Thermoplastic polymer composites with a special focus on high functional integration,
complexity and recyclability of the parts
Evopro’s R&D programme focuses on high-speed, automated composite production for automotive applications. The company extensively developed the T- RTM technology to produce structural composite parts based on a PA6 matrix. The goal was to use T- RTM with in-situ polymerization of E-caprolactam, supported by fully-automated preforming, according to Industry 4.0 principles.
The technology is known already with the application of overmoulding/back injection (with injection moulding) and some results were published in the past years and presented at JEC World as well. Furthermore, Evopro made significant steps in the frame of their programme to create fully-homogeneous, PA6 shell, core-based sandwich structures (for improved mechanical properties and recyclability) and to apply PA6 in-mould coating to create a near Class A surface on the product.
Sandwich structures are very important for the high dimensional stiffness of low-density composite parts. Usually, closed-cell-structured foams such as PES, PET, PVC or PU foams, balsa wood and honeycombs are used as core materials.
The application of these core materials would rise difficulties in the recycling of PA6-based composites. With this solution, PA6 foam cores can be used for PA6-based composites to create homogeneous sandwich structures for optimal recyclability, which is a key factor for automotive applications.
> Recyclable, homogeneous PA6 composite structural sandwiches for high stiffness
> Recyclable, homogeneous PA6-coated composite for a near Class A surface
> Automated, fast production with Industry 4.0 manufacturing
> Higher level of functional integration of the composite parts
> Up to 20% reduction of manufacturing cost of structural composites
The surface quality of continuous fibre-reinforced thermoplastic composites does not allow their application on visible surfaces because of the polymer shrinkage and fibre read-through. In-mould technology is a known solution in the case of SMC, for example, and other processes based on thermoset materials, but the application of a thermoset coating does not allow the recycling of PA6 composite parts due to the inhomogeneous material complex. With Evopro’s process, a PA6-based surface coating can be created on PA6-based composite parts with in-mould coating. This process allows the use of different fillers, pigments and additives.
What is the value created by the use of composite materials in this innovation?
The most important benefit is that the process creates cost efficiently recyclable composites, what is the basic requirement of the automotive sector. This new developments allow to create structural composites with higher grade of functional integration, like higher structural stiffness (because of sandwich), metallic inserts, weldable and visible surface (because of in-mold coating.), etc. Based on these features, beside of the general weight reduction, the assembly and painting time of the composite parts can be reduced, as well.
Industries: Automotive and Road Transportation