JPS6345931B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an apparatus for forming a particle layer on a layer-receiving surface, and more particularly for forming a particle layer into a mat to be pressed, for example in the production of particle board. The present invention relates to an apparatus for depositing and arranging particles on a conveyor surface so that particles can be deposited and arranged on a conveyor surface.

BACKGROUND OF THE INVENTION Current manufacturing technology allows particle boards of various thicknesses with a wide range of densities to be produced for a variety of purposes ranging from load-bearing structural applications to thermal insulation or decorative applications.

The term particleboard is used herein to describe a product formed by applying heat and pressure to a pine of particles, typically wood, with a proprietary or synthetic binder that may be added to the particles.

The particles may be wood chips, produced when wood is ground, and can be considered relatively elongated and therefore oriented.

The particle board stock can be pressed directly onto the platen surface or onto a press underlay, such as a screen that forms a surface pattern on the underside of the particle board, in a single level press or a multi-stage press.

During compaction, the top surface of the board can be embossed to produce a specific pattern, and the board can be pressed very densely for use as a load-bearing member or to support a load. It is sometimes pressed to a relatively low density for use in other applications.

Particleboard is often also referred to as composite board, and may be used as is or laminated to plywood or other decorative boards, coated with a synthetic resin decorative film or protective film, depending on the final use. Good too.

In all cases, however, the precursor to particle board is pine, generally square in shape and having a thickness that can be several times the thickness of the board from which the pine is compressed.

This pine is at best loosely packed and essentially consists of a flat pile of particles or wood chips.

It is well known to form such mats by depositing particles in a generally uniform layer on a layer-receiving surface such as a conveyor, which conveys the mat from the layering position to the layer sideways. The layers can be divided into longitudinal dimensions to form individual mats and transported to a location.

Individual pine can be conveyed directly or indirectly to the press, usually by carefully depositing the pine on a press underlay or tray, which tray is used to convey the pine onto the press platen. used for.

When forming mats or layers from particulate materials, especially wood chips, the elongated particles are oriented in the transverse direction during the formation of the layer, i.e. the larger dimensions of the chips are
It has been found to be advantageous to be at least primarily transverse to the conveyor movement.
Such orientation is referred to herein as alignment.

A lateral arrangement can be performed in combination with a distributor that deposits the particles on the layer receiving surface.

For the production of particleboard, it is therefore known to provide devices or devices for depositing chips on a continuously moving layer receiving surface, for example the above-mentioned conveyor, which conveyor has a transverse array and which The vessels move continuously along an endless path and are on a conveyor and movable in the same direction as the conveyor. A particle distributor is placed above this lateral array.

In forming the layer on the conveyor, the lateral backing plate contacts the particles of the deposited mass and forces the particles into lateral alignment.

Such a system is disclosed in German Patent Application No. 2523515,
This will be briefly explained with reference to FIG.

In this system, the transverse array consists of a drum 16 with a closed circumferential surface 19 and a receiving plate 56 projecting radially from this drum.

The receiving plate 56 thus forms a space which is bottomed by the closed circumferential surface 19 of the drum 16 and rotates about the drum axis.

The particulate material is fed from the distributor 5' and into a second chamber located in these spaces and below the drum 16.
layer receiving surface 2' via the surface 61 of the drum 60 of
supplied to

Although this system has been found to be largely effective, there are some problems associated with drums and space. For example, the resulting layer may not be as uniform as desired, and the uniformity of the lateral alignment may depend to a large extent on the location and manner of contact between the backing plate and the particles.

Particle board formed from mat is not laterally isotropic and may have a range of varying densities or other properties across the board. In some cases this results in distortion, and in other cases weak spots may be found in the board.

In order to eliminate these drawbacks, it has been proposed to provide another drum between the drum receiving plate and the layer receiving surface, which flattens the formed layer and which is originally formed by the receiving plate. This is an attempt to eliminate some of the irregularities that occur when a pocket drum surface is used.

Although the layer formed by this device is indeed more planar and has a uniform appearance, the addition of the drum would diffuse the lateral alignment and thus prevent the desired particle alignment effect and etc. It has been found that many problems regarding orientation or strength remain.

With such a pocket drum, when the distributor drops particles onto the drum from above and the drum pocket collects these particles and conveys them onto the conveyor, the particles accumulate in clumps and these clumps also form. Disturbs the uniformity of the rising layer.

OBJECTS OF THE INVENTION It is an object of the invention to eliminate the above-mentioned drawbacks and to provide a device for forming a homogeneous layer of transverse particles.

