What is Low Pressure Molding?
Low Pressure Molding or LPM is a slight variation from conventional injection molding. As the name suggests, parts are molded at lower pressures, which allows for gentle encapsulation of delicate electronic assemblies.
Low Pressure Molding or LPM is a slight variation from conventional injection molding. As the name suggests, parts are molded at lower pressures, which allows for gentle encapsulation of delicate electronic assemblies.
The overmolding process involves loading bare, unprotected PCBs and cable assemblies into a precision crafted moldset tool, and then filling the cavity with the appropriate low pressure molding material. This effectively surrounds the component in the desired shape, producing a sealed and protected product that can be immediately handled and tested. The LPM process is ideally suited for replacing epoxy potting processes to save on cycle time and reduce material consumption.
Conventional injection molding materials require processing temperatures and pressures that would damage a printed circuit board. Low Pressure Molding (LPM) uses thermoplastic materials with very low viscosity, allowing for overmolding and encapsulation of even the most sensitive circuit board assemblies. Because the materials are natural adhesives, the process is well-suited to sealing circuitry against dirt, dust and moisture…in many cases, up to an IP-68 rating.
Moldflow simulation gives us confirmation in the correct and complete filling of the moldset cavity. By simulating different gating points and flow profiles, we can accurately assess how the material will flow through the cavity, giving us the best chance to deliver sealed, aesthetically pleasing parts the first time.
This video demonstrates a moldflow progression simulation, showing how material flows through a mold during the injection or low pressure molding process. By visualizing the fill pattern step-by-step, engineers can better understand now parts are encapsulated, identify potential defects, and optimize tooling design for improved performance.
Cavist has made mistakes and will be the first to admit it. Over 20 years worth. Many during the development of the world’s leading low pressure molding machines. They key is, these mistakes have not been at the expense of any client, and we’ve gained irreplaceable knowledge and experience we’ve incorporated into our process.
From working with low pressure molding materials, to the durability and longevity of the parts they protect, the Cavist low pressure molding process is unmatched. This kind of experience just isn’t found anywhere else.
Yes. In addition to protection and sealing, low pressure molding can create a clean, finished appearance by encapsulating assemblies within a custom-molded shape.
Yes. Low pressure molding is specifically designed to protect populated PCB assemblies without exposing components to the high pressures typically associated with conventional injection molding.
Yes. Low pressure molding is often used as the first encapsulation step before a secondary overmolding process adds additional durability, aesthetics, or wear resistance.
Yes. By combining sealing, protection, and strain relief into a single manufacturing step, low pressure molding can reduce the need for secondary housings, gaskets, and additional assembly operations.
