DK159248B - PROCEDURE FOR MANUFACTURING FIREPROOF CHIPPING AND OTHER BENEFITS - Google Patents

Description

DK 1592488

The invention relates to a method of making fire-resistant particleboard and other moldings of wood shavings by admixture of fire protection materials, mixing of the wood shavings with glue resin, laying out the pre-glued wood shavings and pressing them.

In the construction sector, the use of non-fireproof chipboard and other parts of wood shavings is limited. Even the area of somewhat fireproof chipboard is severely limited, as fire resistance is also insufficient here. Therefore, attempts have been made to further improve the fire resistance of particle boards and other parts of wood chips, however, there have been ways in which to pay a clearly improved resistance of the boards and the other parts against the effect of flames 15 with a considerable loss of technological properties. .

Fireproof chipboard is manufactured according to known methods by pretreating the wood part with fire protection agents. The wood chips are thereby impregnated under pressure or without pressure by expensive and technically comprehensive methods and then dried to a moisture required for the particle board manufacture. Other methods produce the flame retardant in a prior process, e.g. using boron minerals such as colemanite and inorganic acids. The shavings are pre-treated with this mixture, dried and together with the plaster that is used to make fireproof boards. The wood chips are further added e.g. fly ash or vermiculite. It has further been proposed to work with inorganic binders 30 such as e.g. cement or water glass instead of organic binders, more specifically glue resin. Furthermore, it has been proposed to replace a large proportion of the wood shavings with inorganic fillers, which has led to significant strength losses especially in the tire layers. Using 35 magnesite mixtures as a binder, as disclosed in DE Patent Specification No. 2 550 857, it was found that the plates after pressing and after several days of storage

DK 159248 B

2 had a clear hygroscopicity. The further processing and refinement of such fireproof chipboard is also problematic. A direct coating of such particleboard with decorative layers, e.g. melamine resin-5 impregnated paper is not possible. Special tools are needed for further processing, and special suction devices must be installed, as such materials with inorganic binders such as e.g. cement, a relatively heavy dust appears.

10 from DE Publication No. 3044861, a process of the kind mentioned in the preamble to which an acid, namely sulfuric acid or phosphoric acid, is added in a one-step process, this is not intended to adjust the glue resin to become acidic, but to produce from the boron mineral colemanite, a calcium borate, free boric acid which then acts as a fire protection agent. Working with sulfuric acid forms boric acid and gypsum. When working with phosphoric acid, boric acid and calcium phosphate are formed. Although in this way the relatively expensive boric acid in the principle of calculation can advantageously be introduced into the material, however, the overall possibility of introducing fire protection substances in this way is insufficient. In addition, the chips are conveniently first treated with alkaline additives and thereby neutralized in advance, which, however, reduces their ability to be impregnated.

From DE-patent specification No. 9,66041, it is known in another method for the production of artificial wood pulp to open wood waste through a prior hydrolysis 30 with an organic acid so that the glue substance can penetrate deeper into the cells.

It is a further problem that the adhesive resins preferred for this use, after the addition of usual fire protection agents, especially boric acid, tend to premature cure.

It is an object of the present invention to provide a process for making

DK 159248 B

3 fireproof chipboard and other molding parts of wood shavings, with which a good fire protection can be obtained in connection with a comprehensive retention of the technological properties of the chip materials, so that 5 these chipboards and other parts of wood shavings can be further processed and refined in the same way as non- fireproof boards and other parts of wood shavings.

The process according to the invention is characterized in that the adhesive resin is mixed by admixture of the fire protection substances so that it is strongly acidic and that the pre-laid wood shavings are mixed with fillers which also prevent fire development and with which the mixture of adhesive resin and wood shavings substantially neutralized.

The method of the invention contains several surprising effects. If you add the glue resin in question for example. melamine resin only a little acid first, the acid acts as a hardener. The resin / acid mixture is only slightly stable and cures even at room temperature so quickly that hardly a subsequent bonding with the chips takes place. If, temporarily, according to the invention, the glue resin is adjusted so strongly acid through the admixture of the fire protection substance, a stable, cation-active glue resin solution is obtained which remains viscosity stable so long that the sizing of the chips can be carried out without problems. In addition, this adhesive resin solution has a particularly high ability to impregnate the chips.

