Method of producing composite materials

• US 20120090759A1
• Filed: 03/11/2010
• Published: 04/19/2012
• Est. Priority Date: 03/11/2009
• Status: Abandoned Application

• Current Assignee: Onbone Oy, Co.
• Original Assignee: Onbone Oy, Co.
• Inventors: Pärssinen, Antti, Lahtinen, Petro
• Application Number:
  US13/255,942
• Publication Number:
  US 20120090759A1
• Time in Patent Office: Days
• US Class Current: 156/62.8
• CPC Class Codes: A43B 17/003 characterised by the material made of wood A43B17/12, made of sponge, rubber or plastic materials A43B17/14
• CPC Class Codes: A61F 5/058 Splints
• CPC Class Codes: A61F 5/14 Special medical insertions for shoes for flat-feet, club-feet or the like
• CPC Class Codes: A61L 15/12 containing macromolecular materials
• CPC Class Codes: A61L 15/125 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 15/14 Use of materials characterised by their function or physical properties
• CPC Class Codes: A63B 2071/1258 for the shin, e.g. shin guards
• CPC Class Codes: A63B 2209/18 biodegradable
• CPC Class Codes: C08L 2201/06 Biodegradable
• CPC Class Codes: C08L 2203/02 for biomedical use
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component

Abstract

The invention relates to a method for making light-weight dimensionally stable wood-thermoplastic composite material composed of wood chips and a thermoplastic polycaprolactone. The manufacturing process of composite material comprising the steps of compounding virgin materials with single-screw extruder and production of uniform homogeneous plate-like composite with calendering apparatus. The calendering process comprises of several cycles, folding, cooling and reheating steps. During the gentle manufacturing process fragile wood chips maintain their 3-D structural properties in polymer matrix resulting light, mechanically strong wood-plastic composite.

Claims

18. A method of producing a biodegradable linear composite material capable of being used to form an exo-skeletal device through thermal molding, the method comprising the steps of;

obtaining a desired woody particle mixture, the majority of the woody particles making up the mixture being greater in size than powder,

forming a first component comprising biodegradable polymer pellets,

forming a second component comprising the woody particle mixture,

mixing the first and second component into a single homogeneous mixture, and

forming a linear composite material having a desired shape by heating the single homogeneous mixture and forming it as desired such that woody particles contained in the homogeneous mixture are not substantially degraded.

1. A method of producing a composite useful as an orthopedic material, comprising the steps of;

mixing together a first component formed by a polymer,

a second component formed by a reinforcing material,

mixing a thermoplastic polymer selected from the group of biodegradable polymers and mixtures thereof with a reinforcing material selected from woody materials in the form of platy and granular wood particles, and

carrying out the mixing as melt mixing in an apparatus for melt processing of polymers.

2. The method according to claim 1, wherein 30 to 99 parts by weight of a thermoplastic polymer is mixed together with 1 to 70 parts by weight of reinforcing particles.

3. The method according to claim 1, wherein the mixing is carried out at a temperature of approximately 50 to 190°

C. in order to achieve conditions of melt-mixing in the apparatus.

4. The method according to claim 1, wherein the thermoplastic polymer is selected from the group of epsilon-caprolactone homopolymers, blends of epsilon-caprolactone homopolymers and other biodegradable thermoplastic homopolymers, and copolymers of epsilon-caprolactone homopolymer and any thermoplastic biodegrable polymer.

5. The method according to claim 1, wherein the thermoplastic polymer has an average molecular weight of 60,000 to 500,000 g/mol.

6. The method according to claim 1, wherein the wood particles are orientated and aligned in a melt flow of the thermoplastic polymer before the reinforced material is shaped into an orthopedic material.

7. The method according to claim 1, wherein

the mixing comprises compounding the thermoplastic polymer with the woody material in a melt mixing apparatus to produce a compounded melt mixture,

providing an extrudate of the melt mixture by pultrusion of pulling-out through a mould or nozzle, and

optionally shaping the extrudate into the form of a plate or a sheet.

8. The method according to claim 1, wherein the mixture of the thermoplastic polymer and the woody material is compounded in a mixing apparatus under non-crushing conditions, said mixing apparatus being selected from extruders and kneaders capable of processing polymers in melt phase.

9. The method according to claim 1, wherein virgin materials are compounded in a melt mixing apparatus and shaped into a plate-like composite with calendering apparatus.

10. The method according to claim 1, wherein the melt mixing is carried out in an extruder and the calendering process comprises several cycles of folding, cooling and reheating steps.

11. The method according to claim 1, wherein the wood particles comprise chips of hardwood, softwood or a combination thereof.

12. The method according to claim 1, further comprising producing a continuous product, collecting the product and rolling it or folding it.

13. The method according to claim 1, further comprising the steps of producing a linear product and combining at least two linear products into a laminate.

14. The method according to claim 12, further comprising the steps of providing on said laminate at least one surface layer having a reduced content of woody material.

15. The method according to claim 1, further comprising mixing the thermoplastic polymer with a first woody material and at least one second woody material, said second woody material being different from the first woody material.

16. The method according to claim 1, further comprising the steps of producing an essentially linear product and perforating said linear product.

17. The method according to claim 1, further comprising the steps of producing an essentially linear product, and mechanically modifying the linear product so as to increase its stiffness.

19. A method according to claim 18, wherein obtaining the desired woody particle mixture comprises the step of taking a woody particle feed having a plurality of sized woody particles and sorting the feed to obtain the desired woody particle mixture.

20. A method according to claim 19, wherein the step of sorting the woody particle feed comprises sifting the feed through one or more meshes.

21. A method according to claim 18, wherein more than 70% of the second component is formed by the woody particle mixture.

22. A method according to claim 18, wherein the first and second components have pellets and particles of similar size.

21-1. A method according to claim 18, wherein the desired shape is a substantially rectangular blank formed from an extruder.

22-2. A method according to claim 18, wherein the desired shape is other than a rectangular blank and is formed by optically, chemically or mechanically cutting or stamping the desired form from the composite material.

23. A composite material formed from a homogeneous mixture of a first and second compound according to the method comprising the steps of;

mixing together a first component formed by a polymer,

a second component formed by a reinforcing material,

mixing a thermoplastic polymer selected from the group of biodegradable polymers and mixtures thereof with a reinforcing material selected from woody materials in the form of platy and granular wood particles, and

carrying out the mixing as melt mixing in an apparatus for melt processing of polymers.