Corbion Purac produces lactides from lactic acid, which are then converted to poly lactic acid (PLA), thermoplastic resin, by their partners. The company’s latest development in high heat PLA is said to withstand temperatures of up to 120°C enabling bioplastics to be used for durable applications. At the K show Corbion Purac teamed up with partners in various industries, including packaging, automotive, home interiors and sporting goods. One highlight was a PLA bioplastic touch screen computer.
Corbion Purac’s lactide monomers are sourced from GMO free, renewable feedstocks such as sugarcane, and form the basis for high performance PLA. The resulting homopolymers are already proven to withstand boiling water, and can now boast performance characteristics to rival their oil-based counterparts. As a result, PLA can replace oil-based plastics such as polypropylene (PP), polystyrene (PS) and acrylonitrile-butadiene-styrene (ABS), and thus reduce dependency on fossil fuels. “We are now able to target the ABS market as PLA can be a substitute for PS cups in food packaging,” said Robert Haan, Senior Polymer Technican at Corbion Purac, on the occasion of the K show.
Haan explained to Plastics: “The first PLA generation was able to withstand temperatures of up to 55°C. It was a standard amorphous PLA used for packaging applications. The second generation then offered a more heat resistant solution with a temperature resistance of up to 80 to 100°C required for single-use coffee cups and lids. The third generation is now used for automotive, housings and electrical components and electrical appliances, such as the PLA housing of the touch screen computer developed by resin supplier Supla and OEM Kuender”.
Supla has developed optimised PLA compounds for the consumer electronics industry based on lactides from Corbion Purac. The launch application is the bioplastic touch screen computer, developed in cooperation with Kuender, a Taiwanese OEM/ODM for many brand customers. The high gloss housing of this computer is made from high heat PLA.
Haan continued: “Supla has been working with PLA for many years. But now the building blocks of the lactide have enabled PLA to overcome some limitations: it is able to resist temperatures of up to 120°C, it is stiffer and more impact modified”.
In addition to increased heat resistance, the PLA blends used for the monitor screens are said to also bring improved impact resistance, good high gloss finish and stable, precise processing. This is of critical importance for the large scale consumer electronics market, which also includes applications such as mobile phones, laptops, games consoles and tablets.
In the automotive sector, Corbion Purac displayed an air filter box and interior trim parts. These parts have been produced using high heat PLA compounds, based on lactides from Corbion Purac, under the name of Plantura. Plantura is a material family based on PLA, suitable for automotive applications as well as for durable goods. These materials are said to show improved hydrolysis and thermal resistance up to 140°C with fibre reinforcement as well as a good scratch and UV resistance.
Together with Desso, Bonar, Peter Holland and Synbra, Corbion Purac is working to develop a fully biobased, recyclable, Cradle to Cradle carpet tile. Features of the new type of carpet are the use of clean and healthy materials and the limited burden on the environment, since renewable materials can be recycled. Together, the companies have successfully produced a number of prototype carpet tiles.
Corbion Purac together with Innovia Films, a global manufacturer of biofilms, have developed a high heat resistant, transparent and full stereocomplex PLA (sc–PLA) film. Early product development claim to have shown that these films exhibit less shrinkage at high temperatures compared to existing PLA films and offer properties much closer to oil-based PET.
Possible opportunities for the new bioplastic film include both food and non-food packaging and many industrial applications. In food packaging, for example, in pouches such as juice or soup pouches, the new PLA film will be able to withstand the temperatures required for sterilisation. Non-food applications could include release liners for pressure sensitive products, window films and protective films for smartphone screens. Many of these applications require thermal stability during processing or use.
Together with Weder, Zwartz and the Export Office, a traditional wooden framed chair has been designed with PLA natural fibre laminated panelling. The chair features good scratch and wear resistance, high biocontent and is made from renewable, GMO free raw materials.
High heat single use coffee cups
Huhtamaki is introducing a high heat PLA coffee cup that can replace single use PS coffee cups, while offering a reduced carbon footprint and an increased biobased content. During the K show, Corbion Purac served freshly made coffee in these new coffee cups. WinGram showcased high heat resistant PLA lids for hot drink cups.
Children’s toys have been created using PLA parts: a windmill propeller and housing for a toddler’s learning console. The toys on display showed a good surface finish, good impact resistance and high colourability.
Another highlight at the Corbion Purac booth was the world’s first surfboard made of biobased foam. The foam is produced in a patented process that converts PLA into expanded rigid foam. This expanded PLA foam has properties similar to expanded PS foam and can be used for foam packaging and insulation panels.