CA2303870A1 - Method for producing moulded bodies, moulded body and installation for carrying out said method - Google Patents
Method for producing moulded bodies, moulded body and installation for carrying out said method Download PDFInfo
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- CA2303870A1 CA2303870A1 CA002303870A CA2303870A CA2303870A1 CA 2303870 A1 CA2303870 A1 CA 2303870A1 CA 002303870 A CA002303870 A CA 002303870A CA 2303870 A CA2303870 A CA 2303870A CA 2303870 A1 CA2303870 A1 CA 2303870A1
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- Prior art keywords
- duroplastic
- process according
- basic material
- binder
- moisture content
- Prior art date
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N9/00—Arrangements for fireproofing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N1/00—Pretreatment of moulding material
- B27N1/02—Mixing the material with binding agent
- B27N1/0227—Mixing the material with binding agent using rotating stirrers, e.g. the agent being fed through the shaft of the stirrer
- B27N1/0254—Mixing the material with binding agent using rotating stirrers, e.g. the agent being fed through the shaft of the stirrer with means for spraying the agent on the material before it is introduced in the mixer
Abstract
The invention relates to a method for producing moulded bodies, especially chip boards or fibre boards, wherein a solid duroplastic is added to a defibrateable base material with a moisture content of at least 9 wt. %. The duroplastic and the base material are subjected to a treatment for gluing purposes, whereby the base material is simultaneously defibrated and mixed with the duroplastic and the glued and optionally post-treated fibre-moulding material thus obtained is shaped into a moulded body. The invention also relates to a moulded body, comprising a fibre material and a binding agent based on a duroplast which is solid at room temperature.
Description
MAR-15-00 12:45 +49 511 813830 P.05 R-042 Job-449 15/03 "00 MI 18:40 FAIL +49 511 813830 EIKENBERG-STILKENBOHMER ~ 005/022 a c -2~
PROCESS FOR THE PRQDUCTION OF SHAPED PARTS. A SHAPED PART ANn A PL,A~1T FOR CARRYrNG OUT THE PROCESS
It was the primary object of the invention to provide a new pzocess for the production of shaped parts. Within the framework of this invention, the term "shaped parts~~ in particular also includes panels.
Within the framework o~ the invention, it is mainly chips and/or fibre bundles of re-growing fibrous raw materials, such as wood (in particular annuals? and straw, that are used as the basic material for the sniped parts. This basic material is hEreinafter also referred to as chopped matter.
The situation prior to the invention may be described as follows.
Chip boards and the Like are today produced largely using liquid resiris_ zn this regard, the bonding of the chips (or fibre bundles) used is prov~.ded by duroplastie liquid resins based on urea, melamine and phenol formaldehyde resins or mixtures thereof.
In addition to a limited quality development, there is, additionally, the problem of a subsequent formaldehyde separation. In view of the fact that the systems are MAR-15-00 12:45 +49 511 813830 P.06 R-042 Job-449 _s 15/03 "00 MI 18:40 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 0 006/022 I
PROCESS FOR THE PRQDUCTION OF SHAPED PARTS. A SHAPED PART ANn A PL,A~1T FOR CARRYrNG OUT THE PROCESS
It was the primary object of the invention to provide a new pzocess for the production of shaped parts. Within the framework of this invention, the term "shaped parts~~ in particular also includes panels.
Within the framework o~ the invention, it is mainly chips and/or fibre bundles of re-growing fibrous raw materials, such as wood (in particular annuals? and straw, that are used as the basic material for the sniped parts. This basic material is hEreinafter also referred to as chopped matter.
The situation prior to the invention may be described as follows.
Chip boards and the Like are today produced largely using liquid resiris_ zn this regard, the bonding of the chips (or fibre bundles) used is prov~.ded by duroplastie liquid resins based on urea, melamine and phenol formaldehyde resins or mixtures thereof.
In addition to a limited quality development, there is, additionally, the problem of a subsequent formaldehyde separation. In view of the fact that the systems are MAR-15-00 12:45 +49 511 813830 P.06 R-042 Job-449 _s 15/03 "00 MI 18:40 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 0 006/022 I
simultaneously also aqueous systems, the moisture content of the chips also. increases, such that it is necessary, for example prior to a panel-pressing operation, to carry out pre-dry~.ng which involves a high outlay in respect of energy.
Xt is for this reason, that, in certain instances, use is made of PMDI binders to permit the bonding of difficult raw materials without introducing any additional water.
When using straw (straw chips), the use of PMbr was, however, irxdispensable from a practical point of view, because the wax layer ozx the straw ruled out any other bonding means. Yet, PMDI is not only expensive, but health risks also arise during processing, with the result that special safaguardinr~ measures must be taken.
From a practical point of view, in the group including liquid resins, it is only melamine, alkali phenol resins and PMDI that are available ~or ensuring weatherproof panels or shaped parts .
Since a rapid thorough hardening during pressing is essential.
for short pressing times, these systems are difficult to control. The water introduced via the binding agents must additionally be evaporated (reduction of the steam pressure), a factor which critically affects the pressing process.
If non-flammable or not readily flammable parcels axe to be produced, binding agents previously used in practice also reach LIAR-15-00 12:45+49 511 813A30 P.07 R-042 Job-449 15/03 "00 18:40FAX +49 511 813830EIKENBERG-STILKENBOHMER ~ 007/022 MI
Xt is for this reason, that, in certain instances, use is made of PMDI binders to permit the bonding of difficult raw materials without introducing any additional water.
When using straw (straw chips), the use of PMbr was, however, irxdispensable from a practical point of view, because the wax layer ozx the straw ruled out any other bonding means. Yet, PMDI is not only expensive, but health risks also arise during processing, with the result that special safaguardinr~ measures must be taken.
From a practical point of view, in the group including liquid resins, it is only melamine, alkali phenol resins and PMDI that are available ~or ensuring weatherproof panels or shaped parts .
Since a rapid thorough hardening during pressing is essential.
for short pressing times, these systems are difficult to control. The water introduced via the binding agents must additionally be evaporated (reduction of the steam pressure), a factor which critically affects the pressing process.
If non-flammable or not readily flammable parcels axe to be produced, binding agents previously used in practice also reach LIAR-15-00 12:45+49 511 813A30 P.07 R-042 Job-449 15/03 "00 18:40FAX +49 511 813830EIKENBERG-STILKENBOHMER ~ 007/022 MI
the limits of >uheir efficacy, since they render the incorporation of a fireproof~.ng agent rather difficult.
Accordingly, it was a further object of the present inventioxi to simplify the incorporation of a fireproofing impregnation into a chip-based or fibre-based shaped part. W this regard, reference is made to German Patent Application 196 21 606.0, which relates to non-flammable panels; the concepts, process steps and technical features of a non-flammable panel, as set out in this patent application, are at the disposal. of the person skilled in the art when turning to the present invention. By referring thereto, they constitute part of the present application.
Applying the process accoxd~.ng to the invention, it is further intended to obtain highly waterproof and exposure-fast materials (at least V 100, in accordance with DIN 687637.
According to the invention, the objects set out above axe met by a process for the production of shaped parts, in particular chip and ~i.bre boards, according to which process -- a solid duroplastic material. is added to a defibratable basic material having a moisture content of at least 9, preferably at least 15~ by mass, - for the purpose of applying the binding agent, the duroplastic material and the basic material are subjected to a treatment in which the basic material is simultazaeously defibxated and mixed with the duroplastic MAR-15-00 12:45 +49 511 813830 P.OB R-042 Job-449 15/03 '00 MI 18:41 FAX +49 511 813830 EIKENBERG-STILKENBOHMER f~ 008/022 i, i , material, and - the thus obtained binder-coated fibrous shaping material is shaped to produce a shaped part.
Prior to shaping to produce a shaped part, it is possible, in this regard, for the fibrous shaping material. also to be subjected to a post-treatment as described hereinafter and/or as is known to the person skilled in the art of producing shaped parts.
In the process according to ttie invention, the basic material used is, surprisingly, directly converted into a binder-coated fibrous shaping material which zs designed to be pzocessed to produce a shaped paxt without any further hinder application.
Apparently, two factors are responsible for the effects according to the invention:
(a) the high moisture conter~t o~ tine basic material, i.e. fox' example, of the straw chips, wood shavings ox the like, as used, and (b) the defibra>rior~ of the basic material in the presence of the solid duroplastic matexial.
The results of simply mixing the basic material with the solid duroplastic material (without defibration) are just as unsatisfactory as is a two-step process management which involves initially defibra>ring the basic material in the absence of the duroplastic material, with the subsequent mixing of the fibrous material with the duroplastic material. The MAR-15-00 12:45 +49 511 813830 P.09 R-042 Job-449 15/03 ''00 MI 18.41 FAX +49 511 813830 EIRENBERG-STILBENBOfMER f~ 009/022 i, i results are unsatisfactory because, in both instances, there is an unacceptable virtually quantitative separation of the basic, i.e. fibrous, material from the solid bindir.~g agent, during the processing of the basic or fibrous material/binding agent mixture, i.e. during and after mixing of the components.
Accordingly, it is possible to conclude that ~.t is necessary to provide the solid duroplastic material with adequate quantities of freshly produced surface area, and this is ' provided in a convincing manner by the simultaneous operations according to the invention. A problem of separation thus no longer arises in the process accordiz~.g to the inven>rion.
The binding agents which are used according to the invention and which are solid at roam temperature and are, for example, powdery or gzanular duroplastic materials, are selected from the following groups:
- phenol novolacs (optionally including a hardener);
particularly preferred - epoxy novolacs (optionally including a hardener);
particularly preferred - melamine resins - urea resins - polyester resins - other duroplastic solid resins 'these resins, which, at room temperature, are solid and virtually fxee of water, are mixed in a suitable presentation LIAR-15-00 12:45+49 511 813930 P.10 R-042 Job-449 15/03 '00 18:41FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 010/022 MI
c, . , .
_7_ form (e.g. in powder form? with the basic material used, far example straw chips or wood fibres, optionally together with a suitable hardening agent.
It is possible for the solid binding agents used according to >~he invention to be used, without any difficulty, together with the known hardening accelerators, water repellents and parting compounds, and similar processing adjuvants. It is also possible to add graphite in order to expedite the transfer of ' heat during pressing and to simplify the rendering of the basic material/binding agent mixture more uniform during grinding.
The resins as listed above and as used according to the invention da not contribute any water, provided that they are not used in the form of a dispersion, and are characterized by an irreversible full hardening which, under the usual opex'atiz~g conditions, is no longer susceptible to separation, and, accordingly, they resist the most severe of extreme conditions .
Under the Conditions aGCOrding to the invention, their high ~luidity and the very good anchoring capacity, for example, on the organic raw materials, permit the bonding even of difficult comppnents, e.g. straw_ Additionally of importance, even when using impregnated chips or fibre bundles as the basic maternal and, in particular, chips which have beezz provided with a firepre~ofing impregnation, is that there should be no interruption as far as the bonding is concerned. This is ensurEd, in particular, MAR-15-00 12:45 +49 511 813830 P.it R-042 Job-449 15/03 "00 MI 18:41 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 0 011/022 _g_ by novolac resins which are adapted to these requirements.
