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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Wood & Flax Fibre Polyolefin Composites
In this work natural fiber and wood composites based on neat and recycled polypropylene (PP) were fabricated by melt processing. Different formulations including various reinforcement content different types of coupling agents different types of reactive additives and an impact modifier were developed. The reinforcements were in the form of natural fibers like banana flax rice husk and palm fibers and of wood sawdust. For the long fiber composite systems processing was done by compression molding of piles of long fiber mat and extruded polypropylene film. For the short fiber composite the samples were prepared by extrusion followed by injection molding. The tensile flexural and impact performance were characterized and all composites show superior mechanical properties when compared with the pristine matrix. Mechanical performance of the wood composites was also evaluated before and after conditioning in water for 1 and 7 days. Results indicate that the composites resist to humidity very well. The results also demonstrate the effect of formulations on the performance of the recycled composites.
BMC - Taking Automotive Composites to a New Dimension
BMC composites have long been used in automotive applications because of the excellent mechanical properties creep and thermal resistance. Components such as headlamp reflectors engine/valve covers front timing chain covers and small electric motors have benefited from this technology for many years. Recent advances in the formulations have opened up new opportunities in automotive under the hood applications. BMC composite material technology is quickly finding its way into applications that require extremely tight molded dimensions and dimensional stability over a temperature range. Some of these applications include Electronic Throttle Controls (ETC) Air Control Valves (ACV) and transmission components. This paper investigates the critical characteristics of these performance parts and the properties of BMC composite which help make the system work.
New Developments in PUR Composite Spray Molding PUR-CSM Technology for Multiple Processes
Hennecke with its PUR-CSM Technology developed a flexible and efficient production system that has already proven successful in numerous applications. There are now six (6) PUR-CSM variants of the system w hich address various transportation parts¶ m anufacturing needs Multitech multi layered composite construction; Baydur thin walled high strength glass reinforced; Baypreg NF high strength reinforced with natural fibers; Baypreg–high strength/low weight sandwich structure with added fiberglass partial reinforcement capability; Baytec polyurethane spray skin technology; Bayflex filled flexible polyurethane with enhanced properties especially acoustical.
EMI Shielding Solutions Using Stainless Steel Filled Thermoplastic Composites
With the increasing amount of onboard electronics and microprocessor-controlled systems on automobiles it is important that the electronic sub-assemblies (ESAs) in a vehicle are designed to be electromagnetically compatible (EMC). Design for electromagnetically compatibility can be achieved in a number of ways including the use of enclosures or housings with shielding capabilities. There are a variety of enclosure design options to provide shielding to help meet EMC requirements including the use of conductive thermoplastic composites that offer intrinsic shielding. This paper will present information on GE Plastics LNP* Faradex* melt process able stainless steel filled thermoplastic composites and their potential for use as electromagnetic shields. Shielding models product performance features along with design and processing information critical to achieving effective shielding will be discussed.
Innovative High Strength Glass Microspheres for Lightweight Injection Molded Plastics & Composites
High strength low density glass microspheres have been developed and commercialized for use in injection molded plastic parts and pressed composite structures. This new and innovative 3M TM Performance Additives iM30K product is low in density but has very high compressive strength survivability providing OEM designers and Tier 1 molders new application opportunities. This paper will detail potential application benefits for injection molded plastic parts containing iM30K including lower weight improved thermal expansion properties improved processing and improved dimensional stability (less warpage and sink marks). Addition of these materials will also result in the maintenance of important thermoplastic physical properties.
HPPC: DEVE LOPMENT OF A THERMOP LASTIC SOLUTION FOR AUTOMOTIVE HORIZONTA L BODY PANELS
Today there are three global trends that call for a thermoplastic solution for horizontal body panels (hoods roofs and trunk lids): 1.Vehicle differentiation reducing the average annual production per name plate 2. Higher fuel cost demanding lightweight materials 3. Pedestrian safety regulations being enacted in Europe and Japan Market competition globalization new entrants and increasingly demanding consumers continue to drive automakers to differentiate and segment their portfolios. Over the last twenty years there has been a consistent decrease on average annual production per name plate. Parallel to that the same market forces are also reducing the life of models.