In addition, a highly acidic blend has an extremely high ability to penetrate the wood shavings. In this way, a portion of the fire protection substances can be introduced into the material. According to the invention, a further portion of the fire protection substances and the fire-preventing substances are introduced into the already glued wood shavings by admixture of these fillers, which is, above all, again obtained in a trouble-free and, in particular, a very homogeneous manner, since the bonding of the wood shavings

DK 159248B

4 means that the fillers normally supplied in powder form, especially during the laying, are not excreted again, which would lead to an inhomogeneous final product. In addition, through the neutralization by means of this, the fire-preventing filler also reduces the cure time to the size required to run the process. Thus, a highly fireproof end product is obtained while maintaining the technological properties of a product of wood shavings in connection with the strength values and machining possibilities which are also obtained by the use of conventional adhesive resins for particle board production. Thus, by addition of fire-retardant fillers, it is also possible to largely neutralize the highly acidic mixture of binder and wood chips in a manner necessary for further processing because of the binder mixture. Any pre-treatment of the chips will lapse. The manufacture can be carried out with few changes to conventional particleboard systems. Despite the proportion of fillers corresponding to a very good fire protection, which necessarily results in a reduction in the proportion of wood chips in the final product, it has surprisingly been found that in practice this method has in practice only the same binder requirement as for an unprotected plate, which may indicate that the salts and additives have some stretching effect.

Despite the proportion of fillers, the final product in this process has a surprisingly high strength and, on the other hand, a very low flue density on burning.

It has further been found that some of the technological properties of the non-fireproof chipboard have been significantly improved, especially with regard to water absorption swelling of the thickness and smoke evolution. Thus, with plates prepared by this method, the 2-hour swelling was about 5 hours. 2% and 24-hour swelling

DK 159248 B

Of about 3-4%. The fume density was around 10%. Extensive fire tests have also shown that significant residual strength values were also found. After a 20 minute fire test at 700 ° C, conducted in a muffle oven from 5 company W.C. Heraeus, Hanau, the bending strength (measured according to DIN 52 562) of the test bodies decreased only to about 1/3 of the bending strength of the raw plate.

The sheets of high strength values produced by the method according to the invention, especially of the coverings, can be processed without problems, such as non-fireproof chipboard, for example. by veneering or coating with resin impregnated paper. The machining of the coated or veneered sheets can be done with known tools for machining particleboard.

15 It is not necessary for these fireproof particle boards to use special extraction plants at the workplaces where they are machined.

Plates made according to this method can be manufactured with the usual press factors and pressing temperatures usual for chipboard. According to this method, both single-layer and multi-layer particle board, as well as other similar parts of wood chips, can be easily manufactured.

further preferred embodiments of the method of the invention are set forth in the subclaims, which relate essentially to the use of certain selected fire retardants for the addition of the glue resin, as well as the use of certain selected fire evolution preventive fillers as well as the appropriate proportions of the various components.

As glue resin, i.e. as a binder, melamine-formaldehyde condensation products, urea-formaldehyde condensation products, or melamine-urine's two f-phenol-formaldehyde condensation products or mixtures thereof may be used. Further, it is possible to use additions of pp to 25% by weight of isocyanates calculated

DK 159248 B

6 on adhesive, such as e.g. diphenylmethane-4,4'-diisocyanate.

In this case, the amine resin is suitably added to a hardener, e.g. an addition of 2-10% by weight of ammonium chloride, ammonium sulfate or diammonium peroxide disulfate in the form of a 10-30% aqueous solution. Suitable phosphoric acid, boric acid and / or aluminum sulphate are added as a fire protection substance which leads to a strongly acidic adjustment of the mixture of glue resin and fire protection substance. With this very acidic setting 10 of the mixture, the phosphoric acid is of particular importance.

The weight ratio of the glue resin and especially the phosphoric acid can be varied within relatively wide limits and ranges from 4: 1 to 1: 4, preferably from 1: 2 to 2: 1.

The concentration of the adhesive resin joints and the fire protection substances is preferably adjusted such that at an initial moisture of the chips of approx. About 4% a humidity of about 10-15% is obtained of the blend of 20 shavings which are pre-treated and with fire-retardant fillers. Thereby, the concentration of the glue charge can range from 55-80% by weight of the solids content.

As inorganic fillers that prevent a fire from developing, in particular, alumina hydrate, aluminum sulfate, dolomite, kaolin, silica and heavy spat, as well as 25 mixtures of these substances in weight proportions each from approx. 10 to approx. 50% of the plate weight proved to be useful.

A highly fireproof chipboard manufactured according to these particulars consists of three roughly equal proportions of wood shavings, a mixture of binder and 30 fire protection substances as well as inorganic fire-retardant fillers. In the following, detailed examples of raw material mixtures for the process according to the invention are described in detail.

EXAMPLE 1;

DK 159248 B

7 1200 g wood chips with a thickness of 0.2-0.6 mm and a length of 1-15 mm are mixed at a residual humidity of 5 4-5% with 390 g melamine resin (60%), molar ratio melamine: formaldehyde of 1: 2 8 g of ammonium chloride (25% aqueous solution) 10 410 g of phosphoric acid (60%)

After this, the pre-bonded chips are added a mixture of: 500 g aluminum sulphate 130 g boric acid 15 340 g silica, and 360 g heavy spatula and further mix.

