CHIPBOARD WITH A WELL ORDERED STRUCTURE

Abstract: The invention relates to a chipboard with oriented structure comprising fibres (1) of vegetable origin e.g. wooden chippings having been fixed with some binding material (5) in their oriented position. The characteristic feature of the invention lies in that the fibres (1) of vegetable origin comprise ferromagnetic particles (2).

Description: CHIPBOARD WITH A WELL ORDERED STRUCTURE The Field of the Invention The invention relates to a chipboard with a regular well-ordered structure comprising fibre of vegetable ' origin so e.g. wood chippings, having been fixed with some binding material- in its oriented position. Description of the Prior Art Several types of chipboards are known, so for example the traditional single- or multilayer chipboards, the multilayer chipboard made of wide flat wooden chippings bound with formaldehyderesin /flakeboard/ or the single- or multilayer board /waferboard/ made of large sized (20-40 mm) long wooden chips. Chipboards containing sawdust or other kinds of chippings covered on both sides with plywood (comply) are also known. Mechanical characteristics - not meeting always requirements - with traditional chipboards as well as ever increasing prices of raw materials forced researchers of the wood industry to develop chipboards differing from the traditional embodiments. A chipboard of newer type is represented by recent¬ ly developed so-called OSB board (oriented structural board) made of 30-50 mm long and of 1015 mm wide, large-sized wooden chippings, being a single or multi- -layer product. (Holzrundschau 1981/12. p. 386-388.) Mechanic features of the OSB boards correspond to those of the sandwich boards coated with plywood, the more, they yield better characteristics (Forest Product Journal 33/2. p. 43-49.) US-PS 3.164.511 discloses an apparatus being suitable for the production of oriented structural boards. The apparatus disclosed therein directs echani- cally the large-sized chippings. Mechanical guidance takes places with cylinders provided with cells. Later guidance of chippings by means of cylinders with discs became known. Drawback of said mechanical guidance lies in that operation is rather slow, accordingly these apparatuses are less suitable for large-scale plants. Mechanical guidance was further developed by Bison Works (USA) : guiding plates provided with chain rows have been employed. To enhance production later electrostatic orientation was introduced (Forest In¬ dustries 12/4. p. 26-27) - Sizes needed for electrostatic orientation were as follows: length of the chippings: 75 ram to 100 mm, width: 10-15 mm thickness: 0,3 - 0,5 mm (Holz-Zentralblatt 105/84, p. 1236) . US-PS 5.045.528 describes an electrostatically orienting apparatus. For the sake of electrostatic orientation chippings have to fall freely in vertical direction. Free fall takes place between caset-te inserts forming the electrodes. Drawback of said method lies in that chippings must be possibly homogeneous as due to different sizes particles of chippings may have different mass inertia. Moisture of chippings may influence too efficiency of the apparatus, accordingly moisture o.f chippings must lie in the range between 10 and 15 % considered as rather disadvantageous chipboards will be pressed, as a consequence fibres of vegetable origin will be subjected to deformation, they are losing their original features. All known processes in wood-industry have the common disadvantage in so far as that exploited round logs serve as starting basic material, accordingly 60 % of the living tree will be wasted. The requirement has arisen - taking in consideration the need in round logs and high prices - to produce chipboards in course of which branches of the foliage and thicker roots can be utilized, a further require¬ ment lies in that waste could be reduced to a minimal level. Summary of the Invention The aim of the invention is to eliminate all drawbacks of known solutions and to develop a chipboard with which branches of the foliage can be well-utilized, mechanical characteristics are excellent, production can be realized quickly and with minimal expendure on costs . Basic conception of the invention rests on the recognition in so far as bundles of fibres resp. single fibres are treated with ferromagnetic materials, fibres will be automatically oriented in the magnetic field, in this position they can be fixed by means of some binding material into a chipboard more advantageously, than before. The conception according to the invention includes the process, in so far as ferromagnetic material is to mixed with water and introduced so into the fibres of vegetable origin. According to the aim set our invention relates to an oriented structural board, comprising in its oriented position fibres of vegetable origin having been fixed with some binding material, so e.g. wooden chippings, comprising ferromagnetic particles. A further characteristic of the invention lies in that on the surface of the fibres of vegetable origin or in their channel precipitations of ferromagnetic . particles are present. The chipboard according to the invention has several advantages. By distortion of the magnetic field fibres can be oriented not only straightly, but also an arrange¬ ment in an arched way becomes possible. By increasing of the magnetic field strength fibres can be compacted beside each other, accordingly pressing can be avoided. By avoiding pressing process not only technological process can be shortened and rendered more economical, but fibres will preserve their original mechanic features, mechanic characteristics of the chipboard according to the invention surpass all the solutions according to prior arts and is considered as far more advantageous. It is also considered as advantageous in so far as the chipboard can be produced while travelling horizontally, as a consequence the number of layers can be increased continuously. Application of large-sized wooden chippings can be omitted. Rate of production can be accelerated. It is considered as advantageous in so far as required fibres of vegetable origin can be obtained from branches and roofs. Instead of the 40 % achieved up to now, 90 % of the tree will be suitable for processing. Brief Description of the Drawings The invention will be detailed by means of an embodiment with reference to the drawings wherein Fig. 1 shows the side view of the fibre of vegetable origin, Fig. 2 shows the cross-section of the fibre of vegetable origin, Fig. 3 is a schematical illustration of the production of the chipboard in the magnetic field. Description of the Preferred Embodiments Fig. 1 illustrates the fibre of vegetable origin with the dispersed ferromagnetic particles , (e.g. iron- oxide) on its surface. Under fibres we mean the aggrega- tion of long-shaped cellbundles. Fig. 2 illustrates the cross-section of the fibre of vegetable origin. As it becomes obvious from the figure, ferromagnetic particles as precipitation do not adhere only on the surface of the fibre of vegetable origin but they are embedded into the channels of the fibre. Fig. 3 shows diagrammatically the chipboard itself and the process of production. In the magnetic field defined by the northern (N) and southern (S) poles fibres 1 of vegetable origin as elementary dipoles are oriented unidirectionally. By increasing intensity of magnetic field 3 fibres 1 can be compacted next to - each other. Fibres 1 of vegetable origin are lying on the conveyor 4 travelling horizontally and steadily fibres 1 are sprinkled with the binding material 5. Binding material 5 varies in dependence of the final use of the chipboard, it may be some synthetic resin or some natural gluingmaterial having been extracted from wood, between the cell-walls. In course of the continuous travel of the conveyor- -belt 4 further fibres 1 of vegetable origin can be applied, so number of layers can be increased. By increasing the number of layers even wooden railway sleepers can be manufactured. By changing the ■ direction of the magnetic field or by distorting lines of magnetic force fibres 1 of vegetable origin can be oriented and fixed in different positions _. The chipboard according to the invention can be used primarily in the building industry, furniture industry and in all fields of industrial economy where wood used to be utilized.

Claims: - 1 - CLAIMS 1. Chipboard with oriented structure comprising fibres of vegetable origin e.g. wooden chippings having been fixed by means of a binding material in their oriented position, c h a r a c t e r i z e d in that fibres (1) of vegetable origin include ferromagnetic particles (2) . 2. Chipboard with oriented structure as claimed in claim 1, c h a r a c t e r i z e d in that on the surface of the fibre (1) of vegetable origin and in the channels thereof ferromagnetic particles (2) precipitate.

Inventors: ZBISKO ENDRE, ZBISKO, ENDRE
Applicants: ZBISKO ENDRE, ZBISKO, ENDRE
Application year: 1992
Main classification: D21J1
IPC codes: B27N3, D21H17, D21J1