A Modular Automotive Roof System Design Concept Based on Polyurethane Composite Technology
There is a growing trend in the automotive industry to offer more “non-traditional” roof configurations to the consumer. In many cases the non-traditional roof contains glass guides drives and other hardware that increase the cost and weight of the vehicle. Consequently suppliers are being challenged to offer designs that use lightweight materials integrate or eliminate components while maintaining or improving overall structural and dimensional performance of the vehicle. Based on a standard body in white" roof structure the innovative concepts described in this paper use molded polymers and composite materials that allow a vehicle to be fitted with a wide variety of roof “modules” each having customized performance content and value. The modules are designed to integrate components eliminate post painting increasing vehicle rigidity and reduce weight. Conceptual designs illustrated in this paper will include two different vehicle architectures and two different roof module constructions. Three different composite materials will be reviewed for their suitability in the roof module. Detailed section views are included to illustrate important part design features attachment methods performance considerations and general composite “know-how”. The concept’s value proposition is examined in four areas: cost weight safety and assembly. Technical and economic benefits to the value proposition include weight reduction design and styling freedom in-mold features attachment points color options fixed or moveable window design and improved roll-over safety due to the lowered center of gravity. Since the modular roof system starts with a component that is ready to assemble it offers a path forward for the supply chain which enables OEMs to decrease capital expenditures and reduce labor hours required to manufacture a vehicle. The backbone of the value proposition is a recently conducted case study comparing a traditional vehicle to the same vehicle fitted with a composite pol"
Carbon Fiber Composites for Improved Performance of the Murcielago Roadster
When modern saloon cars are re-engineered as roadsters it is typical for them to lose 50% or more of the body's torsional rigidity. Consequently the vehicles rarely handle quite as crisply nor do they ride as well as the coupes from which they derived. This presentation highlights the fundamental contributions of advanced composites in achieving the desired value of handling of the Murcièlago Roadster without penalizing the overall weight of the vehicle. To compensate for the absence of the roof structure the vehicle was strongly redesigned by introducing new structural members and reinforcing existing critical components. A new all-carbon/epoxy composite sub-frame which spans the entire engine bay compartment is comprised of elliptical tubular members and it is the first of its kind in a production vehicle. The paper highlights the fundamental contributions of advanced composites in the production of the body panels and integrated chassis components for the Murcièlago Roadster.
Design Fabrication & Testing of a Composite Side Door for a Mid-Size SUV
As part of a mass-savings initiative a composite intensive side door project was started at GM R&D. In order to allow more innovation in the design two normally limiting constraints were eliminated. Firstly the Class A requirement for the outer surface was relaxed and secondly labor intensive handcrafting was allowed for the purpose of prototyping. The composite door was constrained to fit the existing door opening and to use carry-over internal hardware. Using stiffness criteria finite element analysis was used to develop a minimum mass design using composite sandwich structures. Preforms were handcrafted from molded foam cores wrapped with a combination of woven and stitch-bonded unidirectional glass.
Toward the Development of a Test Method for Characterizing the Energy Absorption of Composite Materials
As part of the design for vehicle crashworthiness energy-absorbing structural elements have been successfully used in every field of transportation and composites have shown great advantages in energy absorbed per unit mass of material. One of the key factors preventing the widespread adoption of composites in primary crash-resistant structures is the absence of specialized test methods for the characterization of specific energy absorption (SEA). A relatively simple and inexpensive method is required to compare candidate material systems laminate designs fiber architectures processing methods to build an adequate property database. This paper reviews a portion of the existing body of literature concerned with the development of crush test methodologies and identifies the areas that require the most attention before being considered for adoption as test methods. The recently formed MIL-HDBK-17 Working Group (WG) on Crashworthiness which comprises representatives from the aerospace and automotive industry academia and government laboratories is presently dedicated to developing suitable test methods. In particular two test methodologies have been identified as the most mature for development and standardization one for plate coupons and the other for tubular specimens. The WG has started to collect and summarize current industry test practices which are many and not currently agreed upon and is already working in conjunction with ASTM Committee D-30 on Composite Materials to lay the foundations of tests standards for composite crashworthiness.
