Materials New
Materials New transparent alloy Plexiglas Rnew alloys a new technology for the durables and semidurables market space By Carmen L. Rodriguez and Robert Barsotti Arkema Inc. Altuglas International Division Bristol, Pennsylvania, USA Plexiglas Rnew sheet offers some of the best of all worlds, display aesthetics, and ease of fabrication using renewable materials. As current commercial biopolymers prove out their long-term performance, finding sustainable substitutes for conventional petroleum-based plastics continues to gain market acceptance. A prime focus of biopolymer performance enhancement is for semi- and durable goods. Some of these advances stem from blends of conventional and renewable polymers. Recently Arkema Inc.’s Atluglas International group, presented a new family of Plexiglas ® Rnew alloys for consumer, electronics, lighting, building and construction, point of purchase, sign and displays, medical, optical, automotive, and other markets. The renewable content actually improves the processability and end-use performance of the conventional polymer. To enable its customer to identify products derived wholly or in part from renewable raw materials (over 20% carbon of non-fossil origin), Arkema has devised the ‘Arkema Rnew’ label. The evaluation of products’ renewable carbon content is carried out internally based on the ASTM D6866 standard. By combining insights into resin formulation design and the miscibility of PLA, specifically Ingeo biopolymers from NatureWorks LLC, and polymethyl methacrylate (PMMA) polymer technology from Altuglas International, the development team uncovered enhanced performance in weatherability and heat resistance versus pure polylactic acid. The resultant Rnew alloys also feature lower processing temperatures, greater melt flow, and a reduced carbon footprint relative to PMMA itself. Meanwhile, the exceptional optical properties of PMMA are only marginally compromised. The incorporation of biopolymers allows for excellent acrylic formulations with a ‘step change’ in impact strength (comparable to PETG and PC) without sacrificing modulus. Increased chemical resistance is also achieved, drastically outperforming traditional acrylics and other transparent resins. As a result, Rnew formulations can be designed to meet a wide variety of application requirements. A look at a few of these applications is useful in framing the practicality Rnew resins will have in the targeted durables and semidurables market. Signage In signs and displays, Rnew alloys retain PMMA-like qualities of transparency, formability, toughness, are easily decorated, and adhere to all commonly used plastics. Rnew sheet products cut quietly and smoothly without chatter or melting, and with less dust. The cut is clean and acceptable as a finish by itself, but, when polished, it affords a high quality finish. Rnew sheet is easily heated and formed, and application of vinyl graphics is equal to other commonly used signage substrates. Additionally, backlit signs display the beauty and color definition expected of PMMA. 32 bioplastics MAGAZINE [03/12] Vol. 7
Materials While long-term weathering testing is not complete, results after >1 year of accelerated Xenon Arc weathering suggest Rnew resins will be viable options for outdoor signage as well. Point of Purchase (POP) Rnew resins offer the versatility and flexibility needed for the most attractive POP designs and installations. The versatility in Rnew is formulated into these resins in the form of a variety of color and effects, allowing designers an attractive surface for applications like shelving, tabletops, backdrops, and fabricated visual displays. The flexibility of the Rnew resins starts with tailor made formulations that combine excellent light transmission with chemical resistance as well as impact and mechanical properties. Plexiglas Rnew sheets for POP are easily cut, thermoformed, and cemented for totally unique and sustainable applications. Consumer Goods Whether for cosmetic packaging, lighting, house wares, small and large appliances, or other items designed for visual aesthetics and clarity, injection molded Rnew resins provide high performance and a sustainable alternative, including higher impact resistance for part protection, exceptional chemical resistance for part longevity, surface properties for better lifetime aesthetics, and exceptional toughness for property retention over time. The excellent melt flow provides for a wide processing latitude. The ease of handling and processability, advantages of these alloys, translates to potential cost savings with greater throughput. Innovative colors and special effects, such as pearlescent, marbleized, granite, and even metallic, also can be achieved. Thermoformed Parts Plexiglas Rnew resin offers excellent and synergistically optimized performance and manufacturing properties that reduce fabrication time and temperatures for thermoformed parts in lighting, security, signage and additional applications. Plexiglas Rnew sheet thermoforms at low pressure, so molds can be made of low-cost materials, such as wood and plastics. These attributes allow the thermoformer the option to tool molds, at reasonable costs, for complex, low volume, custom-designed panels. Innovative colors and special effects provide the opportunity to realize aesthetically unique thermoformed parts. In addition, Altuglas International is able to utilize its experience and expertise in light management to provide choices for translucent finishes which service the lighting market, especially for energy efficient LED light fixtures. The shear thinning properties, ease of handling, and versatility open up a whole new chapter for bio-based Plexiglas Rnew alloys in injection molding applications “Rnew cuts quietly and smoothly without chatter or melting, and [with] less dust. The cut was clean and acceptable as a finish by itself, but, when polished, it affords a nice finish.” Phil Dubroff, PMDI Signs (photo: ITR Sign/Monet) Excellent detail and draw, even at lower forming temperatures. Faster set/cooling time allows for shorter forming cycles. www.plexiglas.com/Rnew bioplastics MAGAZINE [03/12] Vol. 7 33
