Cellular - Blowing agents - Eiwa Chem. Ind. Co. Ltd

Kunststoffe international, 2005-11-21, Composite Parts: Flexibility in Rigid/Flexible Combinations
...ons, as is highlighted by its market leadership in roof system linings (Fig.2). The company is similarly market leader in the field of tail-lights in Germany, with its stamped parts made of flexible materials, and particularly of cellular rubber. Weigelt, which was founded in Worms/Germany, in 1906 and has now been handed down to the third and fourth family generations (Fig.7), views itself as a system partner to the international automotive industry, the automotive supplier industry, the electr...

Kunststoffe international, 2005-11-21, Cost Consciousness: Modern Technology is More Economical than Low-spec
...on of Specific Cases In numerous tests the production costs for various injection moulded parts were determined, specifically computer keyboards, truck floor pans, stackable cases, cellular phone housings, camera cases, cable holders, ball bearing cages, plugs and stoppers. It was found that, after taking into consideration the loss in value of the machines, the production costs for the plastic parts moulded on European machines - were 8 to 38% lower, depending on the moulded part, than on “lo...

Kunststoffe international, 2005-11-21, Foam Injection Moulding: It's Not the Bubble Size that Counts
Injection Moulding It's Not the Bubble Size that Counts Foam Injection Moulding. The familiar advantages of the microcellular foaming of engineering thermoplastics have to be set against drawbacks such as a poor surface structure on the moulded parts and a reduction in their mechanical characteristic values. The latest investigations show that microcellular foamed parts even possess poorer mechanical properties than fine-cellular foam parts with an integral foam structure. By foaming the...

Kunststoffe international, 2005-11-21, Functionality is the Key Factor
...e in the operating theater or hospital ward made by GMP Poliurethani, Oderzo/Italy takes full advantage of the potential offered by a modern high-performance plastic such as Baydur 60 (Fig. 6). The material has a sandwich structure consisting of a cellular core and a solid smooth surface. This results in high strength properties and impact strength in combination with low weight and low wall thicknesses. It can also be used for complex moulding geometries which are difficult to achieve with ther...

Kunststoffe international, 2005-11-21, Gas - Not just because of the Cell Structure
... thermal, acoustic and electrical insulation properties and high specific flexural rigidity (due to lower density) with good non-warping characteristics. Such a combination of properties cannot be achieved with any other plastic. The principle of cellular thermoplastic production is basically the same whether chemical or physical foaming is used. A gas is dissolved in the thermoplastic melt and the subsequent decrease in pressure induces a thermodynamic instability which initiates the formatio...

Kunststoffe international, 2005-11-21, Graphic-based Control Technology: Full Automation of One-component Foaming Lines
...makes the process possible to run in-line and to automate. The components can be installed without temporary storage after five to ten minutes. Fluctuations in the component or ambient temperature have no influence on the quality of the closed cellular foam bead. "According to computations use of the one-component foam from Sunstar is always economically advantageous compared to two-component systems if the quantity per component is less than seven grams", explains Andreas S. Kreissl, Ma...

Kunststoffe international, 2005-11-21, Gravimetric Precision Metering
... was previously carried out by more cost-intensive methods. The main features of the new system are its rapid metering via metering valves, combined with outstanding accuracy. Alternatively, for particularly fine metering, the process can be run via cellular wheel sluices. The new metering system, which bears the name Graviko GK, was shown at Fakuma by Werner Koch Maschinentechnik GmbH, Ispringen/Germany. A balance weighs all the individual components with an accuracy of between 0.05 and 0.1 g...

Kunststoffe international, 2005-11-21, Large Investment Plans: Polyurethanes (PU)
...or are as always distinguished by their size or special complexity. Both cold- and hot-cast elastomers also enjoyed pleasing growth in 2003. Hot-cast systems with cellular elastomers recorded double-digit growth last year. Rotational coating also showed above-average growth. New applications are also continually being found for the unusual material class of polyurethane gels. These applications exploit the pressure-distributing properties and unusual tactile characteristics of the gel materials...

Kunststoffe international, 2005-11-21, Opportunity and Challenge
... without components, right: with components (manufacturer: HSG-IMIT, Villingen-Schwenningen/Germany); Circuit pattern creation via 2-shot injection moulding; material combination LCP-Pd (plated)//LCP (unplated) Fig. 3. Coaxial connector for cellular phones (manufacturer: W.C. Heraeus, Hanau/Germany; Tyco Electronics / AMP GmbH); Circuit pattern creation via 2-shot injection moulding, material combination LCP-Pd//LCP Fig. 4. Sensor holder for automatic bank printer (manufacturer: Vogt electroni...