Design and Structural Performance Assessment of a Composite Intensive Passenger Vehicle
Decoma International Inc. contracted Multimatic to develop a modular Composite Intensive Vehicle (CIV) concept including closures and suspension suitable for production volumes of 50000 units per year. The proposed CIV was required to meet all typical OEM vehicle packaging standards and stiffness and applicable crash safety standards while offering the potential for overall mass reduction and meeting manufacturing cost and volume requirements. The primary structural materials considered in this study were fiberglass composite and metallic materials. The study to develop the CIV Body-In-White (BIW) closures and suspension systems concepts was conducted in 3 phases: (1) Development of the vehicle content requirements vehicle occupant and component package and structural performance targets based on program requirements provided styling surface and vehicle benchmarking. (2) Development of a package-feasible three-dimensional structural CAD concept model for the BIW closures and suspension system. (3) CAE-based structural stiffness optimization and crash performance assessment of the structures developed in (2). The resulting CIV vehicle concept was developed to a level suitable for prototype build detailed manufacturing feasibility verification and mass and cost assessment.
Control of Moisture & Volatile Organic Compounds by Sorbent-Loaded Composites
The integrity performance and service time of certain automotive subsystems is adversely affected by moisture ingress into contained environments. Corrosion of air conditioning (AC) system components caused by moisture initially present in the refrigerant and moisture permeated through the seals during the AC unit service life is one example. Another one is water vapor condensation in optical components used for night and rear vision systems as well as optical proximity sensors often causing their malfunction in changing environmental temperature and humidity conditions. Desiccating multiforms attached to a condenser coil have long been used in automotive AC units to absorb the residual moisture and the moisture permeating from outside. The new direction in AC moisture control is the use of sorbent-loaded polymer composites in AC structural parts that eliminate the need for individual desiccating multiforms their assembly operation as well as the associated noise from the assembly. Desiccating composite enclosures and seal materials are simultaneously targeted for improving performance of optical components. Volatile organic compound (VOC) emissions from fuel tanks and lines into atmosphere can also be reduced by using VOC absorbing composite materials as reactive barriers to permeation in fuel tank and supply line design. The performance of sorbent-loaded composites is evaluated from the standpoint of two distinct design targets: removal the target vapor from the contained environment and reducing the rate of ingress from the external environment. The concepts of the layer reactivity the adsorptive capacity and the sorption rate are applied to the homogeneously reactive media and the sorbent-loaded polymer composites. The corresponding differences in performance and design requirements are discussed.
Method of Assembling a Vehicle and Integrated Composite Roof Module Technology - Paradigm Shift in Automotive Vehicle Assembly
This method of vehicle assembly consists of fabricating a vehicle body with floor and door openings roof pillars defining window openings and a roof supported on the pillars with a defined roof opening. The vehicle body is placed on a chassis. Then interior components are inserted through the opening in the roof and secured to the interior of the vehicle body. A roof module panel is placed on the roof to close the opening after the interior components have been inserted. One of the advantages of this method is that workers can assemble the vehicle without the problems of a cramped and hectic work area. Still another advantage is the reduction in cost of labor and workers compensation due to less labor required in the assembly process. Also all interior and exterior components including but not limited to roof racks skid racks sunroof radios DVD players antenna farms decorative lining etc. can be preassembled into the roof module panel with ease. A completely assembled roof panel can be attached to the vehicle body at the last sequential step when all interior components have been installed on the assembly line. Therefore this method of assembling a vehicle and integrated roof module is new efficient and provides an economical way to assemble vehicles that will help reduce assembly time and not be labor intensive.
