EP1651421A2 - Procede de production de matieres thermoplastiques a base d'amidon - Google Patents

Procede de production de matieres thermoplastiques a base d'amidon

Info

Publication number
EP1651421A2
EP1651421A2 EP04766150A EP04766150A EP1651421A2 EP 1651421 A2 EP1651421 A2 EP 1651421A2 EP 04766150 A EP04766150 A EP 04766150A EP 04766150 A EP04766150 A EP 04766150A EP 1651421 A2 EP1651421 A2 EP 1651421A2
Authority
EP
European Patent Office
Prior art keywords
process according
section
extruder
previous
components
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.)
Withdrawn
Application number
EP04766150A
Other languages
German (de)
English (en)
Inventor
Giorgio Romano Bertolino
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.)
Natu Raw Ltd
Original Assignee
Natu Raw Ltd
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 Natu Raw Ltd filed Critical Natu Raw Ltd
Publication of EP1651421A2 publication Critical patent/EP1651421A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/74—Bypassing means, i.e. part of the molten material being diverted into downstream stages of the extruder
    • B29C48/745—Bypassing means, i.e. part of the molten material being diverted into downstream stages of the extruder for plasticising or homogenising devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/375—Plasticisers, homogenisers or feeders comprising two or more stages
    • B29C48/38—Plasticisers, homogenisers or feeders comprising two or more stages using two or more serially arranged screws in the same barrel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/92—Measuring, controlling or regulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/92019—Pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/92085—Velocity
    • B29C2948/92104—Flow or feed rate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/92114—Dimensions
    • B29C2948/92161—Volume or quantity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/9218—Weight
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/92314—Particular value claimed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92323—Location or phase of measurement
    • B29C2948/92333—Raw material handling or dosing, e.g. active hopper or feeding device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92323—Location or phase of measurement
    • B29C2948/92361—Extrusion unit
    • B29C2948/92371—Inlet shaft or slot, e.g. passive hopper; Injector, e.g. injector nozzle on barrel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92323—Location or phase of measurement
    • B29C2948/92361—Extrusion unit
    • B29C2948/9238—Feeding, melting, plasticising or pumping zones, e.g. the melt itself
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92514—Pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92704—Temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92809—Particular value claimed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92819—Location or phase of control
    • B29C2948/92828—Raw material handling or dosing, e.g. active hopper or feeding device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92819—Location or phase of control
    • B29C2948/92857—Extrusion unit
    • B29C2948/92866—Inlet shaft or slot, e.g. passive hopper; Injector, e.g. injector nozzle on barrel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92819—Location or phase of control
    • B29C2948/92857—Extrusion unit
    • B29C2948/92876—Feeding, melting, plasticising or pumping zones, e.g. the melt itself
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92819—Location or phase of control
    • B29C2948/92971—Fluids, e.g. for temperature control or of environment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/04—Particle-shaped
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. films
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2003/00—Use of starch or derivatives as moulding material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2005/00—Use of polysaccharides or derivatives as moulding material

