1. Eco-Houses Based on Eco-Friendly Polymer Composite Construction Materials
Conventional molding techniques applied for manufacturing of eco-composites
Workshop , Ohrid September 2007

2. Originally plastics were developed to replace natural materials,
Nowadays, natural materials are
developed to replace plastics

3. MOLDING TECHNIQUES WHICH WERE APPLIED IN ECO-PCCM PROJECT
1. Compression molding
CM was the major method for processing plastics during the first half of the previous century.
It is a process of applying heat and pressure to a plastic material in matched or open dies. The plastics melts due to the heat, then the pressure causes it to form into a desired shape.
This is done in a compression molding press.
This process is classified as high pressure process.
Although this technology is the main processing method used with thermoset plastics, it can also be employed to process themoplastic materials
The advantages of compression molding are short cycle time, high production rate and excellent surface finishes.

4. Materials used for CM SMC ( Sheet Molding Compounds)
BMC (Bulk Molding Compounds)
Pellets/granules

5. CM Techniques No mold technique - appropriate for SMC, prepregs
Matched die technique – appropriate for BMC, pellets

6. 1.a SMC Piston Guide No mold, single-opening press Stack of material
Supporting plate
Heated press platen

10. Blown-out press package
Hot plate
SMC layers
Press piston
Press plate
Polster
Release foil
Thermocouple

11. 2. No mold, multi-opening press MULTI-PANEL PACKAGE Release foil SMC
Stainless steel press plate

12. SMC Piston Guide Stack of material Supporting plate Press platen
MATCHED DIE
TECHNIQUE
Stack of material
Supporting plate
Press platen

13. Matched die molding SMC
Appropriate for BMC , pellets and for SMC (simple shapes only)
SMC
Open mold
Closed mold

14. Pellets
MATCHED DIE
TECHNIQUE

16. MOLDING TECHNIQUES WHICH WERE APPLIED IN ECO-PCCM PROJECT
2. Injection molding
Injection molding is a manufacturing technique for making parts from both thermoplastic and thermosetting plastic materials . Molten plastic is injected at high pressure into a mold, which is the inverse of the product's shape.
Injection molding is widely used for manufacturing a variety of parts, from the smallest component to entire body panels of cars.
Injection molding is the most common method of production, with some commonly made items including bottle caps and outdoor furniture.

17. INJECTION MOLDING PROCESS SCHEME

18. PLA

19. Injection molding
Appropriate for rather complicated and dimensional precise shapes
Kenaf / PLA molding
IM is the mostly used processing technique for PHB, PLA, PLLA plastics

20. Major differences between applied forms of materials
SMC
Pellets
Appropriate for big size panels
No molding tool is required
Multiple panels can be produced in one molding cycle
Cheaper manufacturing process
Better mechanical properties since longer fibers can be applied
Applicable only for flat and/or slightly curved shapes
Inappropriate for big size panels
Molding tool is required
One panel only per cycle
Expensive manufacturing process
Only very short fibers can be used making panels with limited mechanical properties
Better control of fiber/resin ratio
Applicable for 3D shapes

21. CONCLUSION
Biodegradable plastics can be processed as classic thermoplastics
No exclusive technology for processing is required
Typical processing techniques: IM, CM, extrusion
No limitation for processing on classic machines
Biodegradable plastics (PLA, PHB, PLLA) are polyesters obtained from renewable resources. The products are waterproof, heat resistant, have appealing surfaces, and are fully biodegradable. The pellets are processed on standard machines. The melt behaves like liquid crystalline polymers (LCP's). This property allows to mold thin walled or complex structures even on small machines.

22. THANK YOU FOR YOUR ATTENTION