Enabling Design Innovation in Automotive Composite Applications
Today many technical and economic factors are triggering increased interest in the use of composite materials for the automotive industry. The reduced cost of composites and rising steel production costs are both significant factors. With higher oil prices consumers demand lighter more fuel-efficient cars. New material forms and innovative processes are emerging to help reduce manufacturing cycle times and consolidate part counts. Demand for car customization is enabling lower production volumes better-suited for composite parts manufacturing. Finally the use of advanced simulation tools and increased domain expertise is spreading from aerospace and car racing engineering into mainstream automotive design and production. However the real enablers to any revolutionary breakthrough in composites need to be considered more closely: Engineers must be given the ability to reconsider the rationale and the way automotive components are designed in order to fully integrate all the benefits of using composites Engineers must be given the appropriate tools to freely explore alternative new methods of using and incorporating composites into the engineering and manufacturing of production cars. In this presentation the ingredients of Renault F 1 Teams unique success in composites design as well as other significant automotive initiatives will be presented to the audience. These proofpoints will demonstrate how actual design freedom domain expertise and excellence in the mastering of composites complexity can be leveraged to develop innovative solutions that unlock the potential of composites for advances in real world practical automotive engineering.
Finite Element Modeling of Composite Tubular Crash Structures With an Explicit Code
As emissions regulations tighten worldwide automotive manufacturers must look for ways to reduce structural vehicle weight. While employing alloys and exotic metals may provide a degree of weight reduction a more significant reduction can be achieved through the use of composite materials. Importantly composites have shown an ability to improve vehicle crashworthiness through higher levels of specific energy absorption and almost ideal crush characteristics. These advantages have not been exploited in mass-produced vehicles due primarily to the high cost of component manufacture and lack of computational methods for simulation of the crash behavior of such materials. While development of rapid inexpensive production processes can increase the production volume and reduce cost manufacturers will still be required to prototype components. The provision of accurate computational models for the failure behavior of composite materials will reduce the demand on manufacturers to prototype designs and ultimately result in structures of higher performance. Herein a phenomenological Finite Element (FE) modeling methodology is presented the development of which focused on the accurate consideration of the experimentally observed failure mechanisms typical of the splaying mode of failure. LS-DYNA has been employed to validate a multi-shell model of Continuous Filament Random Mat (CFRM) glass/polyester tubes. This modeling approach utilizes a spotweld approach to modeling delamination with deformable beam elements. Typical constraint-type delamination approaches do not allow shear deformation prior to delamination and result in an inaccurate representation of laminate stiffness. Spotweld validation simulations were performed on 3-point-bend Double Cantilever Beam (DCB) and End Notch Flexure (ENF) tests with excellent correlation before application in full-tube simulations. Initiation of the splaying mode of failure was accomplished by pre-definition of a debris wedge the geometr
Measurement of Static and Dynamic Friction Energy Absorption in Carbon/Vinyl Ester Composite
Experiments have suggested that sliding friction plays an important role in the energy absorption of composite crush tubes. In an attempt to separate the sliding friction specific energy absorption SEA from the SEA attributable to matrix damage due to bending an innovative strip testing fixture was designed fabricated and tested. With this fixture strips of composite can be crushed under two fixture configurations; with and without sliding friction. The resulting load vs. deflection data is then analyzed to calculate SEA attributable to sliding friction. Strips of braided carbon/vinyl ester composite were tested statically and dynamically. The relative SEA attributable to sliding friction similar to that found when a tube is crushed with a plug type trigger was measured. It was observed that matrix damage due to bending did not change significantly when loaded dynamically compared with the quasistatic result. Sliding friction SEA however did show significant decrease when loaded dynamically vs. the quasistatic result and accounts for nearly all of the difference in SEA between dynamic and quasi-static loading.