Kunststoffe international, 2005-11-21, Physical Blowing Agents: Foaming Plastics with Inert Gases
...ferent processes make it possible to produce various types of foam (open- or closed-cell, integral-skin), which are used in many sectors, including packaging, thermal/acoustic insulation and upholstery. Main Principles of the Production Process The cellular structure of foamed plastics is produced by so-called blowing agents. Additives such as nucleating agents and stabilisers are also frequently required. Commercially important manufacturing processes are extrusion foaming, in future probably ...

Kunststoffe international, 2005-11-21, Piezoelectric Effect and Electrostriction: Porous Plastics as Sensor Materials
Electronics Porous Plastics as Sensor Materials Piezoelectric Effect and Electrostriction. Mechanical-sensory characteristics are usually based on the piezoelectric effect and on electrostriction. Newly developed cellular plastics show outstanding performance parameters. At present research and development is concerned with sandwich systems based on porous and compact plastic foils, from which still better characteristics are expected. Here the possibility of active sound and/or noise insulation...

Kunststoffe international, 2005-11-21, Plastics Handling in Extrusion
...sion is no exception, Koch-Technik has developed a new-patented gravimetric metering system (type: Graviko GK, Fig. 5). The new system is characterised by rapid, high precision metering and may be used instead of extremely fine metering with, e.g., cellular wheel feeders. All the individual components are weighed on a balance with an accuracy of between 0.05 and 0.1 g. A stirrer mixes the components. Depending on the throughput of the processing machinery, four to six different materials can be ...

Kunststoffe international, 2005-11-21, Polycarbonate (PC)
...C has benefited considerably from the trend toward miniaturization and thin-wall technology: A few years ago, the first mobile phones weighed several kilograms, but a weight of less than 200g is nowadays state-of-the-art for a modern cellular phone. Because the electrical performance has to remain the same or be even higher, the demands made on the material have also increased. Smaller, thinner components require materials with outstanding flow properties, good dimensional stability even at elev...

Kunststoffe international, 2005-11-21, Polyurethane Elastomers
...d amines. In NDI (naphthylene diisocyanate) casting systems, butanediol-1,4 is normally used and only in special cases is crosslinking carried out with other glycols. The time required to process the crosslinked prepolymer system is 30 to 90 s. For cellular PU elastomers with high densities (300 to 600 kg/m3), the prepolymer is produced together with the crosslinking agent, water and additives for cell stabilisation. The CO2 formed in the water-isocyanate reaction serves as the blowing agent and...

Kunststoffe international, 2005-11-21, Process Technology: Polyurethane Processing Systems
...s have designed machines for a multitude of important applications based on PUR chemistry. Processing of foamable reaction mixtures is called Reaction Injection Moulding (RIM) [1-4]. Using this process, both integral skin foam parts (where the cellular core has a largely non-cellular skin) and microcellular foam parts that are microporous and, thus, almost solid can be produced in extremely short cycle times. The term RRIM (Reinforced Reaction Injection Moulding) designates the process when gr...

Kunststoffe international, 2005-11-21, Routes to Microcellular Foam
Routes to Microcellular Foam Principles of Material and Process Control Walter Michaeli, Oliver Pfannschmidt and Sasan Habibi-Naini, Aachen/Germany Thermoplastic foams are nothing new. Nevertheless, new developments in the field of microcellular foams today can lead to new application areas. The differences between these and conventional foams lie primarily in process control. This article, together with one to follow later, takes a look at the principles behind microcellular foams and at ...

Kunststoffe international, 2005-11-21, Worldwide Stable Growth: Polyurethanes (PUR)
...ress. Even if the applications (e.g. rollers, seals and sieves) have hardly changed over the past year, there is a continuous trend towards simpler processes in PUR processing. The hot-runner systems with cellular elastomers have shown two-figure growth in the previous year. Rotational coating has also shown above-average growth. The high-performance polyurethane elastomer Vulkollan has been able to maintain its position because the industrial field (wheels and rollers) has continued to grow as...

Kunststoffe international, 2005-12-08, A Status Report (1): Versatility for Mass Production in MuCell Injection Moulding
Injection Moulding Versatility for Mass Production in MuCell Injection Moulding A Status Report (1). The injection moulding of physically foamed plastic parts with a microcellular foam structure (“MuCell”) has found its feet. In the first part of this series of articles, this is demonstrated using the example of Engel technology, with state of the art plant technology and process control, and the growing number of applications and process combinations. The injection moulding of foamed parts by ...

