A lightweight and transparent plastic material with the mechanical strength of aluminum could be an ideal replacement for traditional and polymeric glass in automotive glazing, buildings and other applications. These properties were realized in a high-density polyethylene film by controlling process parameters during hot A lightweight, transparent plastic material with the mechanical strength of aluminum could be an ideal replacement for traditional and polymeric glass in many applications. Source: University of Warwickdrawing of polymer sheets.

Researchers from Queen Mary University of London, University of Warwick (U.K.), Nanoforce Technology Ltd (U.K.) and Eindhoven University of Technology (the Netherlands) tuned the drawing temperature during synthesis to yield highly oriented polyethylene films with a transmittance of about 90%. The transparent films possess a maximum Young's modulus of 27 GPa and a maximum tensile strength of 800 MPa along the drawing direction, both of which are more than 10 times higher than those of polycarbonate and poly(methyl methacrylate). These values also exceed those for aluminum while the film’s density, documented at 1000 kg/m³, is considerably lower than that of the metal (2700 kg/m³) or glass (2500 kg/m³).

Drawing in this context involves pulling the material under tension, generally at an elevated temperature to allow the molecules to be reoriented. The technique aligns strands of polymer molecules within the sheet and enhances the material’s mechanical properties. Drawing the polymer sheets at temperatures between 90° and 110° C afforded an optimal balance between strength and transparency.