Tine problem of a formaldehyde emission does not arise with the process according to the invention.
zn the process according to the invention, the mixture of basic material and durop7.astic material is advantageously subjected to a drying treatment during or after the defibration treatment, during which drying treatment the moisture content is reduced. Since solid and at least substantially water-free duroplastic materials are used as binding agents, a drying treatment of this kind is carried out re J. atively inexpensively.
In the event that th~.s should still be necessary, the basic material used is pre-crushed to the extent required, pric7r tc~
admixture of the duroplastic material.
Prior to or during the admixture of the duroplastic material, the basic material (e-g. chips or fibres) is adjusted to a moisture content of moxe than 15~ by mass, preferably mere than 30% by mass and, in many instances, more than 45°s by mass , The adjusting of the moisture content is, in this regard, routinely achieved in that the basic material is mixed with water, prior to or during the admixture o~ the duroplastic material, or it is treated with water vapour.
On occasion, it is advantageous when the duroplastic materials used according to the invention are introduced into the basic MAR-15-00 12:45 +49 511 813830 P.12 R-042 Job-449 15/03 "00 MI 18:42 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 1012/022 r , matez~ia~ in the form of a predominantly aqueous dispersion.
It is possible for the water to contain a fireproofing substance, for example a protective salt, for impregnating the shaping material.
rn order to achieve particularly good results, the mixture of duroplastic material and basic material is subjected to a thermal treatment, preferably simultaneously with the def ibrata.on and binder-coat~.ng treatment , during which thermal treatment the melting temperature of the duroplastic material is momentarily reached or exceeded. As a result hereof, a particularly stable fixing o>e the duraplastic material on the shaping material is achieved; it is, however, necessary to ensure that the duroplastic material does not hardEn pretnatuxely. It is advantageously possible for the thermal treatment and the above-mentioned drying treatment to be carried out simultaneously iz~ a single process step, for example by hot air drying.
A further object of the invention is a shaped part comprising (a) a fibrous material (such as straw fibres) and (b) a binding agent on the basis of a duroplastic material which is solid at room temperature, A final object of the invention is a plant for carrying out the process according to the invention and/or fox producing the shaped pant according to the invention, in which plant means MAR-15-00 12:45 +49 511 913830 P.13 R-042 Job-449 15/03 ''00 18:42 FAX +49 511 8198x0EIKENBERG-STILKENBOHMER 1~01a/022 MI
i ~10-are provided for the simultaneous defibration and binder-coating of a defibratable basic material.
Individual aspects of the invention are first explained in more detail hereinafter with reference to examples of processes.
Example 1:
Comparison of different processes:
a) Addition of phenol novolac powder to chopped wheat straw, depending on the fibre length and on the moisture content (binder-coating operation without simultaneous defibration) wheat straw was cut in a cutter. Using the usual screexxing means, the cut wheat straw (chopped matter including straw chips) was divided into 5 fibre fractioz~s (main fractions) which are defined zn Table 1 below under particulars relating to Cl~elr fibre-length distribution.
The bulk density of each of the 5 main fractions is determined according to DIN 1306; see the corresponding column of Table 1 below.
Each of the 5 main fractions were then divided into 3 subfractions and, in each case one of the 15 sub-fractions was adjusted to a moisture content of 15, 30 and 50~ by mass of MAR-15-00 12:45 +49 511 813830 P.14 R-042 Job-449 _ 15/03 ''00 MI 18:42 FAX +49 511 813830 EIKENBERG-STILKENBOHMER f~ 014/022 i , water by storage in a climatic chamber.
Each of the total of 15 subtractions was mixed in a plough-share mixer for 8 minutes with 15~ by mass of a phenol novolae powder (grain-size distribution: 4~), in the course of which operation no noteworthy shortening or de~ibration of the straw/chopped matter used took place.
Subsequently, each mixture from the respective subfraction and the phenol novolac powder used was screened via a screen having a mesh width of 100 ~cm, and the non-attached phenol no~rol.ac powder was recovered. The difference between the phenol novolac powder used and the recovered phenol novolac powder corresponds to the quantity of added powder. On the basis hereof, the quantity of added phenol novolac powdex added was calculated as a percentage; see the corresponding column in Table 1.
Table 1 shows that chopped straw matter having a shorter fibre length takes up distinctly more powdery resin than chopped matter having a greater fibre length. The main fraction, in which B5~ of the fibres had a length of less than z0 mm, showEd the best take-up behaviour at every moisture content. For technical uses, this main fraction would still be practicable.
Chopped-matter fractions which were not examined here and which consisted of even shorter straw particles (e.g. 95~ < 20 mm) do not, once processed to produce a shaped part, however, contririute appreciably to the strength of sand shaped part.
MAR-15-00 12:45 +49 511 913930 P.15 R-042 Job-449 15/03 ''00 MI 18:42 FA2; +49 511 813830 EIKENBERG-STILKENBOHMER C~ 015/022 i -~z-Table 1 also shows that, within each main fraction, the take-up propexty in respect of phenol no.rolac powdex increases with the moisture content. The above-mentioned main fraction (85~ ~ zo mm fibre length) at a moisture content of 50% showed the greatest take-up capacity of all (sub-)fractions examined, Nevertheless, in this instance, it was only 46~ of the phenol novolac powder used that was taken up by the chopped matter, while 54% of the duroplastic material was recovered after screening through the 100 ~.m screen.
All the subfractions examined were, moreover, very non-uniformly bznder-coated, i . a . the phenol riovolac powder wa& not uniformly distributed on the chopped matter fibres used. It appeared fzom this non-uniformity that the binder-coated chopped matter of each individual subtraction was not particularly suitable for further processing to produce a shaped part, b) Addition of phez~ol novolac powdex to chopped wheat straw with simultaneous defibration and binder-Coating; take-up depend~.ng on the moisture content of the basic material As described under a) above, wheat straw was cut in a cutter and divided up into fractions.
A single fraction having a fibre-length distribution of 85%
< 50 mm and 26~ a 20 mm was exama.ned_ This corresponds to the MAR-15-00 12:45 +48 511 813830 P.16 R-042 Job-449 15/03 '00 MI 18:43 FAX +49 511 813830 EIKENBERG-STILKENBOHMER I~ 016/022 i -7.3-third main fraction according to Table 1.
The fibre fraction was divided up into ~ Subfractions and one each of these subtractions was adjusted to a moisture content of B, 15, 30 and 50°s by mass of water, as described under a) above, in respect of which see Table 2.
Each df the 4 subfractions was treated in a defibration mill with 7.5°s by mass of a phenol novolac powder fc~r 8 minutes.
After passing through tl~E mill, each binder-coated subtraction was again dried to a moisture content of ~ 6% by mass, anal the fibre-length distribution and the bulk density were determined.
The (first) subfraction having a moisture content of $~ by mass was, on the one hand, defibrated in a defibration mill, but, on the other hand, a cons a.derable shortening of the fibres also took place, such that, after passing trirough the mill, 95% of the straw fibres had a length of less Ghan 20 mm (after an original figure of 26~) . The bulk density of the binder-coated fibrous matter of the first subfraction was 0_1 g per litre (see Table 2), in comparison to 0_35 g per l~.tre in respect of the non-binder-coated chopped matter (see Table 7.).
By recovering and weighing the phenol novolac powder (as described under a) above), it was established that B6~ of the powder used had been taken up on the fibrous matter.
MAR-15-00 12:45 +49 511 813930 P.1T R-042 Jab-449 15/03 '00 18:43 FAX +49 511 813830EIKENBERG-STILKENBOHMER f~017/022 MI
In an analogous manner, the subfractions having a moisture content Qf 15, 30 and 50g by mass were also examined. It was established that the shortening of fibres decreased substantially commensurately with increasingly high moisture contents, whereas the splitting of the straw particles used in a longitudinal direction, i.e. the~.r defibration, came to the fore. Parallel. therewith, the bulk density of the binder coated fibre material (after passing through the mill) decreased commensurately in the subtractions having a high ' moisture content.
The take-up property of the subtractions having a moisture content of 25, 30 and 50~ by mass was, in each case, very good, but the best values were achieved with the subfracrions having a moisture content Qf 30~ by mass and 50~ by mass, in respect of which 9B~ and 99~, respectively, of the resin used was ta7cen up.
Summary and Evaluation:
zn comparison to the process management under a), each individual subfractian under b) was not only mixed with the duroplastic material, but it was simultaneously also defibrated. This results in a surprisingly steep increase zn the take-up capacity in respect of the duroplastic material used, which is probably attributable to the fact tk~at fresh surface area is made available by the defibration procedure.
thereby reducing the amount of wax-coated surface area as part MAR-15-00 12:45 +49 511 813830 P.18 R-042 Job-449 .15/03 ~'00 MI 18:43 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 018./022 Z
i i of the total surface area available.
When comparing, for example, the binder-coated fibrous matter according to Table 1, fourth maize fraction (40~ c 20 mm) , a subfraction having a moisture content of 30~, with the product according to Table 2, third subfraction (post;--milling fibre length of 42g < 20 mm, moisture content 30~), it will be seen that, when the process management is according to the invention as under b), a virtually compJ.ete (~8~) take-up of the duroplastic material used has taken place, whereas with the process management which does not conform to the invention and as set out under a), only 25~ of the duroplastic material is taken up.
wzth the process management according to the invezxtxon, the respective product was a uniformly binder-coated fibrous shaping material, whereas a non-uniformly binder-coated product was, in each case, obtained with a process management which does not conform to the invention.
MAR-15-00 12:45 +49 511 813830 P.19 R-042 Job-449 15/03 '00 18:43 FAX +49 511 813830EIKENBERG-STILKENBOHMER C~I019/022 MI
i.
i _iS_ Tables with respect to Examnla 1:
addition of 7.5% by mass o~ pheno3. n.ovQ~ac powder on wheat straw Tab~.e 1 Fibre length Bulk density gll Moisture contentResin take-up mm (DiN 1308) .6 ga 85'~ < 100 0-5 15 1 5 .' < 20 3 0 8 850, < SO 0.4.6 . i 5 7 20 ,'o G 20 3 0 1 5 35.'e < BO o.35 15 i0 f 26,5 < 20 - 30 19 8 5 ,b c ap 0.25 --__ _ __ - 1 5 1 5 C
40 ,' < 20 3 0 z 5 I
8 S .'a < 20 0 . 13 1 5 z0 30 31 i so ~s I
Tab ~ ° 2 Fibre lengthMoisture Past-millingPost-millingResin take-uo content fibre lengthbulk density mrn ,' mm 9l~
85'o c a0 8 9S~ < 20 0.1 86 2fi~~6 <
20 i5 _ ~ 70.'0 < 20 0.08 ~ 92 ~
~a az~ r zo o.os gs 50 3Q~6 < 20 0.02 99 , MAR-15-00 12:45+49 511 913930 P 20 R-042 Job-449 15/03 "00 18:43FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 020/022 MI
Example 2:
Exemplified process : metering-zz~ of resin without impregnating with protective salt a) Follow-up comrninution and/or homogenizing treatment:
Pre,comminuted wood ck~ips (chopped matter/basic material) having a moisture content of about e0s by mass are delta ezed to a defibration mill via a metering screw at a rate of 10 t/h absolutely dry. Along this path, 10% or 1 t/h of novolac powder resin are added via a gravimetric meter, the batch then being premixed.
