DE2460392A1 - Incombustible chipboard prodn using magnesium cpds - by treating with chloride soln., caustic oxide, sulphate soln. and oxide powder - Google Patents

Abstract

In the prodn. of incombustible chipboard in which the individual wood fibres are impregnated with MgCl2 in aq. soln. with simultaneous addn. of caustic calcined MgO and then dried, drying of the fibre mixt. takes place at over 100 degrees C. then MgSO4 soln. and ground MgO powder are added and the resultant pulp is moulded to boards, which are dried at temps. of over 100 degrees C. The first drying stage can be omitted. The board pref. is dried for 3 hr. at 150 degrees C pref. under pressure. Even boards contg. a high proportion of wood are incombustible. Mineralisation with MgSO4 and MgO greatly reduces the drying time at high temp. and prevents corrosion due to MgCl2. The hygroscopic behaviour of conventional boards is also largely avoided.

Description

Homann Plattenwerke Herzberg Branch of Fritz Homann GmbH, 3420 Herzberg

H 151 - Ws / Be

Process for the production of non-combustible chipboard

The invention relates to a method for the production of non-combustible chipboard, in which the individual wood fibers soaked with magnesium chloride in aqueous solution with the simultaneous addition of caustic burned magnesium oxide and then to be dried.

In a known method of this type, the wood fibers After impregnation with magnesium chloride in aqueous solution and the addition of magnesium oxide, subjected to a swelling process. The resulting fiber pulp is shaped into plates and kept at about 50 to 60 ° C. for a longer period of time of about Dried for 24 hours.

By sheathing the fibers with magnesium chloride and the resulting magnesite formation (Sorel cement)

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Deutsche Bank AQ ₁ Wolfsburg 01/18653 - Kreissparkaase Qlfhorn, Fallenleben branch 120 541 - Savings and loan office Hattorf 1262 Commerzbank Hannover, account no. 3/106101

ORIGINAL INSPECTED

achieved that the plates produced in this way at certain Mixing proportions and proportions of wood are non-flammable. Disadvantages of the known method and of those according to this Process manufactured plates is, however, that the magnesium chloride to corrosion phenomena on the plates for the plate production machines used or also on the tools for further processing or on those components which will later be connected to the plates. It is also disadvantageous that the known plates are highly hygroscopic Show behavior.

Finally, it is disadvantageous that, as a result of the long drying time, the manufacturing process for such a plate is very great takes a long time and is complex and expensive.

The invention is accordingly based on the object of creating a method of the type mentioned at the outset, with which Can quickly and inexpensively produce non-combustible chipboard, which has the disadvantages of the known method Do not have manufactured panels and are non-combustible in particular even with a high proportion of wood.

This object is achieved in that the Drying of the fiber mixture at temperatures of over 100 ° C

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It is taken that then Epsom salt in lye form (Hg SO,. 7 HgO) and powdery ground magnesium oxide is added and that the resulting pulp is then shaped into plates, which are dried at temperatures of over 100.degree.

With this method it is achieved that by the subsequent mineralization with Epsom salt and magnesium oxide considerably shorter drying times at considerably higher temperatures are possible and that the erosion phenomena can no longer occur due to the previous coating of the fibers with magnesium chloride. Likewise are the disadvantages of the Hygroscopy of the known plates largely abolished.

The method of making the panel of the invention moreover has the advantage over the known method that e »works relatively dry because, on the one hand, on the Vorwellgang, which also costs time, is dispensed with and by on the other hand, only as much water needs to be added as is needed to maintain a spreadable water Breies is required. In contrast, it brings the familiar Process with calibration that a relatively high addition of water is required, including making the mixture pumpable. As a consequence, that the mass poured out to the plate drips heavily and onto it In addition, the drying process is extended many times over will.

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The fire behavior of the method according to the invention according to de * produced plate corresponds in an advantageous manner to that which is achieved with other plates, the one Have asbestos base. Compared to these plates, however, the plate produced by the method according to the invention has the advantage that it can be processed in a more environmentally friendly manner.

Surprisingly, I also found that it it is possible to further enhance the process according to the invention rationalize that on the intermediate drying after pretreatment with magnesium chloride and caustic burned magnesium oxide can be waived if the results are equivalent.

It is advantageous if the drying of the shaped plates at temperatures of about 150 C and a duration of about 3 hours takes place, as this means that manufacturing processes can be shortened further leaves! Depending on ν · η of the required structure of the Plates can also take the drying of the formed plates under Printing.

Advantageously, 20 to 33 parts by weight are absolute dry wood chips with 6 to 10 parts by weight of magnesium chloride soaked in aqueous solution, above 25 to 30 parts by weight Caustic magnesium oxide is added to the mixture dried and then 15 to 25 parts by weight of Epsom salt liquor

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and 14 to 20 parts by weight of powdered magnesium oxide are added, whereupon the shaping and drying of the plates takes place.

Example!

28.3 parts by weight of wood shavings (sawdust absolutely dry) Bit 8.4 parts by weight of magnesium chloride are soaked in aqueous solution and 27.3 parts by weight are caustic burnt magnesium oxide added, whereupon the mixture, if necessary dried and then 18.2 parts by weight of Epsom salt liquor and 17f8 parts by weight of powdered magnesium oxide are added, whereupon the shaping and drying of the plates takes place.

As tests have shown, a chipboard made according to the example is non-combustible according to DIN 4102.

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Claims (6)

Expectations 1. Process for the production of non-combustible chipboard, in which the individual wood fibers with magnesium chloride soaked in an aqueous solution with the simultaneous addition of caustic burned magnesium oxide and then dried, characterized in that the drying of the fiber fabric at temperatures of is carried out above 100 C, that then Epsom salt in lye form and powdery ground magnesium oxide is added and that the resulting pulp is then shaped into plates, which at temperatures of over 100 g to be dried. 2. Process for the production of non-combustible chipboard, in which the individual wood fibers are soaked with magnesium chloride in an aqueous solution with the simultaneous addition of caustic-burned magnesium oxide, 609826/0 500 Bwtk AQ, Welftbur «OVItMB - KnIMpUkMM OHhOm, ZtMtOnKM FaIImMMm 120Mi- Spar- und DarMmakMM Hattorf 1 * 2 Commwzbank Hhmov *, Koma no. VKM 0f characterized in that then Epsom salt in lye form and pulverulent ground magnesium oxide are added and that the resulting pulp is then made into plates formed, sometimes at temperatures of over 100 ° C to be dried. 3. The method according to claim 1 or 2, characterized in that that the drying of the formed plates takes place at temperatures of about 150 ° C and a duration of about 3 hours. 4. The method according to any one of claims 2 or 3t, characterized in that the drying of the formed plates takes place under pressure. 5. The method according to any one of the preceding claims, characterized in that 20 to 33 parts by weight absolute dry wood chips are soaked with 6 to 10 parts by weight of magnesium chloride in aqueous solution and that 25 to 30 parts by weight of caustic burned magnesium oxide are added so that the mixture is optionally dried and then 15 to 25 parts by weight of Epsom salt liquor and 14 to 20 parts by weight of powdered magnesium oxide are added, whereupon the molding and drying of the plates takes place. 609826/0500 6. The method according to claim 5 »characterized in that 28.3 parts by weight of absolutely dry wood chips are soaked with 8.4 parts by weight of magnesium chloride in aqueous solution and that 27.3 parts by weight of caustic magnesium oxide are added, that the mixture is optionally dried and then 18 , 2 parts by weight of Epsom salt liquor and 17.8 parts by weight of powdered magnesium oxide are added, whereupon the panels are shaped and dried. 609826 / 05Ü0