Definitions

  • the present invention concerns a process for the processing or, more in particular, for the production, of polysaccharide-based thermoplastic materials, more in particular of starch-based thermoplastic materials.
  • Said materials are suitable, for example, for applications in the industrial, human and veterinary pharmaceutical, human and veterinary alimentary, agroindustrial and cosmetic fields.
  • PRIOR ART Plastic materials are widely used is various fields: in particular in the field of packaging and other throwaway items such as disposable crockery, containers for food and other items, and articles for animals.
  • the process in question is geared to the use of largely natural raw materials, widely available, easy to find and with limited cost such as polysaccharides and more in particular starches, which are biodegradable, compostable and edible, qualities highly appreciated for applications in the field of food packaging.
  • Starches are natural carbohydrates present in nature in cereals, tubers, pulses and fruit. When extracted and refined, they have the form of a white or whitish powder. In the presence of natural plasticization agents, temperature and energetic mixing, starches are modified to form a biodegradable compostable thermoplastic material.
  • Starch on its own, has modest physical-mechanical characteristics and is therefore processed together with other synergic components such as plasticizers and natural additives; often synthetic polymers are also added to make the material more workable and/or improve its characteristics.
  • the starch is first mixed cold with the other components, then the mixture is heated and pressurised, after which it is vigorously mixed and the melted material is extruded to form the finished, semi-finished or intermediate product required (for example granules). Due to the pressure and the heat, the presence of water and other components, it is modified until it forms a thermoplastic material, maintaining the biodegradability qualities of starch. Total biodegradability is obtained only if all the components in the mixture are biodegradable, hence it is desirable to avoid, in formulation of the product, the use of non-biodegradable components such as thermoplastic resins.
  • the first and the second section are preferably part of one single extruder, but the screw extruder can also comprise a screw mixer, which constitutes the first section connected via said valve to a final extruder which constitutes said second section.
  • the pressure in the extruder immediately upstream of the valve is kept to at least 20 bars, preferably at least 40 bars.
  • the process can involve the formation of semi-finished products such as film, sheets or tubes, ready for direct use or for subsequent thermoforming process, or finished pieces by introducing the melted material coming out of the die directly into suitable moulds, or an intermediate material, such as granules which can then be extruded in a subsequent process, which can be similar to the one described or injection moulded.
  • polysaccharide is starch.
  • the process according to the present invention can be a production, process, starting from pure starch but also from raw materials containing starch, such as cereal flour and other types of flour, or processing of a material already produced in this way, alone or with the addition of other components.
  • the water, fed with the polysaccharide performs a plasticizing and fluidising action in the melted material and can be the water naturally contained in it, or further water can be added as required.
  • Other components can be present, such as plasticizers or natural additives; preferably a natural plasticizer is present.
  • Synthetic, preferably thermoplastic, resins can also be added.
  • the extruder sections are thermoregulated, with areas provided with heating system, such as metal-clad electrical resistances to contribute the necessary heat to the process, and areas provided with cooling system, for example by air, or preferably with diathermic liquid control unit (for example circulating in jackets or ducts provided in the extruder walls) to rapidly remove any excess heat or heat generated by the mechanical action of the screw or mixing devices.
  • heating system such as metal-clad electrical resistances to contribute the necessary heat to the process
  • cooling system for example by air, or preferably with diathermic liquid control unit (for example circulating in jackets or ducts provided in the extruder walls) to rapidly remove any excess heat or heat generated by the mechanical action of the screw or mixing devices.
  • the first section comprises heating devices and the second section comprises cooling devices. Cooling devices can also be provided for the first section, and heating devices can be provided for the second section, for improved temperature control and for the management of transitory process phases such as start-up.
  • the components are fed into the extruder together, optionally premixed in an appropriate manner, by means of a turbo-mixer for example.
  • the water content of the mixture is maintained the same throughout the process, from feeding into the extruder to final extrusion.
  • the water is present in over 2% in weight, preferably at least 8% in weight, more preferably at least 12% in weight out of the total components.
  • the invention also concerns an extruder designed to perform a process according to any previous claim, comprising a first section for feeding, compression and homogenisation of the material supplied to said extruder, a second section comprising means for feeding and compression of said material and a pressure control valve positioned between the two sections, so that said valve constitutes an obligatory route for said material.
  • said valve comprises means for control of the pressure upstream, such as mobile shutters or variable width sections, for example a shutter operated by a hydraulic cylinder.
  • upstream of said valve a homogenisation area is provided in which the profile and geometry of the screw changes, for example it is replaced by a series of appropriately-shaped cams.
  • figure 1 schematically represents a device comprising an extruder suitable for performing a process according to the present invention.
  • FIG. 1 shows a possible embodiment of the process.
  • the components, preferably premixed, contained in the hopper 1, are fed to the extruder via the inlet 2, by means of the metering unit 7 (which can be a screw volumetric metering unit or a weight loss gravimetric metering unit or a metering unit, preferably adjustable, of any other type), into the first section 8 which runs from the inlet 2 to the valve 5.
  • the shaft 3, provided with screw 9, conveys the components fed to a first compression area 10 (where the pressure increase can be obtained for example by narrowing of the passage section, for example due to the increase in diameter of the shaft 3, as in figure 1).
  • the pressure is brought to an adequate value, and the mixture of components reaches the homogenisation area 4, where the shaft can be provided with appropriate homogenisation devices; for example, this screw part can be replaced by a series of cams or other systems, which provide for homogenisation of the components without generating a forward thrust. In this way, an area with uniform pressure is created with adequate stay time.
  • the pressure in this area is preferably above 20 bars.
  • appropriate heating devices such as thermal resistances positioned along the extruder casing, the temperature is brought to an adequate value to obtain the formation of a melted material with appropriate characteristics.
  • the temperature reached in this section, and in any case upstream of the valve 5, can be above 100°C; preferably it is at least 110°C.
  • the stay time in the homogenisation area, and in any case at the temperature and maximum pressure reached in the first section, is preferably above 5 s, more preferably at least 8 s.
  • the mixture flows through the valve 5, which permits control of the pressure upstream.
  • the valve 5 can be positioned on a duct 11 which can, for example, be obtained in the casing 13 of the extruder.
  • the melted material is forced to flow through the valve due to the widened section 12 of the shaft 3 which, by creating a seal with the casing 13, prevents the mixture from flowing through the aperture 14 of the extruder.
  • the mixture therefore flows to the second section 15, losing pressure (which can drop for example to values near ambient pressure).
  • the temperature in this section is at least 10°C below that of area 4; the temperatures depend, however, on the components used and on other process requirements. For example, in particular if the components do not include synthetic thermoplastic resins, it is preferable to maintain the temperature in the second section at values not exceeding 100°C.
  • the removal of heat from the second section occurs without substantial evaporation of water from the mixture. Heat removal can occur through the walls, for example by means of a cooling fluid fed into ducts present on the casing 13 or obtained in it.
  • a compression area 16 similar to the area 10 of the first section, can be present in the second section. In this way the mixture can be pushed through the appropriately-shaped extrusion die 6 to produce semi-finished products such as sheets, tubes or other continuous profiles, or to produce finished pieces by direct moulding or to produce intermediate products such as granules or cubes by cutting.
  • the extruder can be provided with single or twin screw. In particular in the latter case it is possible to feed the components at several different points of the first section. According to a preferred aspect of the invention, the components are fed all together, as has been seen, at one single inlet point, after premixing them, in order to simplify the process.
  • the starch is the basic component of the mixture and can be introduced in the refined and pure form, but products can also be obtained with good physical- mechanical characteristics and at lower cost by using, for example, wholemeal cereals and flours that contain high percentages of starch.
  • materials that can be used are: starches and flours in general, wheat flour (soft or hard), maize flour, rice flour and in general wheat gluten, micronised whole wheat, micronised whole maize, bread (for example bread-making scraps), micronised soft wheat bran (milling scraps) and others.
  • the starch-based materials can preferably constitute 60-85% in weight (alone or as a mixture) of the component mixture, plus other materials of natural origin.
  • Plasticizers can be present, preferably of pharmaceutical or alimentary class; preferred plasticizers are polyhydric alcohols in general, glycerol, sorbitol, propylene glycol, polyethylene glycol, esters of fatty acids and others.
  • the plasticizers can preferably constitute 1-35% in weight (alone or as a mixture) of the component mixture.
  • structure or process additives can be introduced or technological auxiliaries such as zinc or calcium stearate, waxes, stearic acid and derivatives, paraffin, colourings, fragrances, aromas, preservatives (such as citric acid, potassium sorbate, isobutyl vanillate.)
  • common percentages for these components are usually 0.1-5%.
  • synthetic resins are not present, however special applications can be envisaged where the same are required. Examples of synthetic resins that can be used are: polyvinyl alcohol, polyvinyl acetate, carboxymethyl cellulose, polyethylene, ethylene/acrylic acid polymers, polylactate and others.

