Inexco - Foam Extrusion
Challenges in Foam Extrusion
In foam extrusion, the blowing-agent-loaded polymer melt must be brought to the correct thermal condition before expansion. It is not only the average melt temperature that matters, but also achieving a uniform temperature profile across the melt stream.
As throughput increases, the demands on both melt homogenization and heat removal increase as well. Thermal conditioning therefore becomes a critical part of overall process control, helping to establish the melt conditions required for stable expansion, consistent cell structure, and uniform product quality
CMX Approach
The CMX combines intensive melt redistribution with active heat removal. The polymer melt is continuously split, redistributed, and recombined while heat is transferred from the melt through temperature-controlled surfaces.
This integrates melt homogenization and cooling into a single compact process stage, creating controlled thermal conditions before the melt enters the expansion stage.
Key Benefits
- Intensive thermal homogenization of the melt
- Active heat removal directly from the polymer melt
- Controlled melt conditioning prior to expansion
- Compact combined mixing and cooling stage
- Modular configuration for different process requirements
- Application-specific design based on polymer, blowing-agent system, and throughput
Mixing and cooling in one system – for precise melt conditioning before expansion.
Foam Products for Different Process Requirements
Whether the objective is uniform sheet density, consistent film thickness, dimensional accuracy in profiles, or defined properties in technical foams, each product requires specific melt conditions before expansion.
The CMX combines active melt cooling with intensive homogenization, allowing the thermal condition of the melt to be matched more precisely to the product, polymer, blowing-agent system, and target throughput.
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More uniform density, consistent cell structure, and improved dimensional stability.
Foam sheet production requires the blowing-agent-loaded melt to enter the die within a controlled and uniform temperature range. Temperature variations across the melt stream can affect expansion behavior and ultimately sheet quality.
The CMX actively removes heat while homogenizing the melt, helping to establish uniform thermal conditions across the melt stream. This supports stable expansion and consistent sheet properties, particularly at higher extrusion rates. -
More consistent film thickness and stable, repeatable expansion.
In thin foam film extrusion, even small variations in melt temperature and homogeneity can affect expansion behavior, thickness distribution, and overall film quality.
The CMX continuously redistributes and cools the melt upstream of the annular die, helping to provide a more uniform temperature profile at the die inlet and more consistent conditions for controlled expansion. -
Improved dimensional stability and more uniform expansion across complex profile geometries.
Local variations in melt temperature can influence expansion, profile dimensions, and cell structure – particularly in complex cross-sections.
By homogenizing and thermally conditioning the melt upstream of the profile die, the CMX provides more consistent die inlet conditions and helps maintain a stable processing window across different polymers, profile geometries, and extrusion rates. -
More precise control of density, cell structure, and mechanical properties.
Technical foam products often require tightly controlled and repeatable material properties. Consistent melt conditions before expansion are therefore critical to achieving the required product performance.
The CMX provides an application-specific combination of melt homogenization and active cooling. Cooling capacity, mixing configuration, and system geometry can be engineered around the polymer, blowing-agent system, throughput, and required foam properties.
Potential for Higher Throughput
As throughput increases, additional viscous heat generation can push the melt outside the optimum temperature range for controlled foaming. The CMX removes part of this additional thermal load, helping to maintain the required melt conditions before expansion.
Depending on the polymer, blowing-agent system, available pressure margin, die design, and cooling capacity, this can provide additional process headroom for higher throughput while maintaining stable expansion and consistent foam quality