A newly developed cooling system for blown film extrusion increases output and improves film quality

Kiefel Extrusion GmbH has developed the ECP (Enhanced Cooling Package) and Perfect Cool internal cooling systems. These are based on installation of a cooling body inside the bubble. The surface of this cooling body is chilled by an internal closed cooling water circuit. The geometry of the cooling body and its surface have been designed such that attracting and repelling forces between the film and cooling body are balanced, ensuring that the bubble remains stable even at high output rates. Turbulent air flow that assures good heat transfer between the air and cooling surface is created between the bubble and surface of the cooling body. As a result, the air is kept at a low temperature all the way to the frost line, providing extended internal cooling of the bubble. The system ensures that the film never comes in contact with the cooling medium (water) or the surface of the cooling body. Read more

The fortnightly Trend-setting Technology Report from Harald Sambale, doctor of plastics engineering and former chief editor of Kunststoffe, reports exclusively with high focus on practical ideas and with additional background information on trend-setting technologies for the plastics industry.

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Today, up to 12,000 tons of fishing lures, heavily loaded with plasticizers, are lost in the aquatic environment around the world. To solve this problem, using advanced composites technology, a Wisconsin entrepreneur and a research team at the Polymer Engineering Center at the University of Wisconsin-Madison developed a sustainable soft-plastic fishing lure. The new fiber reinforced fishing lure is still rubbery and soft,  but will no longer rip when being pulled on by a fish or under other loading conditions. Consequently, fishing lures, which almost always end up on the bottom of a lake or river, can now be reused time and again, not only taking a load of the environment, but also of the pockets of millions of fishermen around the world. Entrepreneur Ben Hobbins with the University of Wisconsin team in the Lab of the Polymer Engineering Center (Photo Jeff Miller) 

In-Mould-Forming as an efficient process for the production of steering column-connection hybrid structure
from: Thomas Müller & Ahamd Al-Sehyyab, Institute of Polymer Technology (LKT)

The AVK-Innovation Prize, University Category has been awarded to the Institute of Polymer Technology (LKT), University of Erlangen-Nuremberg within the Composites Night of the 10. Composite Europe Fair on 05. Nov. 2007.

Under the grant of SFB-396 and the finical support by the Deutsche Forschungsgemeinschaft (DFG), a new innovative manufacturing technique (In-Mould-Forming, IMF) has been developed at the institute of polymer technology (LKT). Using this new technique, it was possible to manufacture a fibre-reinforced hybrid structure in a series production scale. The innovation of this new technique is the integrated forming of a pre-heated thermoplastic-based insert directly in the injection moulding machine as well as the overmoulding of short glass fibre-reinforced thermoplastic ribs at the same production cycle.

In addition to the support of the Deutsche Forschungsgemeinschaft, the presented new technique has been developed within a cooperation between the Institute of Polymer Technology and three project partners from the industry and research institutes (Siebenwurst Modell- und Formbau GmbH & Co. KG, Dietfurt/Altmühl, www.siebenwurst.com, DST Draexilmaier Systemtechnik GmbH, Vilsbiburg, www.draexlmaier.de) and Neue Materialien Fürth GmbH (http://www.nmfgmbh.de). The main objective of this cooperation was the developing and manufacturing of a demonstrator part which can be transferred into the automotive applications. A steering column connection has been manufactured after conducting detailed modelling and experimental investigations.

Hybrid structures have been produced so far in batch assembly processes which have a disadvantage of the additional process step for the joining of the different components. These structures have been produced through long manufacturing cycle (pre-heating, pre-forming, trimming, pre-placing and injection moulding). This long process chain has been shortened through the new feasible and robust In-Mould-Forming technique. By IMF, it is possible to form the pre-heated thermoplastic-based fibre-reinforced fabric directly in the mould of the injection moulding machine and in the same processing cycle. The short- or long fibre-reinforced thermoplastic is being moulded over the formed sheet in a form of strengthening ribs. The produced part presents a light-weight hybrid structure which combines the positive properties of both components.

The realisation of the new IMF-technique opened a wide range of possible applications for the manufacturing of high-performance parts such as in motor sports, medical applications, aviation and space technology. In these applications, the light-weight performance has a key role in the development of the load-bearing structures. Weight-reduction with maintained mechanical properties is possible through the optimization of the structural design. The optimization is achieved mainly through the utilization of the an-isotropic material properties and the local strengthening as well as the constructive design of the ribs geometry. Additionally, it is possible to integrate other special moulding processes with the In-Mould-Forming process, such as Foaming process especially in case of sandwich structures or In-Mould-Decoration IMD process for the production of high quality surfaces.

Load-bearing light-weight structures which are safer and stronger than the current in-use structures have a key role in the development of mobility and energy technologies. Hybrid modules consisting of plastic ribs and metal inserts combine the structural advantages of both materials so as to improve the net performance with relatively light weight. Steel sheet had been considered as a conventional insert for hybrid structures. Since serious global environmental problems are caused by automobile emissions such as COx and NOx, greenhouse effect; further reduction in the weight of motor vehicles is strongly recommended. Based on this need, further development of light-weight modules in this industry field had been accomplished with the aim to have a high relative strength; assure low cost, low energy consumption, compatibility with complex engineering structures and less effect on the environment.

