EP0441835A1 - Method for the manufacture of contour-stable objects. - Google Patents

Method for the manufacture of contour-stable objects.

Info

Publication number
EP0441835A1
EP0441835A1 EP89912229A EP89912229A EP0441835A1 EP 0441835 A1 EP0441835 A1 EP 0441835A1 EP 89912229 A EP89912229 A EP 89912229A EP 89912229 A EP89912229 A EP 89912229A EP 0441835 A1 EP0441835 A1 EP 0441835A1
Authority
EP
European Patent Office
Prior art keywords
mould
accordance
pulp
fact
suction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89912229A
Other languages
German (de)
French (fr)
Other versions
EP0441835B1 (en
Inventor
Torben Rasmussen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Brodrene Hartmann AS
Original Assignee
Brodrene Hartmann AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Brodrene Hartmann AS filed Critical Brodrene Hartmann AS
Publication of EP0441835A1 publication Critical patent/EP0441835A1/en
Application granted granted Critical
Publication of EP0441835B1 publication Critical patent/EP0441835B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
    • D21J7/00—Manufacture of hollow articles from fibre suspensions or papier-mâché by deposition of fibres in or on a wire-net mould

Definitions

  • the present invention concerns a method for the manu ⁇ facture of contour-stable objects by the depositing of a fluidized fibre raw material on a moulding foundation by suction of a pulp of the fibre raw material on this foun- dation.
  • a fluidized fibre raw material means a starting mate ⁇ rial, which may be in wet form, of a fibrous nature and suited for the manufacture of the desired objects.
  • Such starting material may for instance be a fibre pulp material as used for instance for trays and cartons for packaging of fragile and sensitive objects such as fruit, flowers, eggs and objects of for instance glass.
  • the pulp material usually consists of a suspended, fibrous cellulose.
  • the object of the invention is to indicate how this in itself suitable production technique may be used not only to manufacture relatively small and light objects but also to manufacture large, rather heavy objects with extremely high load capacity characterized by a contour stability which is substantially based on a corresponding thickness of the material layer deposited on the moulding foundation.
  • the wall thickness of the said small and light objects is rather thin and the rigidity necessary in practice is usually obtained by deliberately moulding the wall panels which for instance support the said objects as the walls produce a rather rigid total object by mutually supporting each other.
  • the stated objective is a- chieved by applying to the foundation a pulp formed by the fluidized fibre raw material and easily to be drained in such quantity and by controlling the suction in such a way that on the foundation is deposited a fibre raw material layer of such thickness as to provide in all essentials the contour stability desired for the object by suction.
  • the contour stability of this object may according to the invention also be increased by procuring in the fiber raw material layer and distributed over this one or more va- riations in the layer thickness by correspondingly locally varying the suction effect during a joint suction process for the fibre pulp volume necessary for the manufacture of the whole object.
  • the contour stability of this object may according to the invention also be increased by procuring in the fiber raw material layer and distributed over this one or more va- riations in the layer thickness by correspondingly locally varying the suction effect during a joint suction process for the fibre pulp volume necessary for the manufacture of the whole object.
  • a contour stability in ⁇ creasing moulded structure in the actual material object forming the object According to the invention such a struc- ture will for instance be able to be shaped as a connected -structural pattern with a thicker layer thickness compared with the other parts of the object.
  • a suitable way for the car ⁇ rying through of the method is characteristic in that,- for suction of a pulp of the fibre raw material, which is easily to be drained, in the desired thickness, a mould is used which at negative pressure is permeable by a gaseous active working medium and which has a by the working medium per- meable mould surface the permeability of which is adjusted to the thickness of the fibre raw material layer to be de ⁇ posited by suction of the pulp on this surface.
  • a mould having a mould surface with a permeability varying in accordance with the layer thickness of the local variation or variations respectively or the coherent structural pat ⁇ tern of the easily drainable fibre pulp layer deposited on the mould surface by suction may be used according to the invention.
  • an embodiment of this me- thod may be characterized by the use for suction of an easi ⁇ ly drainable pulp of the fibre raw material in the desired thickness of a mould which at negative pressure is permeable by a gaseous active working medium which at least as regards the outline-forming part consists of a partial composite ma- terial the particles of which are fixed together for the formation of a contour-stable mould surface at the same time as they together limit passages open to the working medium, which passages extend through the composite material to the outside surface of the mould, and that the thickness of at least the composite material layer forming the mould surface is adjusted according to the thickness of the fibre raw ma ⁇ terial layer to be deposited by suction of the pulp to this surface.
