SPE Library

The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.

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Conference Proceedings

ADVANCED PROCESS CONTROL FOR INJECTION MOLDING BASED ON CAVITY PRESSURE

Walter Michaeli , Andreas Schreiber, May 2008

The manufacturing of complex and high-grade molded parts in the injection molding process places high demands on the process control. Unlike the conventional control of the injection molding process which is based on machine variables the presented advanced process control system performs an online control of the quality determining process variable ‘cavity pressure’. In the holding pressure phase it conducts an online optimization of the process based on the pvT-behavior of the used plastic material. By this means an optimal course of the process in the pvT-diagram is realized in each production cycle and thus the quality constancy of the produced parts can be considerably increased.

ADVANCED PROCESS CONTROL FOR INJECTION MOLDING BASED ON CAVITY PRESSURE

Walter Michaeli , Andreas Schreiber, May 2008

The manufacturing of complex and high-grade molded parts in the injection molding process places high demands on the process control. Unlike the conventional control of the injection molding process, which is based on machine variables, the presented advanced process control system performs an online control of the quality determining process variable ƒ??cavity pressureƒ??. In the holding pressure phase it conducts an online optimization of the process based on the pvT-behavior of the used plastic material. By this means, an optimal course of the process in the pvT-diagram is realized in each production cycle and thus, the quality constancy of the produced parts can be considerably increased.

MODELLING THE NON-LINEAR VISCOELASTIC AND LOCALLY DISTRIBUTED MATERIAL BEHAVIOR OF SEMI-CRYSTALLINE THERMOPLASTICS

Walter Michaeli , Markus Brinkmann, May 2008

High simulation suitability can only be achieved by a precise modelling of the material properties. However the influencing factors on the non-linear viscoelastic mechanical properties of thermoplastics are numerous. Additionally injection-moulded parts exhibit inhomogeneous properties depending on their processing conditions. Semi-crystalline thermoplastic parts exhibit strong gradients in their inner properties. This paper describes an approach to include all these influencing factors by modelling the non-linear viscoelastic material behaviour and coupling injection-moulding simulation and structural analysis. This approach is evaluated by comparing simulation and test results.

MODELLING THE NON-LINEAR VISCOELASTIC AND LOCALLY DISTRIBUTED MATERIAL BEHAVIOR OF SEMI-CRYSTALLINE THERMOPLASTICS

Walter Michaeli , Markus Brinkmann, May 2008

High simulation suitability can only be achieved by a precise modelling of the material properties. However, the influencing factors on the non-linear viscoelastic mechanical properties of thermoplastics are numerous. Additionally, injection-moulded parts exhibit inhomogeneous properties depending on their processing conditions. Semi-crystalline thermoplastic parts exhibit strong gradients in their inner properties. This paper describes an approach to include all these influencing factors by modelling the non-linear viscoelastic material behaviour and coupling injection-moulding simulation and structural analysis. This approach is evaluated by comparing simulation and test results.

ECO-FRIENDLY FLAME RETARDANT POLYCARBONATE AND POLYESTER ALLOYS

XY Li , Mike Nyers , Rudiger Gorny , Jim Mason , Marie Urick , Marty Boykin, May 2008

Bayer MaterialScience has developed flame retardantalloys of polycarbonate and polyester. These productscontain no brominated or chlorinated flame retardants making them eco-friendly. To counter the adverse effectof flame retardants on the hydrolysis resistance ofPC/Polyester blends stabilization against hydrolysis ofthese products has been developed. Makroblend?ÿ?? EC100?ÿ?ÿ?? EC150 resin has?ÿa UL 94 V0 rating at 1.5 mm and 5VA at 2.3 mm it hasgood impact resistance at room temperature low specificoptical smoke density and passes the FAR 25.853a-60stest at 2.0 mm.and EC100HR resins have UL 94 V0 and 5VA ratings at3.0 mm with excellent low temperature impact resistanceand hydrolysis resistance. Makroblend

RESEARCH ON THE MICRO-EXTRUSION CHARACTERISTIC OF MINI-SCREW IN THE SCREW EXTRUDING SPRAY HEAD

Liu Bin , Xie Yi , Huang Xingxing , Feng Yanhong, May 2008

Based on hydrodynamics and melt conveying theory the micro-extrusion characteristics of mini-screw used in the screw extruding spray head of FDM were researched in detail in this paper. The research was about the relationship between extrusion production capacity and the main geometrical parameters of screw and barrel( the active length of screw the diameter of screw the helix angle the width of screw arris the depth of screw channel the clearance between screw and barrel etc) and the processing parameters such as screw speed the pressure of nozzle. Theoretical analysis was performed to find out the quantitative relationships between production capacity of extrusion and main parameters (the screw speed main geometrical size of screw the clearance between screw and barrel the pressure of nozzle etc) were found out so that the theoretical guidance on the design of spray head with screw could be provided.

