Materials New PLA Resin
Materials New PLA Resin The application of PLA has been limited due to its disadvantageous properties such as brittleness, low heat resistance and impact strength, and slow crystallization rate. This is now a thing of the past as SK Chemicals, the leading polyester company from Korea, has launched new PLA products, EcoPlaN-FLEX and EcoPlaN-DURA. EcoPlaN-FLEX is 100% bio-based PLA resin developed for packaging films, sheets and injection molding applications with highly enhanced flexibility (Young’s modulus of about 2500 MPa) and crystallization rate while maintaining high transmittance of 95%. Films and sheets made of EcoPlaN-FLEX are remarkably ‘quiet’ and show much better anti-wrinkle resistance. When used for injection molding applications, EcoPlaN-FLEX offers highly reduced molding cycle time. EcoPlaN-DURA has much improved crystallization rate and resistance against heat and mechanical impact, and attracts great attention for injection molding application including cosmetic containers, mobile phone housings and tableware. EcoPlaN-DURA has several grades of products with various bio-contents, heat distortion temperature up to 150°C (HDT B at 0.45 MPa) and Izod impact strength up to 800J/m. SK Chemicals has started working with several world leading manufacturers to commercialize EcoPlaN- FLEX and EcoPlaN-DURA and welcomes new partners to cooperate. MT www.sk.com 24 bioplastics MAGAZINE [05/11] Vol. 6
Materials High-Heat, Impact-Resistant PLA New technology from Teknor Apex, Pawtucket, Rhode Island, USA, eliminates a property tradeoff that has prevented polylactic acid (PLA) from serving as a ‘green’ alternative to polystyrene (PS) and polypropylene (PP) in high-heat thermoformed sheet for microwavable frozen food trays, lids for hot beverage cups, and carry-out containers such as those for restaurant food, the company announced today. New Terraloy ® BP-39070 series enhanced-PLA compounds for extrusion and thermoforming have a bio-based content level of around 90% and are biodegradable, making them an effective alternative to petrochemical-based resins in applications where sustainability and compostability are critical considerations. They meet FDA requirement for food-contact applications. Teknor Apex expects the new compounds to meet ASTM specification D-6400 and qualify for Biodegradable Products Institute certification for composting, according to Edwin Tam, manager of new strategic initiatives for the Bioplastics Division of Teknor Apex. Terraloy BP-39070 compounds are based on innovations by Teknor Apex that have overcome an inverse relationship in standard PLA between heat distortion temperature (HDT) and Izod impact strength. The new products exhibit up to two times the HDT and more than four times the impact strength of standard PLA resins. Previous work to enhance PLA performance beyond standard levels had generated resins with either higher HDT or greater impact strength—but not both in the same grade The formulations on which the new compounds are based differ from those of Terraloy enhanced-PLA products recently introduced for injection molding. “Teknor Apex has optimized Terraloy BP-39070 for extrusion and thermoforming, building in greater melt strength than is available with standard PLA and providing for a faster crystallization rate,” Tam said. “As a result, we expect users of these compounds to achieve higher throughputs in extrusion and benefit from a broader processing window in thermoforming than standard PLA.” In microwavable carry-out containers such as those used for leftover restaurant foods, Terraloy BP-39070 compounds would replace pulped fiber as well as polypropylene. As a replacement for PS in lids for hot beverage containers such as those for coffee, the compounds would be used with cups that typically are themselves compostable. In property tests, a typical grade in the new series, Terraloy 39070A, exhibits HDT B of 100 ºC and Izod impact strength of 69 J/m. By comparison, approximate values for standard extrusion-grade PLA are 55 ºC and 16 J/m. www.teknorapex.com bioplastics MAGAZINE [05/11] Vol. 6 25
