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Manufacturing Technology Portfolio
 
Rapid Composite Manufacturing
Molds
Injection molding poses several challenges:
the cost of tool and die for mold makes design changes difficult,
the mold must be kept in good condition, large production
quantities are required to recoup cost, a mold can only produce
one part at a time, and the mold or the part being made can
be damaged in demolding. CRG has developed a tooling process
for rapidly and inexpensively manufacturing composites. This
patent pending process replaces expensive metal molds with
Veriflex®,
the registered trade name for CRG’s shape memory polymer
(SMP) resin systems.
Creating molds with SMP provides several advantages
over metal molds:
- Relatively inexpensive
- Versatile, producing a range of geometrically
different parts from one sheet
- Increased production rates
- Capability of fabricating many molds
- Prototype production possible
- Gentle demolding process
CRG's SMP system is capable of being
thermally formed into a precise negative image of a master part,
cooled, and made to retain the new shape. Veriflex functions on
thermal activation customizable from -29°C to 271°C (-20°F
to 520°F). This material can withstand the elevated temperatures
needed to cure composite parts without deformation and offers
a gentle, simple demolding process. After the composite part has
cured, the mold is raised above its glass transition temperature
(Tg), which allows it to retract to its memorized shape.
SMP tooling processes provide the opportunity to mitigate the
drawback of traditional fabrication techniques for advanced composite
parts. This tooling system also possesses versatility in size
variations, including being capable of micro (nanometers) to macro
(meters) replication.
Mandrels
An object with a diameter larger in the center
than at either end is a problematic shape for current fabrication
techniques because rigid mandrels cannot be extracted after the
composite is cured. Conventional approaches to this problem include
multipiece or water-soluble mandrels. Rigid multi-piece mandrels
are complex and labor-intensive, and water-soluble mandrels require
the disposal of hazardous or noxious waste and are costly and
time-consuming.
 CRG's
Veriflex is a fully cured, high-performance thermoset system that
is elastic above set transition temperatures. The SMP can be placed
in a clamshell mold, shaped into a complex curved mandrel, and
cooled. The SMP mandrels, trade named Smart Mandrels™, can
be filament-wound, and then heated and removed from the finished
, cured part. CRG’s patent-pending mandrel process allows
composites with problematic geometry to be easily fabricated and
the mandrels easily removed. This technology offers the filament
winding industry an improved process with relatively low-cost
and reusable material components.
Advantages to an internal thermoset mandrel system
include the following:
- Speeds up fabrication process
- Reduces cost of developing and removing
mandrels
- Offers a simple extraction process
- Allows for reusable mandrels with shape
versatility
See
Smart Mandrels
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