DE102007044161A1 - Method for manufacturing damping or noise insulating plate as impact sound insulation made of wood fiber in dry process without active redrying, involves drying wood fiber below ten percent atmosphere of wood - Google Patents

Abstract

The method involves drying wood fiber below 10 percent atmosphere of wood and simultaneously or after gluing with a water-free binding material, particularly polymeric methylene diphenyl diisocyanates (PMDI) belonging to a group of reactive isocynate. The damping or noise insulating plate (12) made of wood fiber or different material soluble in a refiner. The diffused matter is ventilated with a precompassing unit before an entry in the continuously working calibrated and hardening unit (8) for manufacturing of damping or noise insulating plate with a product concentration. An independent claim is included for a plant for manufacturing damping or noise insulating plate made of wood fiber in dry process without active redrying.

Description

The The invention relates to a method for the production of insulating and / or soundproofing panels made of wood fibers in a dry process without active post-drying according to the preamble of claim 1 and a plant for the production of insulating and / or sound insulation panels according to the preamble of the claim 5th

With the increasing demand for thermal insulation materials for the production of energy-saving houses (heat protection ordinance from 1982 and the subsequent tightening same including that after the millennium newly introduced energy pass for houses) has been in thermal insulation for the past 30 years again an ecologically degradable and renewable resource brought into conversation, the wood fiber. In recent years, Due to the timeliness of climate change, the Thermal insulation based on wood fibers, again conquered a market and there is a great need for innovation wood fiber insulation produce economically. Wood fiber insulation materials are available currently loose on the market, thereby becoming the wood fibers blown into prepared cavities and form this the insulating layer or in solid form as Holzfaserdämmplatten. Since the global rise in crude oil and energy prices one is anxious the house insulation not only on oil-based You want to carry out insulating materials also possible in the production of insulating materials save a lot of energy and oil-based insulation materials be independent. At the same time, the created insulation materials easy to process for wall insulation, sufficient strength during transport or handling against breakage or cracks and at the same time no harmful organic Emit pollutants. In addition, the previous hard foam products or used mineral wool besides the ecological problems also no optimal living environment within a building could ensure. The previous reasons for Building owners have been ecologically unimpaired so far the high cost of wood fiber insulation due to of high energy consumption.

So far known and common methods are the wet method and the dry process. Basically, the raw material is out Logs or sawmill residues processed into wood chips, cooked under pressure and heat and by means of a shredding device (Refiner) shredded. In the wet production of Holzfaserdämmplatten is the Suspension spread from the refiner to a wet soft fiber mat and mostly calibrated and pressed by calender. Then done the drying and the associated curing over a hydraulic cycle press. In addition to an insufficient Dimensional stability is also the bad environmental compatibility and the enormous energy consumption of disadvantage.

In the dry production of Holzfaserdämmplatten the emerging from the fiberizer (refiner) fibers are dried and formed after the addition of binders dry to a mat. Calibration, drying and curing are then carried out in a throughflow dryer in which hot air flows through the wood fiber insulation board ( EP 0 330 671 B1 ). The simplification of the plant components and the advantage of being able to produce considerably thicker insulating boards with independent strength have made the dry process widely used despite the enormous energy costs for drying.

In the article "Holzfaserdämmstoff nach dem Super-Trockenverfahren" by Hans Korte, Wismar, published in the wood-Zentralblatt number 110, page 1300, issue of 13 September 2002 , the development of previous dry processes is described to a super-dry process. The procedure is as follows: After defibration, the wet fibers are dried in a tube dryer to a final moisture content of about 6% and then mixed with an anhydrous binder (PMDI). Subsequently, the fibers are scattered to a mat and compacted after forming in a calibration and curing unit to product thickness and cured. The curing takes place by the introduction of a vapor-air mixture, which condenses in the previously dry fiber mat. Due to the rapid introduction of moisture and heat, the binder can set quickly and after a short distance, the product leaves the calibration and curing unit with a moisture content of about 12%. The advantage of this method over the prior art is the formaldehyde-free production, the low energy consumption by no longer necessary drying and the possible production of low density wood fiber insulation boards (60 kg / m ³ -80 kg / m ³ ). Also the DE 102 42 770 A1 is the subject of this procedure.