  • Such a mould may be manufactured on the basis of a cheap, inorganic raw material such as sand as well as by means of a production technique which is simple, of short duration and thus also cheap.
  • the total production costs of the mould may be kept at a low level and this embodiment will consequently be suitable for the production of a small number of products.
  • a mould may, according to the invention, be used in which the com ⁇ posite material formed by the mould surface has a thickness that varies in accordance with the layer thickness of the local variation or variations, respectively, or the desired coherent structural pattern of the easily drainable fibre pulp layer deposited on the mould surface by suction.
  • a mould may be used the per ⁇ meable mould surface of which is composed of particles with varying particle size, the particle size being small in the part forming the mould surface of the mould and larger in an underlying supporting layer for this part.
  • the mould strength necessary for the carrying through of a production process may be achieved in a simple way by mixing the mould particles with suitable binding agents which may contain adhesion-improving agents and by hardening the mould manufactured by such mixture by for instance heat treatment,. Also wedging between the particles may be used to give the mould strength.
  • a mould having at the bottom a basic part in which the composite particles are linked together by a real fusion compound whereas the particles in the rest of the mould are linked together by a hardening conglutinating compound.
  • Such a mould is characterized by good strength which will also enable it to resist considerable working pressure. It is also within the scope of the invention to use a mould the mould surface of which is shaped with such strength that the mould may be used for the finishing pres ⁇ sing of a moulded object.
  • Finishing pressing may not only be used for quick removal of water from the pulp layer de ⁇ posited on the mould surface, but also to achieve an espe ⁇ cially good material density in the deposited, rather thick fibre material layer and thus an especially high degree of contour stability in the final object.
  • the desired porosity of the mould may be achieved by an appropriate choice of the grain size and the distribution of the particles of which the permeable mould surface may be composed both to obtain favourable conditions for the fixing compound between the particles and for a suitable di- mensioning of the porosity in order to avoid an undesired pressure drop across a building material which is unneces ⁇ sarily dense.
  • the above procedure and mould may as mentioned in prac ⁇ tice be used for the production of objects of various fibre- containing suspensions, everything in the presence of the auxiliary materials which may be necessary to create connec ⁇ tion in the material layer obtained by suction onto the mould.
  • the removal of an object formed by the depositing of a fluidized fibre raw material on the outline-forming out ⁇ side of the mould surface by means of a gaseous working me ⁇ dium may in practice be performed place by the object being affected by compressed air through the air passages of the mould and thus lifted free of the mould.
  • the ob- ject will, however, usually still be rather soft and it may therefore for the purpose of removing the object from the casting mould be appropriate to use a transfer mould which is adapted to interact with the side of the object pointing away from the mentioned outline-forming outside for the. re- moval of the object from this outside and for the subsequent placing of the object on for instance a conveyer belt taking the object to a drying chamber.
  • the transfer mould is producible directly on the basis of an object produced on the casting mould as on this object a first auxiliary mould (negative) of for instance gypsum is produced corresponding to the side of the object pointing away from the casting mould and on this first auxiliary mould (negative) a second auxiliary mould (positive) is pro ⁇ **d for instance also from gypsum and the transfer mould (negative) is then formed directly on this second auxiliary mould.
  • the permeable mould surface may be kept clean by, prior to the start of the depositing process or the transfer pro ⁇ cess, exposing for cleaning purposes the mould surface to an air current passing through the mould passages for a ga ⁇ seous medium.
  • a mould used in accordance with the invention and con ⁇ structed by a particle composite material may be manufac ⁇ tured in such a way that it may after use or in case of wear be regenerated as the particle-shaped building material of the mould may be recycled.
  • a pulp which is to be easily drained it is possible, according to the invention, as fibre raw material at least partly to use a starting material con ⁇ taining long fibres which is processed to a pulp partly by means of a shake-out in a pulper, partly by a preceding, se- parate, controlled dry grinding by which the starting mate ⁇ rial is divided into dosage amounts and divided into its fibres whereupon the object is manufactured from the pulp thus created.