The mill which ~.s next in line defibrates the chopped matter and promotes the mixing of the components_ A binder-coated fibrous shaping material is produced.
This binder-coated Fibrous shaping material ("chip/fibre resin mixtuze") is directed, in the usual manner, to a drum-type drier which is set at an outlet temperature of about 90° C.
The moisture content at the outlet is then still about 2s, and the resin is caused to melt. The further cooling which then Cakes place results in a particularly firm connection between the fibres and the resin grains.
A next-Following scattering station produces a matting for a panel thickness of 20 mm, with a density o~ 680 lzg/m3. This matting is fed into a heating press, where pressing ta}ces place MAR-15-00 12:45 +49 511 813830 P.21 R-042 Job-449 .15/03 '00 18:44 FAX +49 511 813830EIKENBERG-STILKENBOHMER 0 021/022 MI
I
_18_ at temperatures of 220° C, at a heatinr~ rate of 10 see/mrn, with hardening of the durop7.astie material. The panels produced are subjected to further processing in the manner known per se.
b) Simultaneous process management:
'fhe process is carried out as under a) , but the novolac powder resin is, in this instance, meterEd directly into the intake zone of a correspondingly designed defibration mill.
Exemplified process: Metering-in of Resin with Protective-salt Impregnat~.vn a) Follow-up comminution and/or homogenizing treatment:
Bales of straw were loosened up and chopped to a length of about 60 mm. The chopped matter (basic material), having a moisture content of about 12~, is transported through an impregnating screw at a rate of 6 t/h absolutely dry. rn the intake zone of said SGrew, an aqueous fireproo~ix3.g agent is added in an amount of 30% of protective salt as a 40°s solution, and is mixed with the straw chips. A further metering means ensures the conveying, via a discharge screw, of the impregnated chopped matter to a defibration mill. Along this route, 25~ or 900 3cg/h of novvlac powder (resin) are added and distributed uniformly. The mixture has a moisture content o~
about 50~, 'The mill is equipped with grinding jaws and carries out the defibration of Ghe straw ck~.ips, the uniform mixing and tha MAR-15-00 12:45 +49 511 813930 P.22 R-042 Job-449 15/03 ''00 MI 18:44 FAg +49 511 813830 EIKENBERG-STILKENBOHMER f~ 022/022 :a.
i binder-coating operations.
The binder-coated fibzous shaping material is then passed through an electric drier having an outlet temperature of about 75° C. Drying is carried out down to a mozsture content of about 6%. At the same time, the novolac resin powder, which is adjusted to these conditions, is fixed particularly firmly on to the straw fzbres.
In a next-following scattering station, a matting is produced for a panel thickness of 8 mm with a density of 750 }eg/m3. A
heating press Compresses the matting into panels and hardens the resin at temperatures of 190° C, at a heating rate of 15 sec/mm. The further processing of the panels is carried in the usual manner according to the state o~ the art.
b) Simultaneous Process Management:
Rice straw is cut to a length of about 40 mm. The chopped matter thus obtained has a moisture content of about 8% and, at a rate of 4 t/h, is metered into a vacuum impregnating machine, in which it is impregnated with an aqueous 40%
f fireproof ing agent at about 25 mbar ~or at least 5 minutes .
In so doing, the take-up o~ protective salt is about 25-35~_ A metering silo, which is provided with a discharge means, ensures that the impregnated chopped matter, which now has a moisture content of about 40%, is delivered to a next-in.-line defibration mill.
MAR-15-00 12:54 +49 511 913930P.02 R-043 Job-450 15/03 "00 18:47 FAX +49 813830EIKENBERG-STILKENBOHMER ~ 002/023 'MI 511 i i In its intake region, said mill additionally comprises a metering means for powdery resins. During the breaking-up operation, said metering means is used for continuously distributing a total amount o~ ~2~ of novolac resin, i.e_ 480 3cg/h, on to the straw material (chopped matter, or the fibres resulting therefrom), Accordingly, a thorough mixing, deEibration and binder-coating o~ the straw material take place simultaneously in the mill.
The mill is advantageously operated using air. 'fhe air serves to transport the raw materials (rice-straw chips/fibres, resin) through the mill to a combined settling/filter system. In this regard, it is preferable for hot transportation air to be used, such that moisture is removed and, at an outlet temperature of , for Example, about 80° C, the resin is simultaneously fixed particularly firmly on the fibres.
The binder-coated and dried fibrous shaping material then has a moisture content, which is adapted for the pressing operation, for example o~ about 8~ _ While the matting is being produced in the scattering station, there. is no separation of the resins and the fibres, with the result that a uniform cross-section is obtained. Using this material, a panel is produced to have a thickness of 30 mm and a density of 350 kg/nij. To this end, a heating press is used with a steam plate temperature of 270° C, and a heating rate of about 20 sec/mm is maintained.
MAR-15-00 12:54 +49 511 813830 P.03 8-043 Job-450 -15/08 ''DO~itI 18:48 FAX +48 511 813830 EIKENBERG-STILKENBOHMER ~ 003/023 The panels produced are fuxther processed zn the usual mazzner .
It is possible fox panels for all spheres of application to be produced in the manner described above. A particularly suitable sphere is in the building sector, which has high demands with regard to quality. panels bonded using novolac meet all the requirements for the use thereof in humid enviror~ments .
m the ~~ fireproof version" , they are approved as far as building regulations are concerned, and they find further possible application wherever high degrees of fire-resistance are required.
A plant according to the invention is designed such that it meets the desired process management; an adjustment of this kind is within the expertise of the person skilled in the art, who will, in this regard, be guided by the above exemplified processes which may also be expanded upon, An important aspect when designing a plant according to the invention is that, in the simultaneous defibration and binder-coating step according to the invention, no resin is to be lost and, for this reason, a possibly existing suction and air-transportation plant is advantageously designed to be a closed circuit or a drier/circulating air unit.
Preferred embodiments of the plant according tv the invention, MAR-15-00 12:54 +49 511 913830P.04 R-043 Job-450 ~15/D9 '00'MI18:48 FAX +49 815850EIKENBERG-STILKENBOHMER f~ 004/023 for carry~.ng out the process according to the invention, are described in more detail hereinafter by way of example with reference to the Figures, in which:
Figure 1 is a basic flow chart explaining preferred embodiments of the plant according to the invention.
Figuze 2 shows a plant for the production of chip boards (flow chart) Figure 3 shows a plant for Che production of single-layer panels (flow chart), comprising an apparatus for mozstaning dry chips/fibres prior to the addition of resin Figure ~ shows a plant for the integrating binder-coating, defibration and drying of shaping material (flow Chart ) .
All, the parts of the plant, with the exception of a de~lbrating apparatus, which is provided according to the invention, are shown in a non-differentiated manner in the form of squares in the );aasic flow chart according to Figure 1_ Alternative designs of the plant acCOrding to the invention and alternatives to the process aCCOrdW g to tkle invexltiQn are indicated by capital letters.
In the diagrammatic illustration according to Figure 1, chopped material (basic material) is conveyed from the left-hand side into an apparatus 1 for moistening and/or impregnating the chopped matter. In said apparatus, water (or an aqueous MAR-15-00 12:54 +49 511 913830 P.05 R-043 Job-450 15/03 "00'MI18:48 FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 005/023 fireproofing solution) from a water source (or from a tank containing fireproo~ing agent) 2 is added to said chopped matter. In the moistening apparatus 1, the moisture content of the chopped material is adjusted with water to more than 3o~
by mass. (Note: The chopped matter is treated with a fireproofing solution whenever W is intended to produce fireproofed panels. Impregnation is particularly intensive when a vacuum impregzzating process is used, which also involves a reduced out7.ay in respect o~ impregnatinr~ substance, in comparison to processes carried out at normal pressure.) Depending on the actual requirements in each individual case, it is particularly advantageous, when adjusting appropriate humidity cpnditions, for the moistening apparatus to be designed such that it is possible to carry out one of the following process steps:
- Moistening the chopped matter (as the basic material) with water by spraying. This may be carried out in an air cuxrent or in a spiral conveyor or in a continuous mixer.
- Moistening o~ the chopped matter, using steam (low-pressuxe steam), this being carried out in a manner similar to that using water. Steam has the advantage that it is xapidly and thoroughly dispersed in the chapped matter, further assisting the take-up as a resu~.t of the entra~.ned heat .
LIAR-15-00 12:54+49 511 813830P.06 R-043 Jab-450 .15/03 ~'OO~iHI18:48FAX +49 813830EIKENBERG-STILKENBOHMER ~ 008/023 According to an important alternative A, the chopped matter, after moistening, is conveyed to an adding station 3 where a solid duroplastic material from a container 4 is introduced.
The mixture comprising the moist chopped matter and the solid duroplastic material is Conveyed from the station 3 tQ a dafibration apparatus 5, in which the simultaneous defibration and binder-coating treatment according to the invention is carried out.
l~ccording to an alternative B, the solid duroplastic material is added to the chopped matter, not in a separate adding station 3, but already in the moistening apparatus 1. 'rhe mixed material, comprising the chopped matter and the solid duroplastic material, is then conveyed from the moistening apparatus 1 to the defibration apparatus 5.
According to a further alternative C, the moistened chopped matter and the solid duroplastic material are conveyed, either simultaneously or in succession, to the defibration apparatus 5, where they axe then mixed. zrz this case, it is also not necessary to provide a separate adding station 3_ Common to all C.he designs according to alte~cnatives A, B and C is that a permanent bonding between the shaping material, i.e. the chopped matter which has been comminuted, for example, to produce fibres, and the solid duroplastic material is produced o~J.y at the stage of the de~ibration apparatus 5.
According to an alternative D, the binder-coated shaping MAR-15-00 12:54 +48 511 813830 P.0'f R-043 Job-450 15/0'3 ''00 'MI 18:49 FAX +49 511 813830 EIKENBERG-STILKENBOHMER X1007/023 material. is conveyed from tk~e defibration apparatus S into a drying apparatus in which the moisture content of the now binder-coated fibre material is zeduced. The binder-coated fibre material is directed from the drying apparatus 6 to an apparatus ~ for producing a shaping-material matting. The matting produced in the mat-forming apparatus is finally further processed to produce a shaped part in an apparatus S
for producing shaped parts, for example a panel-pressing apparatus_ According to an alternative embodiment E, the drying treatment is carzied out, not in a separate drying apparatus 6, but already in the def~.brating apparatus 5. This then involves a combined defibrating, binder-coating and drying apparatus.
zt is obvious that only the essential plant components and process steps are shown in the basic flow chart according to Figure 1. Plant components which have not been illustrated include, for example, conveyor means, dust-extracting means, transporters, cyc7.ones and the like.