Research group (Light-weight hybrid structures) at the Chair of Polymer Technology, Erlangen-Nuremberg University, Germany has current work which is related to the investigation of the potential for using of glass-reinforced fabrics instead of steel inserts as well as the creation of a new flexible assembly technique. A super light-weight hybrid structure has been produced, in less than 60 seconds and in one manufacturing step. This was possible by means of the new manufacturing technique called In-Mold-Forming (IMF), which has been developed at the Chair of Polymer Technology. The main innovation of this new technique is the possibility to integrate several process steps in one, which means shortening the production cycle-time. This has been realized by forming the insert thermoplastic-based fabric directly in the injection molding machine instead of being pre-formed in separate processing step. IMF has a considerable potential to be used in a cost-effective series production in many industrial fields especially automotive industry where light-weight performance with adequate load-bearing function is required. In order to demonstrate the applicability of the IMF-process, a steering column connection has been manufactured after conducting detailed modeling and experimental investigations.

Steering Column Connection Hybrid structure / Insert: TEPEX® dynalite 104-RG600(4); 45% Roving Glas/PP; 2,0 mm / Ribs: Stamax / PP-GF30 der Fa. Sabic

For further information you can contact:
Dipl.-Ing. (FH) Thomas Müller, muellert@lkt.uni-erlangen.de
M. Sc. Ahmad Al-Sheyyab , alsheyyab@lkt.uni-erlangen.de

The Polymer Engineering Center at the University of Wisconsin-Madison and Resilient Technologies of Wausau, Wisconsin, through funding provided by the US Army Research Laboratory, is taking the air out of tires.  The tire’s design, replaces compressed air with an innovative patent pending structure, making it resistant to shrapnel and bullet punctures. The tires are intended to be used by the U.S. Army on military wheeled vehicles such as the HMMWV.  By not going flat these tires may help troops escape attack while on mobile patrol. Currently, the tire design is being optimized, as prototypes are tested in Resilient Technologies facilities in Wausau, Wisconsin.  Current test results are exceeding all expectations. Dynamic testing of a non-pneumatic tire prototype at Resilient Technologies facility in Wausau, WI.    

On the 20-21 of November, the LKT (Plastics Technology Institute) at the University of Erlangen-Nuremberg organized the international conference Assembly Injection Molding. At the conference not only was the term “Assembly Injection Molding” coined, but also several presentations that discussed injection molding as technique that can be used to integrally manufacture and assemble complex products were presented. In assembly injection moulding, a part’s various constituents, consisting of different or even identical materials, are assembled into a component at the same time as moulding is taking place. The term assembly injection moulding augments the existing definition of joining effected in multi-component injection moulding with the assembly elements of handling, controlling and special processes. On account of process development and expansion in recent years, it has grown substantially in terms of production depth. It has been aided in this inter alia by the implementation of joining processes during multi-component injection moulding. Assembly Injection Molding includes the secondary functions of handling, adjusting, checking, and additional special operations. Assembly injection moulding is particularly interesting because the choice of material combinations, geometry, injection parameters and additional process steps can be used to selectively determine the properties of the bonds produced: ranging from material-bond, form-fit or frictional bond to mobile and flexible.  

Professor Ernst Schmachtenberg of the LKT introduces concepts of Assembly Injection Molding

Over 90 participants attended the 53rd Madison Thermoset Molding Conference held October 18-19 in Madison, Wisconsin. Attendees from all over the United States heard diverse presentations from the keynote speaker from Boeing Company to Bio-Composits and More GmbH, Germany. This year’s agenda included topics on new thermoset composite materials, integrity testing of composites, overcoming color and appearance challenges, thread forming technology in thermosets,  meeting the challenges of the new “green” world, and protecting intellectual property.

At the “Assembly Injection Molding” Conference (Fachtagung Montagespritzgiessen) in November 2007 in Fürth, Germany, a Metal-Plastic Hybrid Automotive Body Panel was presented by REHAU AG+Co of Rehau Germany. The hybrid body panels are based on a three layer concept: Injection molded ribs reinforce a metal back, and a plastic class-A layer covers the ribbed structure (see photo below). The concept renders a very effective use of materials, structures and synergistically brings a strong and lightweight automotive body panel and structural component.

Metal-Plastic Hybrid automotive rear hatch by REHAU (Photo Tim Osswald)

On November 7, 1957, the first phenolic-cotton composite bodied car rolled off the assembly line in Zwickau, East Germany. When the  Trabant factory closed its doors, and the last Trabi rolled off its assembly line in 1991, it had produced over 3 million cars, making it, for better or for worse, an East German symbol. Today, only 50,000 of the two-stroke engine Trabants roll on Germany’s roads, primarily in the east, and there is renewed talk about reviving this nostalgic cult vehicle.  

On October 14, 2007, Governor Arnold Schwarzenegger signed a bill banning phthalate plasticizers from children’s toys and articles sold in the state of California. Some scientific studies have linked phthalates to the premature onset of puberty, low sperm count, testicular cancer and liver problems.   

Photo Wikimedia.org   

Schwarzenegger commented: “I am signing Assembly Bill 1108, which would restrict a group of chemicals called phthalates, a type of plasticizer, from use in children’s toys and child care articles. While I believe the circumstances related to phthalates warrant taking action now, I do not believe that addressing this type of concern in the Legislature on a chemical by chemical, product by product basis is the best or most effective way to make chemical policy in California. I strongly believe there needs to be a systematic way to address these types of concerns where California’s scientists can work together with experts from throughout the world to evaluate the health effects of chemicals, assess the risks they pose, and ensure that the safety of possible alternatives receives the same consideration.”He continued: ”I am looking forward to the recommendations being developed as part of the Green Chemistry Initiative led by my Secretary for Environmental Protection. I encourage the Legislature and all California stakeholders to participate in this important initiative so that we can develop policies that will again allow California to lead the nation and the world in health and environmental protection.”

One aspect of Bill AB 1108 that warrants attention from the plastics industry is what was scratched from the original bill, namely, also banning bisphenol-A used in the production of polycarbonate.