The object of the present invention is to provide a method by which insulation and / or sound insulation mat or panels with a density above 200 kg / m ^{3 can be produced} on a system according to the prior art, at the same time the wear of the steam plates and the screen belts should be reduced. In the context of which, the advantages of the known from the prior art simplified process flow of the above-described dry process without the necessary post-drying can be used with accompanying simple plant construction. For this purpose, a system for performing the method is shown.

The solution to this problem for a method is that for the production of insulation and / or soundproofing plates with an intended product density of over 200 kg / m ³ , preferably over 250 kg / m ³ , the scattered mat with a pre-compression unit before the inlet in the continuous calibration and curing unit is vented and precompressed to a density two to four times higher than the intended product density.

The Solution for a facility is that between Spreading device and calibration and curing unit one Pre-compression unit is arranged.

With the proposed method and the system it is now possible Dämmund / or soundproofing mat or plates with the advantages the simple super-dry process without post-drying ecological and to produce economically. At the same time, it is an advantage that due to the massive compaction with a pre-compaction unit the machine elements of the calibration and curing unit subject to less wear. This is possible, because according to the teachings of the invention, the loosely scattered mat ago Intake into the calibration and curing unit two to is compressed four times as strong as the intended product density.

The necessary for the procedure, but also alone for without the process as a production plant usable plant consists of a fiberizing device, a drying device, a gluing station, a spreader with arranged underneath Forming band and a subsequent precompression unit, which in Production direction before a calibration and curing unit is arranged.

In a particularly preferred embodiment, according to the method according to the invention, the necessary parameters and method steps from the prior art are adopted and modified with the teaching of the invention:
Accordingly, chips or the like are ground in a dry process in a refiner, the wet fibers emerging from the refiner are dried to a moisture of 4% to 8% dry wood, preferably with a tumble dryer and with an anhydrous binder in a mixer or during the run mixed by a pneumatic conveyor line. Subsequently, the dry fibers are scattered together with the binder on a forming belt to a mat. Depending on the plant shape, the mat is transferred to a calibration and curing unit where it is compacted and cured to the desired product thickness with a bulk density of 40-200 kg / m ³ . In this case, in the compressed mat, a steam or a vapor / air mixture is introduced, which still leads during the passage through the calibration and curing unit for complete curing of the mat to a workable end product, wherein the equilibrium moisture content is about 12%. The anhydrous binder used, preferably PMDI, will cure from a temperature of 90 ° C. The advantage of the extremely dry production is that the moisture on the end product no longer has to be removed and expensive energy and installation costs for this previously customary drying are eliminated.

According to the prior art, plate densities of up to 200 kg / m ³ can be achieved by this method. The curing unit consists of 2 rotating sieve belts, which are pulled over perforated steam plates. The perforated plates direct the fluid (vapor or vapor-air mixture) into the mat to heat the mat. As a result, depending on the back pressure of the mat in the curing unit, a frictional force on the screen belt. This friction force leads to high belt tension with the risk of cracks in the screen belt and the mechanical abrasion of the steam plates. The attempt with a known system to implement the super-dry process according to the article by Korte for the production of insulating or soundproofing plates with densities greater than 200 kg / m ³ , fails accordingly.

In order to produce insulating panels or soundproofing panels with densities above 200 kg / m ³ , very high opposing forces would have to be generated in the known calibration and curing unit. Under certain circumstances, these also have such an effect during operation that the screen belt tears or the drive drums spin. For this reason, according to the method according to the invention, a pre-compaction of the mat to a density significantly lower than the subsequent product density of the insulating or soundproofing performed. Although, after prepressing, the mat springs back somewhat to a lower density, but contrary to the general expectation does not spring back to the bulk density of the fibers. For example, a mat with 20 kg / m ³ bulk density is compressed to a density in the pre-press of 600 kg / m ³ and springs back to a density of 190 kg / m ³ . This mat is now compressed to a dam plate of 210 kg / m ³ in the calibration and curing unit and cured. The resulting compression forces are significantly lower than in the first compression in the pre-press. After measurements, the compaction forces in the second compaction in the calibration and curing unit are only 5% -30% compared to the first compaction, if the mat is compacted significantly more during the first compaction than in the second compaction.

