Why Using Low Pressure Injection Molding, Comparing To High Pressure Injection Molding

Developed in 1970’s, low pressure molding (LPM) was introduced to solve the protection problem found in automotive industry.  Electronic components are wildly found in more sectors nowadays than ever. The sector includes the industrial, military, medical, electronic vehicle, outdoor electronic, lighting, and consumer sectors. It achieves exceptional protection and insulation of mechanical and electrical components in higher productivity. 

Its materials, polyamide, and polyolefin, are reusable that the material can be melted again and again.  

Here are the differences between low- and high-pressure molding (HPM). 


What is the meaning of the above figures? In general speaking, the low pressure molding technology does not stress a delicate electronic components or solder joint components on PCB.  Overmolded and sealed by low pressure, it gives environmental protection from EMI, humidity, dust, vibration, and temperature.  The relatively low injection temperature has less impact on sensitive electronic components. 

Additionally, both steel and aluminum can be applied as the tooling material of LPM. It offers more cost effective on the tooling and flexibility on the choosing of material than high pressure molding or traditional injection molding. 

The high pressure from traditional molding may damage or impact sensitive electronic components. Yet,  it benefits on faster cycle time that its productivity is more efficient. It fits the products for high volume and with not sensitive parts.  

The epoxy potting will give longer cycle time.  We’ll discuss it in next article then. 



Custom cable solutions and electronic mechanical design for harsh environments would utilize LPM to encapsulate the sensitive components. It gives a better protection for the components to withstand the impact from the harsh environment.