The mixture of shavings is then laid out like a carpet of shavings and pressed into a floor press.

The emerging plate is then sanded and coated with decorative paper impregnated with melamine resin.

EXAMPLE 2:

DK 159248 B

1200 g wood chips, thickness 0.2-0.6 mm, length 1-35 mm, humidity: 4-5%, 5 mixed with a mixture of 600 g melamine resin (60%), molar ratio melamine: formaldehyde 1: 1.6 60 g of diammonium peroxide disulfate (10%) 10 400 g of phosphoric acid (60%), and 130 g of boric acid.

Then add 500 g of aluminum sulphate, 340 g of silica and 15 360 g of heavy spatula.

The mix of shavings is applied to a carpet of shavings and press in a floor press. The particle board is glued after grinding with a 60% melamine resin solution, coated with a wood veneer and pressed into a floor press.

The particleboard thus veneered is formed under heating, the veneer is lightly sanded and then treated with a fire protection varnish.

EXAMPLE 3;

DK 159248 B

9 1200 g wood chips, thickness 0.2-0.6 mm length 1-15 mm, humidity 4-5% mixed with 5 800 g melamine urea resin (60%), molar ratio melamine: urea 1: 1, molar ratio melamine / urea: formaldehyde 1: 1.4 400 g phosphoric acid (60%), 80 g boric acid

Then add to the pre-glued shavings 500 g of silica, 700 g of heavy spatula, and mix further until a uniform distribution is obtained.

The chips are further processed as described in Example 1.

EXAMPLE 4i

DK 159248 B

10 1200 g wood chips, thickness: 0.2-0.6 nun, length: 1-15 mm, humidity: 4-5% mixed with 5 400 g melamine resin, molar ratio melamine: formaldehyde 1: 1.4, which is hardener 500 g of ammonium sulphate, 30%, and 800 g of phosphoric acid (60%), as well as 10 250 g of boric acid, and then 250 g of alumina hydrate, 300 g of silica and 700 g of heavy spatula are added and further mixed.

The chips thus treated are re-worked as described in Example 1.

EXAMPLE 5;

DK 159248 B

11 1200 g wood chips, thickness: 0.4-0.8 ram, length: 5-25 ram, humidity: 4-5%, treated with a mixture of 5 600 g melamine resin (60%), molar ratio melamine: formaldehyde 1: 1.6 g of phosphoric acid (60%) and 200 g of boric acid are then added to the pre-bonded 10 chips a mixture of 400 g of heavy spatula, 400 g of kaolin, 400 g of silica and further mixed.

15 The chips are applied to the middle layer of the plate.

EXAMPLE 6 i

DK 159248B

12 1200 g wood chips, thickness 0.2-0.6 mm, length: 2-8 mm, humidity: approx. 5% is glued with a mixture of 5,600 g of melamine resin (60%), molar ratio of melamine: formaldehyde 1: 1.6 100 g of boric acid 400 g of phosphoric acid (60%), and 200 g of aluminum sulphate 10 and further mixed with 500 g of kaolin, and 500 g of silica.

The chips are applied to the cover layer.

EXAMPLE 7:

DK 159248 B

1200 g wood chips, thickness; 0.2-0.6 mm, length; 2-8 mm, humidity; ca. 5% is glued with a mixture of 5,400 g of melamine resin (60%), molar ratio of melamine: formaldehyde 1: 1.8 400 g of phosphoric acid (60%), and 200 g of aluminum sulphate, and then further mixed with 10 500 g of heavy spatula, 500 g kaolin, 400 g boric acid.

The processing of the treated wood chips is done as described in Example 1.

EXAMPLE 8:

DK 159248B

14 1200 g wood chips, thickness: 0.2-0.6 mm, length; 1-15 mm, humidity: 4-5% is mixed with 400 g melamine resin (60%), molar ratio 5 melamine: formaldehyde 1: 1.8 100 g phosphoric acid (60%), and 150 g boric acid and then further mixed with 400 g heavy spatula, and 10 400 g of alumina hydrate.

The processing is done as described in Example 1.

EXAMPLE 9:

DK 159248 B

1200 g wood chips, thickness: 0.2-0.6 mm, length; 1-15 mm, humidity: 4-5% treated with a mixture of 5,200 g of melamine resin (60%), molar ratio melamine: formaldehyde 1: 2.0 200 g of phosphoric acid, 200 g of aluminum sulfate.

