hard The late wood portion of the annual rings formed, which Late wood part, compared to the brightly colored and much softer early wood part of the tree rings, dark colors.

The present invention is based on the idea that strongly changing weather conditions, despite the Presence of a paint, to change the Of wood. With this change, the softer one disappears Early wood content stronger than the harder late wood content of the Annual rings. As a result, the hard late wood parts, in the form of a grain, higher than the soft In other words, early wood components lay the grain stands out clearly in the surface of the wood. Of the Height difference between the higher and lower parts in the wooden surface leads to considerable tension in the painting above. Since the color layer is a has limited elasticity, the color layer will easily show cracks, reducing the protective effect is lost and the paint quickly weathered.

In the known fully tangential / tangential glued wooden beams is the mark described above of the tree rings to a very high degree on the side surfaces of the Bar present. With the well-known rift / semi-rift glued wooden beams is the strong one mentioned above Drawing particularly on the top and bottom of the facade element manufactured in this beam. That is why the well-known finger-jointed laminated Facade elements undesirably much maintenance of the paint necessary. The pattern of the grain has one additional disadvantage that shows up when a new one Color layer is applied as part of the maintenance. Before applying a new layer of paint, the old one Layer to be sanded to cover the weathered top layer to remove the paint, and to ensure good adhesion receive. The fact that in the known wooden beams uneven surface is created when grinding too much of the old on the high-lying surface parts Paint layer removed while the intermediate one low parts are being sanded too little. After this Applying the new layer is the layer thickness insufficient for the high parts of the surface to be protected, while the adhesion of the new paint layer in the lower Sharing is not satisfactory. This disadvantage too contributes to an undesirably high maintenance effort.

This measure according to the invention ensures that in the surface to be protected by a layer of paint facade element to be produced considerably less grain than occur with the well-known laminated wooden beams, thereby eliminating the disadvantages described above, or but be greatly reduced. In other words, they are Tree rings now instead of a grain as side by side, narrow stripes in the surface recognizable and is the part of the harder late wood parts in the surface considerably larger than in the known Bar. The presence of a grain continues to grow reduced if the slats are sawn in such a way that the tree rings in the wood parallel to the longitudinal direction of the bar. The application of the laminated Wooden beam according to the present inventive concept particularly advantageous for windows, especially for their Hem sleepers.

The advantage of the laminated wooden beam according to the invention is through a comparative weathering study been confirmed. There are test pieces in this investigation made of finger-jointed, laminated spruce wood with four Slats have been manufactured according to the prior art, and completely tangential and completely rift / semi-rift, and according to the invention with a semi-rifts / tangentials / tangentials / half-rifts Orientation. The specimens had a width of 120 Millimeters and a height of 72 millimeters and a length of 20 centimeters. Part of the specimen was painted and the other part unpainted. The Test pieces are subjected to an aging cycle several times in which the test pieces are successively with a Radiant heating heated to a temperature of 40 °, sprinkled with cold water until below freezing cooled, sprinkled again with cold water and again until were irradiated at 40 °.

It has emerged from the weathering investigation that the markings on the annual rings in the surface of the laminated wooden beam according to the invention, both painted and unpainted, are considerably less than in the known laminated wooden beams. In particular, the four sides of the test pieces according to the invention remain smooth and unevenness is hardly visible, while the test pieces according to the prior art have a rough, uneven surface after weathering. The results of the painted test pieces are shown in the table below. Sample piece Structure of the test piece Marking below / above Marking side faces 1 rift / semi-rift no no 2nd rift / semi-rift strong no 3rd rift / semi-rift strong strongly left 4th rift / semi-rift very low no 5 rift / semi-rift low no 6 tangential / tangential no strongly left 7 tangential / tangential low strong left and right 8th tangential / tangential low strong left and right 9 tangential / tangential very low no 10th tangential / tangential no slight left 11 semi-rift / tangential no no 12th semi-rift / tangential low slight left + right 13 semi-rift / tangential very low no 14 semi-rift / tangential very low no 15 semi-rift / tangential very low no

It is noted that in the Keuringsbureau of the Stichting Hout SKH (Stiftung Prüfstelle Holz) published to State of the art and in the Netherlands applicable "National Assessment Guideline for the KOMO product certificate for laminated wood for non-load-bearing Applications "dated May 1, 1994, number BRL 2902 is what laminated wood demands for Wood facade elements should meet.