  • a pulper as an essential step in the pr ces- sing of the fibre raw materials for the creation of a pulp from which the desired objects are to be manufactured takes place among other things in cases where the fibre raw mate ⁇ rials are received in the form of dry substances in bales, for instance as paper waste.
  • the method according to the invention achieves that to the pulper is at least partly added a fibre raw material the fibres of which are already to a substantial degree sepa ⁇ rated into single fibres why they are more instant and at the same time susceptible to the self-grinding effect and mixing effect obtained in the pulper.
  • the pulper proces- ses a more uniform raw material also the grinding degree ob ⁇ tained in the pulper through self-grinding may be adjusted to be more uniform and the above-mentioned binding of water in the pulp leaving the pulper will thus be more control ⁇ lable.
  • the same procedure will, however, also result in other advantages which are especially valuable in case of recyc ⁇ ling of paper waste.
  • Recycled paper waste exists in many different qualities and grading ⁇ . If this material prior to the shake-out in the pulper is exposed to a separate, controlled dry grinding, it is often possible to use a poorer and thus cheaper mate ⁇ rial quality, than if the division process was only carried out as a shake-out in the pulper.
  • the preceding separate dry grinding as mentioned above as a multiple-stage process whereby it is possible to separate the starting material in dosage amounts in a special effi ⁇ cient manner.
  • waste paper material containing plastic, water resistant paper, plastic laminated cartons and paper to the degree desired can be separated into fibres and other particles. Separated constituents not being paper can be screened off before entering the pulper, or it is possible to let these constituents since they exist in pulverized form enter into the following production pro ⁇ cess.
  • a long fibre starting material having been subjected to a separate controlled dry grinding be added to an already in the pulper formed pulp and be subjected to a joint time-limited shake-out with this.
  • the separate, controlled dry grinding suggested accord ⁇ ing to the invention of the fibre raw materials prior to their shake-out in the pulper also provides the possibility for the co-application of recycling waste paper in cases where the objects to be manufactured must be shrink proof and measure proof.
  • a starting material with a high content of wooden fibre causes less shrinkage that if the fibre were cellulose fibre. It has turned out that by applying the me ⁇ thod according to the invention it is even possible to add to a wooden paper raw material a substantial amount of cheap recycling paper including carton waste which not necessarily is wooden since it is possible to manufacture due to the preceding separate controlled dry grinding of the raw mate ⁇ rial a pulp which causes no undesired shrinkage of the ob ⁇ jects manufactured.
  • auxiliary materials such as filling material and chemicals and binding agents.
  • the auxiliary materials decide whether the objects manufactured shall be more or less strong, hard or transpa ⁇ rent, or weak, soft and absorbing.
  • the present invention is also advantageous in connection with the application of such auxiliary materials.
  • auxiliary materials at different stages of the total manu ⁇ facturing process.
  • the achieved open structure of the final pulp obtained as a result of this particular invention, •even facilitates a better access for auxiliary materials so that e.g. a binding material may be applied more or less in ⁇ tegrating on the surface of the objects in order to increase the strenght of the wall.
  • auxiliary material under the preceding separate, controlled dry grinding will in a especially good manner be able to further a particular uniform distribution of the auxiliary materials in the ma- nufactured fibre mass. It is of course also still possible to add the auxiliary materials to the pulper.
  • the shake-out in the pulper is carried out as a manu- facturing process dependent on the preceding separate, con ⁇ trolled grinding.
  • the obtained degree of self-grinding in the pulper can be adjusted in accordance with the degree of the grinding which according to the cir ⁇ cumstances has been carried out at the preceding dry grin- ding stage(s).
  • a paper pulp which in the pul ⁇ per is separated into a normal, at self grinding obtained grinding degree of 60o SR (Schopper-Riegler) , be added dry grounded fibre material whereafter the mixture is processed in the pulper for 5 minutes more.
  • Objects manufactured from such a mixture pulp may be provided with a special heavy thickness, porosity and permeability. That means that the products can have good drainage qualities and therefore also can be manufactured with large wall thickness.
  • An easily drainable pulp manufactured according to the invention facilitates unproblematically a uniform addition of the fibre suspension over the mould even in cases of manufacturing objects with large wall thickness.
  • Waste paper also called return paper
  • Waste paper may be very com ⁇ posite, and contain fibre with a large variety of fibre lengths.
  • the method according to the invention will also be a- vailable for the processing of so-called virgin material.

