EP1475205A2 - Apparatus for the longitudinal orientation of wood strands - Google Patents

Abstract

Device for longitudinal orientation of elongated scattering material, especially flat elongated wood chips (strands) used in the manufacture of oriented strand board, comprises an orientation unit (5) for scattering the scattering material in a longitudinally oriented manner onto a continuous belt (6). The orientation unit consists of parallel rotating shafts with vertically aligned disks (10) arranged an axial distance part. Blade elements (11) arranged between axially adjacent disks form chambers. Preferred Features: Four blade elements are uniformly distributed between two adjacent disks.

Description

The invention relates to a device for longitudinal orientation of elongated wood chips, especially for the production of Boards with oriented chips, according to the generic term of the Claim 1.

Panels with oriented chips, which in professional circles as OSB panels (oriented strand board) Chipboard with higher strength properties.

Long wood chips are used in the production of OSB boards (Strands) oriented on a ribbon, and then pressed into plates. Usually they have Wood chips a length of 100 - 150 mm, a width of 10 - 30 mm and a thickness of 0.4 - 1.0 mm. The OSB panels own usually a 3-layer structure, but recently for the use of different glue systems also 5-layer Plates are made.

In the case of 3-layer OSB panels, the Middle-layer wood chips oriented transversely and the top layer wood chips sprinkled lengthways on a ribbon. Through the The arrangement gives anisotropic properties. Wood owns in Grain direction much higher strength than across the grain. The arrangement of longitudinally oriented wood chips in the Cover layers that are subjected to bending loads in the longitudinal direction of the OSB Panels subjected to tensile and compressive stress lead to high ones Flexural strength of the plate. In the transverse direction there is still one sufficient flexural strength of the panels through the cross oriented middle class reached.

Studies have shown that the quality of the Longitudinal orientation has a very large influence on the Has longitudinal bending strengths. Already 10 to 15 ° Deviation of the grain of the chips from the longitudinal axis lead to significantly lower strength properties.

To achieve the longitudinal orientation are currently in the Spreaders different mechanical devices for Alignment of the wood chips used.

From EP 0 175 015, for example, an as Washer oriented mechanical device for Longitudinal orientation of wood chips known.

With such disc orienters a variety of transversely arranged shafts with thin sheet metal washers are equipped, spaced parallel and lying horizontally arranged above the forming belt. The disks of neighboring waves overlap each other and form longitudinal ones By chutes.

The principle of operation of this disc orienter is based that the diarrhea chutes are narrower than the length the wood chips and therefore the wood chips are not oriented transversely can step through. The wood shavings that hit the Disc orienters will not step straight through by rotating the disc rollers in the same direction Movement and thereby change their orientation, until they are oriented approximately longitudinally and fall into the diarrhea slots.

System-related deviations occur with this functional principle from the longitudinal orientation. For one, they can Wood chips in different orientations in all three axes fall through the diarrhea slit. At a Wood chips from e.g. the dimensions 100 x 20 x 0.5 mm and the wood chips can have a diarrhea slot with a width of 30 mm step down with the front edge 20 x 0.5 mm, with the side edge 100 x 0.5 mm or with the surface 100 x 20 mm length-oriented, as well as any combination of these. ever depending on the type of case, it can deviate more or less from the ideal longitudinal orientation.

Because the disc orienter is spaced from the forming belt is, it can continue to happen that upside down through the Wood chips penetrating through diarrhea when they hit tip the ribbon over. This leads to undesirable ones Deviations in the longitudinal direction of the wood chips from the Longitudinal axis.

DE-OS 195 44 866 is another embodiment of a mechanical device for longitudinal orientation of wood chips known.

In this device, a plurality of parallel and Wall elements arranged vertically next to each other and associated elongated orientation elements arranged. The orientation elements are on a drive connected and can perform a movement that a Component along and vertical to it.

From GM 297 07 143 is a device for aligning and Dropping of elongated particles known in which the Degree of orientation of the particles with high throughput can be improved. This is an embodiment variant provided with a mechanical orientation unit is provided in the direction of movement of the pad has vertical straightening surfaces, with adjacent Straightening surfaces can be driven in the opposite direction. The movement of the straightening surfaces is parallel to the moving one Underlay and also has movement components perpendicular to Base for the longitudinal orientation of the wood chips.

The invention has for its object a device for Longitudinal orientation of elongated wood chips at the beginning to improve the type mentioned so that an exact Longitudinal orientation of the wood shavings is achieved and thus panels with improved strength properties can be produced can.

This object is achieved by the specified in claim 1 Features solved.

Due to the configuration of the Orientation unit as chamber rollers, they fall to orienting wood chips between axially adjacent disks on blade elements. They lie on the blade elements Wood chips flat, which gives them a defined position take in. With the further rotary movement of the chamber roller the wood chip slides with its at a certain point Front edge in the direction of the forming belt.

