Method for improving Imprägnierbarkeit of lumber.

[0001] The present invention relates to a method for the production of lumber with increased capacity for liquid wood-modifying substances.

[0002] The trend in the wood industry away from layer-forming coatings to wood treatment process, in particular surface treatments, modifying substances penetrate into the wood the wood. The obtained thereby from the natural substances cannot see and exfoliation.

[0003] Normally be as precisely as possible along the longitudinal axis of the strain logs or parallel to the longitudinal axis of the strain and to saw cut products such as boards, planks, post, prisms or veneers processed. It is also known and usual, that wood log axis transversely, i.e. at an angle of 90 deg for strain axis, as so-called "end grain" is cut, which for example can be used for the preparation of brain wood floors.

[0004] Woods, are cut parallel to the strain axis, but only have a very limited capacity and loading capacity for liquid wood-modifying substances, short: impregnating agent. There is therefore a need for a method, with braiding the capacity and loading capacity of lumber for the load with impregnating agents of different kinds and which can increase for an application in industrial production and processing lumber - is suitable. Such a method is defined in claim 1, further advantageous embodiments are described in the dependent claims.

[0005] In the course of the present invention has turned out, that in wood, are cut parallel to the strain axis, the absorption capacity for liquid impregnating agent, the intended to penetrate into the wood, is very limited. But as soon as the tree "strands" of the tree - - more or less guide vessels are cut, increases the absorption capacity even at very small, flat intersection angles, relative to the longitudinal axis of the log or branch, very substantially immediately. After logs and branches not always run straight and not strictly rectilinear guide the tree candle containers extend, in a longer board can also several such zones with obliquely cut tree guide vessels at slightly different orientation, so that the length of the board different loading characteristics both occur, and a varied, optical appearance is created.

[0006] By a preselected angle can cut the total desired characteristics are induced board. In any case this measure causes a substantially increased capacity for total liquid impregnating materials compared with wood, the strain along the longitudinal axis or parallel to this conventionally is cut. Also in the surface treatment also improved uniformity.

[0007] The invention therefore relates to a method for increasing the absorption capacity in a first embodiment of lumber for liquid wood-modifying substances, wherein an elongate wood blank with longitudinal guide tree vessels, in particular a tree trunk, branch or an elongated part of a tree trunk or branch, at an angle of between 0 and 75 deg, in particular from 3 to 0 30 degrees, relative to its longitudinal axis, is cut obliquely, so that at least a part, usually the whole, located in the wood blank tree through the incision is cut obliquely at - or by conducting vessels.

[0008] Wood parts, prepared according to this invention, typically at an angle of between 0 and are 75 deg, preferably in a range from 3 to 0 30 degrees, cut longitudinal axis. As a further, positive side effect resulting from that a novel cutting direction, characteristic with a particular sequence of open or closed cross section, oval or elliptical annual rings, to a rift valley encephalitis - or semi-like pattern. Is surprising, that structure arms woods such as beech, maple or birch by the oblique cutting not only a new sectional view, a detail drawing rich but differentiated wood obtained, the them is wholly conventional longitudinal cuts.

[0009] The invention also relates to such bias cut lumber products with increased capacity for liquid wood and wood parts-modifying substances, in which at least some, usually all, of the present guide vessels through the incision to cut wood product tree - or are cut obliquely. This is the result of the oblique incision of an elongate wood blank, the longitudinal guide vessels has tree, at an angle of between 0 and 75 deg, in particular at an angle of 3 to 0 30 degrees, relative to the longitudinal axis of the wood blank. The wood blank can be a tree trunk, a branch or incision made therefrom according to conventional manner, elongated part of a tree trunk or branch be.

[0010] According to the invention produced wood parts with all conventional wood modifying substances of natural or synthetic origin can be applied. These are particularly lacquers, mordant, colorant, natural resins, synthetic resins, bleach, substances for pH change, waxes, oils, and/or other wood modification substances tanning agents.

[0011]Amethod for treating wood, in particular timber, wood with modifying substances are known in the art (see for example the EP 0,891,244 b1, entire document) and comprise a method as spraying, coating, soaking or immersion and other by dipping. Also known from EP 0,891,244 b1 many, for wood modification insertable substances, such as in claims 2 to point 6 of EP 0,891,244 b1 cited.

[0012] Biodegradable polymers such as polyhydroxy butyric acids including plummet, polycaprolactones, polylactic acids, polyester based on diols and dicarboxylic acids, polyamides, polyester urethanes, chemically modified natural polymers such as Celluloseacetate; but also fats, oils, waxes, the lignin, alcohols. The fats can cured or modified, be animal or vegetable fats, for example hydrogenated vegetable fats, oils epoxidized, wool grease, tallow, but also salts of various fatty acids, such as stearic acid, behenic acid, or lauric acid.