Regarding the construction of laminated wood for the Manufacture of windows, revolving windows and doors above mentioned guideline: "With regard to the tree ring course the structure is on average free to the extent that Directive should be noted that the difference in Tree ring course between adjacent slats as low as is possible, and that the course of the annual rings (on the Face seen) compared to the glue joint as much as is alternately located. Extreme deviations from the previous directive, as in Figure 3 of the directive are fundamentally incorrect and not "As an explanation of this, the directive mentions: "If the structure is incorrect, cracking can occur the dimensional stability is insufficiently ensured ". FIG. 3 This guideline shows "examples of a unauthorized construction of laminated wood "right above a structure with three slats, in which the Tree ring course rift / tangential / rift is.

The structure of the wooden beam according to the invention therefore seems contrary to that on the above date published policy. The one to be described in more detail Investigation has shown that the invention laminated wooden beams knows no cracking, as in the Directive is suggested, and that the dimensional stability is acceptable. In particular, it turns out that at large cross-sectional dimensions of the wooden beam, as with wood for the construction of a winter garden, the formation of cracks is even lower than with the known bars.

The investigation included a delamination exam, as well as an examination of the dimensional stability.

In the delamination investigation are unpainted Test pieces made of finger-jointed laminated spruce wood according to the prior art, namely completely tangential and completely rift / semi-rift, with inventive Test pieces with a tree ring orientation half-rift / tangential / tangential / half-rift have been compared. The test pieces had a width of 120 millimeters and a height of 72 millimeters. The test pieces are according to the Dutch guideline NPR 7071, enclosure C, tested been. The test included one autoclave treatment and one subsequent drying. After the passage of the Drying period are the end faces of the specimens the presence of open glue joints has been assessed. It has been found that not a single specimen Delamination showed, therefore it can be said that contrary to what is mentioned above Assessment guideline suggests increased tension the glue line due to a different shrinkage and Swelling behavior between the adjacent fins does not increase leads to delamination. It is noted that for the Gluing the lamellae of the test pieces is a common glue has been used.

In the weathering test described above both the painted and the unpainted Test pieces were checked for any delamination, and there is no significant difference between that wooden beams according to the invention on the one hand and the laminated On the other hand, bars according to the prior art were found been.

With regard to the dimensional stability, it turned out that the Laminated wooden beams according to the invention reasonably worse than the laminated wooden beams according to the state the technology behaved. The differences found are but not significant.

Preferably, the thickness of each lamella is less than 30 millimeters to avoid delamination problems on the glue surfaces to avoid.

Fig. 1

einen Querschnitt durch eine erste Ausführungsform eines lamellierten Balkens aus Nadelholz für ein Fenster gemäß dem Stand der Technik,

Fig. 2

einen Querschnitt durch eine zweite Ausführungsform eines lamellierten Balkens aus Nadelholz für ein Fenster gemäß dem Stand der Technik,

Fig. 3

eine perspektivische Ansicht des Balkens der Figur 1 nach Verwitterung,

Fig. 4

eine perspektivische Ansicht des Balkens der Figur 2 nach Verwitterung,

Fig. 5

einen Querschnitt durch eine erste Ausführungsform eines lamellierten Balkens aus Nadelholz für ein Fenster gemäß der Erfindung,

Fig. 6

eine perspektivische Ansicht des Balkens der Figur 5 nach Verwitterung, und

Fig. 7

einen Querschnitt durch eine zweite Ausführungsform eines lamellierten Balkens aus Nadelholz für ein Fenster gemäß der Erfindung.

In the attached figures:

Fig. 1

2 shows a cross section through a first embodiment of a laminated beam made of softwood for a window according to the prior art,

Fig. 2

2 shows a cross section through a second embodiment of a laminated beam made of softwood for a window according to the prior art,

Fig. 3

2 shows a perspective view of the bar of FIG. 1 after weathering,

Fig. 4

2 shows a perspective view of the bar of FIG. 2 after weathering,

Fig. 5

3 shows a cross section through a first embodiment of a laminated beam made of softwood for a window according to the invention,

Fig. 6

a perspective view of the bar of Figure 5 after weathering, and

Fig. 7

a cross section through a second embodiment of a laminated beam made of softwood for a window according to the invention.

Figure 1 shows a known laminated wooden beam 1 for the making of a window. The bar 1 is made up of four Wood slats 1a, 1b, 1c, 1d, especially spruce wood, built up, with the orientation of the annual rings in the Slats with the hint completely tangential is marked. The wooden window beam 1 has here a width of 120 millimeters and a height of 72 Millimeters. The bar 1 shown in general known profiled a window beam.

Figure 2 shows another known wooden beam 2 for the Making a window. The bar 1 is made up of four Wooden slats 2a, 2b, 2c, 2d, especially spruce wood, built up, with the orientation of the annual rings in the Slats with the hint completely rift / semi-rift is marked. The wooden window beam 2 points here a cross-section of 120 x 72 millimeters.