Abstract

Dans le procédé décrit, qui sert à la fabrication d'objets présentant des contours stables, un matériau brut fibreux fluidisé est disposé sur une base de moulage par aspiration d'une pulpe du matériau brut fibreux sur cette base. A cet effet, on applique sur la base une pulpe facilement drainée créée à partir de la couche de matériau brut fibreux fluidisé, dont la quantité et le réglage de l'aspiration sont prévus de sorte qu'il se dépose sur la base par aspiration une couche de matériau brut fibreux ayant une épaisseur de paroi assurant aux contours de l'objet la stabilité désirée.In the method described, which is used for the manufacture of objects having stable contours, a fluidized fibrous raw material is placed on a base of suction molding of a pulp of the fibrous raw material on this base. For this purpose, an easily drained pulp created from the layer of fluidized fibrous raw material is applied to the base, the quantity and adjustment of the suction of which are provided so that it is deposited on the base by suction. layer of raw fibrous material having a wall thickness ensuring the contours of the object the desired stability.

Description

Method for the manufacture of counter-stable objects.
The present invention concerns a method for the manu¬ facture of contour-stable objects by the depositing of a fluidized fibre raw material on a moulding foundation by suction of a pulp of the fibre raw material on this foun- dation.
A fluidized fibre raw material means a starting mate¬ rial, which may be in wet form, of a fibrous nature and suited for the manufacture of the desired objects. Such starting material may for instance be a fibre pulp material as used for instance for trays and cartons for packaging of fragile and sensitive objects such as fruit, flowers, eggs and objects of for instance glass. The pulp material usually consists of a suspended, fibrous cellulose.
It is well known for this purpose to use a production technique by which the starting material in the form of a pulp is by a depositing process placed against the outline- forming outside of a mould which is permeable to let a gase¬ ous working medium, through a suction effect, affect the ma¬ terial through the material of the mould and thus mould the contour of the material on the mould through suction.
The object of the invention is to indicate how this in itself suitable production technique may be used not only to manufacture relatively small and light objects but also to manufacture large, rather heavy objects with extremely high load capacity characterized by a contour stability which is substantially based on a corresponding thickness of the material layer deposited on the moulding foundation. In comparison with this the wall thickness of the said small and light objects is rather thin and the rigidity necessary in practice is usually obtained by deliberately moulding the wall panels which for instance support the said objects as the walls produce a rather rigid total object by mutually supporting each other.
According to the invention the stated objective is a- chieved by applying to the foundation a pulp formed by the fluidized fibre raw material and easily to be drained in such quantity and by controlling the suction in such a way that on the foundation is deposited a fibre raw material layer of such thickness as to provide in all essentials the contour stability desired for the object by suction.
This will by using the above production technique also enable the manufacture of elements with high load capacity such as pallets and building elements which may, contrary to the said packaging examples, display rather even and smooth outer surface and which in itself displays a high de¬ gree of contour stability. The depositing of a fibre raw ma¬ terial layer of the defined thickness means that the nega- tive pressure used for suction may procure a material den¬ sity in the fibre raw material layer which is highest at the outside of the material layer directed towards the mould surface and which will have a reinforcing effect as it is placed at a distance from the through-going centre plan of the deposited object.
By using the layer thickness of the object thus manu¬ factured the contour stability of this object may according to the invention also be increased by procuring in the fiber raw material layer and distributed over this one or more va- riations in the layer thickness by correspondingly locally varying the suction effect during a joint suction process for the fibre pulp volume necessary for the manufacture of the whole object. In this way it will be possible in one and the same working process, i.e. the depositing of the fibre raw material on the moulding foundation, to mould both the final outside desired for the object and, by using the thickness of the material layer, a contour stability in¬ creasing moulded structure in the actual material object forming the object. According to the invention such a struc- ture will for instance be able to be shaped as a connected -structural pattern with a thicker layer thickness compared with the other parts of the object.
According to the invention a suitable way for the car¬ rying through of the method is characteristic in that,- for suction of a pulp of the fibre raw material, which is easily to be drained, in the desired thickness, a mould is used which at negative pressure is permeable by a gaseous active working medium and which has a by the working medium per- meable mould surface the permeability of which is adjusted to the thickness of the fibre raw material layer to be de¬ posited by suction of the pulp on this surface.
In this way it is possible to achieve such interaction between the draining ability of the pulp and the suction ca¬ pability of the mould surface that also elements having thick fibre layer thickness owing to the desired load ca¬ pacity may be manufactured rationally.
In order to achieve local variations in the layer thickness of the fibre raw material layer of the object, a mould having a mould surface with a permeability varying in accordance with the layer thickness of the local variation or variations respectively or the coherent structural pat¬ tern of the easily drainable fibre pulp layer deposited on the mould surface by suction may be used according to the invention.
This means that the depositing of fibre raw material on the mould surface will vary according to the permeability of this surface which results in local variations in the suction effect which, in areas with poor mould surface per¬ meability, causes reduced depositing of fibre raw material in the mould surface whereas the depositing will be high in areas with high mould surface permeability.