[0013] Also various salts, such as phosphates, borates, sulfates, chlorides, or silicates can together with the liquid substances or mixtures are used for impregnating wood. They can exert a positive influence on the reduction of the swelling and shrinking behavior -, flame retardant and/or fungicide also act.

[0014] As "solvent" can glycerol, or humectant plasticizers are used, alkali metal and alkaline earth metal resinates substances act as drying during -, but also as wetting agent and emulsifiers can be used to promote the penetration of molten resins and wood.

[0015] For pH change can for example sodium hydroxide or citric acid are used. Under the "other wood modification substances" substances such as acetic anhydride or plummet furfuryl alcohol.

[0016] "Liquid" referred herein extent on wood-modifying substances, including both should be understood such means and liquid at room temperature, while the room temperature are fixed, but melted by heating or heating and then in liquid form can be used for impregnation of the woods. Most resins and waxes e.g. included in them.

[0017] The impregnation of the invention essentially distinct from those of conventionally cut wood parts saw products, since the absorption capacity of the invention for any kind of wood is considerably increased wood parts modifying substances. This is particular evident therein, that most deeply into the wood and the wood substance together with substances retract into an intimate connection. This will make it possible surprisingly, wood parts over the entire cross section to color or to load with tanning agents, what conventionally produced parts is practically impossible in lumber.

[0018]Aeffect of this substantially increased substance containing is, that these wood parts also larger layer thicknesses, i.e. in a range of 5 To is 20 m m is, translucent can be made. On the other hand it is more difficult under this increased capacity, a greater layer thickness to achieve a desired impregnating agent on the wood surface, as for example in painted wood surfaces usually is desired. Here but with a multilayer coating structure can increase the viscosity of the lacquer and/or by corresponding redress.

[0019] Contrary to the experience gained in impregnation of wood vertüllten, such as spruce, it is now possible, these types of wood to load with a wide variety of substances, to modify their performance properties and thus improve so much. The spontaneous closure of the tree under "Vertüllung" is understood to guide vessels immediately after the precipitation, especially as observed spruce wood. A further, it is also positive side effect of this julienne, that the hardness, unlike longitudinal cuts produced from wood parts, is greatly increased hardness can be increased by modifying substances or.

[0020] The preparation according to the invention can be done by wood parts, that a wood blank, a tree trunk or branch usually, in a suitable saw, for example a band saw, is constrained, a cut angle in a range between 0 and 75 deg that, particularly in a range of 3 to 0 30 degrees, the longitudinal axis of the log in one operation is achieved.

One can also alternatively first at a first saw, e.g. a gang saw, elongate wooden blanks in the form of posts, planks or prism according to conventional longitudinal steep manner, the subsequently at a second saw, band saw or a circular - e.g., in the desired angle in the range between 0 and 75 deg parent longitudinal axis, in particular ranging from 3 to 0 30 degrees, are cut obliquely.

[0021] The thickness of the obliquely cut timber thus produced can vary widely, but it is usually in a range of 1 to point 40, in particular from 5 to 0 30 millimeters. It is further possible, typically 0.5 to 8 mm thickness by means of suitable knife veneers of wood cutting plane with the corresponding new and improved produce loading properties.

[0022] The produced such wood parts, including the veneers, other conventional wood or wood materials as carrier parts can be bonded. Especially to layer thicknesses in the lower region, i.e. in the range of 0.5 to 10 mm, since the bending strength of the oblique cut timber is reduced compared with conventionally longitudinally cut wood parts. The use of the oblique cut timber for constructive purposes is possible, but limited, d.h.

in response to the addition of support material for layer thickness may be required for mechanical reinforcement. For use in the production of multilayered parquets produced according to the invention seems to be almost predestined however oblique cut wood.

[0023] The following examples show a comparison of the different types of wood wood treatment agents with different loading bias cut.

[0024] Oil used: the Legno oil Fa. eagles.

The loading was by immersion of the wood pattern in the oil pressure at a temperature of about 22 type 25°c (room temperature) free. As reference the amount of oil of a conventional kind of cutting under identical conditions along the strain axis cut wood received 100% as indicated, the angle of intersection is 0 deg.

[0025] a is) spruce wood

Table 1

[0026]

[0027] b is) wood ash

Table 2

[0028]

[0029] d) beech wood

Table 3

[0030]

2: Loading different woods with wood lacquer Paint used: including floor and classic the Fa. eagles

Loading by immersing the wood pattern in a tub filled with lacquer was, pressure-free, (room temperature) at one temperature of 22 type 25°c. The amount of the recorded under identical conditions as reference

of a conventional kind of cutting along the cut wood as indicated 100% strain axis, cut angle is 0 deg.

a is) fir wood

4

b is) pine wood

5

d) oak wood

6

in degrees paint inclusion in %

100

210

The substance mixture consists of 66% by weight Tall resin (85 Sacotan, Fa. of Krems chemistry) and 34% by weight Montanic (Iscoblend 207, Fa.Schliekum), the softening point is 80 deg celsius. Prior to the loading of the substance mixture and the wood parts on 110 deg celsius fell trees iso probably heated. Is then applied to the wood parts to no further seating occurs.