RESEARCH ON THE MICRO-EXTRUSION CHARACTERISTIC OF MINI-SCREW IN THE SCREW EXTRUDING SPRAY HEAD

Liu Bin Xie , Yi Huang Xingxing , Feng Yanhong, May 2008

Based on hydrodynamics and melt conveying theory, the micro-extrusion characteristics of mini-screw used in the screw extruding spray head of FDM were researched in detail in this paper. The research was about the relationship between extrusion production capacity and the main geometrical parameters of screw and barrel (the active length of screw, the diameter of screw, the helix angle, the width of screw arris, the depth of screw channel, the clearance between screw and barrel, etc), and the processing parameters such as screw speed, the pressure of nozzle. Theoretical analysis was performed to find out the quantitative relationships between production capacity of extrusion and main parameters (the screw speed, main geometrical size of screw, the clearance between screw and barrel, the pressure of nozzle, etc) were found out so that the theoretical guidance on the design of spray head with screw could be provided.

EVALUATION OF DISPERSION CHARACTERISTICS OF POLYMER-CLAY NANOCOMPOSITES BY X-RAY DIFFRACTION MEASUREMENT AND MICROSCOPY

W. Michaeli , U. Klemradt , A. Elas , K. Berdel , D. Carmele, May 2008

Although polymer-clay nanocomposites have been investigated for a long time there are only few publications on the characterisation of the state of dispersion of clay in polymers. X-ray diffraction (XRD) measurements and microscopy are usually applied. However results of both can easily be misinterpreted. Nanocomposites of clay and polypropylene are prepared. The state of dispersion is analysed by XRD optical and electron microscopy. XRD measurements show the effect of sample preparation and geometry and clay orientation on the results. Sample preparation also affects the results of microscopic analyses. These effects have to be considered when nanocomposites are analysed.

MEASURING DISTINCTNESS OF IMAGE OF HIGH GLOSS SURFACES

Dieter P. Gruber , Michael Buder-Stroisznigg, May 2008

Human eye-apparatus notices varying distinctness of image (DOI) of glossy surfaces very accurately. Therefore high resolving measuring techniques are required. This paper aims on presenting the Intensity Profile Analysis (IPA) a novel methodology for the measurement of distinctness of surface reflected images. IPA enables measuring fine detail reproduction of glossy surfaces with good correlation to standard DOI measurements while featuring considerably enhanced preciseness. IPA is a non-contact technique and therefore applicable for uncured or hot surfaces.

MEASURING DISTINCTNESS OF IMAGE OF HIGH GLOSS SURFACES

Dieter P. Gruber , Michael Buder-Stroisznigg , Gernot Wallner , Bernhard Strauß , Lothar Jandel, May 2008

Human eye-apparatus notices varying distinctness of image (DOI) of glossy surfaces very accurately. Therefore high resolving measuring techniques are required. This paper aims on presenting the Intensity Profile Analysis (IPA), a novel methodology for the measurement of distinctness of surface reflected images. IPA enables measuring fine detail reproduction of glossy surfaces with good correlation to standard DOI measurements while featuring considerably enhanced preciseness. IPA is a non-contact technique and therefore applicable for uncured or hot surfaces.

FEASIBILITY STUDY OF THE USE OF DDGS PLASTIC COMPOSITES

David Grewell , Gowrishankar Srinivasan , Maria Baboi, May 2008

Recently, an increase in the demand for ethanol as a fuel additive has resulted in a dramatic increase in its coproducts namely distiller’s dried grains with solubles (DDGS). This work studied a composite of DDGS and conventional petrochemical plastics (polyvinyl chloride) for applications in windows construction. The goal was to characterize the composite and its processibility for “green” plastics. The experiments showed that DDGS can be effectively extruded with PVC; at low filler levels (5- 10%) of DDGs strengthening of the PVC was seen. However, higher filler levels (>10%) of DDGS degraded the mechanical properties of PVC/DDGS composites. Also, ground DDGS perform better as reinforcement agents compared to standard DDGS. Caustic pretreatment was also studied and it was found not to effect the mechanical properties significantly. Also, the addition of PVA had little effect on the properties of the composite.

TRANSFER OF TEMPLATE PATTERNED CARBON NANOTUBES TO A POLYMER SURFACE USING THE THERMOFORMING PROCESS

Arun Kumar , Ming Wei , Carol M. F. Barry , Stephen Orroth , Ahmed Busnaina , Joey Mead, May 2008

Carbon nanotubes (CNT’s) are of interest because of their high thermal, mechanical, and electrical properties. They are often combined with polymers to enhance the properties; however, it would be useful for a number of applications to incorporate the CNT’s in a patterned structure. In this work we investigate approaches to pattern the carbon nanotubes and transfer this pattern to a polymer substrate using thermoforming, a commercially relevant process. We have used electrophoretic deposition of multi-wall carbon nanotubes (MWCNT) onto the circuits followed by transfer to a polyurethane film by thermoforming. The electronic circuit had a copper (Cu) wire with a width of 55 &m. MWCNT’s were deposited onto the copper wires using the electrophoresis method with direct current (DC) voltage. A novel mold design for the thermoforming process was developed, which has a removable insert to keep the patterned MWCNT circuit inside the mold. The thermoforming process parameters (temperature (heating time), forming time and vacuum) were optimized to obtain transfer of the patterned MWCNT’s to the polyurethane surface