Polymeric Composites with Rice Hulls for Extrusion - Introduction to Polymeric Composites with Rice Hulls - page 125

planning may include the use of different polymer matrices. It is best to work closely
with a selected machinery supplier who will recommend a system with maximum
potential and also supply technological guidance backed up by his/her in-house
laboratories. In the extrusion of PCRH profiles, screw designs need special attention
because the composite mixture will contain silica, which is an abrasive component.
The lifespans of screws used in PCRH extrusions will probably be different to standard
ones. In a project of this nature, a manufacturer must pay attention to an effective
lay-out plan, especially of the complete in-line system is to be installed. Other areas
that need thought are heating, water, air, power, ventilation, and safety factor.
WPC/PCRH extrusion systems have different output rates depending on the extruder
type and system selected. This factor will also depend largely on the end products to
be manufactured and planned volumes of production.
Manufacture of PCRH products can be carried out in two stages (compounding,
pelletising and extrusion thereafter of these pellets) or in one operation (compounding
and direct feeding into the extrusion system). Figure 10.1 shows the first stage of a
process flow of producing pellets. Figure 10.2 shows an extrusion system for producing
profiles for outdoor applications.
Figure 10.1 Process flow of production of PCRH pellets. Reproduced with
permission from Wuhan Industries Ltd., China. ©Wuhan Industries Ltd.