For example, the bulk density of the Fibers after spreading 10-40 kg / m ³ In order to produce a plate with 300 kg / m ³ density, the mat in the pre-press is at least briefly precompressed to a density of 600-1200 kg / m ³ . After the pre-press, the less resilient mat is transferred to the calibration and curing unit. The pre-pressing is preferably carried out so that the density before the calibrating and curing unit is at least 5% lower than the product density.

The Teaching the invention thus shows that it is more advantageous a pre-compression unit to establish before a calibration and curing unit, as the calibration and curing unit in the areas Sieve belt, drive rollers, drive motor, compaction rollers and like to reinforce. In addition to the investment costs, which brings such a gain is the wear of the mostly made of plastic screen belts and The frictional steam plates are too high to be economical in the long run to produce.

• – der Abrieb der perforierten Dampfplatten in der Kalibrier- und Aushärteeinheit ist geringer,
• – die Siebbänder in der Kalibrier- und Aushärteeinheit weisen auch höhere Standzeiten auf,
• – die Gefahr von Siebbandrissen ist gering,
• – einher gehen längere Wartungsintervalle und weniger Reparaturstillstandszeiten,
• – das Dichteprofil der Dämm- oder Schallschutzplatten ist sehr homogen, da sofort oder nach nur sehr kurzer Verdichtungsstrecke in der Kalibrier- und Aushärteeinheit mit der Bedampfung begonnen werden kann,
• – der Verdichtungsbereich in der Kalibrier- und Aushärteinheit kann nun sehr kurz ausgeführt sein, was hier die Anlagenkosten wieder minimiert, denn durch die flexible Einstellung der Vorverdichtungseinheit kann gewährleistet werden, dass immer ein vorgegebener Verdichtungsgradient im Bereich der Vorverdichtung eingehalten werden kann und
• – einher tritt der Effekt auf, dass in der Kalibrier- und Aushärteinheit der Kontakt zwischen einem aufgeheizten Siebband und der Matte möglichst kurz gehalten werden kann. Damit werden Voraushärtungen an der Oberfläche der Matte vermieden.

In summary, the advantages of the present method and the associated system are as follows:

• The abrasion of the perforated steam plates in the calibrating and curing unit is lower,
• - the sieve belts in the calibration and curing unit also have longer service life,
• The risk of screen belt tears is low,
• - go along longer maintenance intervals and less repair downtime,
• - The density profile of the insulation or sound insulation panels is very homogeneous, since immediately or after only a very short compression section in the calibration and curing unit can be started with the evaporation,
• - The compression range in the calibration and curing unit can now be made very short, which minimizes the system costs again, because the flexible setting of the pre-compression unit can ensure that always a predetermined Verdichtungsgradient can be met in the field of pre-compression and
• - In addition, the effect occurs that in the calibration and curing of the contact between a heated screen belt and the mat can be kept as short as possible. This prevents pre-curing of the surface of the mat.

In In a preferred embodiment, the screen belts in the calibration and curing unit during the Compression or just before the passage of steam from the steam plates heated. This is necessary for a perfect passage of the Steam or the vapor-air mixture through the sieve belts to obtain. Otherwise, the steam would already on Sieve belt condense and uncontrollable in the further course of the procedure either on the end product, the insulation or sound insulation board, remain or uncontrolled in the return of the screen belt drain in the calibration and curing unit. The usage of sieve tapes also includes the use of so-called sieve fabric tapes of metal or plastic.

In Advantageously, the venting and compression in the pre-compression unit initially with a peripheral open Sieve band and then with a only partially with the Sieve belt with running tear-resistant pre-pressing is done. Depending on the configuration, the pre-pressing belt in the high-compression zone also be tight. Depending on your needs can or should even after the high compression zone or after the pre-compression unit gently bleed the mat. This can either be on an oversized radius of the last deflection and Compaction be performed, for example, more than 250 mm, preferably over 500 mm, in diameter. Due to the oversized radius on the deflection and compaction roller (above), the mat can gently spring open and there is no density shift through incoming air. Alternatively, there is the possibility following to the deflection and compression roller a hold-down device to arrange. Preferably, it must be ensured that the mat before entering the continuous calibration and curing unit has a 2% to 30% lower density than the intended product density. To achieve this goal it may be necessary in the high compression zone to exercise high pressures, so that as possible close arrangement of compaction rollers down and up there necessary is.