Kunststoffe international, 2005-12-08, News
...aused by a stagnation or regressive demand in Engel’s major markets Germany, Italy and France. VarioLine New Website VarioLineSystems GmbH, Dresden, launched its new website with a focus on the VarioLine light-weight system – a cellular polymer panel produced by means of high-pressure injection moulding, which combines the specific benefits of wood and plastic. Lightweight, easy to machine and water-resistant, VarioLine can replace traditional panel materials such as wood, plastic and lightweig...

Kunststoffe international, 2006-01-15, A Status Report (2): Versatility for Mass Production in MuCell Injection Moulding
...hase. The available process window was found to be very narrow. … and Improved Mechanical Properties The characteristic feature of MuCell parts foamed without gas counterpressure is always a relatively distinct boundary between the microcellular foam core and the unfoamed skin layer. Parts produced by gas counterpressure, on the other hand, can foam into the surface layer (Fig.3). The reason for this difference is the laminar melt filling of the mould cavity in the gas counterpressure process: ...

Kunststoffe international, 2006-02-02, Injection Moulding: Perfection in Panels
...lly harmonised in an ideal manner. “We only use chemical blowing agents, since in the area we work in, chemical foaming is clearly superior to physical foaming. This way, we succeed in producing foams of very fine cellular structure“, Hansen says. As laborious as it may be for his team to develop the necessary know-how in material tests as well as in control of the individual process sequences, Sven Hansen considers integration of these criteria and their application to a product like this a uni...

Kunststoffe international, 2006-12-06, Compounding Technology: Striving for Technology Leadership
... very challenging process will also be greatly simplified. Integrated Processes for Foaming Polymers A foaming process on a Micro 27-GL extruder was presented in collaboration with the Fraunhofer Institute ICT. A pentane gas in a cellular polymer carrier was incorporated and pelletised by means of an underwater pelletiser. In his talk, Dr. Diemert explained the most important principles for foaming polymers and the important parameters for extrusion foaming. Various plant concepts for presented...

Kunststoffe international, 2007-09-19, Mastering Demanding Challenges
...anded up to 80 % using the gas injection technique, is used to sheath small and medium-sized cable. The material offers minimum dielectric loss even at frequencies of 3,000 MHz (Fig. 2). Its high breaking strength, which results from the cellular structure and soft skin, allows cable manufacturers to produce longer cables and thus larger lot sizes. With its PE-HD Lupolen 4261 A IM, Basell, Hoofddorp, Netherlands, is introducing a material especially suited for use in automobile fuel tanks and ta...

Kunststoffe international, 2007-10-21, Foamed Thin Wall Packaging
...rties of the film used for the label, the machine capabilities and process strategy all make an equal contribution to significantly reducing the manufacturing costs under production conditions. Trexel’s patented MuCell process for producing micro cellular foam structures has previously only been used for thick wall and/or high precision components. For thick wall products, by incorporating nitrogen and carbon dioxide at high pressure as a super critical gas into the melt, the processor is able t...

Kunststoffe international, 2007-10-21, Three-Dimensional Structural Analysis of Foam
...nststofftechnisches Kolloquium (22nd International IKV Plastics Technology Colloquium), Aachen, March 10-12, 2004 3. Montminy, M. D.; Tannenbaum, A. R.; Macosko, C. W.: New Algorithms for 3-D Imaging and Analysis of Open-Celled Foams. Journal of Cellular Plastics 37 (2001), pp. 501–515 4. Ohser, J.; Mücklich, F.: Statistical Analysis of Microstructures in Materials Science. John Wiley & Sons, 2000 5. Heilbronner, R.: How to derive size distribution of particles from size distribution of sectiona...

Kunststoffe international, 2008-01-15, Elastomer Industry Has Understood
...on of high-quality, robust interior surfaces. In a similarly complex way to the Dolphin process, a PC+ABS blend (Bayblend from Bayer MaterialScience) is combined with a cold-crosslinking cellular PU elastomer (PuroSkin from Rühl, Friedrichsdorf, Germany) to produce a four-color interior door panel (Fig.13) to OEM specifications. The door panel is produced on a KM 2300-12000 MX SkinForm reversing plate machine with a multicolor PU mixing head from Krauss Maffei, Munich, Germany. The mold was deve...

