The first step to producing a quality item by plastic extrusion is choosing the right raw material. Even with the same mold, line and process, the chosen material directly shapes mechanical strength, flexibility, dimensional stability and service life.
A successful profile is the result of both the right mold and the material best suited to the application. Selection must consider environment, mechanical loads, temperature swings, chemical exposure and end use — not price alone.
Why Material Selection Matters
The wrong material can cause premature stiffening, cracking, dimensional drift, sealing loss, color fade and rising production cost. The right material extends service life, lowers maintenance and delivers reliable performance.
Key Selection Factors
Every application has different operating conditions. The following criteria should be evaluated together.
Use Environment
Indoor or outdoor? Constant sun exposure? Contact with rain, moisture or seawater? For outdoor applications, materials with high UV resistance should be preferred.
Temperature Range
Each material has a defined working range. Wrong choices in high-temperature settings cause deformation; some materials stiffen or lose elasticity at low temperatures.
Mechanical Movement
Is the profile continuously flexed, part of a moving system, or under compression? Sustained-movement systems demand highly elastic materials.
Chemical Resistance
Some industrial applications contact oil, cleaning agents, acids or alkalis — materials with strong chemical resistance should be chosen.
UV and Weather Resistance
Outdoors, sunlight, ozone and weather directly shape performance. UV-stabilised or weather-resistant materials deliver long life.
Correct Hardness (Shore)
Hardness is as important as the base material. The same polymer can be produced at different Shore values. The wrong hardness causes assembly difficulty, insufficient sealing, excess deformation, and shorter life. Shore should be selected together with the product design.
Cost Alone Is Not the Right Criterion
The lowest-cost material is not always the most economical. Wrong choices lead to more maintenance, shorter life, production loss, customer complaints and warranty cost. Over time, the right material significantly reduces total cost of ownership.
Evaluate Material and Mold Together
Changing only the material in an extrusion project does not always yield the right result. Mold design, wall thickness, cooling, line speed and draw settings also shape performance. Success comes from evaluating the entire process together.
Material by Application (Examples)
- Lightbox systems: high UV resistance, flexibility, color stability
- Automatic shutter systems: wear resistance, tolerance for continuous movement, low deformation
- Inflatable boat seals: seawater resistance, UV resistance, adhesive compatibility, flexibility
- Fire door profiles: high-temperature performance, standards-compliant material, sustained mechanical durability
Common Mistakes
- Selecting only on price
- Ignoring the application conditions
- Not evaluating mold and material together
- Assuming a material behaves identically across every application
- Starting production without technical consultation
Conclusion
Quality and longevity in extrusion begin with the right raw material. The right choice is not just picking a polymer — it requires evaluating environment, mechanical loads, profile design and production parameters together. The best results come from combining the right material, the right mold and the right production technology.
CNR SEAL Expert View
Every extrusion profile has different operating conditions. Rather than a one-material approach, analysing the project's needs technically and choosing the right material is critical for long-term performance.
Alongside standard products, on custom projects developed from drawings or samples we evaluate material selection, profile design and production coordination together — and develop the most suitable technical solution for the application.