According to the invention, an embodiment of this me- thod may be characterized by the use for suction of an easi¬ ly drainable pulp of the fibre raw material in the desired thickness of a mould which at negative pressure is permeable by a gaseous active working medium which at least as regards the outline-forming part consists of a partial composite ma- terial the particles of which are fixed together for the formation of a contour-stable mould surface at the same time as they together limit passages open to the working medium, which passages extend through the composite material to the outside surface of the mould, and that the thickness of at least the composite material layer forming the mould surface is adjusted according to the thickness of the fibre raw ma¬ terial layer to be deposited by suction of the pulp to this surface. Such a mould may be manufactured on the basis of a cheap, inorganic raw material such as sand as well as by means of a production technique which is simple, of short duration and thus also cheap. The total production costs of the mould may be kept at a low level and this embodiment will consequently be suitable for the production of a small number of products.
In order to achieve local variations in the layer thickness of the object's fibre raw material layer a mould may, according to the invention, be used in which the com¬ posite material formed by the mould surface has a thickness that varies in accordance with the layer thickness of the local variation or variations, respectively, or the desired coherent structural pattern of the easily drainable fibre pulp layer deposited on the mould surface by suction.
According to the invention a mould may be used the per¬ meable mould surface of which is composed of particles with varying particle size, the particle size being small in the part forming the mould surface of the mould and larger in an underlying supporting layer for this part. In this way it is possible to procure good passage for air and at the same time procure for the object to be manufactured a rather smooth mould outside which will result in the object obtain¬ ing an even surface. The mould strength necessary for the carrying through of a production process may be achieved in a simple way by mixing the mould particles with suitable binding agents which may contain adhesion-improving agents and by hardening the mould manufactured by such mixture by for instance heat treatment,. Also wedging between the particles may be used to give the mould strength.
Furthermore, according to the invention it is possible to use a mould having at the bottom a basic part in which the composite particles are linked together by a real fusion compound whereas the particles in the rest of the mould are linked together by a hardening conglutinating compound. Such a mould is characterized by good strength which will also enable it to resist considerable working pressure. It is also within the scope of the invention to use a mould the mould surface of which is shaped with such strength that the mould may be used for the finishing pres¬ sing of a moulded object. Finishing pressing may not only be used for quick removal of water from the pulp layer de¬ posited on the mould surface, but also to achieve an espe¬ cially good material density in the deposited, rather thick fibre material layer and thus an especially high degree of contour stability in the final object. The desired porosity of the mould may be achieved by an appropriate choice of the grain size and the distribution of the particles of which the permeable mould surface may be composed both to obtain favourable conditions for the fixing compound between the particles and for a suitable di- mensioning of the porosity in order to avoid an undesired pressure drop across a building material which is unneces¬ sarily dense.
The above procedure and mould may as mentioned in prac¬ tice be used for the production of objects of various fibre- containing suspensions, everything in the presence of the auxiliary materials which may be necessary to create connec¬ tion in the material layer obtained by suction onto the mould.
The removal of an object formed by the depositing of a fluidized fibre raw material on the outline-forming out¬ side of the mould surface by means of a gaseous working me¬ dium may in practice be performed place by the object being affected by compressed air through the air passages of the mould and thus lifted free of the mould. In practice the ob- ject will, however, usually still be rather soft and it may therefore for the purpose of removing the object from the casting mould be appropriate to use a transfer mould which is adapted to interact with the side of the object pointing away from the mentioned outline-forming outside for the. re- moval of the object from this outside and for the subsequent placing of the object on for instance a conveyer belt taking the object to a drying chamber. It is within the scope of the invention also to manufacture such a transfer mould from a particle composite material as mentioned above by binding the material particles together for the creation * of an open, stable structure with air passages extending to the outside of the mould and by connecting with a source for a suction provoking vacuum.
The transfer mould is producible directly on the basis of an object produced on the casting mould as on this object a first auxiliary mould (negative) of for instance gypsum is produced corresponding to the side of the object pointing away from the casting mould and on this first auxiliary mould (negative) a second auxiliary mould (positive) is pro¬ duced for instance also from gypsum and the transfer mould (negative) is then formed directly on this second auxiliary mould. The permeable mould surface may be kept clean by, prior to the start of the depositing process or the transfer pro¬ cess, exposing for cleaning purposes the mould surface to an air current passing through the mould passages for a ga¬ seous medium. A mould used in accordance with the invention and con¬ structed by a particle composite material may be manufac¬ tured in such a way that it may after use or in case of wear be regenerated as the particle-shaped building material of the mould may be recycled. For the manufacture of a pulp which is to be easily drained it is possible, according to the invention, as fibre raw material at least partly to use a starting material con¬ taining long fibres which is processed to a pulp partly by means of a shake-out in a pulper, partly by a preceding, se- parate, controlled dry grinding by which the starting mate¬ rial is divided into dosage amounts and divided into its fibres whereupon the object is manufactured from the pulp thus created.
The use of a pulper as an essential step in the pr ces- sing of the fibre raw materials for the creation of a pulp from which the desired objects are to be manufactured takes place among other things in cases where the fibre raw mate¬ rials are received in the form of dry substances in bales, for instance as paper waste.
Heavy whirl formation is produced in the pulper by which the single parts of the material rub against each o- ther and is thereby pulverized and the raw materials divid- ed into fibres.
Especially in case of heterogeneous material such as waste or recycled paper it has to be anticipated that this separation is carried out successively so that the fibres released first are exposed to a higher degree of additional substantial processing than the fibres released later. In other words the processing in the pulper will in its pro¬ ceedings thus be uncontrolled and thus heterogeneous. The said additional processing results in an increase in both the degree of grinding ( °SR-Schopper-Riegler) and thus the formation of mucus in the pulper, which negatively affects the subsequent draining of the object manufactured from the pulp and increases the shrinkage of the object during drain¬ ing and drying of its material.