Kunststoffe international, 2008-01-15, The Circle Closes
...urn air temperature is, the smaller is the throughput. With optimal operation this is approx. 40°C. The process has to be regarded as a batch process. Removal is performed via an extraction box with a conveying device connected or by a cellular wheel sluice into a receiving container or cooling hopper. Feeding of the amorphous material is performed by a conveying device or by gravity via a cellular wheel sluice. Air guidance is realized by a circulation air/outdoor air device, the air volume onl...

Kunststoffe international, 2008-02-29, Social Behavior with a Cost Benefit
...y. The purpose of these covers is to provide access to the fuel pump located beneath the rear seat in the sedans built by a Swabian automobile manufacturer. About 15 mentally handicapped individuals were employed in manually applying a 720mm long cellular rubber sealing strip to each 220mm diameter cover, which protects the pump against moisture and corrosion. In autumn of 2006, the automaker put the contract out to bid throughout Europe. At the same time, two major criteria were changed: first,...

Kunststoffe international, 2008-04-14, Better Hearing with Polymers
...implant in direct contact with tissue can be modified by the micro injection process in such a manner that they encourage osteointegration by particular types of cells. The main aspects include surface texture, which should be clearly finer than cellular texture, and surface structure the size of individual cells. Then an implant can be realized that encourages growth of connective tissue toward the eardrum (Fig. 3). The stirrup side, on the other hand, can be optimized for osseous joining, thus...

Kunststoffe international, 2008-09-23, Foaming in the Mold
...cavity, where the evaporation cooling can be used more effectively. Molded parts produced in this way have a better surface, as the skin component does not contain any foam. On the other hand, the better mixing of the MuCell process results in micro-cellular foam structures, making it very suitable for thin-walled products. As the SmartFoam system creates macro-cellular structures because of the short mixing zone, it is better suited for thick-walled (>3.2 mm) components. If a chemica...

Kunststoffe international, 2008-10-17, Polyurethanes (PU)
...des light weight and high bending resistance. PU is also increasingly demonstrating its value as an alternative to sheet metal or SMC for large, highly integrated body components in commercial vehicles. Flowable, microcellular PU systems are especially well suited for such applications. They can be used to produce geometrically complex parts with undercuts, ribs and abrupt changes in wall thickness in a single shot in inexpensive aluminum molds. The side panel for a Claas forage harvester with d...

Kunststoffe international, 2009-02-17, Micro Needles as Biological Sensors
...ces [1]. The Fraunhofer Institute for Manufacturing Technology and Applied Materials Research (Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung – IFAM) is working to develop a biological sensor for the measurement of cellular forces. In order that the sensor’s functionality may be ensured, its surface must possess a certain pattern. Flawless production of these presents a challenge for micro injection molding. Cells Adhere to an Acicular Landscape Generally, cells that ...

Kunststoffe international, 2009-07-16, PU Molded Parts with No Parting Line
Polyurethane (PU) parts consisting of flexible integral foam have a solid (compact) outer skin and a cellular (foam) core. They meet demanding technical requirements with regard to functionality and haptics. Manufacturing involves the use of two- or multi-piece molds, so that even parts with a spherical or cylindrical shape as well as parts with complex geometries and even undercuts can be demolded reliably. Since the PU mixture has a low viscosity when entering the mold, it is squeezed into the...

Kunststoffe international, 2009-11-19, Centralized Feeding by Vacuum
...convinced the operators to depart from the conventional practice of running at least one blower for each extrusion line. Especially decisive were the elimination of noise, dust and exhaust heat from the production hall, which usually come along with cellular solutions. The strong underpressure also enables lower conveying velocities and less abrasion than usual, a fact that constitutes a benefit for product quality. Demand based air volume generation lowers maintenance and energy costs, since th...

Kunststoffe international, 2010-09-24, Stable PET Foaming
...s the final articles’ function. Foamed materials, for instance, have better isolating properties than compact components. In injection molding, a foamed core inside the component can reduce internal stress, shrink marks and warpage. A soft-touch cellular structure can also cause a haptic design effect, for instance in bottles or thermoformed packagings. When foaming is linked to extrusion, the focus is always on weight reduction. For food packaging films, weight saving is of outstanding importan...

Kunststoffe international, 2012-08-22, Accelerated Humid Aging of Polyurethane Moldings
...ase at three of the applied temperatures (residual hardness > 100%). This is not at all a quality improvement but a consequence of the density change which goes along with the foam degradation. Hardness (or modulus) of cellular material correlate with density d according to Gibson et al [3] with following relation: CLD [d1]/CLD [d2] = ??? (1) That effect compensates partially the hardness loss due to degradation by a hardness increase due to foam shrinkage equal to a density increase. Figure ...