The Teaching the invention further shows that by the pre-compression the mat in the pre-compression unit of the calibration in the calibration and curing unit is not running as long must be as described in the prior art. There takes the calibration zone usually a quarter to a third of the total calibration and Curing unit. This can now be massively shorter be executed, since a calibration range of 500 mm sufficient appears. For a theoretical total length of a calibration and curing unit of 10,500 mm is thus opposite the prior art, a visible saving on system components and space requirements recognizable.

Further advantageous measures and embodiments of the subject matter The invention will be apparent from the subclaims and the following Description with the drawing out.

It demonstrate:

1 A schematically illustrated production plant of insulating or soundproofing panels made of wood fibers in a dry process without active post-drying,

2 a section of the manufacturing plant after 1 from the spreader with pre-compaction unit and subsequent calibration and curing unit and

3 a calibration and curing unit in a preferred embodiment for the inventive system.

As in 1 The insulation or sound insulation panels are shown 12 from a raw material 1 made in a shredder device 2 as dry as possible and defibred. In a drying device 3 , here shown as rotary drum dryer, becomes the wet fiberized raw material 1 dried to about 4% to 8% and finally in a gluing station 4 glued. The gluing can take place in different ways. When using PMDI, it would be useful to spray this in a pneumatic conveyor line on the fiber material or even to mix in a suitable mixer. Subsequently, the fibers are in a spreader 5 on a form band 6 to a mat 7 scattered and to pre-compacting unit 13 spent. There the precompression takes place below the product density 23 , The following calibration and curing unit 8th is divided according to the teachings of the invention into two areas, wherein in the production direction 22 first the calibration range 9 for dimensionally accurate compression to the product density 23 is arranged and then the curing area 10 , After leaving the calibration and curing unit 8th becomes the endless strand in a dividing device 11 , preferably a diagonal saw or a rotary clipper, divided into insulation or sound insulation panels.

In 2 Now, the preferred embodiment of the pre-compression unit 13 shown. This consists of a top and bottom rotating possibly driven screen belt 14 , associated deflection drums 18 , Pressure rollers 17 and compaction rollers arranged in the high-compression zone 26 , To set a high mat density, it may be useful in the high compression zone 25 a pre-press belt 15 above in addition to the screen belt 14 to revolve around higher pressures on the mat 7 to be able to apply. After venting and pre-compaction of the mat 7 through the pre-compaction unit 13 springs the mat 7 in production direction 22 before the calibration and curing unit and then in the calibration area 9 the calibration and curing device by the rotating sieve belts 20 to final dimension or to the product density 23 compacted. In the subsequent curing area is through the over the steam plates 19 applied steam-air mixture the mat 7 to a still to be split strand of insulation or sound insulation boards 12 hardened.

In 3 there is a preferred embodiment for the calibration area 9 a calibration and curing unit 8th , This is the screen belt 20 just before contact with the steam plates 19 with a heater 24 heated, so that the steam passed through the steam plates 19 not on the screen belts 20 condensed. Within the scope of the teaching of the invention is in a system with a pre-compression unit 13 the calibration area 9 the calibration and curing unit shortened executed. In an advantageous manner, the calibration unit no longer requires a great deal of work to compact the mat 7 be made. This also has the advantage that on the one hand the calibration and pre-compression unit 8th can be executed in total shortened and at the same time becomes the mat 7 as soon as possible after contact with the screen belts 20 with steam or a vapor-air mixture from the steam plates 19 applied. It can thus be on the insulation or sound insulation board 12 do not cause irritation due to pre-hardening or water droplets. As a rule, the insulation or sound insulation panels 12 discoloration would not be a critical factor, however, such irritations on the mat surface may result in subsequent notch effects which lead to cracks or fractures in the handling of insulating or soundproofing plates or mats and necessitate reworking during installation , In 2 For better clarity of the teaching of the invention, the location of the maximum precompression density 28 the mat 7 compared to the product density 23 the insulation or sound insulation board 12 illustrated by drawings.

