, transfer molding
and injection molding
are common molding
ways for silicone rubbers.
In 1976, Union Carbide filed for a patent on a new "web" molding
process that injected gas to hollow out substantially all of a part and leave only a random pattern of supporting ribs between two skins.
Figure 1 follows the cavity pressure profile over time during the molding
In the same molding
cycle, five fixtures for swiveling ducts are also molded in.
By comparison, the overall injection molding
business will grow only around 4% a year.
About 70% of those in the field are SB series suction blow molding
(SBM) units that use directed air to guide parisons into a segmented mold cavity before blowing.
He says there is a general perception that gas-assist molding
is mainly applicable to large or thick-section parts.
The most common method of molding
polypropylene reinforced with long-glass fiber is to use precompounded 0.
evolved over the last decade to include more specialized and sophisticated parts, it also became subject to increasingly stringent manufacturing requirements for cost, quality, productivity, and speed.
A collection of several different techniques, multi-component molding
offers the ability to combine different materials or colors in a single one-shot or multi-shot process.
You'll also have the opportunity to view in person recently introduced machines (previously reported in this magazine) for multi-component molding
, liquid silicone rubber, and low-pressure molding
It helps the tool designer verify that the chosen processing window, polymer, gate positions, and part geometry will give desired molding
Polarite 490FW and 494FB are calcium carbonate-based, low-profile additives that reportedly provide zero-shrink moldings
While he cites no specific research program or OEM partnership, McGill says applications development at the Center will concentrate on complex-geometry, under-hood tubular parts, manifolds, bumpers, side moldings
, and fuel-intake pipes.
This can have the added virtue of virtually "erasing" the weak weld lines that can plague LCP moldings