When it hits the forming belt, the wood chips are opened Forming belt speed slowed down or accelerated and then at the belt speed of the Blade elements subtracted. Through this process of Pulling off will further improve the longitudinal orientation achieved because the wood chips only with the rear edge on the The transport sheet is resting on it and rubbed into the Longitudinal axis are rotated.

Another improvement in the longitudinal orientation results when the blade elements are bent in a V-shape are executed. In this variant, the wood chips slide to the side of a pane and come to rest there. Thereby the last degree of freedom is also taken and the Wood chips lie on the three axes in a defined manner Vane element.

Fig.1

eine Seitenansicht eines Deckschichtstreukopfes für OSB Platten mit Dosierbunker, Verteilerwalzen und Orientierungswalzeneinheit;

Fig.2a

einen vergrößerten Ausschnitt einer Draufsicht auf eine erfindungsgemäß ausgestaltete Orientierungseinheit;

Fig.2b

eine schematische Darstellung einer Seitenansicht auf eine vergrößerte Darstellung gemäß Fig. 1 der Orientierungseinheit;

Fig.3a-d

eine schematische Darstellung des Ablaufes der Orientierung eines Spanes bei Drehbewegung einer Kammerwalze.

The invention is explained in more detail with reference to exemplary embodiments which are illustrated in the drawings. Show it:

Fig.1

a side view of a top layer spreading head for OSB boards with dosing hopper, distributor rollers and orientation roller unit;

2a

an enlarged detail of a plan view of an orientation unit designed according to the invention;

2b

a schematic representation of a side view of an enlarged view of FIG 1 of the orientation unit.

3a-d

is a schematic representation of the course of the orientation of a chip with rotary motion of a chamber roller.

1 schematically shows a molding station 1 with a Dosing hopper 2, which has a discharge roller arrangement 3, Distribution rollers 4, an orientation unit 5, and a Form tape 6 shown.

In Fig. 1 from the dosing bunker 2, a material flow over the Discharge roller arrangement 3 carried out. The non-oriented Material flow consists of flat elongated wood chips that usually a length A of 100 to 150 mm, a width B of 10 up to 30 mm and a thickness C of 0.4 to 1.0 mm. This glued wood chips first reach the distributor rollers 4 which distribute the chip flow to the orientation unit 5.

The orientation unit 5 consists of chamber rollers 7, which in Direction of conveyance (represented by arrow 8) one after the other are arranged and with constant speed in Are driven clockwise. The chamber rollers 7 exist made of rotating shafts mounted and driven in a housing 9, each with a predetermined number vertically aligned discs 10 are arranged axially spaced. The disks 10 have the same distance. In In a further embodiment, the distances can be more adjacent Rolls with different axial disc spacing dimensions be executed. This gives you a Separation of smaller and larger wood chips. The disks 10 shown all have the same Outer diameter. Alternatively, the disks 10 can also have different diameters.

The disks of adjacent shafts can be aligned with each other be arranged, but can also be transverse to the conveying direction be arranged offset to each other, whereby a Traces of the scattered fleece is avoided.

The axially spaced disks 10 are each divided into V-shaped chambers 12 by blade elements 11. As shown schematically in FIG. 1 and FIG. 2b is, the blade elements 11 are in a first Embodiment executed as rectangular sheets that the connect axially adjacent disks 10 and proceed from the surface of the rotating shafts 9 tangential to Extend the outer diameter of the disc 10 out. In which illustrated embodiment are four blade elements 11 evenly distributed over the circumference of the rotary shaft 9 arranged so that between axially adjacent disks 10 four chambers 12 each are formed. The neighboring ones Sheets 11 have an angle α of 90 ° to one another on.

• die Anzahl der Schaufelelemente und damit die Anzahl der Kammern;
• die Anordnung der Schaufelelemente (beispielsweise radial nach außen sich erstreckend);
• die Ausbildung der Schaufelelemente

variiert werden.In further exemplary embodiments, which are not shown, however, can also

• the number of blade elements and thus the number of chambers;
• the arrangement of the blade elements (for example, extending radially outwards);
• the formation of the blade elements

can be varied.

The blade elements designed as sheets 11 can be of this type be designed so that they are compared to the outer diameter of the Discs 10 flush, protruding or recessed are.

As can be seen from FIG. 2a, the chamber rollers 7 also be arranged in such a way that the disks 10 of the opposite rotating shafts 9 in the middle of each Intervene slightly overlapping spaces. At this The arrangement of the blade elements 11 is recessed executed.

The wood chips of the material flow can be due to the arrangement the discs 10 whose axial distance is less than that Length A of the wood chips is not oriented transversely into the between the Discs 10 formed chambers 12 fall into it.

The wood chips that do not fall directly into a chamber 12 are due to the rotary movements of the chamber rollers 7 in Movement moves and change their orientation until they are oriented approximately longitudinally and into the Chamber 12 fall.

As can be seen from Fig. 2b, this alignment in the longitudinal direction by alternating arrangement of am Structured and smooth outer discs 10 supported become.

