摘要:
The present invention relates to a process for continuously manufacturing composites of polymer and cellulosic fibres, comprising the steps of: a) feeding a polymer upstream into an extruder; b) melting and mixing the polymer in a zone (A) of the extruder; wherein zone (A) comprises at least one positive transportation screw element; c) feeding cellulosic fibres into the extruder in a zone (B) of the extruder, which zone (B) is located downstream of zone (A); d) transporting the mixture of polymer and cellulosic fibre obtained in zone (B) through a degassing zone (C), which zone (C) is located downstream of zone (B), wherein zone (C) comprises at least one positive transportation screw element and e) transporting the mixture obtained in zone (C) through a pressure building zone (D) of the extruder, which zone (D) is located downstream of zone (C), wherein zone (D) comprises at least one positive transportation screw element; f) releasing the mixture obtained in zone (D) into a die, characterised in that zone (B) comprises at least one positive transportation screw element, at least one kneading section and at least one negative transportation screw element such that in zone (B) of the extruder the cellulosic fibres are fibrillated to obtain cellulosic fibres with an aspect ratio as high as possible, while simultaneously mixing the cellulosic fibres with the melted polymer. This process results in a compounded material comprising polymer and cellulosic fibres, wherein the cellulosic fibres are elementary fibres and have a high aspect ratio. As a result the compounded material has excellent mechanical properties.
摘要:
The invention relates to a method and device for producing an extrusion profile out of a mixture of small parts, especially out of a wood chip mixture. According to the invention, the mixture of small parts is pressed through a pressing area and into a channel by means of a pressing device, said channel being heated in a section-like manner. The resulting compacted mixture forms a section in the channel. The cross-section of said section essentially corresponds to the cross-section of the channel, and the mixture bonds along the path thereof through the channel to form a profile. The cross-section of the pressing area and/or of the filling zone enlarges in the direction of pressing. The invention also relates to a configuration of the spindle element and to a spindle box provided for accommodating the same.
摘要:
A substantially continuous method for forming a structural panel (2) of indefinite length. The method comprises the steps of preparing a settable mixture, conveying the mixture in a flowable state to a load chamber (6), and progressively forcing the mixture from the load chamber (6) through an inlet (15) toward an outlet (16) of an open ended mould chamber (17) by compression means at least partially curing the mixture within the mould chamber (17), resisting movement of the mixture through the mould chamber (17) until a predetermined consolidation pressure or density within the mould chamber (17) is achieved, subsequently allowing movement of the mixture through the mould chamber (17) in response to further mixture being first forced through the inlet (15) by the compression means, allowing the mixture to cure, and thereby progressively forming a structural panel of substantially indefinite length.
摘要:
An apparatus and process for combining an organic fibrous material with a thermoplastic material forming a wood-imitating composite. The mixed material is extruded into a die system (14) comprising a transition die (25), a stranding die (40), and a molding die (78). The flow rate of the material through the die system is equalized by preforming the mixed material with a transition die to a shape approaching the end product, stranding the material with the stranding die to form individual strands, and compressing the individual strands with the molding die after it exits the stranding die. The die system may also include an adapter die (16) positioned between the extruder (12) and the transition die which functions to control the amount of mixed material which enters the die system. A product comprised of recyclables shredded and mixed to form a wood-imitating composite from a low-temperature extruder is also provided.
摘要:
A process for making a polyvinyl chloride and wood composite pellet by extrusion, in which the polyvinyl chloride and wood fibre are introduced into the extruder in a ratio of approximately 6:4 by weight. The polyvinyl chloride is melted and blended with the wood fibre so that the interstitial voids of the wood fibre are filled with polyvinyl chloride. After being extruded through a die, the molten material is cut into pellets having a bulk density of preferably between 0.7 and 0.8 g.mm⁻³.
摘要:
A composite structural member, made of a polymer and wood fibre composite material, in the form of an extruded or injection moulded thermoplastic member in residential and commercial structures. The structural member can be used in a window or a door. The structural member has a hollow cross-section with at least one structural web (109) and at least one fastener web (110) formed within the member. The exterior of the extruded member is shaped and adapted for installation in a rough opening and to support window and door components. Such structural members can be assembled in a thermoplastic weld process. Welding is performed by heating and fusing the heated surfaces together to form a welded joint.
摘要:
Polymer and wood composite structural members are manufactured by extruding and injection moulding a composition comprising polyvinyl chloride, wood fibre and optionally a concentration of an intentionally added waste stream. Such structural members have strength, workability, fastener retention, resistance to rot and insect attack, and thermal properties sufficient to constitute an advanced composite wood replacement material. The advanced structural member can be used as a component in construction of any structure requiring sized lumber or specifically shaped wood products. In such an application, the structural members can be extruded in the shape of commonly available lumber. The structural members of the invention can also be extruded in complex shapes adapted to the assembly of windows and doors used in both residential and commercial structures. The structural members have a modulus, a coefficient of thermal expansion, a coefficient of elasticity, a compressive strength and other related properties ideal for use as a replacement for either metal or wood, window or door structural components. The preferred structural member is manufactured from a polyvinyl chloride and wood fibre composite that optionally contains an intentionally recycled impurity component. Such components comprise waste materials common in the manufacture of wood doors and windows. The cooperation between the amount of polymer material, the amount of an oriented wood fibre, and control over water content results in improved structural properties.
摘要:
Die Erfindung betrifft eine Vorrichtung zum Strangpressen von mit Bindemitteln vermischten pflanzlichen Kleinteilen, mit einem in einem Gehäuse (1) verschiebbaren, stirnseitig profilierten Preßkolben (5), wobei das Gehäuse eine Einfüllöffnung (3) für das Gemisch (14) aufweist und das Gehäuseinnere den Preßraum (2) für das Gemisch bildet. Um mit einfachen baulichen Mitteln einen Preßstrang herzustellen, der ein unterschiedliches Dichteprofil aufweist und somit eine hohe Festigkeit des erzeugten Produktes gewährleistet ist, wird erfindungsgemäß vorgeschlagen, daß der Preßraum in seiner Längserstreckung (10) senkrecht orientiert ist, der Preßkolben von oben in die Einfüllöffnung einführbar und in Längserstreckung des Preßraums verschieblich ist, ferner der Preßkolben zwei senkrecht zu seiner Verschieberichtung orientierte äußere Flächen (8) und zwischen diesen zwei zueinander geneigt angeordnete und in Preßrichtung (A) des Preßkolbens spitz zulaufende innere Flächen (9) aufweist, sowie das Gehäuse (1) zumindest teilweise beheizbar ist.