Kunststoffe international, 2013-02-22, Effect of Repeated Sterilization
...these cases 1.3 %, 1.0 % and 0.7 %. After stressing over a specified contact time (60 min), the test specimens are visually and mechanically inspected for damage. Immersion in Artificial Blood Human whole blood consists of about 45 % cellular components and 55 % liquid blood plasma. The test medium used, the blood substitute “simulated body fluid”, is very similar to blood plasma in its ionic composition. The liquid used had a temperature of 37°C and a pH of 7.4. However, it does not contain the...

Kunststoffe international, 2014-05-07, ATP Test Device: Rapid Detection Method for Identifying Microorganisms
... cuvette. Here, the sample material is diluted, neutralized and buffered. In the reagent chamber, the ATP content is then determined with a luciferin-luciferase mixture Fig. 2. The sample pen is coated with an extractant to release ATP from cellular sample material THE AUTHORS SABRINA JURGEIT, born in 1990, is a sales assistant at Riegler GmbH & Co. KG, Mühltal, Germany. TOBIAS HOFMANN, born in 1980, is a project manager at Riegler GmbH & Co. KG, Mühltal, Germany. DANIELA PFEUFFER, born in 1981,...

Kunststoffe international, 2014-10-10, Polyurethanes (PU)
... developed. In addition to exceptional thermal insulating performance, these foams are characterized by high thermal stability.Integral-Skin Foams Integral-skin PU foams are processed as molded foams. The parts have a cell-free skin and a cellular core, and can be rigid, semi-rigid or flexible. Typical applications of rigid integral-skin foams include large car body parts, equipment housings (Fig. 6) and cable connections. Semi-rigid integral-skin PU foams are used to cushion instrument panels a...

Kunststoffe international, 2014-12-18, A Little Extra?
.... the property data that are quoted per kilogram of material. Examples of this can also be found in Nature. For example, human bones and a tree trunk each have structure similar to that of a foamed part, in which a non-foamed outer layer surrounds a cellular core structure. In both cases, the core transmits the shear forces or the compressive loads, while the flexural properties are for the most part derived from the non-foamed outer layer.Based on calculations [2, 3], it can be shown how the te...

Kunststoffe international, 2016-02-17, Airy Standard Material
...le for making foams which, if they can be produced at all, are at best of low quality. However, even polylactide can be foamed if it is chemically modified in the right way. Foams are synthetically produced, two-phase (gas-solid) systems that have a cellular structure. This structure imparts characteristic properties, such as a particularly low density and, e. g., good insulating effect. A prime example of polymer foams is extruded polystyrene, which is produced by physical foam extrusion. It is...

Kunststoffe international, 2017-03-27, Cutting the Gordian Knot
Up to now, the prevailing opinion has been that processing of Styrofoam and similarly cellular materials requires complex processes involving steam. Two engineers have now come up with a dry solution that slashes energy consumption. Not only that, but the duo have also devised a production-ready lightweight engineering approach, namely on how foams can offer new application perspectives the automotive industry is desperately looking for. For fifty years, the production of molded articles from ex...

Kunststoffe international, 2017-05-22, Lean Material Mix for Lightweight Interiors
...PET foam core is still in the glass transition to melting range. PET does not attain the molten state until the temperature reaches about 220 °C. Below this temperature, it is possible to adjust other process parameters to prevent the cellular structure of the foam core from collapsing during the molding process, whereas the structural PET base material is moldable. Heat input into the semi-finished sandwich and the necessary thickness calibration are achieved in a contact heating press, which g...

Kunststoffe international, 2018-02-21, Customized Foam
...as been shown that interactions exist in the experimental space investigated and that in addition to the blowing agent content, the mold parameters of opening speed and degree of expansion have a significant effect on the cellular structure (Fig. 6).ConclusionSpecial mold technologies increase the number of influencing parameters in the already complex process of foam injection molding. But as soon as the correlations between the parameters and also the directions in which they act have been und...

Kunststoffe international, 2020-04-08, Custom Implants from the 3D Printer
... Switzerland [2]. In in vitro tests on parts printed by the FFF technique, it was found that bone-forming cells (osteoblasts) grew significantly better on the natural, rough surface after printing: after only five days, cellular activity on the printed parts was twice as high as on polished parts and three times higher than on sandblasted parts. This suggests that the healing process in the body can be accelerated by selectively modifying the surface properties of implants. With resorbable mater...