|By weight, PET consists of 70% terephthalic acid and 30% monoethylene glycol. Bio-PET is made by replacing monoethylene glycol (MEG) with a raw material derived from sugar cane. Toyota plans to replace 20% (by weight) of all oil-based plastics for cars with bio-plastics by 2015, amounting to approximately 360,000 tons of bio-plastics. The Bio-PET may be used in seats and carpeting and other interior components that require a high level of performance unattainable by previously available bioplastics. The opening of Braskem plant in Brazil is speeding Toyota�s use of bioplastics. The Japanese major has committed to buy 40% of the output of Braskem�s new 200,000 tpa ethylene from sugar.
Toyota�s first use of Bio-PET was liner material in the luggage-compartment of the Lexus CT200h. The new material features enhanced performance like heat-resistance, durability performance, shrink resistance when compared to conventional bioplastics as well as performance parity with petroleum-based PET. Costs will be comparable to oil-based PET once high production volumes are achieved. The car maker plans to increase both the number of vehicle series featuring the new material, as well as the amount of vehicle-interior area covered.
As per designnews.com, in 2003, Toyota became the first in the world to use bio-plastics in a mass-production vehicle. Polylactic acid was used in the spare tire cover and floor mats of the Japanese-market �Raum� small car. The Sai hybrid uses bio-plastics to cover 60% of the exposed surfaces of interior parts. Fibers made from DuPont Sorona are being used for the ceiling surface skin, sun visor and pillar garnish. Floor mats for the remodeled third-generation Toyota Prius uses an advanced PLA-based fiber. Other applications for bio-plastic in the Prius are seat cushion foam, cowl side trim, inner and outer scuff plates, and deck trim cover. Toyota used PLA from NatureWorks to replace petroleum-derived nylon resin used in floor mats. DuPont Zytel RS 6/10 is being used in a radiator end tank in the 2010 Camry sedan, offering exceptional heat resistance, durability and road salt resistance. One of the new applications in 2011 will be a fiber that backs vinyl in sheets used to cover seats, dashes and door interiors. Working with Toyota engineers, Canadian General-Tower (CGT) developed a calendared vinyl called Vehreo that is processable on existing equipment. The fabric layer under the vinyl is made 55% from recycled PET bottles. A plasticizer made from soybean oil and castor bean oil makes up 10-35% of the main layer. A surface coating on the sheet is a protein that can replace a petroleum-derived thermo-set such as polyurethane or vinyl-acrylic resin. As per Toyota, the name biodegradable plastics emphasize the post-use disposal aspect, but actually the term bio-plastics, which emphasizes the manufacturing process, is also used. Biodegradable plastics can be made like conventional plastics using petroleum resources, in which case despite degrading following disposal, they use up limited petroleum resources. Bioplastics, being plant-based, are different. The carbon dioxide and water which is generated when they degrade is simply returning to where it came from; the carbon dioxide into the atmosphere and the water into the ground, so that over their whole lifecycle they cause no additional generation of carbon dioxide, apart from the energy consumed in their manufacture. These are the bio-plastics that Toyota is currently developing. This feature of not increasing the volume of carbon dioxide is called carbon neutrality. Achieving widespread use of carbon neutral materials is a major hurdle on the way to a recycling-oriented society. The bioplastics which Toyota aims to create are carbon-neutral materials using sweet potatoes, sugar cane, etc. as raw materials. The manufacturing process starts by taking the starch of the sweet potatoes and other materials and breaking it down with enzymes to turn it into sugar, which is then fermented to produce lactic acid.