The embodiments of a plant according to the invention as described with reference to Figure 1 do, of course, correspond to the corresponding variatiozls of the process according to the invention. In a typical variation of the process according to the invention, the introduction and addition of the powder-res~.n binding agent, ensuring that it does not separate from the shaping material, is carried out in the following steps MAR-15-00 12:54 +49 511 813930 P.09 R-043 Job-450 15/03 '00'~MI 18:49 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 008/023 5.
i which correspond to alternative A.
Step 1 The vegetable fibre raw materials (as the basic or starting material for the shaping material) are chopped and moistened (in SYhe moistening apparatus 1), and optionally impregnated.
Step 2 Solid powder resin (from container 4) is mixed (in the adding station 3) in the desired mass ratio with the chopped matter which is still moist or has, optionally, been impregnated.
(When using natural~.y dried (a~.r-dried) raw materials which are zlot intended to be impregnated at a later stage, a ta3ce-up promoting state is not provided fox the, for example, powdery duroplastic material.) Step 3 fhe pre-mixed batch thus obtained is transported from the adding station 3 into the def~.bration apparatus 5, which may, for example, be a special defibratic~n mill, which is used to carry out a continuous process, and in which the chopped matter is defibrated in the manner according to the invention, while being coated with the duroplastic material.
Step 4_ ~rhe no binder-coated fibrous moulding maternal which is obtained according to Step 3 and is still moist (impregnated), is dried (in the drying apparatus 6 according to alternative MAR-15-00 13:00 +49 511 913930 P.02 R-044 Job-451 15/Oa '04 18:54 FAX +49 511 813890EIKENBERG-STILKENBOHMER ~ 009/023 l4iI
D or, according to altErnative E, still within the defibration apparatus 5) , with the moisture requ~.red fox pressing being adjusted and, if required, a fuxther fixing of the duroplastic material on the shaping material being carried out.
With the process being managed in the above manner, it is possible for subsequent working steps, such as mat formation and pressing, to be carried out without the drawbacks described in respect of customary processes.
It is advantageously possible for steps 2 and 3 to be carried out simultaneously. 'this corresponds to alternative C of the basic flow chart accordincg to Figure 1. In like manner, it is possible fox steps 3 and 4 to be carried out simultaneously.
This corresponds to alternative E_ In a particularly economic variation, steps 2, 3 and 4 are carried out simultaneously. This corresponds to a combination of alternatives C and E.
when, for example, steps 2 and 3 are carried out simultaneously according to alternative C, the take-up of the powder resin on the shaping material is particularly promoted.
When steps 3 and 4 are carried out simultaneously according to alternative E, a particularly good fixing of the resin on the shaping material is achieved. In this regard, it is also possible for step 4 to be carried out at the same time as a MAR-15-00 13:00 +49 511 813830 P.03 R-044 Job-451 -15/03 "00'MI 18:54 FAX +49 511 813830 EIKENBERG-STILKENBOHMER l~ 010/023 thermal treatment.
It is pvseible to achieve particularly good results when, in order to carry out step 3 (optionally simultaneously with steps 2 and/or 4), use is made of a defibratzon apparatus which internally screens or grades the fibrous shaping material.
coated with the duroplastic material, and which returns it to the comminution process (grinding process) in the event that it exceeds a specific particle size or particle length. When the defibration apparatus 5 is designed to be an internally screening comminution apparatus, the coated moulding material is provided in a particularly uniform manner.
~n the plant according to the invention and as illustrated in Figure 2, bales of straw are fed into the straw,bale shredder 51, wherE they are shredded (comminuted) and then conveyed into a metering silo 53 by means of a carrying-chain conveyor 52.
The shredded straw is then quantitativezy transported onward on a discharging metering screw 54, and a fireproof~.ng impregnating solution, from a fireproofing-agent big bag 22 which is associated with a dissolving stat~.on comprising mEtering means, is added to the straw shaping material izz the intake zone of the impregnating screw 21, After impregnatior~, the impregnated shaping material is transported into the meterir~g silo 5~ (capacity: 50 m') which is provided with a discharge screw 23_ A powdery duroplastic material (powder resin) according to the MAR-15-00 13:00 +49 511 813830 P.04 R-044 Job-451 '15/03 ~'OO~MI18:54 FAX +49 511 813830EIKENBERG-STILKENBOHMER (~ 011/023 invention is fed from a powder-resin big bag 24 comprising a metering station, and is added to the impregz~ated and, accordingly, moist straw shaping material on the discharge screw 23_ The shaping material to which the powder resa.n has been added is then weighed Qn a roller conveyor type weighex 56, whence it is conveyed into the defibratior~ mill 25.
Defibration and binder-coating according to the invention take place in said defibration mill.
Following on this process step, the shaping material is dried in the current drier 26. Drying is carried out up to a moisture content of, for example, 6~, At the same time, the resin powder, which has been adjusted to these conditions, is fixed on the shaping material fibres or chips.
Once discharged from the current driEr 26, the shaping maternal is conveyed to a scattering bin 27 (w~.th discharging means) which produces a matting from the straw shaping matezial, depositing said matting on a shaping belt 57 comprising a gauge S8 for measuring the mass per unit area. The matting is transported on the belt 57 to a mat separating and suction apparatus 59, finally reaching a press-feed~.ng belt 5o for transporting the sirraw matting into a heating press 28 (e. g.
a single-opening press). In said heating press, the matting is then compressed to form a panel and the duroplastic material.
is hardenEd. Finally Cafter passing through the heating press) , the finished panels are transferred to a discharge belt 61 and, thence, on to an elevating platform 62.
LIAR-15-00 13:00 +49 511 813830 P.05 R-044 Job-451 15/03 'OO MI 18:54 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 1012/023 s In the plant illustrated in Figure 3, shaping material bales (e.g. bales of straw or hemp) are transported by means of a bale conveyor into a bale breaker 63, in which they axe broken up. From the bale breaker, the shapiz~.g material fibres or chips are placed on a belt conveyor 64 which is allocated an overhead magnet 65. 'rhe shaping material is conveyed from the belt conveyor into an impact hammer mill 66, in which a pre-commiz~utlon of the fibres or chips of the rhapz.ng material takes place.
In a next-in-line moistening apparatus 31, a desired moisture content of the shaping material is adjusted; in this regard, it is possible for moistening to be provided, for example, by means of spraying water or by means of water vapour.
An, alr~transportation apparatus transports the moistened comminuted shaping material to a si7.o housing 6~ which is allocated a discharging apparatus 68 comprising a metering screw. The shaping material arrives in a detibrating machine 35b, e.g. an ultrafibrator or refiner, via a meterixxg chute.
zn said defibrating machine, (pre-) defibration takes place.
An aiz-transportation apparatus then transports the shaping material into a suspension drier 36 which comprises a control means and a gas surface burner, and in which, if required, drying of the shaping material takes place to a desired mO~.sture Content.
MAR-15-00 13:00 +49 511 813830 P.O6 R-044 Job-451 15/03 '00 MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 013/023 -31.-The shaping material is transported from the suspension drier 36, which provides additional screenir~g, to a revers~.ng screw 69 which, in the event of a ~zre, is opezated in a direction opposite to the usual conveying direction, in order to isolate any burning matter transported from the further parts of the plant. ~rhe shaping material then passes through a screening machine 70, Via a further air-transportation apparatus, the shaping material then arrives in a silo housing 71 which is allocated a d~.sGharging apparatus 72 comprising a metering screw and, next in line, a conveyor-type weigher ~3, whence the shaping material arrives in a second defibrating machzne 35a, in which it is uniformly mixed with a duroplastic matez~ial according to the invention, said duroplastic material being injected fzom a binder-preparing and metezing apparatus 34.
According to an important alternative design of the plant, the following plant components are omitted_ conveyor-type weigher 73, second defibrating machine 35a and binder-preparing and me>rering apparatus 34. The duroplastio material is then admixed in the form of a dispersion in the moistening apparatus, while the de~ibration and binder-coating according to the invention take place in the defibration machine 35b.
'The shaping material which is coated with the duroplastic material in the manner as set out by the invention, is conveyed by means of a troughed belt conveyor Qr an air-transportation i~AR-15-00 13:00 +49 511 A13930 P.O7 R-044 Job-451 '15/03 'OO MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 014/023 I
apparatus (as an alternative to the belt conveyor) to a scattering bin 37 which is provided witk~ a shaping head ~or farming a matting.
The bindex-containing shaping material is discharged from the shaping head in the form of a matting and is moved onward between scattering walls on a shaping belt 74 with a chain conveyor and a press-allocation chain conveyor; in this regard, the shap~.ng belt is allocated a mass per unit area gauge for controlling the scattering bin. A transverse-cutting saw (z10 mm) 75, comprising a catchir~.g means, cuts the matting to the size desired, and a metal detector arxanged behind said saw detects any metal contamination which may be present in the matting. If metal is detected, a faulty-scattering device 75 which co-operates with a suction apparatus, removes the Flawed matting.
The mats are subsequently directed to a press~.ng appax-atus 38, in front of which, however, a surface-spraying device 77 is arranged For spraying watex ox parting compounds on to the mats. Paxlels according to the invention are produced in the pressing apparatus . Th.e usual apparatus for ~ur>rher treatments are connected after the pressing apparatus , in respect of which see also Figuxe 2.
In the plant for the integrated binder-coatzng, detibration and drying of shapzng material as illustrated in Figure 4, a spiral conveyor ~B for pre-comminuted shaping material (for example MAR-15-00 13:00+49 511 813930P.08 R-044 Job-451 15/03 ~'DO 18:55FAX +49 813830EIKENBERG-STILKENBOHMER ~ 015/023 pre-comminuted straw) is illustrated, said conveyor transporting said shaping material to a dust screen 79, whexe dust is largely removed Ezom the shaping material.
'The pre-commznuted shaping material is then quantitatively transported onward on an impregnating screw 41, and a fireproofing impregnating solution, Pram a metering station 42 cahich is allocated a dissolving station with metering means, is added to the shaping material. in the intake zone of the impregnating straw 43.. Impregnation takes place Qn the impregnating screw at a reduced pressure of, for example, 25 mbar. After impregnation, the impregnated shaping material is t~canspozted into the metering silo 80-On a next~fo~.l.owing roller conveyor-type weigher 81, the shaping material is weighed and then transported into an ultra-rotor defibration mill 45 comprising an integrated screening device, a metering screw 82 and a hot air apparatus 83 (for drying and for thermal treatment). At the same time as the shaping maternal is charged into the defibration mill 45, powder resin from a meterir~g station 44 is introduced via a metering screw 82 into the de~~.bration mill. Means 84 are provided to ensure that the quantity of shaping material charged into the mill per unit of time and the quantity of powder resin introduced are in ~. substantially predetermined ratio to each other. rt is, ~or e~cample, possible for the weighing signal of the roller conveyor-type weigher 81 to be used as a reference signal for determining the quantity of MAR-15-00 13:00 +49 511 913930 P.09 R-044 Job-451 15/03 ~'00 MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 016/023 r powder resin which is to be introduced from the powder-resin metering station 44 via the metering screw 82 and into the defibration mill 45_ In the defibration mill 45, the shaping material is simultaneously defibrated, coated with powder resin and dried.
Drying is carried out by means of through-~lowing hot air which is produced, for example, zz~. a radiator 29 and injected into the mill from below.