1

raw material

2

Zerfaservorrichtung (Refiner)

3

drying device

4

gluing station

5

spreader

6

forming belt

7

mat

8th

calibration and curing unit

9

calibration

10

curing area

11

partitioner

12

insulation or soundproofing board

13

Vorverdichtungseinheit

14

screen belt

15

Pre-press

16

17

printing rollers

18

Umlenktrommel

19

steam plates

20

screen belt

21

Umlenktrommel

22

production direction

23

product density

24

heater

25

High compression zone

26

compaction rollers

27

Deflection and compaction roller

28

maximum Vorverdichtungsdichte

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0330671 B1 [0004]
• - DE 10242770 A1 [0005]

Cited non-patent literature

• - "Holzfaserdämmstoff nach dem Super-Trockenverfahren" by Hans Korte, Wismar, published in the wood-Zentralblatt number 110, page 1300, issue of September 13, 2002 [0005]

Claims (12)

Process for the preparation of insulating and / or soundproofing of wood fibers in the dry process without active post-drying, which are digested from wood chips or similar material in a refiner, then the wood fibers are dried to less than 10% atro wood and simultaneously or subsequently with an anhydrous, to group of reactive isocyanates belonging binder, preferably PMDI, glued and sprinkled after gluing with a fiber spreading machine on a forming belt and formed into a mat, said mat then compressed in a continuously operating calibration and curing unit and with steam and / or a Steam-air mixture is applied and cured, characterized in that for the production of insulating and / or soundproofing plates with an intended product density of over 200 kg / m ³ , preferably over 250 kg / m ³ , the scattered mat with a pre-compacting before the entry into d The continuously operating calibration and curing unit is deaerated and precompressed to a density two to four times higher than the intended product density of the insulating or soundproofing panel to be manufactured. Method according to claim 1, characterized in that that the deaeration and compression in the pre-compression unit initially with a revolving open screen belt and then with only partially with the screen belt with running tear-resistant Prepressing tape is done. Method according to claim 1, characterized in that that to avoid springing of the mat after the pre-compression unit and before the continuous calibration and curing unit the mat is held down. Method according to claim 1, characterized in that that the mat is precompressed so that the mat before entry into the continuous calibration and curing unit has a 2% to 30% lower density than the intended product density. Plant for the production of insulating and / or soundproofing boards ( 12 ) of wood fibers by dry process without active post-drying, consisting of a fiberizing device ( 2 ), a drying device ( 3 ), a gluing station ( 4 ), a spreading device ( 5 ) with a molding strip arranged underneath ( 6 ) and a subsequent calibration and curing unit ( 8th ), for carrying out the method according to claim 1, characterized in that between scattering device ( 5 ) and calibration and curing unit ( 8th ) a precompression unit ( 13 ) is arranged. Plant according to claim 5, characterized in that the precompression unit ( 13 ) from a revolving upper screen belt ( 14 ) that later in the high compression zone ( 25 ) by a likewise endlessly rotating tear-resistant pre-pressing belt ( 15 ) and at the same time the lower band ( 6 ) by one over the entire length with a pre-pressing belt ( 15 ) or only in the high-compression zone ( 25 ) with a pre-pressing belt ( 15 ' ) and wherein in the high-compression zone ( 25 ) Compaction rollers ( 26 ) are arranged. Plant according to claim 5, characterized in that in the high-compression zone ( 25 ) of the precompression unit ( 13 ) the compaction rollers ( 26 ) are arranged as close as possible to each other. Plant according to claim 5, characterized in that in the high-compression zone ( 25 ) the precompression unit, the upper deflection and compression roller ( 26 ) is made oversized with respect to the compaction rollers. Plant according to claim 5, characterized in that the calibration range ( 9 ) in the calibration and curing unit ( 8th ) is not longer than 500 mm. Plant according to claim 9, characterized in that the calibration and curing unit ( 8th ) is not longer than 10,500 mm. Insulating or soundproofing panel made of wood fibers, produced by a method according to claim 1 or in a system according to claim 5, characterized in that the density of the insulating or soundproofing panel ( 12 ) is more than 250 kg / m ³ . Insulating or soundproofing panel according to claim 9, characterized in that insulating or soundproofing ( 12 ) is used as impact sound insulation between a screed floor and a surface covering.