Materials invest in
Materials invest in smaller scale plants, the efficiency of PLA production can be enhanced by focusing on dedicated grades for certain application areas. Further value can be added to these (co-) polymers by compounding them into plastics and using nano- and other technologies to improve the properties. PURAC allows polymer producers to add value in a revolutionary new way by offering two types of lactide (L-lactide and D-lactide). By combining these lactides in new and unconventional ways, the improvement of the PLA heat-stability – one of its key issues – can become a reality. PURAC will deploy a business model, where lactide is manufactured at an advantageous scale and offered as a premium quality, competitively positioned product to PLA producers. Based on this lactide monomer customers will be able produce superior quality polymer. This business concept allows medium size and starting PLA companies to be competitive in the PLA market. The production of lactide is integrated into the manufacturing of lactic acid and as such different grades will be either processed or marketed through PURAC’s global sales network. PURAC partners do not have to concern themselves with the production of lactic acid or lactide and hence will see a reduced risk profile for the investment, product management, logistics and warehousing and operation of facilities. Outlook The flexible production unit in PURAC production site in Spain will be used for lactide production for selected partners early 2008. This unit will be extended with the required steps to make high quality lactide shippable to selected customers all over the world. The investment path leads to the industrial scale availability of a lactide production unit in Thailand. Since the availability of D(-) lactid acid is essential for the highest PLA grades, PURAC’s lactic acid production unit in Spain is being revamped into a high quality D(-) production plant. The product will also become available as D-lactide for PDLA production. PURAC has commenced a focused application development effort to support customers in their use of lactide and D(-) products. www.purac.com 24 bioplastics MAGAZINE [07/04] Vol. 2
Practically everybody uses them to protect sensitive goods – high-quality stretched plastics are undoubtedly the number one within the world of packaging material. More and more they are replacing paper, cardboard, tin foil and other materials. Upon applying a particular process, mono- or biaxial orientation, the films obtain a wealth of advantageous properties, due to a change in the morphology of the film’s molecular structure: • excellent mechanical properties, e.g. stiffness, tear, shock or puncture resistance • impermeability to moisture and water vapour • high resistance to oils, fats and solvents, as well as to heat and cold • dimensional stability and scratch resistance • attractive glossy appearance, thanks to brilliant surface quality and high transparency • excellent convertibility, printability and sealability. Packaging has become a key marketing tool at the point of sales. As a result, customers in supermarkets and stores are placing greater emphasis on attractive packaging. This leads to a greater demand for a variety of speciality films: • co-extruded multi-layer structures, up to 7 layers for ultra-high barrier • shrink film and sleeves for trendy, full body sleeves • ultra-high barrier film for lamination • bio-degradable films for environmental protection and sustainability • BOPA (bi-axially oriented Polyamide) film highly suitable for freezable and cookable (microwavable) packaging • mono-axial shrink films for bundles and labels Orientation methods The orientation methods applied to manufacture such films are the film blowing process and the tenter frame process. Blown film extrusion process is based on the principle of extruding a tube having a thickness that is 40 – 50 times thicker than that of the film to be produced. As part of the tenter frame process, the cast film derived from plastic granulate by means of extrusion is stretched in longitudinal and transverse direction to attain the required film dimensions. This film is then processed either sequentially or simultaneously in order to obtain a very thin, high-rigid end film. Sequential lines first stretch the cast film in machine direction through a system of rollers. This stretching is achieved by different speeds between groups of rolls. Then the film enters the tenter, an ovenlike device, which uses two endless chains to grip and stretch the web in transverse direction on diverting rails. Simultaneous systems stretch the film in both directions at the same time. The limited yield and inflexibility of mechanical solutions led to the development of LISIM ® Oriented films continue their Processing successful run – even with PLA Article contributed by Christian Aigner, Marketing Manager, Brückner Maschinenbau GmbH & Co. KG, Siegsdorf, Germany Photo: Treofan bioplastics MAGAZINE [07/04] Vol. 2 25
