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Joining Dissimilar Plastics – EWI Moves to the Next Level

April 21, 2021

Welding of dissimilar polymers is becoming more commonplace in manufacturing. There are several key reasons for this trend.  First, many new plastics are being used in environments where adhesives cannot be easily applied. Typical examples include medical products for which finding adhesives that pass FDA regulations and join materials with low surface energy (like polyolefins) is very challenging. 

Dissimilar polymers are also joined in many highly engineered applications which require unique and often expensive materials for their very specific engineered properties.  Often, a more costly material needs to be joined to a less expensive material in an area of the assembly which does not require the same specialized properties. 

A third factor – as more products are miniaturized across industrial sectors – is the need to save space in very small or compact assemblies.  Even a thin layer of adhesive can be a significant barrier to performance for some products, such as small electronics.  Lastly, an assembly may require the joining of components that must be manufactured via different processes, such as joining an injection molded frame to an extruded bag.  Due to the different plastics production processes used, the two parts can have very different thermal properties, even if they are the same type of polymer.

System concept to allow IR and hot plate
welding of two dissimilar plastic materials.

At EWI, we’ve seen an influx of the above types of applications.  To provide better service to our customers, EWI is building a system which will allow heating of two parts to different temperatures using either infrared (IR) or hot plate heating to attempt to match viscosity during welding.  We expect this equipment to be ready to support new research and development work in the late summer.

To learn more about this project, contact Miranda Marcus at [email protected].

Miranda Marcus will present this system at EWI’s upcoming Member Day on May 11, 2021. Click here for details.