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10

Technical field

The invention refers at a woodsubstitute with lignino- cellulosic material and mineral particles which are moulded in

15 sheets such as plates or panels of varied thicknesses or divers forms, in stencil, using, at choice, wooden components, in pricipal, vβgetals and cellulosics as splinters woodchips, sawdust and / or woodwool, dried leaves, paperwastes, cerealchaff, aquatic plants etc. with a binder and the

20 obtaining method.

Background of the invention

It is known a woodsubstitute, patent RO 37832, which, 25 consists of"a mixture composed of 500 kg / n ricechaff with or without wood massaddition, 70-80 kg / m3 technical urea, the ratio refering to the ricechaff volume.

The product consists in the fact that the ricechaff is artificially dried to 2 % humidity and then it is added non- 30 diluted viscous Urelit C as adhesive, ammonium sulphate as accelerator and technical urea as inhibitor and then the whole stuff is mixed in a stirrer, in order to obtain a complete homogenizing, then it is poured as a carpet with 60-80 mm thickness and pressed with a pressing force between 2-6 kg/cπ.2 35 during 15-25 minutes at a temperature between 130-150 °C in order to finish the polimerization process.

The product and the obtaining method present the disadvantage of a hard working and a limited using area, therefore it cannot be moulded in forms in order to obtain 40 finished products.

In accordance with the patent FR 2578187 it is known another woodsubstitute and realisation process, which has in

. its composition, resinbark and leaves tied together through a

•ψ mineral binder which assures exclusively the cohesion, in order

45 to obtain this product, the bark is grided or crushed at varied dimensions, then contacted with a mineral binder and a quantity of water which represents the difference between the necessary water quantity for a good setting of the bark used in the process.The mixture, bark, mineral binder and water is realised

50 through the aid of a mechanic equipment then drained before the setting or pressed to obtain plates or panels.

The used mineral binders can be construction plasters,

stencil plasters or hydraulic binders as Portland cement.

This product presents the disadvantage of some limited physical and mechanical characteristics and restricted using area. Also the patent RO 9262 makes reference to a woodsubstitute realisation method constituted of sawdust or splinters or a mixture of both these materials, with a possible addition of a fibred stuff, preferably peat, which are mixed with approximately 3-10% setting material which consists of albumin, preferably bloodalbumin, limestone and soluble glass to which it is added a necessary water quatity, then the mixture is pressed with a pressure over 100 atmospheres, at a temperature of 110 Ocin order to obtain the woodsubstitute, in accordance with this patent, are mixed approximately 450 kg sawdust or splinters with 12-20 kg bloodalbumin, 3-6 kg limestone, 3-6 kg soluble glass and 30-40 kg water, the obtained mixture being pressed at 140-150 atm a temperature of 110 OC in flat forms.

This product presents the disadvantage of some limited physical and mechanical properties, the impossibility to be moulded in profiled forms in order to obtain some final products and the using of a setting material such as bloodalbumin which is a shortcoming product.

Summary of the invention

In accordance with my invention, the technical problem that must be solved consists in the obtaining of a woodsubstitute from raw cellulosic materials(lignino- cellulosic) with great diversity and with physical and mechanical properties superior in working and using to the natural wood.

In accordance with this invention the technical solution solves this problem, through that the woodsubstitute includes in the mixture tree leaves particles, sawdust,rotten- wood particles splinters, paperwastes, roots, foragecultu- res,cerealerops, sorg umwastes, bark, stems, etc., being included among the mineral materials, limestone in sulphates form, carbonates, calcium oxides with synthetical binders of varied chemical structure with or without dyes, which proportions are included between 35-60 by weight wooden or cellulosic particles, 5-35 by weight limestone particles and between 5-30 by weight synthetic binders of varied harmless chemical structures with or without other addition required by necessity.

The method for producing this woodsubstitute consists, in the first phase, in drying the lignino-cellulosic materials, irrespective of their nature and dimensions, then are brought at equal dimensions through hashing, grinding and desintegration under pressure, the obtaining particles being then mixed in a ratio of 35-60 by weight lignino-cellulosic

particles, 5-35 by weight limestone particles and with 5-30 by weight synthetic binders of varied chemical structure with or without other additions, during 10-40 minutes at a temperature between 5-30 °C till a perfect homogenizing, obtaining a paste of honeyviscosity, which is then moulded in flat or different other forms according with the destination, followed by a drying operation in a closed space at a temperature between 5- 50 OC during 10-30 days, the humidity in the closed space being maximum 8% during the whole drying process. Through the using of this woodsubstitute, in accordance with the invention, it is obtained a large scale of appliances, leading to the reduction of cost price, it is realised with minimum effort and does not require special endowments, presenting higher physical and mechanical properties then the natural wood and every other known woodsubstitute.lt can be moulded in various forms, irrespective of the profiled surface, the obtained sheet can support subsequent workings, varying with the necessities and strainforces, presenting a chemical stability and a lasting homogenity of the material.

