Principle of extrusion
Principle of extrusion bow molding [1] Shiseido URARA extrusion blow molded Ingeo shampoo bottle (photo courtesy of NatureWorks LLC) is retained and utilized to orient the final bottle, thus thicker sections stay hotter and stretch further while thinner, cooler sections will stretch less. In many injection stretch systems, the preform is transferred from the injection mold into a conditioning station that can be used to heat or cool sections of the preform to adjust the final container’s material distribution. Depending upon the system, this conditioning station may include IR reheating lamps or touch-off cores to cool sections. Finally, the preform enters the blow mold and a process similar to reheat stretch blow molding is employed to produce a container. Experience with biopolymers in injection stretch blow molding applications is more limited than RHSB systems. Injection stretch blow molding PLA containers takes advantage of the material’s heat capacity and does not require reheat additives to produce a high quality container. In addition, the stretch ratios for single-stage containers tend to be lower than RHSB containers. Other biopolymers that are capable of producing packages on two-stage equipment would be expected also to be suitable for single-stage blow molding. Extrusion blow molding (EBM) is a process in which polymer is melted and then extruded through an annular die head into an open tube called a parison. The parison is then pinched off as the chilled mold closes around the plastic and then blown into a final container shape. Unlike most RHSB and ISM applications, in EBM, the threaded area forms during blow molding. After blowing, the mold opens and the container is ejected. Frequently, excess plastic in the neck and base requires trimming outside the mold. Extrusion blow molding is commonly used for polyolefin or amorphous materials and requires sufficient melt strength to form the parison without collapse. Both continuous and intermittent EBM systems exist, with the type of system depending upon the equipment supplier and desired throughput rates as well as on melt strength. Lower viscosities (melt strength) may require an accumulator. Ingeo PLA extrusion blow molded containers were introduced in 2010 with a modified PLA blend. The modification provided improved melt strength to the polymer to allow for the parison formation. Bio-based PE and PP are drop-ins for their petrochemical counterparts for extrusion blow molding applications. In addition to these biopolymers, PHA also targets replacement of PE and PP in extrusion blow molding applications. First extrusion blow molded PHA bottles (PHB/PHV copolymer) for shampoo were introduced in Germany and the USA in the mid 1990s. However, they disappeared from the shelves and are now waiting for their renaissance. www. plastictechnologies.com [1] Thielen, M. et.al., Blasformen, Carl Hanser Verlag 50 bioplastics MAGAZINE [04/11] Vol. 6
Order now! A new study from The Freedonia Group, Inc. Degradable Plastics Book-Review Bookstore The degradable plastic industry has been on the verge of commercial success for decades. However, demand growth was limited because most degradable plastics were too expensive, were unavailable in large enough quantities or had performance drawbacks that limited them to niche markets. This situation began to change in the early 2000s, as interest in environmentally friendly products gained strength, boosted by the efforts of major users like Wal-Mart. At the same time, the availability of biodegradable plastics increased significantly due to expansions by key producers. These and other trends are presented in Degradable Plastics, a new study from The Freedonia Group, Inc., a Cleveland-based industry market research firm. The full report (202 pages, published 08/2010) is available through the bioplastics MAGAZINE bookstore at www.bioplasticsmagazine.com/books. Order now for US-$ 4,800 (+ VAT where applicable) order at www.bioplasticsmagazine.de/books, by phone +49 2161 6884463 or by e-mail books@bioplasticsmagazine.com Reduced Price ! “Thank you Jan. It is obvious that you went to great lengths on this work. You have listed biopolymers I haven‘t even heard of. This report will be very helpful to all involved in the biopolymer world.“ A reader‘s remark Hans-Josef Endres, Andrea Siebert-Raths Engineering Biopolymers Markets, Manufacturing, Properties and Applications 660 pages, hard cover. 278 coloured pictures, 70 tables Reduced Now available Price ! Author: Jan Th. J. Ravenstijn, MSc The state of the art on Bioplastics, January 2010 The report ‘The state-of-the-art on Bioplastics 2010‘ describes the revolutionary growth of bio-based monomers, polymers, and plastics and changes in performance and variety for the entire global plastics market in the first decades of this century. Trends, issues, technologies, products, markets, manufacturers, investment plans, performances, needs, expectations, and new opportunities are reviewed and discussed. This includes the assimilation of the agricultural industry with the polymer industry to a new value chain. Today, bio-based thermosets are larger than bio-based thermoplastics, while also the volume of bio-based durable materials exceeds the volume of bio-based biodegradable plastics. Order now for reduced price of EUR 1,500.00 (+ VAT) order at www.bioplasticsmagazine.de/books, by phone +49 2161 6884463 or by e-mail books@bioplasticsmagazine.com (Special prices for research and non-profit organisations upon request). Hans-Josef Endres, Andrea Siebert-Raths Technische Biopolymere Rahmenbedingungen, Marktsituation, Herstellung, Aufbau und Eigenschaften 628 Seiten, Hardcover This book is unique in its focus on market-relevant bio/renewable materials. It is based on comprehensive research projects, during which these materials were systematically analyzed and characterized. For the first time the interested reader will find comparable data not only for biogenic polymers and biological macromolecules such as proteins, but also for engineering materials. The reader will also find valuable information regarding microstructure, manufacturing, and processing-, application-, and recycling properties of biopolymers Rainer Höfer (Editor) Sustainable Solutions for Modern Economies ISBN: 978-1-84755-905-0 Copyright: 2009 / Format: Hardcover / 497 pages Finally it‘s there ! Bestellen Sie das deutschsprachige Buch für EUR 279.44 + MwSt Order the new english version now ! € 279.44 +VAT Order now for just EUR 99.00 plus shipping & handling (please ask for shipping cost into your country) order at www.bioplasticsmagazine.de/books, by phone +49 2161 6884463 or by e-mail books@bioplasticsmagazine.com order at www.bioplasticsmagazine.de by phone +49 2161 6884463 or by e-mail books@bioplasticsmagazine.com