The method according to the invention achieves that to the pulper is at least partly added a fibre raw material the fibres of which are already to a substantial degree sepa¬ rated into single fibres why they are more instant and at the same time susceptible to the self-grinding effect and mixing effect obtained in the pulper. As the pulper proces- ses a more uniform raw material also the grinding degree ob¬ tained in the pulper through self-grinding may be adjusted to be more uniform and the above-mentioned binding of water in the pulp leaving the pulper will thus be more control¬ lable. The same procedure will, however, also result in other advantages which are especially valuable in case of recyc¬ ling of paper waste.
Recycled paper waste exists in many different qualities and gradingε. If this material prior to the shake-out in the pulper is exposed to a separate, controlled dry grinding, it is often possible to use a poorer and thus cheaper mate¬ rial quality, than if the division process was only carried out as a shake-out in the pulper. the preceding separate dry grinding as mentioned above as a multiple-stage process whereby it is possible to separate the starting material in dosage amounts in a special effi¬ cient manner. In this particular way also e.g. waste paper material containing plastic, water resistant paper, plastic laminated cartons and paper, to the degree desired can be separated into fibres and other particles. Separated constituents not being paper can be screened off before entering the pulper, or it is possible to let these constituents since they exist in pulverized form enter into the following production pro¬ cess.
At a performance of the method a long fibre starting material having been subjected to a separate controlled dry grinding be added to an already in the pulper formed pulp and be subjected to a joint time-limited shake-out with this.
In this manner an object can be manufactured whose fibre material is partly mainly bound by hydrogen fibre bin- dings partly have been mixed with air suspended fibre mate¬ rial for whose binding glue is normally used. It has turned out that in this way it is possible to abandon a traditional complete hydrogen binding of the whole pulp, which means that the drain and thereby the production time for the ob- ject can be substantially reduced. Furthermore the method makes it possible to obtain a strict control of the desired object strength characteristics as it will be possible to have strict control of these by the addition of glue.
These advantages are of major importance for a rational and thus economic industrial manufacture also of large, form stable objects by the application of the suction technique described.
It will e.g. be possible to carry out a multiple-stage dry grinding by the application of a tearing machine also called a shredder followed by a treatment in a hammer mill which thus can receive the material from the shredder in do¬ sage amounts and which exposes the material to a further grinding process before it if required also in special do- sage amounts is added to the pulper for the actual shake-out processing.
The separate, controlled dry grinding suggested accord¬ ing to the invention of the fibre raw materials prior to their shake-out in the pulper also provides the possibility for the co-application of recycling waste paper in cases where the objects to be manufactured must be shrink proof and measure proof. A starting material with a high content of wooden fibre causes less shrinkage that if the fibre were cellulose fibre. It has turned out that by applying the me¬ thod according to the invention it is even possible to add to a wooden paper raw material a substantial amount of cheap recycling paper including carton waste which not necessarily is wooden since it is possible to manufacture due to the preceding separate controlled dry grinding of the raw mate¬ rial a pulp which causes no undesired shrinkage of the ob¬ jects manufactured.
It is a well known principle for the manufacture of ob¬ jects of a fluidized fibre raw material to utilize auxiliary materials such as filling material and chemicals and binding agents. The auxiliary materials decide whether the objects manufactured shall be more or less strong, hard or transpa¬ rent, or weak, soft and absorbing. The present invention is also advantageous in connection with the application of such auxiliary materials.
The division of the manufacturing process in multiple- stages actually increases the possibility of adding the auxiliary materials at different stages of the total manu¬ facturing process. The achieved open structure of the final pulp, obtained as a result of this particular invention, •even facilitates a better access for auxiliary materials so that e.g. a binding material may be applied more or less in¬ tegrating on the surface of the objects in order to increase the strenght of the wall. The addition of auxiliary material under the preceding separate, controlled dry grinding will in a especially good manner be able to further a particular uniform distribution of the auxiliary materials in the ma- nufactured fibre mass. It is of course also still possible to add the auxiliary materials to the pulper.
Furthermore, it lies within the scope of the invention that the shake-out in the pulper is carried out as a manu- facturing process dependent on the preceding separate, con¬ trolled grinding. In other words the obtained degree of self-grinding in the pulper can be adjusted in accordance with the degree of the grinding which according to the cir¬ cumstances has been carried out at the preceding dry grin- ding stage(s). As an example, a paper pulp which in the pul¬ per is separated into a normal, at self grinding obtained grinding degree of 60o SR (Schopper-Riegler) , be added dry grounded fibre material whereafter the mixture is processed in the pulper for 5 minutes more. Objects manufactured from such a mixture pulp may be provided with a special heavy thickness, porosity and permeability. That means that the products can have good drainage qualities and therefore also can be manufactured with large wall thickness.
An easily drainable pulp manufactured according to the invention facilitates unproblematically a uniform addition of the fibre suspension over the mould even in cases of manufacturing objects with large wall thickness.
Waste paper, also called return paper, may be very com¬ posite, and contain fibre with a large variety of fibre lengths. However, it has actually turned out that the ave¬ rage fibre length is so large that the above mentioned ad¬ vantages especially as regards drainage and structure may be obtained when this paper material forms part of the ma¬ nufacturing process. The method according to the invention will also be a- vailable for the processing of so-called virgin material.