In Figure 3 it is shown that on the side surfaces of the Bar 1, for example for the outer slat 1d, one there is a strong mark on the tree rings. This Marking is done by tree rings that are not parallel to the Longitudinal direction of the beam are caused and is thereby visible as a grain 3 in the surface. At Weathering of bar 1, even if it has been painted a strong drawing of the tree rings and thereby an uneven surface on the side surfaces of the Bar 1, for example with lamella 1d. This drawing is not only disadvantageous for the appearance of the beam 1, but it also leads to increased tension in the Color layer, which therefore has a short lifespan. In addition, the unevenness causes problems when applying a new layer of paint. From the bar 1 can Standard window beams are manufactured, which is dashed in Figure 3 is shown.

From Figure 4 it can be seen that in this known beam a strong mark of the grain 3 on the side surfaces of the inner slats 2b, 2c occurs. From the bar 2, a standard window beam can be made what is shown in broken lines in Figure 4.

Figure 5 shows a cross section of an inventive Wooden beams 5 for the production of windows and the like Facade elements. The wooden beam 5 has a width of 120 Millimeters and a height of 72 millimeters and is here made up of four lamellae 5a, 5b, 5c, 5d. According to the invention the outer fins 5a and 5d have one Semi-rift orientation and the intermediate slats 5b, 5c a tangential orientation. From the bar 5 can Standard window beams are manufactured, which is dashed in Figure 6 is shown. FIG. 6 also shows that the tree rings are not or hardly in the form of a Mark grain in the surface, which is also due to this It is encouraged that the annual rings as much as possible lie parallel to the longitudinal direction of the beam. The outer slats 5a, 5d have after the manufacture of the Window bar aligned at right angles to each other Outside surfaces that are protected by a layer of paint must, namely a vertical side surface and a lying surface. To be an optimum for both surfaces with regard to the desired minimum copy of the They have to create grain on these surfaces outer slats a semi-rift orientation.

FIG. 7 shows a laminated wooden beam according to the invention 7 with a width of 120 millimeters and a height of 72 Millimeters shown. With a dashed line is schematic a window bar indicated, which from the bar 7 can be manufactured. The beam 7 is made up of six slats 7a - 7f constructed, the outer slats 7a and 7f semi-rift and the intermediate slats are tangential.

As mentioned, the structure of the laminated bar according to the invention in particular the advantage that the Mark the hard parts of the tree rings in the shape of a Grain in the outer surface of the from the beam manufactured facade element on all four sides considerably less than when using the known bar is, or is even completely missing. By reducing the Marking increases the life of the paint.

In the foregoing is the situation in particular shown in which the glue surfaces of the wooden beam lay parallel to the facade surface, which arrangement is preferred. However, the invention is not based on this limited and the bar according to the invention is also advantageous in situations where the glue surfaces are be placed at right angles on the facade surface.

Claims (8)

Laminated wooden beams (5; 7), in particular for the production of wooden facade elements, such as windows, revolving windows and doors, comprising three or more wooden slats, which are glued side by side in the beam,
characterized in that, seen in cross-section, the outer lamellae (5a, 5d; 7a, 7f) are semi-rift and the intermediate lamellae (5b, 5c; 7b-e) are tangential. Wooden beam according to claim 1, wherein the dimension and mutual position of the slats in the beam in such The way is that the orientation of the tree rings in the essentially symmetrical to the central longitudinal surface of the Bar is. Wooden beam according to claim 1 or 2, wherein the beam is rectangular in cross-section and adjacent Slats each have a rectangular cross-section, and where the largest cross-sectional dimension of each Slat perpendicular to the largest cross-sectional dimension of the Is aligned. Wooden beam according to claim 1 or 2, wherein the beam is rectangular in cross-section and adjacent Slats each have a rectangular cross-section, and where the largest cross-sectional dimension of each Lamella parallel to the largest cross-sectional dimension of the Is aligned. Wooden beams according to one or more of the previous ones Claims where each slat is thinner than 30 millimeters is. Wooden beams according to one or more of the previous ones Claims where one or more slats are made by Finger jointing of longitudinally connected lamella parts are. Wooden facade element for the outer facade or an add-on part, for example a winter garden, of a building, in particular a window, comprising a laminated wooden beam, which beams (5; 7) comprise three or more wooden slats which are glued side by side in the beam, characterized in that that, seen in cross-section, the outer slats (5a, 5d; 7a, 7f) are semi-rift and the intermediate slats (5b, 5c; 7b-7e) are tangential. Facade element according to claim 6, wherein the beam Hem sill beams with an inclined drain surface is at the top, and in which the drainage surface of the lamella delimiting the outside of the facade element with a semi-rift orientation and several adjacent ones Slats with a tangential orientation is formed.

Images