SPE Library

PowerPoint Presentation at ACCE 2002.

PowerPoint Presentation at ACCE 2002.

PowerPoint Presentation at ACCE 2002.

Continuous fibre reinforced thermoplastic (CFRTP) composites offer many advantages over thermoset composites and metallic materials especially their resistance to corrosion their recycling possibilities and their high specific stiffness. The shaping of these materials into complex forms however requires a good knowledge of the combined behaviour of the molten thermoplastic matrix and of the fibres because of the high intra and interlaminar shear deformations involved during the forming process. In this paper the influence of laminate consolidation parameters on the microstructure and mechanical properties of the laminate are first presented. Next the deformation mechanisms induced in the laminate in typical forming conditions are presented and discussed in regard to their influence on the physical and aesthetic properties of the moulded part. Numerical moulding predictions obtained from a commercial code are finally presented.

Contemporary vehicles utilize a mix of materials in their construction consisting of metals plastics and composites. These materials must possess suitable surface properties to achieve desired performance when these parts are adhesively bonding or painted for field service. Surface preparation methods now in place oftentimes use solvents or caustics an increasingly unacceptable approach in an era of mounting environmental regulations. New methods of surface preparation are called for that are environmentally benign and economically feasible while meeting the stringent quality standards of the automotive industry. The use of energetic ultraviolet light is emerging as a promising technology to compete with the old methods of surface preparation. This paper reports the utility of using energetic UV light to generate appropriate surface chemical composition on plastics composites and metals for subsequent painting or adhesive bonding operations. UV treatments have the potential to replace the old methods of treating assorted materials used in the automotive industry in an environmentally responsible and cost-effective manner.

Recycling or reprocessing of “multi-layer” or “multi-material” plastic products is a particular problem for plastic compounders or recyclers. Examples of multi-layer plastic products include painted or coated plastic items, such as automotive body panels, or multi-layer plastic packaging, such as that used in high barrier applications. In each of these cases, the coating or multi-layer structure is utilized to enhance either the product's overall performance or appearance. Unfortunately, the presence of other material layers will generally have a negative impact on the recyclability of the primary thermoplastic material as they often act as incompatible contamination. For example, most of the paints or coatings used in the automotive industry are thermosetting in nature and act as solid particulate inclusions in the recycled matrix material. Methods to remove coatings from coated plastic parts have been developed, but are not always cost effective. As an alternative, these complex material constructions can sometimes be effectively recycled if the contaminating layers can be reduced in particle size and effectively mixed into the continuous thermoplastic matrix material. A single screw mixing or “grating” section has been designed and evaluated experimentally in this study. Experimental trials were conducted using reground, painted thermoplastic olefin automobile bumpers. The reground bumper scrap was extruded using a single screw equipped with this grating sections, and several more conventional extrusion screw designs. The paint flake size distribution of the extrudate, and the physical properties of samples molded from the extrudate were evaluated for each screw design, both with and without melt filtration.

Material recycling requirement gradually opens the automotive body sealing market to thermoplastic elastomers (TPE), which is primarily dominated by EPDM thermosetting elastomers. Due to special material behaviors of elastomers, careful attentions should be taken when analyzing the body seal performance using material testing data, especially for TPE materials. This paper will address some of the issues by analyzing body seal products using TPE materials. The general guidelines for body seal analysis and result evaluation will also be discussed.

Soft polyolefinic TPEs are increasingly being favored over PVC based TPEs for automotive interiors. The major drivers for this change are the recycling and environmental aspects of PVC. Some strengths of polyolefinic TPEs are good low temperature performance, retention of properties after exposure to sunlight and high temperatures, low fogging, and little or no odor. The challenges in switching from PVC to polyolefinic TPEs involve attaining the desired melt processing characteristics and the mechanical and aesthetic properties at a relatively low cost. This paper will discuss Eliokem's use of a specialty acrylate elastomeric modifier in designing polyolefinic TPEs for automotive interiors and other applications

In order to make an injection moldable product with consistent properties from recycled carpeting, quantitation of the polymeric and non-polymeric components of the carpet feed stream is required. Feed mixtures containing nylons, polypropylene and PET as well as latex and calcium carbonate from backing material have been studied. A combination of DSC and TGA measurements is shown to provide compositional data on both polymeric and non-polymeric components in a rapid and inexpensive manner. More exact determination of polyamide components is accomplished using hydrolysis and derivatization to prepare samples for gas chromatography.

Silicone polymer release liner surfaces on paper, for self stick stamps and labels, become contaminants in paper recycling. Low print adhesion is one major problem limiting the inclusion of silicone release liners in recycling feed stock. A very sensitive method of analysis of silicone polymer during and after recycling employs pyrolysis GC/MS. The analysis provides a measure of siloxanes, ignoring inorganic silicon compounds such as silicates. The method also distinguishes between linear and branched polysiloxanes by different pyrolysis products. High sensitivity, to ppb, may be possible using single ion monitoring or selected ion data collection of mass spectra.