Another object of the present invention is to provide a system for producing particleboard with improved isotropic properties and strength, in which a homogeneous array of laterally aligned particles does not have the disadvantages of arraying in a drum with radially oriented backing plates. An object of the present invention is to provide an apparatus for forming layers.

Yet another object of the present invention is to provide an improved and relatively simple layering apparatus for producing particleboard with a high degree of uniformity and strength.

Structure of the Invention These objects and other objects that will become apparent in the future are achieved according to the present invention as follows. That is to say, in a layer-forming device for forming layers of particles to be made into particleboard, for example in a heated platen press, a continuously movable layer-receiving surface, for example a surface forming the upper horizontal path of a conveyor, and a layer arranged above this surface, A transverse array is provided in the form of an endless lattice with lower channels that are inclined with respect to the layer receiving surface, the lower channels of this moving grating moving away from the layer receiving surface in the direction of movement of the lower channels. A receiving plate extending below the moving grid scoops and aligns the particles during layer formation, and is arranged in the same direction. A distributed distributor is provided which deposits particles onto the layer receiving surface through the upper and lower channels of the moving grid.

If the particles to form a layer pass through both paths of the moving grid array and form a layer, which layer is entrained by the inclined surface formed by the path of the lower edge of the grid backing plate, Truly laterally aligned layers with a surprisingly high degree of uniformity are formed. This effect is believed to be due to the free fall of the particles onto the layer receiving surface through the array-moving grid.

Said inclined surface forming a small acute angle with the layer receiving surface starts at a distance of only a few mm from this layer receiving surface, and the distance of the inclined surface from the layer receiving surface is equal to the thickness of the layer of the pine to be produced. If it continues until
Get the best results.

The system of the present invention therefore does not use such spaces and thus does not provide spaces in which particles can concentrate or become clogged. This free fall allows the particles to more naturally align laterally and without waving, humping or distorting the laterally aligned within the layer.

Best results are obtained if the linear velocity of the lower path of the grating is lower than that of the layer receiving surface, so that the layer is drawn out from under the moving grating by the layer receiving surface.

It has proven further advantageous to arrange the support plate along the lower path of the moving grid in such a way that it is preferably tilted downwards with respect to the vertical plane and in the direction of movement of the moving grid.

It has also proven advantageous to provide the moving grid with a vibration unit which imparts vibrations to the support plate as it moves along said inclined path.

Particle distributors can deposit sorted or unsorted particles, i.e. particles with a wide size range, or particles that are ranked from fine to coarse and become progressively finer in successive layers. can.

However, best results are obtained if the distributor has rows of scattering disks arranged over the horizontal distance of said inclined surface and interdigitated with each other.

In such a distributor, the discs between which the particles fall are axially spaced from each other on their respective axes, with the discs of one shaft interdigitating between the discs of the preceding and following shafts.

In most cases, best results will be obtained if all disks are driven in the same direction and only disks at the ends of the array are driven in opposite directions.

In such a disk sieve, classification can be performed by gradually increasing the distance between the disks from axis to axis.

In a particularly advantageous construction, first the fine particles, then the medium-sized particles and then the coarse particles are deposited on the bed receiving surface through a moving grid.

Of course, the dimensions of the particles may be reversed and two layer-forming units according to the invention may be provided in succession, or two such disc sieves may be used for one moving grid device. may be provided, all depending on the particle size distribution desired in the finished product. For example, the layers may be ranked with particularly fine grains at the top and bottom of the layer, coarse layer regions in the middle of the layer, and intermediate sized particles between the coarse grain regions and their respective fine layers. Good too.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

The illustrated device provides a device for dispensing particles 1, generally wood chips, onto a continuously moving bed receiving surface 2, for example on the upper path of a horizontal conveyor.

The resulting layer 1a of thickness T can be divided laterally, made into individual mats and placed on an underlay in the form of a screen or tray, sent to a platen press, for example to a multistage press, and subjected to heat and pressure. can be compressed and made into particle board. The direction of movement of the layer receiving surface 2 is indicated by the arrow B, and the particles 1 are elongated and preferentially aligned transversely within the layer, ie perpendicular to the drawing plane of FIG.

The layers are ranked and shown in Figure 1 as areas Z1 and Z.
Separate regions may also be provided, as schematically indicated by Z2, Z3, Z4 and Z5. If five such zones are provided, zones Z1 and Z5 will consist of very fine particles forming the finished surface of the particle board, zones Z2 and Z4 will consist of particles of intermediate size, and zone Z3 will consist of relatively fine grains. It can consist of coarse particles.

The particles may be pre-coated with a heat-activated binder or pressed into a cohesive state utilizing a wood-specific binder material. Alternatively, a liquid binder may be added to layer 1a.

