Mold Set used for Low Pressure Molding differs from these other types of mold used in traditional high-pressure molding. In particular, we have to take some different aspects including materials, dimensions cavity design, etc. into consideration when designing. GLUMO is confident to work as a part of your engineer team, carefully inspect each element, then design the layout and finalize to provide the customer with the most appropriate mold set.
Mold sets for low pressure molding are commonly manufactured from 7075 aluminum which is compatible with polyamide – LPM materials. Besides the negligibly wear-on feature, Aluminum is also a cost-effective material to be excellent at dissipating heat resulting in shorter cycle times. High wear-out areas where components are inserted should have steel inserts. Mold sets for very high production rates can be manufactured from P-20 material or any other conventional tool steel.
The mold set guides shall be approximately 35 mm long with 6 mm long tapered lead. Two different diameters shall be used such as 9 mm and 10 mm respectively.
3. Cavity Design
When designing a mold set, it is important to position the parting line so that the molded components stay in the lower mold half, when the mold set is opened. This may require a stepped parting line in some applications. It is often possible to avoid the use of locating pins as the low-pressure fill of the cavity is unlikely to dislocate components. When circuit boards are over-molded, these can be positioned by locating pins if necessary.
For some applications where holes from locating pins are unacceptable in the molded parts, a two-step over-mold should be considered. One side/portion of the component is over-molded first, then the other side/portion. These mold sets will have two different cavities and components are moved from the first to the second cavity for completion.