Dynamic Energy Absorption Modes of Braided Carbon/Vinyl Ester Composite Crush Tubes
Energy absorption of fiber reinforced composite structures is of interest to the automotive industry as their specfic energy absorption SEA) i.e. the energy absorption capability per unit mass is higher than many metallic counterparts.The SEA of composite structures has been observed to decrease under dynamic crush loading when compared with quasi-static compression. The observed energy absorbing modes include tube corner splitting composite delamination matrix damage due to bending and sliding friction of the composite with a plug type crush trigger. Corner splitting was estimated to absorb less that 1% of the total energy absorbed. Energy absorption attributable to delamination was estimated to be 2.8% of the crush tube SEA. The SEA attributable to matrix damage from bending was 62.2% for quasi-static loading and 78.1% under dynamic loading. The percentage of total SEA attributable to sliding friction between the plug type trigger and composite tube was 34.8% under quasi-static loading and 18.1% under dynamic loading. The decrease in sliding friction SEA of 6.3 J/gm accounted for nearly all of the decrease in crush tube SEA of 6.6 J/gm between dynamic crush and quasi-static compression. Sliding friction was concluded to be responsible for the decrease in overall tube SEA when compression loaded at a quasi-static rate vs. a dynamic rate.
Innovative Use of Thermoplastic Film Adhesives in Automotive Airbags
Side curtain airbags or headbags are a recent development in the automotive airbag industry. They aim to reduce injuries as a result of roll over accidents. A side curtain airbag has to stay inflated for a minimum of six seconds and to reach this goal silicone layers of 90g/m² and more have to be used. This technique has several draw backs. TRW Occupant Restraint Systems one of the worlds largest airbag-suppliers developed together with adhesive company Collano a multi layered thermoplastic composite film to substitute silicone by a much thinner coating with excellent friction and air proof properties. Author will demonstrate how this development was accomplished and which properties have been achieved.
Application of Fibre Assemblies as Damping Elements in Automotive Industry
This investigation aims to characterise the damping properties of the nonwoven materials with potential applications in automotive and aerospace industry. Nonwovens are a popular choice for many applications due to their relatively low manufacturing cost and unique properties. It is known that nonwovens are efficient energy dispersers for certain applications such as acoustic damping and ballistic impact. It is anticipated that these energy absorption properties could eventually be used to provide damping for mechanical vibrations. However the behaviour of nonwovens under dynamic load and vibration has not been investigated before. Therefore we intend to highlight these aspects of the behaviour of the nonwovens through this research. In order to obtain an insight to the energy absorption properties of the nonwoven fabrics a range of tests has been performed. Forced vibration of the cantilever beam is used to explore damping over a range of resonance modes and input amplitudes. The tests are conducted on aramid glass fibre and polyester fabrics with a range of area densities and various coatings. The tests clarified the general dynamic behaviour of the fabrics tested and the possible response in more real application condition as well. The energy absorption in both thickness and plane of the fabric is tested. The effects of the area density on the results are identified. The main absorption mechanism is known to be the friction. The frictional properties are improved by using a smaller fibre denier and increasing fibre length this is a result of increasing contact surface between fibres. It is expected the increased friction result in improving damping. The results indicate different mechanism of damping for fiber glass fabrics compared to the aramid fabrics. The frequency of maximum efficiency of damping is identified for the fabrics tested. These can be used to recommend potential applications.
New Textile Composites with Thermo-Regulating Properties for Automotive Interior Applications
Energy can be saved and the thermal comfort inside the passenger compartment can be enhanced by the application of textile composites with thermo-regulating properties. The thermo-regulating properties are provided by the application of phase change material (PCM) ± a highly productive thermal storage means. In order to create the textile composites with thermo-regulating properties the PCM is contained in a polymeric film that is laminated to a textile carrier. A study has indicated that the application of the developed composites is especially beneficial in car seats headliners and instrument panels. In the paper specific solutions for the application of the textile composites in car seats headliners and instrument panels will be introduced and test results received in rigorous field tests will be discussed.
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