The mill 45 comprises means fox screening or grading the shaping material (in its binder-coated or non-coated state) contained therein. Coarse particles are screened out in the head of the machine and are recycled for grinding in a downstream intake region. In this way, it is also possible for knots in stalks and the like to be loosened, axed for this reason iG is also possible to dispense with a separate downstream screening device.
The ~~nally binder-coated and dried shaping material fibres are transported into a separator 85 for dry fibres, whence they ultimately arrive in a metering silo (scattering bin) 47, where matting is produced from the binder-coated shaping mar.erial, ~or example by means of an associated scattering apparatus.
Accordingly, it was a further object of the present inventioxi to simplify the incorporation of a fireproofing impregnation into a chip-based or fibre-based shaped part. W this regard, reference is made to German Patent Application 196 21 606.0, which relates to non-flammable panels; the concepts, process steps and technical features of a non-flammable panel, as set out in this patent application, are at the disposal. of the person skilled in the art when turning to the present invention. By referring thereto, they constitute part of the present application.
Applying the process accoxd~.ng to the invention, it is further intended to obtain highly waterproof and exposure-fast materials (at least V 100, in accordance with DIN 687637.
According to the invention, the objects set out above axe met by a process for the production of shaped parts, in particular chip and ~i.bre boards, according to which process -- a solid duroplastic material. is added to a defibratable basic material having a moisture content of at least 9, preferably at least 15~ by mass, - for the purpose of applying the binding agent, the duroplastic material and the basic material are subjected to a treatment in which the basic material is simultazaeously defibxated and mixed with the duroplastic MAR-15-00 12:45 +49 511 813830 P.OB R-042 Job-449 15/03 '00 MI 18:41 FAX +49 511 813830 EIKENBERG-STILKENBOHMER f~ 008/022 i, i , material, and - the thus obtained binder-coated fibrous shaping material is shaped to produce a shaped part.
Prior to shaping to produce a shaped part, it is possible, in this regard, for the fibrous shaping material. also to be subjected to a post-treatment as described hereinafter and/or as is known to the person skilled in the art of producing shaped parts.
In the process according to ttie invention, the basic material used is, surprisingly, directly converted into a binder-coated fibrous shaping material which zs designed to be pzocessed to produce a shaped paxt without any further hinder application.
Apparently, two factors are responsible for the effects according to the invention:
(a) the high moisture conter~t o~ tine basic material, i.e. fox' example, of the straw chips, wood shavings ox the like, as used, and (b) the defibra>rior~ of the basic material in the presence of the solid duroplastic matexial.
The results of simply mixing the basic material with the solid duroplastic material (without defibration) are just as unsatisfactory as is a two-step process management which involves initially defibra>ring the basic material in the absence of the duroplastic material, with the subsequent mixing of the fibrous material with the duroplastic material. The MAR-15-00 12:45 +49 511 813830 P.09 R-042 Job-449 15/03 ''00 MI 18.41 FAX +49 511 813830 EIRENBERG-STILBENBOfMER f~ 009/022 i, i results are unsatisfactory because, in both instances, there is an unacceptable virtually quantitative separation of the basic, i.e. fibrous, material from the solid bindir.~g agent, during the processing of the basic or fibrous material/binding agent mixture, i.e. during and after mixing of the components.
Accordingly, it is possible to conclude that ~.t is necessary to provide the solid duroplastic material with adequate quantities of freshly produced surface area, and this is ' provided in a convincing manner by the simultaneous operations according to the invention. A problem of separation thus no longer arises in the process accordiz~.g to the inven>rion.
The binding agents which are used according to the invention and which are solid at roam temperature and are, for example, powdery or gzanular duroplastic materials, are selected from the following groups:
- phenol novolacs (optionally including a hardener);
particularly preferred - epoxy novolacs (optionally including a hardener);
particularly preferred - melamine resins - urea resins - polyester resins - other duroplastic solid resins 'these resins, which, at room temperature, are solid and virtually fxee of water, are mixed in a suitable presentation LIAR-15-00 12:45+49 511 813930 P.10 R-042 Job-449 15/03 '00 18:41FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 010/022 MI
c, . , .
_7_ form (e.g. in powder form? with the basic material used, far example straw chips or wood fibres, optionally together with a suitable hardening agent.
It is possible for the solid binding agents used according to >~he invention to be used, without any difficulty, together with the known hardening accelerators, water repellents and parting compounds, and similar processing adjuvants. It is also possible to add graphite in order to expedite the transfer of ' heat during pressing and to simplify the rendering of the basic material/binding agent mixture more uniform during grinding.
The resins as listed above and as used according to the invention da not contribute any water, provided that they are not used in the form of a dispersion, and are characterized by an irreversible full hardening which, under the usual opex'atiz~g conditions, is no longer susceptible to separation, and, accordingly, they resist the most severe of extreme conditions .
Under the Conditions aGCOrding to the invention, their high ~luidity and the very good anchoring capacity, for example, on the organic raw materials, permit the bonding even of difficult comppnents, e.g. straw_ Additionally of importance, even when using impregnated chips or fibre bundles as the basic maternal and, in particular, chips which have beezz provided with a firepre~ofing impregnation, is that there should be no interruption as far as the bonding is concerned. This is ensurEd, in particular, MAR-15-00 12:45 +49 511 813830 P.it R-042 Job-449 15/03 "00 MI 18:41 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 0 011/022 _g_ by novolac resins which are adapted to these requirements.
Tine problem of a formaldehyde emission does not arise with the process according to the invention.
zn the process according to the invention, the mixture of basic material and durop7.astic material is advantageously subjected to a drying treatment during or after the defibration treatment, during which drying treatment the moisture content is reduced. Since solid and at least substantially water-free duroplastic materials are used as binding agents, a drying treatment of this kind is carried out re J. atively inexpensively.
In the event that th~.s should still be necessary, the basic material used is pre-crushed to the extent required, pric7r tc~
admixture of the duroplastic material.
Prior to or during the admixture of the duroplastic material, the basic material (e-g. chips or fibres) is adjusted to a moisture content of moxe than 15~ by mass, preferably mere than 30% by mass and, in many instances, more than 45°s by mass , The adjusting of the moisture content is, in this regard, routinely achieved in that the basic material is mixed with water, prior to or during the admixture o~ the duroplastic material, or it is treated with water vapour.
On occasion, it is advantageous when the duroplastic materials used according to the invention are introduced into the basic MAR-15-00 12:45 +49 511 813830 P.12 R-042 Job-449 15/03 "00 MI 18:42 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 1012/022 r , matez~ia~ in the form of a predominantly aqueous dispersion.
It is possible for the water to contain a fireproofing substance, for example a protective salt, for impregnating the shaping material.
rn order to achieve particularly good results, the mixture of duroplastic material and basic material is subjected to a thermal treatment, preferably simultaneously with the def ibrata.on and binder-coat~.ng treatment , during which thermal treatment the melting temperature of the duroplastic material is momentarily reached or exceeded. As a result hereof, a particularly stable fixing o>e the duraplastic material on the shaping material is achieved; it is, however, necessary to ensure that the duroplastic material does not hardEn pretnatuxely. It is advantageously possible for the thermal treatment and the above-mentioned drying treatment to be carried out simultaneously iz~ a single process step, for example by hot air drying.
A further object of the invention is a shaped part comprising (a) a fibrous material (such as straw fibres) and (b) a binding agent on the basis of a duroplastic material which is solid at room temperature, A final object of the invention is a plant for carrying out the process according to the invention and/or fox producing the shaped pant according to the invention, in which plant means MAR-15-00 12:45 +49 511 913830 P.13 R-042 Job-449 15/03 ''00 18:42 FAX +49 511 8198x0EIKENBERG-STILKENBOHMER 1~01a/022 MI
i ~10-are provided for the simultaneous defibration and binder-coating of a defibratable basic material.
Individual aspects of the invention are first explained in more detail hereinafter with reference to examples of processes.
Example 1:
Comparison of different processes:
a) Addition of phenol novolac powder to chopped wheat straw, depending on the fibre length and on the moisture content (binder-coating operation without simultaneous defibration) wheat straw was cut in a cutter. Using the usual screexxing means, the cut wheat straw (chopped matter including straw chips) was divided into 5 fibre fractioz~s (main fractions) which are defined zn Table 1 below under particulars relating to Cl~elr fibre-length distribution.
The bulk density of each of the 5 main fractions is determined according to DIN 1306; see the corresponding column of Table 1 below.
Each of the 5 main fractions were then divided into 3 subfractions and, in each case one of the 15 sub-fractions was adjusted to a moisture content of 15, 30 and 50~ by mass of MAR-15-00 12:45 +49 511 813830 P.14 R-042 Job-449 _ 15/03 ''00 MI 18:42 FAX +49 511 813830 EIKENBERG-STILKENBOHMER f~ 014/022 i , water by storage in a climatic chamber.
Each of the total of 15 subtractions was mixed in a plough-share mixer for 8 minutes with 15~ by mass of a phenol novolae powder (grain-size distribution: 4~), in the course of which operation no noteworthy shortening or de~ibration of the straw/chopped matter used took place.
Subsequently, each mixture from the respective subfraction and the phenol novolac powder used was screened via a screen having a mesh width of 100 ~cm, and the non-attached phenol no~rol.ac powder was recovered. The difference between the phenol novolac powder used and the recovered phenol novolac powder corresponds to the quantity of added powder. On the basis hereof, the quantity of added phenol novolac powdex added was calculated as a percentage; see the corresponding column in Table 1.
Table 1 shows that chopped straw matter having a shorter fibre length takes up distinctly more powdery resin than chopped matter having a greater fibre length. The main fraction, in which B5~ of the fibres had a length of less than z0 mm, showEd the best take-up behaviour at every moisture content. For technical uses, this main fraction would still be practicable.
Chopped-matter fractions which were not examined here and which consisted of even shorter straw particles (e.g. 95~ < 20 mm) do not, once processed to produce a shaped part, however, contririute appreciably to the strength of sand shaped part.
MAR-15-00 12:45 +49 511 913930 P.15 R-042 Job-449 15/03 ''00 MI 18:42 FA2; +49 511 813830 EIKENBERG-STILKENBOHMER C~ 015/022 i -~z-Table 1 also shows that, within each main fraction, the take-up propexty in respect of phenol no.rolac powdex increases with the moisture content. The above-mentioned main fraction (85~ ~ zo mm fibre length) at a moisture content of 50% showed the greatest take-up capacity of all (sub-)fractions examined, Nevertheless, in this instance, it was only 46~ of the phenol novolac powder used that was taken up by the chopped matter, while 54% of the duroplastic material was recovered after screening through the 100 ~.m screen.
All the subfractions examined were, moreover, very non-uniformly bznder-coated, i . a . the phenol riovolac powder wa& not uniformly distributed on the chopped matter fibres used. It appeared fzom this non-uniformity that the binder-coated chopped matter of each individual subtraction was not particularly suitable for further processing to produce a shaped part, b) Addition of phez~ol novolac powdex to chopped wheat straw with simultaneous defibration and binder-Coating; take-up depend~.ng on the moisture content of the basic material As described under a) above, wheat straw was cut in a cutter and divided up into fractions.
