Plas Mec S.r.l.


Advanced Mixing Technology
for Wood Plastic Composites (WPC)

Plasmec, a leading company in the manufacture of mixing equipment and ancillaries for plastic industry, and thanks to the in depth cooperation of major extruder manufacturers and research institutes, has recently developed a new concept for mixing plants for processing wood natural fibres with plastics.

When using Plasmec mixing and cooling equipment, it is possible to increase the bulk density of the components, extract the moisture of the wood fibres and distribute the additives. After that a suitable twin screw extruder line can extrude the profile.
Thanks to this solution, PP/PE/PVC, wood fibres, colour pigments, UV stabilisers, flame retardants and biocides can be mixed very well in the compound.

Moisture levels of up to 10% can be removed with our very good extraction process.

The mixing process consists of feeding (either in automatic or semi-automatic mode) a batch of components.

The next step is the drying of wood fibres, mixing and agglomerating the compound in one operation with a residual moisture of less than 1%.

As a final stage agglomerates are cooled and the particle size is reduced in order to get a narrow size distribution to be suitable for storage and or conveying
Plasmec, after intensive technical research and trials in its development centre, has developed and designed two different mixing technologies and plants for the two principal types of wood plastic composites in common use.
A short description of the different characteristics and workability of these two types of plastics materials is as follows.

 Temp. up to 120 °C
 Product mixed in powder form.
 Process easy to control.
 Vacuum system is necessary.
 Heating mixer + cooling mixer (vertical or horizontal)

 Temp. up to 160-170 °C
 Product mixed agglomerate material.
 Double jacketed vessel of the mixer for cooling water circulation.
 Process control by custom software.
 Vacuum system is necessary.
 Heating mixer + air cooling system or cooling mixer and pulveriser


Heating mixer
Vertical cooling mixer
Horizontal cooling mixer

Heating mixer
Cooling system by air
Vertical cooling mixer

High Intensity Mixer for WPC
The mixer (either for PVC or PP/PE) is composed of stainless steel bowl with double jacket, variable speed motor and explosion suppressant.

Vacuum System
A vacuum system extracts the moisture out of the wood fibres. Materials with moisture contents of up to 16% can be reduced to < 1%.

Mixing Tool
Plasmec mixing tools are special type (sickle type) in stainless steel with special hard coating on the surfaces most subjected to tear and wear. A new fully automated polishing system provides an exceptional, mirror finish on tools and results in an optimal vortex and homogenisation of all the different components of the blend.

As far as the cooling system is concerned, for PVC a traditional high efficiency cooling mixer with several adaptations can be considered, while for the PP Plasmec has developed a special cooling system with horizontal fluid bed for a faster and efficient cooling of the agglomerates and in order to avoid any huge and hard lumps.
A specific “size reduction system” has been developed for the outlet of the system.
A testing unit is already available in our research room.

For companies interested in more information or for trials at Plasmec please contact: comm@plasmec.it