Then, the pre-mixed 10 chip mix is further mixed with 120 g of boric acid, 120 g of silica, 40 g of kaolin, 45 g of dolomite.

The chips are further processed as described in Example 1.

DK 159248 B

Example 10 in 16 1200 g wood chips, thickness: 0.2-0.6 mm, moisture: 4-5%, length: 1-15 mm mixed with 5 400 g melamirih resin (60%), molar ratio melamine: Formaldehyde 1: 1 , 6,200 g of boric acid, and 400 g of phosphoric acid, and then a mixture of 400 g of heavy spatula, 400 g of aluminum sulphate, 400 g of dolomite is added and further mixed.

The chips so treated are further processed as described in Example 1.

EXAMPLE 11:

DK 159248 B

1200 g wood chips, thickness: 0.2-0.6 mm, length: 1-15 mm, humidity: approx. 4% is glued with a mixture of 5,400 g of melamine urea formaldehyde resin, 60 g of diphenylmethane-4,4 'diisocyanate, 460 g of phosphoric acid (60%), 40 g of diammonium peroxide disulfate (10%) and 640 g of aluminum sulphate 10 and then 450 g silica, 150 g kaolin, 150 g dicyandiamide, and 450 g boric acid 15 and mix thoroughly.

The chips thus treated are re-worked as described in Example 1.

EXAMPLE 12:

DK 159248 B

1200 g wood chips, thickness: 0.2-0.6 mm, length: 1-15 mm, humidity: 5% mixed with 5 200 g diphenylmethane-4,4'-diisocyanate, 400 g phosphoric acid (60%), 400 g aluminum sulphate, 200 g of water and then a mixture 10 of 400 g of silica, 150 g of dolomite, 100 g of kaolin, 400 g of boric acid is added and further mixed.

The treated chips are further processed as described in Example 1.

EXAMPLE 13:

DK 159248B

19 1200 g wood chips, thickness: 0.2-0.6 mm, length: 1-15 mm, humidity: 4% mixed with 5 450 g melamine-urea-phenol formaldehyde resin (<60%), 200 g water, 370 g boric acid, and 15 g of sodium hydroxide solution (50%) 10 and then a mixture of 300 g of aluminum sulphate, 100 g of kaolin, 250 g of silica, 120 g of dolomite 15 is added and further mixed.

The chips thus treated are re-worked as described in Example 1.

All of the above-mentioned peculiarities are considered essential to the invention to the extent that they are new to the state of the art.

Claims (12)

1. A method of making fire-resistant particle board and other molding parts of wood shavings by admixture of fire protection materials, mixing of the wood shavings with glue resin, laying out the pre-glued wood shavings and pressing them, characterized in that the glue resin is set by admixture with the fire protection substances. is strongly acidic and that the pre-glued wood chips are mixed with fillers which also prevent fire development and with which the mixture of 10 glue resin and wood chips is substantially neutralized. Process according to claim 1, characterized in that the concentration of the glue resin and the fire protection substances is controlled so that at an initial moisture of the wood chips of approx. 4%, a moisture content of about 10-25% of the mixture of pre-glued and flame retardant fillers is obtained. Process according to claim 1 or 2, characterized in that the glue resin is mixed with phosphoric acid. Process according to claim 3, characterized in that the glue resin is mixed with phosphoric acid in a weight ratio of 4: 1 to 1: 4. Process according to claim 1, 2 or 3, characterized in that the glue resin is admixed with boric acid. Process according to claim 3 or 5, characterized in that the glue resin is mixed with aluminum sulfate. A method according to any one of the preceding claims, characterized in that the adhesive resin is added to a hardener, e.g. 2-10% ammonium chloride or ammonium sulfate or diammonium peroxide disulfate in the form of a 10-30% aqueous solution. Process according to claim 1, characterized in that the pre-glued wood chips as fire-retardants are added to inorganic substances, such as e.g. aluminum oxide hydrate, aluminum sulphate, dolomite, kaolin, silica, heavy spatula or mixtures of these substances. Process according to claim 8, characterized in that the fillers are preferably mixed in weight amounts which constitute between 10 and 50% of the plate weight. Process according to claim 8, characterized in that the pre-glued wood chips together with the fillers are further added phosphoric acid and / or boric acid. Process according to Claim 1 or 2, characterized in that urea, melamine, melamine-urea or melamine-urea-phenol-formaldehyde resin is used as glue resin, the addition of which the amine resins may also contain additions of up to 25% of isocyanates, such as e.g. diphenylmethane-4,4'-diisocyanate or a pure isocyanate can be used as an adhesive resin. The method according to claim 1 or 2, characterized in that the wood proportion according to the fire protection form is between 20 and 85%, preferably between 20 and 50%.