The illustrated device for forming the layer 1a consists of a transverse array, generally designated 3, and a distributor 5 arranged above this array and dispersing the particles 1 onto the receiving surface 2.

The transverse array according to the invention consists of a moving grid, the receiving plates 4 of which extend laterally, i.e. over the width of the layer receiving surface 2, and at both ends of the moving grid. Roller member 1
It is pivotally connected to an endless tensioning means 9 of a chain or belt passing through 0.

Each receiving plate 4 has a respective pivot 4c.
The outer blade 4a is spaced apart on the opposite side with the
and inner blades 4b, and these blades 4a
are arranged inclined forwardly and downwardly over the lower path 11 of the moving grid in the direction of travel C of the lower path of the moving grid, the direction of travel of the lower path being the direction of movement B of the surface 2. is the same as However, the linear velocity of the lower path of the moving grid is lower than that of the conveyor, which may be equipped with drive means indicated at 20.
The moving grid has a drive 21. blade 4b
In order to avoid the roller members 10 and 12, a slot is formed at the location indicated by 4d, and this roller member 1
2 defines the lower end of the inclined surface path relative to the lower edge 4e of the blade 4a. This slope path is
It starts only a few mm above surface 2 at the right-hand end and increases to a substantial distance T from layer 2 at the left-most end.

The distributor 5 extends over the entire horizontal distance of this inclined surface.

The distributor 5 is here designed as a disc screen and consists of a number of discs 6, all of which are free of charge, except for the discs 6a at the ends of the arrangement, which can be driven in opposite directions as indicated by the arrow E. They are driven in the same direction, ie in the direction of arrow D.

The disk 6 is supported by a shaft 6b, and a second
They are summarized as shown in the figure. Center distance F
may vary along the array, forming a gap that is relatively wide in region 8 and relatively narrow in region 7, thereby ranking the particles so that finer layers are deposited first; and subsequently a coarse layer is deposited.

The particles 1 can pass through the upper and then lower paths of the moving grid, fall freely onto the layer receiving surface, and are guided into a highly uniform transverse arrangement. The roller members 12 are adjustable to change the angle of the ramp and the tension of the moving grid conveyor. The lower paths of the moving grating may converge towards the region where the slope begins, and the moving grating is fitted with a vibrator 2, which would further increase the uniformity of the layer created.
I found that it was advantageous to provide 2.

[Brief explanation of the drawing]

1 is a schematic side view of the device according to the invention, FIG. 2 is a plan view showing a part of the device of FIG. 1, and FIG.
The figure shows a known device. DESCRIPTION OF SYMBOLS 1... Particle, 2... Layer receiving surface, 3... Lateral array device, 4... Receiving plate, 5... Distributor, 11... Lower path, 14... Upper path.

Claims (1)

[Scope of Claims] 1. A continuously movable layer receiving surface; a pair of roller members disposed along this surface and spaced apart from each other in the direction of movement of this surface; and a pair of roller members disposed above the layer receiving surface; An endless moving grid is provided forming a loop around the roller member, the moving grid having a lower path moving generally in the direction of movement of the layer receiving surface, and the moving grid being able to move around the layer. The layer has a receiving plate extending transversely to the direction of movement of the receiving surface and is adapted to arrange the particles placed on the layer receiving surface, and the receiving plates are arranged apart from each other in the direction. so that the particles can fall through the paths of said grid between the roller members, the lower edge of the backing plate being below the moving grid moving away from said layer receiving surface in the direction of movement of said lower path. Along the side channel, a particle distributor is provided, which forms an inclined surface channel and is arranged above the moving grid and extends over the entire length of this grid, which distributor comprises roller members. Apparatus for forming a layer of laterally arranged particles, characterized in that the particles are deposited on the layer receiving surface through the upper and lower channels of a moving grid between them. 2. Device according to claim 1, characterized in that a device is provided for driving the layer receiving surface and the moving grating, the linear velocity of the lower path being lower than that of the layer receiving surface. 3. The device according to claim 1 or 2, wherein the outer receiving plate of the endless moving grid is inclined in its direction of movement when it reaches the lower path. 4. The device according to claim 3, wherein a vibration generator is connected to the moving grid to vibrate the moving grid. 5. Claim 3, wherein the distributor has a disk sieve formed by interdigitated rows of disks in an array extending over the horizontal distance of the inclined surface path.
Apparatus described in section. 6. Claims in which the disc is constructed and arranged to sort the particles and deposit relatively fine particles first on the layer receiving surface and then deposit relatively coarse particles thereon. The device according to paragraph 5.