Detailed D-sgoription of the Invention

T following lines will describe illustrative, but not li i- -t examples of the manufacturing of this woodsubstiLJte according to the invention.

First example.For the achievement of this woodsubstitute wooden and cellulosic raw material, a mixture of dried leaves and sawdust(the ratio between the components varying from 50:50% till 17:83%) in proportion of 35 by weight are used; the dried leaves are broken in a chopper until particles with dimensions between 2 μm and 5 cm, are obtained particles which are selected through a sieving-process, then it adds the sawdust and 10 by weight water, homogenizing through mixing for 10 minutes with 15 by weight limestone particles such as calcium carbonate (Ca.--.O ₃ ) or calcium oxide(CaO) at a temperature of 25 OC, then 30 by weight synthetic binder as polymacromoleculare type and its esters or polyformaldehydes are added,for instance vinyl polyacetate,

H — CH- CH — CH2 CH-CH ₂ -CH- OOCCH3 OOCCH3 OOCCH ₃

and or polyoximethylen ( α and β )

CH ₃ 0-(CH ₂ -O) _n — CH ₂ —O—CH ₃

and 10 by weight fireproofing products of varied types of silicates class, preferably hydrates sodiumsilicate or magnesium or organic condensation products such as anhydride

chlorendic esters type, continuing the homogenizing for another 20 minutes until a honeyviscosity paste is obtained.

The material thus obtained is moulded in forms of varied profiles, thicknesses and dimensions according to the destination of the finished product, forms which are submitted to a drying process in a closed precinct at a temperature between 5-50 θC, preferably 35 &C in an atmosphere with 8% maximum humidity during 10-30 days, varying with the physical and mechanical characteristics required by the product. Second examp1e. It takes a mixture composed of rottenwood, bark and paperwastes(the ratio of the components varying between 17:50:33; 50:17:33 or 50:33:17) in proportion of 35-60 by weight which are desintegrated under pressure a ter a preliminary treatment in order to destroy the possible microorganisms, obtaining particles with dimensions between 5μ ⁽ t- and 3 cm, after then it homogenizes through mixing with 10-15 by weight water, for 40 minutes together with 5-35 by weight limestone particles such as calcium sulphate (SO-jCa) , calcium oxide (CaO) or calcium carbonate (CaCθ ₃ ) to which it adds 5-30 by weight synthetic binder as melamin type or phenol-formaldehydes Novolac type.

(and 5-15 by weig t fireproof products and thermoinsulators.) of varying types, for instance bitum foam or blast furnace under a temperature of 30 Oc until a honeyviscosity paste is obtained.

The paste thus obtained is moulded in flat forms or various profiles and submitted to drying at a temperature between 5-50 OC, preferably 45 Oc in an atmosphere with 8% maximum humidity.The flat forms can be submitted to the pressing to obtain plates of varied thicknesses(between 5-60 mm) and dimensions in accordance with the form size.

Third example. It takes a mixture composed of growing forage wastes, sorghumwastes, stemplants (the ratio of the components varying between 10:30:60; 60:10:30 or 30:60:10) in proportion of 35-60 by weight it grinds and brings at equal dimensions between 1-4 cm, after then it adds 5-15 by weight water, 5-35 by weight limestone particles such as calcium sulphate (CaSθ ₄ ) or calcium carbonate (CaCθ ₃ ) to which then it adds 5-30 by weight synthetic binder of polystirenic resins type, boneglue then it homogenizes through mixing during 35 minutes at a temperature of 25 OC then it adds 5-15 by weight fireproof products, antiphonals or thermalinsulators as bitum

foams, blast furnace or thermal power station ash and continuing the homogenizing process for another 15 minutes until a honeyviscosity paste is obtained.

The paste thus obtained is moulded in flat or varied profiled forms being submitted to a drying at a temperature becween 5-50 0C, preferably 50 OC in at atmosphere with 8% maximum humidity, in an interval of 10 to 30 days.

The flat forms can be submitted to the pressing in order to obtain plates of varied thicknesses between 5-60 mm and varied dimensions according to the sizeform.

The products thus obtained can have the following physical and mechanical charac-eristics:

- Specific weight varying with the necessities between 0,2-2 kg / dm3 - Static bending strength : 200-2200 daN / cπ.2

- Modulus of elasticity : 400-150.000 kgf / c 2

- Heat resistance :

- weight loss ≤2 g

- carbonized surface ≤IO cm - Water absorption after 24 hours of immersion

% max : 0,3-12 %

- Acoustic absorption :

- as insulator : 13- >18

- as acoustic insulator : 34- >43