Education for the growing needs of the plastics industry is recognized as needing a different approach that will enable a quicker integration of the graduates in the working world. Under the auspices of the EU programme Leonardo da Vinci a group of universities and institutions developed a course programme and structure for preparing engineers with skills for plastics design and processing with a sound awareness of the environmental issues. Specific characteristics of the course are the project driven methodology and the integration of training periods in the industry as from the first year of the four-year long course.

Polyamides are susceptible to attack by environmental pollutants. The surface layer is degraded and the development of a critical thickness of this layer results in a catastrophic loss of mechanical properties. In this work nylon was exposed to nitrogen oxides and the fracture strength was measured. After a period of no change the fracture strength decreased dramatically. Exposed samples were microtomed and the molecular weight distribution of nylon was determined, as a function of depth from the surface, by Gel Permeation Chromatography (GPC). A critical depth for degradation was established beyond which the specimen exhibited unacceptably low fracture strength.

Three types of specimens of a polyester-amide and a poly-hydroxybutyrate have been tensile and tensile-impact tested. These specimens represent different geometric characteristics; one specimen has a cold weld line. The influence of injection molding settings on tensile behavior was in agreement with tensile-impact results. Embrittlement was found for all specimen types and both materials after 20 months of storage. The beneficial effect of annealing on toughness was shown for poly-hydroxybutyrate specimens without weld line.

The aim of this work is to obtain composite films of polypropylene (PP) to substitute paper. The plastic component is PP from mineral water bottle (PPb) collected from municipal plastic waste (MPW) and the filler component is CaCO3. Composite films with weight ratio of PPb and CaCO3 (70:30) were prepared. These films were surface treated by corone discharge. Preliminary results have shown a good printability with pencil and pen ink on these films without treating and an improved printability with ink jet after surface treatment. These films were then compared to cellulose paper by physico-chemical characterizations.

The blow moulding industry has achieved a good understanding of the process, which has been in large scale operation since the 1960's. Consequently, control of machine settings such as heater band temperatures, die gap position, die and mould temperatures is quite advanced. However, to date, little work has been done to address the control of state parameters describing material behaviour during processing, such as parison weight and temperature distribution. Control of state parameters is essential as material property changes, environmental factors and machine operating drifts can significantly change the dynamic operating point of the machine.

Growing concern for ecological issues, including international standards agreements such as ISO14001, demonstrate a clear requirement to conserve energy for both environmental and cost issues. Energy measurements on injection moulding machines both in the laboratory and in industry demonstrate the potential of process energy measurements in the development of a systematic management approach to the environmental concerns of an organization. The data gathered can also provide useful information to both the processor regarding the performance of the machine in question, and the power companies regarding the specification of supply equipment.Detailed energy measurements during the injection moulding cycle provide data regarding the energy consumption of specific machine components and/or phases of the injection moulding cycle, providing valuable data for machinery manufacturers and processors.

In this paper, an engineered material made from paperboard and powdered polypropylene is examined. A wet, paper process was chosen for converting paperboard waste into an engineered, cost effective composite material. Using a fourdrinier, a 30 inch wide continuous sheet of paper/plastic stock was produced for subsequent thermal molding. Tensile modulus and strength of 6,000 and 50 MPa, respectively, were obtained for a material having just less than 30 percent polypropylene. Additionally, moisture content and water absorption was examined. Testing and failure analysis indicate that increasing the percent of polypropylene will improve the mechanical properties.

This keynote lecture discusses the use of biodegradable polymers as tissue engineering scaffolds. The basic principles of tissue engineering are addressed, going from scaffolds processing to some brief information on biological studies. These topics are introduced in a way that an audience composed by plastic engineers can easily became aware of the importance of the field and understands its complexity, as well as the role of biodegradable polymers on its success.

The overall goal of the paper is to develop recycled plastic lumber products with improved mechanical properties using inorganic filler consisting of Louisiana residuals, such as phosphogypsum, in conjunction with recycled plastic resins. Blends have been established and samples have been prepared by mixing polyethylene derived from detergent bottles with inorganic fillers in the inner chamber of a Haake rheometer. Reactive mixtures have been made in the same way using maleic anhydride in addition to polyolefin and inorganic filler. The actual composition of blends has been calculated from thermogravimetric data. Tensile properties have been determined for each composition using both an INSTRON machine and a dynamo-mechanical spectrometer.

Chlorinated polyethylene (CPE) has been demonstrated to be an effective compatibilizer for dissimilar materials in various mixed-polymer or recycled-polymer systems. In this paper the use of chlorinated polyethylene to compatibilize polymer/natural fiber composites is discussed. Examples of applications in PVC/wood flour composites are given.