A single fraction having a fibre-length distribution of 85%
< 50 mm and 26~ a 20 mm was exama.ned_ This corresponds to the MAR-15-00 12:45 +48 511 813830 P.16 R-042 Job-449 15/03 '00 MI 18:43 FAX +49 511 813830 EIKENBERG-STILKENBOHMER I~ 016/022 i -7.3-third main fraction according to Table 1.
The fibre fraction was divided up into ~ Subfractions and one each of these subtractions was adjusted to a moisture content of B, 15, 30 and 50°s by mass of water, as described under a) above, in respect of which see Table 2.
Each df the 4 subfractions was treated in a defibration mill with 7.5°s by mass of a phenol novolac powder fc~r 8 minutes.
After passing through tl~E mill, each binder-coated subtraction was again dried to a moisture content of ~ 6% by mass, anal the fibre-length distribution and the bulk density were determined.
The (first) subfraction having a moisture content of $~ by mass was, on the one hand, defibrated in a defibration mill, but, on the other hand, a cons a.derable shortening of the fibres also took place, such that, after passing trirough the mill, 95% of the straw fibres had a length of less Ghan 20 mm (after an original figure of 26~) . The bulk density of the binder-coated fibrous matter of the first subfraction was 0_1 g per litre (see Table 2), in comparison to 0_35 g per l~.tre in respect of the non-binder-coated chopped matter (see Table 7.).
By recovering and weighing the phenol novolac powder (as described under a) above), it was established that B6~ of the powder used had been taken up on the fibrous matter.
MAR-15-00 12:45 +49 511 813930 P.1T R-042 Jab-449 15/03 '00 18:43 FAX +49 511 813830EIKENBERG-STILKENBOHMER f~017/022 MI
In an analogous manner, the subfractions having a moisture content Qf 15, 30 and 50g by mass were also examined. It was established that the shortening of fibres decreased substantially commensurately with increasingly high moisture contents, whereas the splitting of the straw particles used in a longitudinal direction, i.e. the~.r defibration, came to the fore. Parallel. therewith, the bulk density of the binder coated fibre material (after passing through the mill) decreased commensurately in the subtractions having a high ' moisture content.
The take-up property of the subtractions having a moisture content of 25, 30 and 50~ by mass was, in each case, very good, but the best values were achieved with the subfracrions having a moisture content Qf 30~ by mass and 50~ by mass, in respect of which 9B~ and 99~, respectively, of the resin used was ta7cen up.
Summary and Evaluation:
zn comparison to the process management under a), each individual subfractian under b) was not only mixed with the duroplastic material, but it was simultaneously also defibrated. This results in a surprisingly steep increase zn the take-up capacity in respect of the duroplastic material used, which is probably attributable to the fact tk~at fresh surface area is made available by the defibration procedure.
thereby reducing the amount of wax-coated surface area as part MAR-15-00 12:45 +49 511 813830 P.18 R-042 Job-449 .15/03 ~'00 MI 18:43 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 018./022 Z
i i of the total surface area available.
When comparing, for example, the binder-coated fibrous matter according to Table 1, fourth maize fraction (40~ c 20 mm) , a subfraction having a moisture content of 30~, with the product according to Table 2, third subfraction (post;--milling fibre length of 42g < 20 mm, moisture content 30~), it will be seen that, when the process management is according to the invention as under b), a virtually compJ.ete (~8~) take-up of the duroplastic material used has taken place, whereas with the process management which does not conform to the invention and as set out under a), only 25~ of the duroplastic material is taken up.
wzth the process management according to the invezxtxon, the respective product was a uniformly binder-coated fibrous shaping material, whereas a non-uniformly binder-coated product was, in each case, obtained with a process management which does not conform to the invention.
MAR-15-00 12:45 +49 511 813830 P.19 R-042 Job-449 15/03 '00 18:43 FAX +49 511 813830EIKENBERG-STILKENBOHMER C~I019/022 MI
i.
i _iS_ Tables with respect to Examnla 1:
addition of 7.5% by mass o~ pheno3. n.ovQ~ac powder on wheat straw Tab~.e 1 Fibre length Bulk density gll Moisture contentResin take-up mm (DiN 1308) .6 ga 85'~ < 100 0-5 15 1 5 .' < 20 3 0 8 850, < SO 0.4.6 . i 5 7 20 ,'o G 20 3 0 1 5 35.'e < BO o.35 15 i0 f 26,5 < 20 - 30 19 8 5 ,b c ap 0.25 --__ _ __ - 1 5 1 5 C
40 ,' < 20 3 0 z 5 I
8 S .'a < 20 0 . 13 1 5 z0 30 31 i so ~s I
Tab ~ ° 2 Fibre lengthMoisture Past-millingPost-millingResin take-uo content fibre lengthbulk density mrn ,' mm 9l~
85'o c a0 8 9S~ < 20 0.1 86 2fi~~6 <
20 i5 _ ~ 70.'0 < 20 0.08 ~ 92 ~
~a az~ r zo o.os gs 50 3Q~6 < 20 0.02 99 , MAR-15-00 12:45+49 511 913930 P 20 R-042 Job-449 15/03 "00 18:43FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 020/022 MI
Example 2:
Exemplified process : metering-zz~ of resin without impregnating with protective salt a) Follow-up comrninution and/or homogenizing treatment:
Pre,comminuted wood ck~ips (chopped matter/basic material) having a moisture content of about e0s by mass are delta ezed to a defibration mill via a metering screw at a rate of 10 t/h absolutely dry. Along this path, 10% or 1 t/h of novolac powder resin are added via a gravimetric meter, the batch then being premixed.
The mill which ~.s next in line defibrates the chopped matter and promotes the mixing of the components_ A binder-coated fibrous shaping material is produced.
This binder-coated Fibrous shaping material ("chip/fibre resin mixtuze") is directed, in the usual manner, to a drum-type drier which is set at an outlet temperature of about 90° C.
The moisture content at the outlet is then still about 2s, and the resin is caused to melt. The further cooling which then Cakes place results in a particularly firm connection between the fibres and the resin grains.
A next-Following scattering station produces a matting for a panel thickness of 20 mm, with a density o~ 680 lzg/m3. This matting is fed into a heating press, where pressing ta}ces place MAR-15-00 12:45 +49 511 813830 P.21 R-042 Job-449 .15/03 '00 18:44 FAX +49 511 813830EIKENBERG-STILKENBOHMER 0 021/022 MI
I
_18_ at temperatures of 220° C, at a heatinr~ rate of 10 see/mrn, with hardening of the durop7.astie material. The panels produced are subjected to further processing in the manner known per se.
b) Simultaneous process management:
'fhe process is carried out as under a) , but the novolac powder resin is, in this instance, meterEd directly into the intake zone of a correspondingly designed defibration mill.
Exemplified process: Metering-in of Resin with Protective-salt Impregnat~.vn a) Follow-up comminution and/or homogenizing treatment:
Bales of straw were loosened up and chopped to a length of about 60 mm. The chopped matter (basic material), having a moisture content of about 12~, is transported through an impregnating screw at a rate of 6 t/h absolutely dry. rn the intake zone of said SGrew, an aqueous fireproo~ix3.g agent is added in an amount of 30% of protective salt as a 40°s solution, and is mixed with the straw chips. A further metering means ensures the conveying, via a discharge screw, of the impregnated chopped matter to a defibration mill. Along this route, 25~ or 900 3cg/h of novvlac powder (resin) are added and distributed uniformly. The mixture has a moisture content o~
about 50~, 'The mill is equipped with grinding jaws and carries out the defibration of Ghe straw ck~.ips, the uniform mixing and tha MAR-15-00 12:45 +49 511 813930 P.22 R-042 Job-449 15/03 ''00 MI 18:44 FAg +49 511 813830 EIKENBERG-STILKENBOHMER f~ 022/022 :a.
i binder-coating operations.
The binder-coated fibzous shaping material is then passed through an electric drier having an outlet temperature of about 75° C. Drying is carried out down to a mozsture content of about 6%. At the same time, the novolac resin powder, which is adjusted to these conditions, is fixed particularly firmly on to the straw fzbres.
In a next-following scattering station, a matting is produced for a panel thickness of 8 mm with a density of 750 }eg/m3. A
heating press Compresses the matting into panels and hardens the resin at temperatures of 190° C, at a heating rate of 15 sec/mm. The further processing of the panels is carried in the usual manner according to the state o~ the art.
b) Simultaneous Process Management:
Rice straw is cut to a length of about 40 mm. The chopped matter thus obtained has a moisture content of about 8% and, at a rate of 4 t/h, is metered into a vacuum impregnating machine, in which it is impregnated with an aqueous 40%
f fireproof ing agent at about 25 mbar ~or at least 5 minutes .
In so doing, the take-up o~ protective salt is about 25-35~_ A metering silo, which is provided with a discharge means, ensures that the impregnated chopped matter, which now has a moisture content of about 40%, is delivered to a next-in.-line defibration mill.
MAR-15-00 12:54 +49 511 913930P.02 R-043 Job-450 15/03 "00 18:47 FAX +49 813830EIKENBERG-STILKENBOHMER ~ 002/023 'MI 511 i i In its intake region, said mill additionally comprises a metering means for powdery resins. During the breaking-up operation, said metering means is used for continuously distributing a total amount o~ ~2~ of novolac resin, i.e_ 480 3cg/h, on to the straw material (chopped matter, or the fibres resulting therefrom), Accordingly, a thorough mixing, deEibration and binder-coating o~ the straw material take place simultaneously in the mill.
The mill is advantageously operated using air. 'fhe air serves to transport the raw materials (rice-straw chips/fibres, resin) through the mill to a combined settling/filter system. In this regard, it is preferable for hot transportation air to be used, such that moisture is removed and, at an outlet temperature of , for Example, about 80° C, the resin is simultaneously fixed particularly firmly on the fibres.
The binder-coated and dried fibrous shaping material then has a moisture content, which is adapted for the pressing operation, for example o~ about 8~ _ While the matting is being produced in the scattering station, there. is no separation of the resins and the fibres, with the result that a uniform cross-section is obtained. Using this material, a panel is produced to have a thickness of 30 mm and a density of 350 kg/nij. To this end, a heating press is used with a steam plate temperature of 270° C, and a heating rate of about 20 sec/mm is maintained.
MAR-15-00 12:54 +49 511 813830 P.03 8-043 Job-450 -15/08 ''DO~itI 18:48 FAX +48 511 813830 EIKENBERG-STILKENBOHMER ~ 003/023 The panels produced are fuxther processed zn the usual mazzner .
It is possible fox panels for all spheres of application to be produced in the manner described above. A particularly suitable sphere is in the building sector, which has high demands with regard to quality. panels bonded using novolac meet all the requirements for the use thereof in humid enviror~ments .
m the ~~ fireproof version" , they are approved as far as building regulations are concerned, and they find further possible application wherever high degrees of fire-resistance are required.