Claims

PATENT CLAIM
1. Method for the manufacture of form stable objects by depositing of a fluidized fibre raw material -on a form giving foundation by means of suction of a pulp of fibre raw material on this foundation characterized by the application to the foundation of a pulp formed by the fluidized fibre raw material, and easily to be drained, in such quantity, and that the suction action is carried out and controlled in such a way that on the foundation by suction is deposited a fibre raw material layer with such thickness that this in all essentials procures the desired contour stability of the object.
2. Method in accordance with claim 1 characterized by one or more variations in the wall thickness are procured in the fibre raw material layer, distributed over this, through the suction effect being correspondingly varied lo¬ cally in a common suction process for the fibre pulp quan¬ tity necessary for the manufacture of the whole object.
3. Method in accordance with claim 2 characterized by the depositing of the fibre raw material with a thickness- corresponding to the desired form stability is carried through as a coherent structured pattern with a larger wall thickness in comparison with the other areas.
4. Method in accordance with any of the claims 1-3, characterized by the fact that for suction of an easily drainable pulp of the fibre raw material in the desired wall thickness, a mould is used which is permeable by a gaseous active working medium at negative pressure, and which has a by a working medium permeable mould surface the permea¬ bility of which is adjusted to the thickness of the fibre raw material layer to be deposited by suction of the pulp on this surface.
5. Method in accordance with claim 4, for the carrying out of the method in accordance with claims 2 or 3, charac¬ terized by the fact that a mould is used whose mould surface has a permeability which varies in accordance with the wall thickness of the local variation(s) , respectively, or the desired coherent structured pattern of the easily drainable fibre pulp layer deposited by suction on the mould surface.
6. Method in accordance with claim 4, characterized by the fact that for suction of an easily drainable .pulp of the fibre raw material in the desired wall thickness, a mould is used which is permeable by a gaseous active working me¬ dium at negative pressure, which at least for the contour giving part of the mould is manufactured by a particle com¬ posite material whose particles are fixed together for the creation of a contour stable mould surface and at the same time defining open passages for the working medium extending through the composite material to the mould outside surface and that the thickness in at least the composite material layer forming the mould surface is adjusted to the thickness of the fibre raw material layer which is to be deposited by suction of the pulp on this surface.
7. Method in accordance with claim 5, characterized by the fact that a mould is used in which the layer of com¬ posite material forming the mould surface is manufactured with a thickness varying in accordance with the wall thick¬ ness of the local variation(s) , respectively, or the desired coherent structured pattern of the easily drainable fibre pulp layer deposited by suction on the mould surface.
8. Method in accordance with any of the claims 4 to 7, characterized by the fact that a mould is used whose perme¬ able mould surface is composed of particles of different particle size the particle size being small in the mould forming the surface part and bigger in a lower supporting layer for this part.
9. Method in accordance with claim 8, characterized by the fact that a mould is used whose particles are clad with a layer formed by a binding agent.
10. Method in accordance with claim 9, characterized by the fact that a mould is used whose binding agent is thermo -setting.
11. Method in accordance with claim 9 characterized by the fact that a mould is used whose binding agent consists of adhesion-improving agent.
12. Method in accordance with claim 8 characterized by the fact that a mould is used in which the particles have a rounded contour.
13. Method in accordance with claim 8 characterized by the fact that a mould is used in which the particles are in a wedging compound with each other.
14. Method in accordance with claims 5 or 6 characte¬ rized by the fact that a mould is used having below a basis part in which the composite particles are connected with each other through a real fusion connection while the par- tides of the rest of the mould are linked to each other through a hardening conglutination connection.
15. Method in accordance with any of the claims 4-14 characterized by the fact that a mould is used whose mould surface is provided with such a strength that the mould is applicable for finishing pressing of an object.
16. Method in accordance with any of the previous claims characterized by the fact that as fibre raw material at least partly a starting material containing long fibres is used which is processed into a pulp partly by the appli- cation of a shake-out in a pulper, partly by a preceding, separate, controlled dry grinding, whereby the starting ma¬ terial is separated into dosage amounts and divided into its fibres whereafter the object is manufactured from the pulp thus created.
17. Method in accordance with claim 16 characterized by the fact that the preceding separate dry grinding con¬ trolled manufacturing process is carried out as a multiple- stage process.
18. Method in accordance with claim 16 or 17 characte- rized by the fact that the shake-out is carried out as con¬ trolled manufacturing process dependent on the separate dry grinding.
19. Method in accordance with any of the claims 16-18 characterized by the fact that a long fibre starting ma-te- rial having been subjected to a separate, controlled dry grinding is added in dosage amounts to a pulp already cre¬ ated in the pulper and subjected to a common time-limited shake-out with this.
20. Method in accordance with any of the claims 16-19 characterized by the fact that an addition of auxiliary ma¬ terial is undertaken in connection with the preceding sepa¬ rate dry grinding.
21. Method in accordance with any of the claims 16-20 characterized by the fact that an addition of auxiliary ma¬ terial during further application of the created pulp.
22. Method in accordance with any of the claims 16-21 characterized by the fact that a pulp is manufactured as stated in claim 16, and that this pulp in dosage amounts are added another already manufactured pulp whereafter the ob¬ ject is manufactured from the mixture thus created.
EP89912229A 1988-10-25 1989-10-25 Method for the manufacture of contour-stable objects Expired - Lifetime EP0441835B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DK592488A DK168020B1 (en) 1988-10-25 1988-10-25 PROCEDURE FOR THE PREPARATION OF FORM STABLE ARTICLES FROM A FLUIDIZED CELLULOSE FIBER MATERIAL
DK5924/88 1988-10-25
PCT/DK1989/000250 WO1990004678A1 (en) 1988-10-25 1989-10-25 Method for the manufacture of contour-stable objects

