Bio-based engineering plastics for low voltage applications

We recognize the increased availability of environmentally friendly thermoplastics on the market today. Besides pure bio-based materials like Poly(lactic acid) (PLA) and Polyethylene (PE), there are also engineering plastics available which are partially derived from renewable resources. For example many Polyamide grades can be found that are partially based on castor oil. The use renewable resources is believed to lower the carbon footprint of these materials compared to their crude oil based counterparts. As a result the use of bio-based engineering plastics can help us to obtain sustainable growth. We have investigated the performance of two bio-based Polyamides, both compounds contain 30 wt% glass fibres and halogen free flame retardant. The first material was a PA 4.10, where 49% of the resin was bio-based. The second compound was a PA 6.10, with 31% renewable content. Housings for a low voltage DIN-Rail product was produced by injection moulding. The selected product was a Residual Current Operated Circuit-Breaker (RCBO) with over current protection. The assembled prototypes were tested according to IEC-Standards. As reference a standard glass fibre filled PA 6 material was used. The bio-based compounds showed outstanding results. For example the moisture absorption of the two grades was at least 50 % lower compared to the standard PA 6. Both materials also reached a CTI value of 600V and passed the glow wire test at 960°C. The prototypes containing the bio-based compounds passed the required type testing, which indicates that there is no problem using engineering thermoplastics that are partially based on renewable resources in low voltage applications.