A plant according to the invention is designed such that it meets the desired process management; an adjustment of this kind is within the expertise of the person skilled in the art, who will, in this regard, be guided by the above exemplified processes which may also be expanded upon, An important aspect when designing a plant according to the invention is that, in the simultaneous defibration and binder-coating step according to the invention, no resin is to be lost and, for this reason, a possibly existing suction and air-transportation plant is advantageously designed to be a closed circuit or a drier/circulating air unit.
Preferred embodiments of the plant according tv the invention, MAR-15-00 12:54 +49 511 913830P.04 R-043 Job-450 ~15/D9 '00'MI18:48 FAX +49 815850EIKENBERG-STILKENBOHMER f~ 004/023 for carry~.ng out the process according to the invention, are described in more detail hereinafter by way of example with reference to the Figures, in which:
Figure 1 is a basic flow chart explaining preferred embodiments of the plant according to the invention.
Figuze 2 shows a plant for the production of chip boards (flow chart) Figure 3 shows a plant for Che production of single-layer panels (flow chart), comprising an apparatus for mozstaning dry chips/fibres prior to the addition of resin Figure ~ shows a plant for the integrating binder-coating, defibration and drying of shaping material (flow Chart ) .
All, the parts of the plant, with the exception of a de~lbrating apparatus, which is provided according to the invention, are shown in a non-differentiated manner in the form of squares in the );aasic flow chart according to Figure 1_ Alternative designs of the plant acCOrding to the invention and alternatives to the process aCCOrdW g to tkle invexltiQn are indicated by capital letters.
In the diagrammatic illustration according to Figure 1, chopped material (basic material) is conveyed from the left-hand side into an apparatus 1 for moistening and/or impregnating the chopped matter. In said apparatus, water (or an aqueous MAR-15-00 12:54 +49 511 913830 P.05 R-043 Job-450 15/03 "00'MI18:48 FAX +49 511 813830EIKENBERG-STILKENBOHMER f~ 005/023 fireproofing solution) from a water source (or from a tank containing fireproo~ing agent) 2 is added to said chopped matter. In the moistening apparatus 1, the moisture content of the chopped material is adjusted with water to more than 3o~
by mass. (Note: The chopped matter is treated with a fireproofing solution whenever W is intended to produce fireproofed panels. Impregnation is particularly intensive when a vacuum impregzzating process is used, which also involves a reduced out7.ay in respect o~ impregnatinr~ substance, in comparison to processes carried out at normal pressure.) Depending on the actual requirements in each individual case, it is particularly advantageous, when adjusting appropriate humidity cpnditions, for the moistening apparatus to be designed such that it is possible to carry out one of the following process steps:
- Moistening the chopped matter (as the basic material) with water by spraying. This may be carried out in an air cuxrent or in a spiral conveyor or in a continuous mixer.
- Moistening o~ the chopped matter, using steam (low-pressuxe steam), this being carried out in a manner similar to that using water. Steam has the advantage that it is xapidly and thoroughly dispersed in the chapped matter, further assisting the take-up as a resu~.t of the entra~.ned heat .
LIAR-15-00 12:54+49 511 813830P.06 R-043 Jab-450 .15/03 ~'OO~iHI18:48FAX +49 813830EIKENBERG-STILKENBOHMER ~ 008/023 According to an important alternative A, the chopped matter, after moistening, is conveyed to an adding station 3 where a solid duroplastic material from a container 4 is introduced.
The mixture comprising the moist chopped matter and the solid duroplastic material is Conveyed from the station 3 tQ a dafibration apparatus 5, in which the simultaneous defibration and binder-coating treatment according to the invention is carried out.
l~ccording to an alternative B, the solid duroplastic material is added to the chopped matter, not in a separate adding station 3, but already in the moistening apparatus 1. 'rhe mixed material, comprising the chopped matter and the solid duroplastic material, is then conveyed from the moistening apparatus 1 to the defibration apparatus 5.
According to a further alternative C, the moistened chopped matter and the solid duroplastic material are conveyed, either simultaneously or in succession, to the defibration apparatus 5, where they axe then mixed. zrz this case, it is also not necessary to provide a separate adding station 3_ Common to all C.he designs according to alte~cnatives A, B and C is that a permanent bonding between the shaping material, i.e. the chopped matter which has been comminuted, for example, to produce fibres, and the solid duroplastic material is produced o~J.y at the stage of the de~ibration apparatus 5.
According to an alternative D, the binder-coated shaping MAR-15-00 12:54 +48 511 813830 P.0'f R-043 Job-450 15/0'3 ''00 'MI 18:49 FAX +49 511 813830 EIKENBERG-STILKENBOHMER X1007/023 material. is conveyed from tk~e defibration apparatus S into a drying apparatus in which the moisture content of the now binder-coated fibre material is zeduced. The binder-coated fibre material is directed from the drying apparatus 6 to an apparatus ~ for producing a shaping-material matting. The matting produced in the mat-forming apparatus is finally further processed to produce a shaped part in an apparatus S
for producing shaped parts, for example a panel-pressing apparatus_ According to an alternative embodiment E, the drying treatment is carzied out, not in a separate drying apparatus 6, but already in the def~.brating apparatus 5. This then involves a combined defibrating, binder-coating and drying apparatus.
zt is obvious that only the essential plant components and process steps are shown in the basic flow chart according to Figure 1. Plant components which have not been illustrated include, for example, conveyor means, dust-extracting means, transporters, cyc7.ones and the like.
The embodiments of a plant according to the invention as described with reference to Figure 1 do, of course, correspond to the corresponding variatiozls of the process according to the invention. In a typical variation of the process according to the invention, the introduction and addition of the powder-res~.n binding agent, ensuring that it does not separate from the shaping material, is carried out in the following steps MAR-15-00 12:54 +49 511 813930 P.09 R-043 Job-450 15/03 '00'~MI 18:49 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 008/023 5.
i which correspond to alternative A.
Step 1 The vegetable fibre raw materials (as the basic or starting material for the shaping material) are chopped and moistened (in SYhe moistening apparatus 1), and optionally impregnated.
Step 2 Solid powder resin (from container 4) is mixed (in the adding station 3) in the desired mass ratio with the chopped matter which is still moist or has, optionally, been impregnated.
(When using natural~.y dried (a~.r-dried) raw materials which are zlot intended to be impregnated at a later stage, a ta3ce-up promoting state is not provided fox the, for example, powdery duroplastic material.) Step 3 fhe pre-mixed batch thus obtained is transported from the adding station 3 into the def~.bration apparatus 5, which may, for example, be a special defibratic~n mill, which is used to carry out a continuous process, and in which the chopped matter is defibrated in the manner according to the invention, while being coated with the duroplastic material.
Step 4_ ~rhe no binder-coated fibrous moulding maternal which is obtained according to Step 3 and is still moist (impregnated), is dried (in the drying apparatus 6 according to alternative MAR-15-00 13:00 +49 511 913930 P.02 R-044 Job-451 15/Oa '04 18:54 FAX +49 511 813890EIKENBERG-STILKENBOHMER ~ 009/023 l4iI
D or, according to altErnative E, still within the defibration apparatus 5) , with the moisture requ~.red fox pressing being adjusted and, if required, a fuxther fixing of the duroplastic material on the shaping material being carried out.
With the process being managed in the above manner, it is possible for subsequent working steps, such as mat formation and pressing, to be carried out without the drawbacks described in respect of customary processes.
It is advantageously possible for steps 2 and 3 to be carried out simultaneously. 'this corresponds to alternative C of the basic flow chart accordincg to Figure 1. In like manner, it is possible fox steps 3 and 4 to be carried out simultaneously.
This corresponds to alternative E_ In a particularly economic variation, steps 2, 3 and 4 are carried out simultaneously. This corresponds to a combination of alternatives C and E.
when, for example, steps 2 and 3 are carried out simultaneously according to alternative C, the take-up of the powder resin on the shaping material is particularly promoted.
When steps 3 and 4 are carried out simultaneously according to alternative E, a particularly good fixing of the resin on the shaping material is achieved. In this regard, it is also possible for step 4 to be carried out at the same time as a MAR-15-00 13:00 +49 511 813830 P.03 R-044 Job-451 -15/03 "00'MI 18:54 FAX +49 511 813830 EIKENBERG-STILKENBOHMER l~ 010/023 thermal treatment.
It is pvseible to achieve particularly good results when, in order to carry out step 3 (optionally simultaneously with steps 2 and/or 4), use is made of a defibratzon apparatus which internally screens or grades the fibrous shaping material.
coated with the duroplastic material, and which returns it to the comminution process (grinding process) in the event that it exceeds a specific particle size or particle length. When the defibration apparatus 5 is designed to be an internally screening comminution apparatus, the coated moulding material is provided in a particularly uniform manner.
~n the plant according to the invention and as illustrated in Figure 2, bales of straw are fed into the straw,bale shredder 51, wherE they are shredded (comminuted) and then conveyed into a metering silo 53 by means of a carrying-chain conveyor 52.
The shredded straw is then quantitativezy transported onward on a discharging metering screw 54, and a fireproof~.ng impregnating solution, from a fireproofing-agent big bag 22 which is associated with a dissolving stat~.on comprising mEtering means, is added to the straw shaping material izz the intake zone of the impregnating screw 21, After impregnatior~, the impregnated shaping material is transported into the meterir~g silo 5~ (capacity: 50 m') which is provided with a discharge screw 23_ A powdery duroplastic material (powder resin) according to the MAR-15-00 13:00 +49 511 813830 P.04 R-044 Job-451 '15/03 ~'OO~MI18:54 FAX +49 511 813830EIKENBERG-STILKENBOHMER (~ 011/023 invention is fed from a powder-resin big bag 24 comprising a metering station, and is added to the impregz~ated and, accordingly, moist straw shaping material on the discharge screw 23_ The shaping material to which the powder resa.n has been added is then weighed Qn a roller conveyor type weighex 56, whence it is conveyed into the defibratior~ mill 25.
Defibration and binder-coating according to the invention take place in said defibration mill.
Following on this process step, the shaping material is dried in the current drier 26. Drying is carried out up to a moisture content of, for example, 6~, At the same time, the resin powder, which has been adjusted to these conditions, is fixed on the shaping material fibres or chips.
Once discharged from the current driEr 26, the shaping maternal is conveyed to a scattering bin 27 (w~.th discharging means) which produces a matting from the straw shaping matezial, depositing said matting on a shaping belt 57 comprising a gauge S8 for measuring the mass per unit area. The matting is transported on the belt 57 to a mat separating and suction apparatus 59, finally reaching a press-feed~.ng belt 5o for transporting the sirraw matting into a heating press 28 (e. g.
a single-opening press). In said heating press, the matting is then compressed to form a panel and the duroplastic material.
is hardenEd. Finally Cafter passing through the heating press) , the finished panels are transferred to a discharge belt 61 and, thence, on to an elevating platform 62.
LIAR-15-00 13:00 +49 511 813830 P.05 R-044 Job-451 15/03 'OO MI 18:54 FAX +49 511 813830 EIKENBERG-STILKENBOHMER 1012/023 s In the plant illustrated in Figure 3, shaping material bales (e.g. bales of straw or hemp) are transported by means of a bale conveyor into a bale breaker 63, in which they axe broken up. From the bale breaker, the shapiz~.g material fibres or chips are placed on a belt conveyor 64 which is allocated an overhead magnet 65. 'rhe shaping material is conveyed from the belt conveyor into an impact hammer mill 66, in which a pre-commiz~utlon of the fibres or chips of the rhapz.ng material takes place.
