Development and Analysis of an In-Mold Coating Procedure for Thermoplastic Resin Transfer Molding to Produce PA6 Composites with a Multifunctional Surface

Abstract

We have developed a complex Thermoplastic Resin Transfer Molding procedure to create polyamide 6 composites and their multifunctional coatings in a single production cycle with low cycle time. The advantage of the new process is that it has low emission of volatile organic compounds due to the closed mold and the products can be recycled easily, decreasing the negative impact on the environment. In addition to developing the process steps and parameters, we produced samples with different curing time and fabric content of the base layer, waiting time before coating injection, surface thickness and titanium dioxide content of the surface layer. Then we analyzed the adhesion between the surface and base layers and the warpage of the complex part. SEM analysis proved that the reinforcement fabrics could be properly impregnated with the reactive thermoplastic system during the production of the base layer. Furthermore, we showed that the strength of the interlayer bonding can be improved when the base layer is properly polymerized in the first step. Using our method developed to assess warpage, we demonstrated that the warpage of the base layer can be reduced by applying the appropriate manufacturing parameters to the surface layer.

Modifying the properties of polyamide 6 with high‐performance environmentally friendly nano‐ and microsized reinforcing materials

“…where l is lamellar thickness, σ e ¼ 5:7 Â 10 4 J=m 2 is the surface free energy of the crystallite, ΔH m ¼ 241 J=g is the enthalpy of crystal melting, ρ c ¼ 1:230 g=m 3 is the density of the crystallite, T m,∞ ¼ 533 K is the theoretical melting point of an infinitely large crystallite and T m is the melting peak from the measured DSC curve. [23][24][25] The properties of PA6 used as a matrix are highly dependent on moisture content and the temperature of the material.…”

“…The latter, particularly in the automotive industry, has implications for reducing emissions during end-use-indirectly through weight reduction-and reducing the technological steps and resource requirements of producing finished products and their raw materials. [1][2][3] Polymer composites have excellent mechanical properties compared to their weight. Glass and carbon fibers are the most common fibrous reinforcement materials for composites.…”

“…With these principles in mind, the plastics industry strives to reduce its ecological footprint by reducing the environmental impact of production, recycling post‐production waste, and choosing the materials of finished products. The latter, particularly in the automotive industry, has implications for reducing emissions during end‐use—indirectly through weight reduction—and reducing the technological steps and resource requirements of producing finished products and their raw materials 1–3 …”