Flint Buchanan wrote:
is the bond between the materials a
mechanical bond-ie keys, is it addhesive/chemical, or a combination of
both?
The bond between polymers can either be mechanical or chemical (if the correct
polymers are chosen).
Here is a description of different types of "comolding" from my experience and
the bonds that can be achieved:
Comolding: involves two polymers being injected or extruded at the same time
during the process. The easiest example of this is blow molded plastic oil
containers that have a clear side that allows the user to see the volume of
liquid inside the container. During this process both a clear polymer and and
opaque polymer are extruded in the same parison prior to the parison being
closed and part being blow molded. This process is also being done in the
injection molding process. (chemical bond)
Insert Molding: Involves injection molding a rigid polymer being molded in a
separate mold. After the component has been molded in one tool it is inserted
into a different mold to have a polymer with different characteristics molded
around this part. (mechanical bond)
Dual Shot Molding: Is a high tech version of insert molding where the
component
with two different materials (i.e. toothbrush) is molded in the same tool and
press. After the rigid part is shot, the mold is rotated automatically in the
press and the softer material is shot around the first. (either bond depending
on polymers chosen)
Regards,
Jamie Ledin
President
Conceptual Engineering LLC
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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