Abstract

L'invention concerne un procédé de production ou de traitement de matières thermoplastiques à base d'amidon. Ce procédé consiste à céder de l'amidon, de l'eau et tout autre composant, comme des plastifiants, par exemple, des alcools polyhydriques, à une première section d'une extrudeuse à vis; à comprimer et homogénéiser le matériau tout en formant un mélange en fusion dans cette première section; à comprimer le mélange dans une deuxième section d'un extrudeur à vis et à l'extruder par une filière de forme appropriée. Ce procédé comprend le passage de ce matériau par une valve de commande de pression située entre cette première et cette deuxième section.
EP04766150A 2003-07-18 2004-07-07 Procede de production de matieres thermoplastiques a base d'amidon Withdrawn EP1651421A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT001472A ITMI20031472A1 (it) 2003-07-18 2003-07-18 Processo di produzione di materiali termoplastici a base di amido
PCT/EP2004/051393 WO2005011956A2 (fr) 2003-07-18 2004-07-07 Procede de production de matieres thermoplastiques a base d'amidon

Publications (1)

Publication Number Publication Date
EP1651421A2 true EP1651421A2 (fr) 2006-05-03

Family

ID=34113429

Family Applications (1)

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TW200826696A (en) 2006-12-13 2008-06-16 Wistron Corp Digital signal processing system and complex signal connector thereof
EP2226309A1 (fr) 2009-03-04 2010-09-08 Daniela Sternini Composition agricole
US9327438B2 (en) * 2011-12-20 2016-05-03 Kimberly-Clark Worldwide, Inc. Method for forming a thermoplastic composition that contains a plasticized starch polymer
US9718258B2 (en) 2011-12-20 2017-08-01 Kimberly-Clark Worldwide, Inc. Multi-layered film containing a biopolymer

Family Cites Families (4)

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DE3744193C1 (de) * 1987-12-24 1989-01-26 Berstorff Gmbh Masch Hermann Verfahren und Extruder zum Entgasen thermoplastischer Kunststoffschmelzen ueber einen weiten Viskositaetsbereich
US5851634A (en) * 1992-08-11 1998-12-22 E. Khashoggi Industries Hinges for highly inorganically filled composite materials
JP3217152B2 (ja) * 1992-10-02 2001-10-09 積水化学工業株式会社 ベント押出機
AU2002316850B8 (en) * 2001-05-30 2006-11-23 Evonik Rohm Gmbh Method and device for regulating pressure in a single-screw degassing extruder or in a cascade extruder

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* Cited by examiner, † Cited by third party
Title
See references of WO2005011956A2 *

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WO2005011956A2 (fr) 2005-02-10
ITMI20031472A1 (it) 2005-01-19

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