The process of longitudinal orientation of the Wood shavings based on Fig. 3a-3d, the time sequence represents when the chamber roller 7 rotates. The For the sake of clarity, only one is to be oriented Wood chip S shown in an oversized representation.

3a shows how the wood chips (by way of example shown on a chip) in the slots between adjacent ones Slices 10 can fall into a chamber K.

As shown in Fig. 3b, the wood chip falls e.g. with the Front (B x C) down first and meets that first turning down towards the forming belt 6 towards the front pointing blade element 11 of a chamber 12. In the further Sequence the wood chips tip onto the sheet metal Blade element 11 (Fig. 3c). You lay down flat the sheets 11. Through the lateral boundaries of the chamber 12, which are formed over the disks 10 and the sheet 11, the wood chips can now only be turned slightly the chamber 12, insofar as this is the difference between Wood particle width and chamber width still allowed.

In a special embodiment of the sheets 11 (Fig. 2a) the blade elements are formed in a V-shape with a longitudinal kink. The Blade elements 11 are arranged such that the Longitudinal edge 13 of the kink forms the highest point and the side elements slope down to the disks 10. This ensures that the wood particles depending on Center of gravity to the left or right to one of the two Disc 10 slides and with its side on the disc Facility is coming. This will also be the last degree of freedom taken and the wood particle is now in all three axes defined in chamber 12.

With the further rotation, a point finally becomes reached, with the wood chips down along the Sheet 11 slipped (Fig. 3d). He will continue to do so the disc led as a chamber wall.

As the longitudinally oriented wood chips slide down from the Chambers 12 on the forming belt 6, always hit the wood chips their front edges on the forming belt 6, the rear part of the wood chip still rests in the chamber 12 on the sheet 11. When they hit the wood chips are first braked or accelerated and then at form speed of peeled off the sheet. Depending on the arrangement or shape of the Bucket elements and the speed of the forming belt can the impact speed of the wood chips is smaller or larger than the forming belt speed. The blade elements always extend from an inner point P1, the first one running through the center of the roller radial line L1 lies to an external point P2 the disc that runs on one through the center of the roller extending second radial line L2, which is in a preferred embodiment in the direction of rotation of the behind the first line. Due to the location of the end points P1 / P2 and the shape of the blade elements between the end points P1 / P2 can be the point at which the wood chips from the Sliding blade elements can be varied.

The wood chips then hit completely in theirs Longitudinal aligned on that continuously in the direction of the arrow 8 running ribbon 6.

For the purpose of adaptation to differently manufactured Panel thickness is a height adjustment of the Orientation unit 5 is provided.

The distance between the orientation unit 5 and the forming belt 6 must be in Dependence on the wood chips to be scattered in any case be adjusted so that when the wood chips slide down the chambers 12 the wood chips when they hit the forming belt rest with their rear edges on the sheets 11.

Claims (14)

Device for the longitudinal orientation of elongated grit materials, in particular flat elongated wood chips (strands) for the production of panels with oriented wood shavings (OSB panels), which has an orientation unit for the longitudinally oriented scattering of the grit materials on a continuously moving forming belt, the orientation unit comprising rotating shafts arranged parallel to one another which have vertically aligned axially spaced disks, the disks forming alignment shafts with one another, characterized in that blade elements (11) are provided which are arranged between axially adjacent disks (10) and chambers are formed by the arrangement of the blade elements (11) , Device for the longitudinal orientation of elongated Scattering goods according to claim 1, wherein between two adjacent discs (10) each have four blade elements (11) are evenly distributed. Device for the longitudinal orientation of elongated Grit material according to claim 1 or claim 2, the blade elements (11) starting from a inner point P1, which is on a through the Center of the roller running first radial line L1 lies to an external point P2 on the disc (10) on one through the center of the roller extending second radial line L2, extend. Device for the longitudinal orientation of elongated Scattering goods according to claim 3, wherein the inner point P1 and outer point P2 a common through the center of the roller radial line. Device for the longitudinal orientation of elongated Scattering goods according to claim 3, wherein an imaginary Connection line between internal point P1 and external point P2 of the blade elements (11) is formed, and this by an angle β in Direction of rotation is inclined to the second radial line L2. Device for the longitudinal orientation of elongated Scattering goods according to claim 3, wherein the Tilt angle β is between 15 ° - 45 °. Device for the longitudinal orientation of elongated Scattering goods according to claim 3, wherein the inclination of the Bucket elements designed in the direction of rotation to the rear is, so that the outside point P2 the inner point P1 follows. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the outer end point of the blade elements (11) compared to the outer diameter of the disks (10) reset. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the disks (10) of adjacent chamber rolls in Transverse direction are axially offset from each other. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the outer edges of the disks being adjacent Chamber rollers alternately structured and smooth are trained. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the blade elements (11) being bent in a V-shape are trained. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the blade elements (11) being adhesive-coated. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the orientation unit with regard to distance and Inclination to the forming tape is adjustable. Device for the longitudinal orientation of elongated Grit according to one of the preceding claims, the outer diameter of the washers being adjacent Rollers are graduated.

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