As reference the amount of received Flarz-wax mixture under identical conditions conventional kind of cutting along the strain axis indicated as 100% cut Flolzes according, the cut is 0 deg.

a is) fir wood

7

b is) pine wood

8

in degrees substance inclusion in %

100

200

200

220

210

230

330

340

d) oak wood

Table 9

[0045]

Notch angle in degrees substance inclusion in %

0,100

5,180

15,210

30,220

45,210

60,230

75,220

90,240

[0046] In the course of tests and experiments carried out have also the following the invention brought findings:

[0047] - Obliquely cut timber, are generated at a cut angle of more than 30 deg, industrially difficult can be processed. They can manipulate bad, transporting or cutting, because some of its mechanical properties, in particular the bending fracture properties, compared to those of conventional longitudinally cut wood are reduced. The industrial planing such cut timber is obliquely hardly any or only from layer thicknesses of 10 mm and more, because they may even break easily and can destroy the planing machine.

[0048] Thus if we want to cut timber processing thin obliquely, with the incision 30 deg angles of greater than have been produced, they must be a stable carrier previously, typically a wood support, up-glue, only then can they be planing.

It has also shown, that these mechanical properties, such as the breaking strength, only when large cut angles, i.e. angles of more than 30 deg incision, in particular angles of 45 - 75 deg essential incision are changed, whereas they cut angles of 3-to-30 degrees only slightly from those of the conventional longitudinally cut woods (=notch angle 0 deg) differ.

[0049] - The advantages of the invention with respect to their modifiable by end obliquely cut timber natural or artificial chemical substances come into very small incision at angles to days. It is surprising, that absorption capacity for such substances in the range of about 3 - 20 deg disproportionately increased already lowermost notch angle is. Nor is there any linear correlation between cut angle and loading capacity, as well as from the examples can be seen well. Resulting discontinuities or abrupt changes rather, amongst others of wood species, wood hardness, the notch angle, the straightness or rest and nerves of the inner wood structure including the tree guide vessels, the content of resins and moisture, an optional filling of the wood, and optionally further factors depend.

[0050] As a whole can be further recognize, that about half to two thirds of the maximum possible angles between 0 and 30 deg incision loading capacity already be achieved. This shows is mostly wood species, wood-modifying substances wherein a conventional longitudinal section hardly receiving, such as spruce. In such types of wood is already at very small incision unexpectedly large angles absorption capacity.

[0051] - By modifying substances can for example specifically the surface - and/wood or the total hardness of the Schnittholzprouktes be increased, since the hardness modifying substances in liquid form are received into the wood, where they then chemically or physically curing. The source - and the inclined cut timber shrinking characteristics can also by impregnation with the water repellent substances improve, since less moisture can be absorbed.

[0052] Due to the obliquely cut tree guide according to the invention obliquely cut timber such vessels can also be included without wood-modifying substances quickly pressure application, as it into the wood preferably along the tree guide vessels drawing. Furthermore if pressure applied, it accordingly is faster. Advantageously the loading with wood modifying substances can freely be accomplished at markedly lower pressure or pressures, for the load than usual or conventional longitudinal cut timbers would be required.

[0053] The capacity can of course by heating the wood and/or wood piece to be machined additionally modifying substances be supported.

[0054] - Angle between 0 and 30 deg incision, in particular from 3 to 0 30 degrees are therefore preferably also, for as long as possible because only oblique cut of up to 3 meters length let steep woods, as part of the record industry usually desired or even required. The parquet industry also preferably 50 - 90 cm long stiles. Even with the use of logs with large strain diameters, relatively expensive so wood, are therefore the selection of cut angles in industrial lumber production practical limits set, through the region of the 0-to-30 degrees, in particular from 3 to 0 30 or 5 To is 30 degrees, will be adequately covered.

[0055]Acarpenters or carpenter can of course use other cut angle, if this desire for the customer. Most of the above-mentioned advantages are obtained in a range of about 3 - 30 deg but already cut angle, so this range being particularly preferred.

[0056] Obliquely cut timber and wood products produced according to the invention can be used for many purposes, for example for preparing parquets, paneling, ceiling, increased elements, veneers, decorative elements, plates, boards, and/or of two - or multi-layer wooden materials in a variety of ways, e.g. in sheet form as so-called cross-ply wood.