The 29th annual meeting of the Association
of Rotational Molders had an interesting presentation
on Rotomolding of nylon 6 parts directly from
caprolactam monomer. Centro Inc. a well-known
roto moulder presented a process that polymerizes
liquid caprolactam in the mold. Called Rotomoulded
Anionic Polymerization, or RAP, the process
is claimed to offer cost savings relative to
using standard nylon 6 resin. Centro developed
the process with several other European companies.
RAP has been used in Europe for several years
to make fuel tanks, but Centro worked with several
US and European companies (which it declined
to name) to improve the safety and productivity
of the process.
In the RAP process, a robot dispenses liquid
caprolactam along with a catalyst as well as
an activator into a heated aluminum mold, which
is then rotated while the mixture reacts to
produce a virgin nylon 6 part. The process is
said to be faster than molding with nylon 6
and reportedly makes superior parts free of
surface porosity. In addition, RAP makes it
easy to customize formulations with pigments,
impact modifiers and UV stabilizers, plasticizers,
etc.
Centro is not currently offering to license
it, but only to use RAP to make parts in house. |