Publications (2)

Publication Number Publication Date
EP0441835A1 true EP0441835A1 (en) 1991-08-21
EP0441835B1 EP0441835B1 (en) 1996-01-03

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP89912229A Expired - Lifetime EP0441835B1 (en) 1988-10-25 1989-10-25 Method for the manufacture of contour-stable objects

Country Status (20)

Country Link
EP (1) EP0441835B1 (en)
CN (1) CN1025060C (en)
AT (1) AT398093B (en)
AU (1) AU636585B2 (en)
BR (1) BR8905455A (en)
CA (1) CA2001296A1 (en)
CH (1) CH677944A5 (en)
DE (1) DE3991216T (en)
DK (1) DK168020B1 (en)
ES (1) ES2017055A6 (en)
FI (1) FI98549C (en)
GB (2) GB2251402B (en)
GR (1) GR890100687A (en)
MX (1) MX169792B (en)
NL (1) NL8921150A (en)
NO (1) NO911634L (en)
NZ (1) NZ231149A (en)
PT (1) PT92098A (en)
SE (1) SE467469B (en)
WO (1) WO1990004678A1 (en)

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FR2667882B1 (en) * 1990-10-12 1993-01-22 Anacellulose PROCESS FOR MANUFACTURING CONFORMED PARTS FROM PAPER PULP AND DEVICE FOR IMPLEMENTING SAME.
JP2836801B2 (en) * 1992-03-06 1998-12-14 日本碍子株式会社 Papermaking mold, papermaking method and papermaking apparatus for fiber molded product, and paper made fiber molded product
JP2836800B2 (en) * 1992-03-06 1998-12-14 日本碍子株式会社 Papermaking mold, papermaking method and papermaking apparatus for fiber molded product, and paper made fiber molded product
DE4402318A1 (en) * 1994-01-27 1995-08-03 Gerhard Dipl Chem Huber Simple, economic process for prodn. of high quality tubes from paper
FR2776224B1 (en) * 1998-03-20 2000-05-26 Kerlane THIN PARTS OF MINERAL FIBERS, METHOD AND MOLD FOR THEIR MANUFACTURE BY VACUUM SUCTION
CN1167851C (en) 1998-12-28 2004-09-22 花王株式会社 Formed body
WO2020150779A1 (en) * 2019-01-24 2020-07-30 Varden Process Pty Ltd Moulded pulp fibre product forming apparatus and process

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Also Published As

Publication number Publication date
BR8905455A (en) 1990-05-29
ATA903089A (en) 1994-01-15
DK592488D0 (en) 1988-10-25
CN1025060C (en) 1994-06-15
GB2243575A (en) 1991-11-06
NO911634D0 (en) 1991-04-24
EP0441835B1 (en) 1996-01-03
PT92098A (en) 1990-04-30
NO911634L (en) 1991-06-24
ES2017055A6 (en) 1990-12-16
SE9101242D0 (en) 1991-04-24
FI912005A0 (en) 1991-04-25
CA2001296A1 (en) 1990-04-25
NL8921150A (en) 1991-08-01
AU4495089A (en) 1990-05-14
AU636585B2 (en) 1993-05-06
GB2251402A (en) 1992-07-08
CN1042389A (en) 1990-05-23
DE3991216T (en) 1991-11-21
GB9108932D0 (en) 1991-06-19
GR890100687A (en) 1990-11-29
GB2243575B (en) 1992-11-18
AT398093B (en) 1994-09-26
GB9108931D0 (en) 1991-06-19
FI98549B (en) 1997-03-27
DK592488A (en) 1990-04-26
MX169792B (en) 1993-07-26
NZ231149A (en) 1992-10-28
SE9101242L (en) 1991-04-24
SE467469B (en) 1992-07-20
DK168020B1 (en) 1994-01-17
CH677944A5 (en) 1991-07-15
GB2251402B (en) 1993-06-23
FI98549C (en) 1997-07-10
WO1990004678A1 (en) 1990-05-03

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