In a next-in-line moistening apparatus 31, a desired moisture content of the shaping material is adjusted; in this regard, it is possible for moistening to be provided, for example, by means of spraying water or by means of water vapour.
An, alr~transportation apparatus transports the moistened comminuted shaping material to a si7.o housing 6~ which is allocated a discharging apparatus 68 comprising a metering screw. The shaping material arrives in a detibrating machine 35b, e.g. an ultrafibrator or refiner, via a meterixxg chute.
zn said defibrating machine, (pre-) defibration takes place.
An aiz-transportation apparatus then transports the shaping material into a suspension drier 36 which comprises a control means and a gas surface burner, and in which, if required, drying of the shaping material takes place to a desired mO~.sture Content.
MAR-15-00 13:00 +49 511 813830 P.O6 R-044 Job-451 15/03 '00 MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 013/023 -31.-The shaping material is transported from the suspension drier 36, which provides additional screenir~g, to a revers~.ng screw 69 which, in the event of a ~zre, is opezated in a direction opposite to the usual conveying direction, in order to isolate any burning matter transported from the further parts of the plant. ~rhe shaping material then passes through a screening machine 70, Via a further air-transportation apparatus, the shaping material then arrives in a silo housing 71 which is allocated a d~.sGharging apparatus 72 comprising a metering screw and, next in line, a conveyor-type weigher ~3, whence the shaping material arrives in a second defibrating machzne 35a, in which it is uniformly mixed with a duroplastic matez~ial according to the invention, said duroplastic material being injected fzom a binder-preparing and metezing apparatus 34.
According to an important alternative design of the plant, the following plant components are omitted_ conveyor-type weigher 73, second defibrating machine 35a and binder-preparing and me>rering apparatus 34. The duroplastio material is then admixed in the form of a dispersion in the moistening apparatus, while the de~ibration and binder-coating according to the invention take place in the defibration machine 35b.
'The shaping material which is coated with the duroplastic material in the manner as set out by the invention, is conveyed by means of a troughed belt conveyor Qr an air-transportation i~AR-15-00 13:00 +49 511 A13930 P.O7 R-044 Job-451 '15/03 'OO MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 014/023 I
apparatus (as an alternative to the belt conveyor) to a scattering bin 37 which is provided witk~ a shaping head ~or farming a matting.
The bindex-containing shaping material is discharged from the shaping head in the form of a matting and is moved onward between scattering walls on a shaping belt 74 with a chain conveyor and a press-allocation chain conveyor; in this regard, the shap~.ng belt is allocated a mass per unit area gauge for controlling the scattering bin. A transverse-cutting saw (z10 mm) 75, comprising a catchir~.g means, cuts the matting to the size desired, and a metal detector arxanged behind said saw detects any metal contamination which may be present in the matting. If metal is detected, a faulty-scattering device 75 which co-operates with a suction apparatus, removes the Flawed matting.
The mats are subsequently directed to a press~.ng appax-atus 38, in front of which, however, a surface-spraying device 77 is arranged For spraying watex ox parting compounds on to the mats. Paxlels according to the invention are produced in the pressing apparatus . Th.e usual apparatus for ~ur>rher treatments are connected after the pressing apparatus , in respect of which see also Figuxe 2.
In the plant for the integrated binder-coatzng, detibration and drying of shapzng material as illustrated in Figure 4, a spiral conveyor ~B for pre-comminuted shaping material (for example MAR-15-00 13:00+49 511 813930P.08 R-044 Job-451 15/03 ~'DO 18:55FAX +49 813830EIKENBERG-STILKENBOHMER ~ 015/023 pre-comminuted straw) is illustrated, said conveyor transporting said shaping material to a dust screen 79, whexe dust is largely removed Ezom the shaping material.
'The pre-commznuted shaping material is then quantitatively transported onward on an impregnating screw 41, and a fireproofing impregnating solution, Pram a metering station 42 cahich is allocated a dissolving station with metering means, is added to the shaping material. in the intake zone of the impregnating straw 43.. Impregnation takes place Qn the impregnating screw at a reduced pressure of, for example, 25 mbar. After impregnation, the impregnated shaping material is t~canspozted into the metering silo 80-On a next~fo~.l.owing roller conveyor-type weigher 81, the shaping material is weighed and then transported into an ultra-rotor defibration mill 45 comprising an integrated screening device, a metering screw 82 and a hot air apparatus 83 (for drying and for thermal treatment). At the same time as the shaping maternal is charged into the defibration mill 45, powder resin from a meterir~g station 44 is introduced via a metering screw 82 into the de~~.bration mill. Means 84 are provided to ensure that the quantity of shaping material charged into the mill per unit of time and the quantity of powder resin introduced are in ~. substantially predetermined ratio to each other. rt is, ~or e~cample, possible for the weighing signal of the roller conveyor-type weigher 81 to be used as a reference signal for determining the quantity of MAR-15-00 13:00 +49 511 913930 P.09 R-044 Job-451 15/03 ~'00 MI 18:55 FAX +49 511 813830 EIKENBERG-STILKENBOHMER ~ 016/023 r powder resin which is to be introduced from the powder-resin metering station 44 via the metering screw 82 and into the defibration mill 45_ In the defibration mill 45, the shaping material is simultaneously defibrated, coated with powder resin and dried.
Drying is carried out by means of through-~lowing hot air which is produced, for example, zz~. a radiator 29 and injected into the mill from below.
The mill 45 comprises means fox screening or grading the shaping material (in its binder-coated or non-coated state) contained therein. Coarse particles are screened out in the head of the machine and are recycled for grinding in a downstream intake region. In this way, it is also possible for knots in stalks and the like to be loosened, axed for this reason iG is also possible to dispense with a separate downstream screening device.
The ~~nally binder-coated and dried shaping material fibres are transported into a separator 85 for dry fibres, whence they ultimately arrive in a metering silo (scattering bin) 47, where matting is produced from the binder-coated shaping mar.erial, ~or example by means of an associated scattering apparatus.
Claims (14)
1. Process for the production of shaped parts, in particular chip and fibre boards, according to which process - a solid duroplastic material is added to a defibratable basic material having a moisture content of at least 9% by mass, - for the purpose of applying the binding agent, the duroplastic material and the basic material are subjected to a treatment in which the basic material is simultaneously defibrated and mixed with the duroplastic material, and - the thus obtained binder-coated, and optionally thereafter treated fibrous shaping material is shaped to produce a shaped part.
2. Process according to claim 1, in which the mixture is subjected to a drying treatment during or after the simultaneous defibration and binder-coating treatment.
3. Process according to one of the preceding claims, in which the basic material is comminuted prior to the admixture of the duroplastic material.
4. Process according to one of the preceding claims, in which, prior or during the admixture of the duroplastic material, the basic material is adjusted to a moisture content of more than 30%, preferably more than 45%.
5. Process according to claim 4, in which the adjusting of the moisture content is achieved by adding water to the basic material prior to or during the admixture of the duroplastic material.
6. Process according to claim 4, in which the adjusting of the moisture content is achieved by treating the basic material with water vapour prior to or during the admixture of the duroplastic material.
7. Process according to one of the preceding claims, wherein the duro-plastic material is added to the basic material in the form of a suspension.
8. Process according to one of the preceding claims, in which the mixture comprising duroplastic material and basic material is, preferably simultaneously with the defibration and binder-coating treatment, subjected to a thermal treatment, in the course of which thermal treatment the melting temperature of the duroplastic material is reached or exceeded.
9. Process according to one of the preceding claims, in which the defibratable basic material includes chips or fibre bundles of fibrous vegetation.
10. Process according to claim 9, in which the defibratable basic material includes straw chips.
11. Process according to one of the preceding claims, in which the basic material is treated with a fireproofing agent.
12. Process according to claim 11, in which the treatment with said fireproofing agent is carried out under a reduced pressure.
13. Shaped part which comprises a fibre material and a binding agent which is based an a duroplastic material which is solid at room temperature.
14. Plant for carrying our the process according to one of claims 1-12 and/or for producing the shaped part according t4 claim 13, in which means are provided for the simultaneous defibration and binder-coating of a defibratable basic material.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19741248.3 | 1997-09-18 | ||
| DE19741248 | 1997-09-18 | ||
| DE19810964 | 1998-03-13 | ||
| DE19810964.4 | 1998-03-13 | ||
| PCT/DE1998/002714 WO1999014022A1 (en) | 1997-09-18 | 1998-09-14 | Method for producing moulded bodies, moulded body and installation for carrying out said method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2303870A1 true CA2303870A1 (en) | 1999-03-25 |
Family
ID=26040115
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002303870A Abandoned CA2303870A1 (en) | 1997-09-18 | 1998-09-14 | Method for producing moulded bodies, moulded body and installation for carrying out said method |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1017549A1 (en) |
| AU (1) | AU1142299A (en) |
| CA (1) | CA2303870A1 (en) |
| WO (1) | WO1999014022A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7994243B2 (en) | 2006-08-07 | 2011-08-09 | Dynea Oy | Stable aqueous novolac dispersion |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10116686C2 (en) * | 2001-04-03 | 2003-08-21 | P & T Gmbh Projekt Und Technol | Process for the preparation of straw and other annual plants for the production of fiberboard, chipboard and insulation boards as well as wall elements and other molded parts and process for the production of fiberboard, chipboard and insulation boards as well as wall elements and other molded parts |
| DE102005061222A1 (en) * | 2005-12-20 | 2007-06-21 | Dynea Erkner Gmbh | Vegetable fiber, fiber-based shaped articles and methods of making novolak-treated vegetable fibers |
| CN107671980A (en) * | 2017-11-17 | 2018-02-09 | 河南鑫饰板业有限公司 | Medium-density plate is mated formation humidification on production line and detection structure |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI862656A0 (en) * | 1986-06-23 | 1986-06-23 | Partek Ab | ANORDINATION FOR DEFIBRATION AV SMAELT MINERALMATERIAL. |
| SE470101B (en) * | 1992-03-13 | 1993-11-08 | Casco Nobel Ab | Procedure for making board |
| DE19621606A1 (en) * | 1996-05-30 | 1997-12-04 | Picon Schmidt & Co Gmbh | Fire retardant for boards or molded parts made of chips or fibers and process for fire-resistant finishing of such boards or molded parts |
-
1998
- 1998-09-14 AU AU11422/99A patent/AU1142299A/en not_active Abandoned
- 1998-09-14 CA CA002303870A patent/CA2303870A1/en not_active Abandoned
- 1998-09-14 EP EP98954173A patent/EP1017549A1/en not_active Withdrawn
- 1998-09-14 WO PCT/DE1998/002714 patent/WO1999014022A1/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7994243B2 (en) | 2006-08-07 | 2011-08-09 | Dynea Oy | Stable aqueous novolac dispersion |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1999014022A1 (en) | 1999-03-25 |
| EP1017549A1 (en) | 2000-07-12 |
| AU1142299A (en) | 1999-04-05 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Discontinued |