Browse Topic: Molding
This research investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5-20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via the injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermal characteristics of the sustainable composites that were systematically evaluated as per the ASTM standards. The addition of RF drastically altered the Delrin matrix's performance. Among the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values, which provide greater dimensional stability at high temperatures; lower CLTE, resulting in less thermal expansion; comparatively better thermal conductivity; and improved heat dissipation. Eventually, there was a moderate drop in the MFI, indicating more rigid polymer chains that restrict the flowability of the composite, thereby increasing its heat-withstanding capabilities. DSC analysis revealed a slight upward shift in Tg and increased crystallinity, suggesting restricted polymer chain mobility and enhanced load transfer at 20 wt.% RF loadings, agglomeration effects, and weaker interfacial bonding with the matrix led to deterioration in properties. Aircraft cabin components like interior panels, ducting supports, and lightweight non-structural fittings requires dimensional stability, thermal resistance, and mechanical reliability under fluctuating flight conditions.
Tire noise reduction is important for improving ride comfort, especially in electric vehicle due to lack of engine noise and majority of the noise generated in-cabin is from tire-road interaction. Therefore, the tire tread pattern contribution is one of the important criteria for NVH performance apart from other structurally generated noise and vibration. In this work a GUI-based pitch sequence optimization tool is developed to support tire design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. The key point to be considered in this pitch sequence is that it should be reducing the tonal sound and equally spread i.e., the same pitch cannot be concentrated on one side which may lead to non-uniformity. So, the restriction is that the highest and lowest pitch types cannot occur adjacent to one another. This design rule helps in reducing undesirable pattern non-uniformity and improves both acoustic and structural performance. This tool helps in faster design iteration and integration with downstream development processes. This tool is also validated in current OE projects showing promising improvements in tire noise behavior while maintaining realistic design feasibility.
Yamaha Motor Engineering Co., Ltd. provides plastic processing technology based on fuel tank press forming technology, and is developing various plastic processing methods, including forging, and developing mold equipment to realize them. This time, the core parts of the YECVT unit mounted on Yamaha Motor Co., Ltd.'s small premium scooter "NMAX" were not made by welding individual parts to each other, but by integrally forming them from a single thick plate using the cold forming method, resulting in lightweight, compact, high-strength, high-precision parts. By incorporating a composite plastic processing method that takes advantage of the characteristics of the material while making full use of analysis technology and mold technology, we were able to develop a composite plastic processing method (plate forging method) that creates new added value and mass produce it. In addition,this development has made it possible to achieve a thickness increase of 1.7 times the standard material thickness as a mass production method.
When it comes to plastics applications, cars are rarely the first products that come to mind. However, with modern vehicles containing 1,000 to 1,500 plastic parts — including dashboards, control elements, clips, trim parts, brackets, door panels, bumpers, and radiator grilles — the material is more important for mobility than we might assume. Some of these plastic parts are relevant for the drivers’ safety: for instance, airbag covers must open correctly in an accident and seat belt guides and retractors could cause severe injuries if they break or deform under load. Their quality is vital. At the same time however, cost pressure and new regulations — for instance regarding an increased use of recycled materials that is under way in the European Union — pose new challenges, especially in plastic injection molding. Digital solutions for measurement technology help control and stabilize the complex process and may even lead to increased product quality despite tougher conditions.
We extend the previously developed integrated VABS (iVABS) framework for rotor blade structural optimization with an enhanced cross-section template for practical manufacture considerations; these include the introduction of curved spar corners, a continuous wrap-around skin, trailing-edge tabs and a conformal non-structural mass. The added fidelity is exercised on a UH-60A-based outer mold line through three multi-objective optimization case studies, including a case where the cross-sections are optimized independent of each other, and two cases where all the cross-sections are optimized simultaneously with manufacture considerations. It was found that the latter cases produce straight spars that are relatively more practical to manufacture when compared to the first case, while achieving significant reduction of up to 80% in the mismatch of stiffness values, inertia properties, and shear center locations, when compared to the prior work. A subsequent sensitivity analysis of the Pareto set isolates five critical combinations of design variables, out of the original nearly 100 variables, such as root/mid-span skin-ply count and spar-web placement, that can be adjusted to refine the Pareto solution. The study demonstrates that manufacturability-aware parameterization and data-driven variable reduction can deliver practical composite-blade designs within a scalable optimization loop.
This article follows a companion article [1] presented at the SAE NVC 2021, in which a new system for the measurement on small samples of the normal-incidence Insertion Loss (IL) of multilayers used for the manufacturing of automotive sound package parts was first introduced. In addition to simplifying the evaluation of the sound-insulation of multi-layers used to produce sound-package components, the system aims at overcoming the limitations of the test procedure based on the ASTM E2611 standard. In this article, the latter point is demonstrated by comparing the insertion loss results obtained with the new system with those obtained with the test procedure based on the ASTM E2611 standard on a few multilayers commonly used for the manufacturing of automotive sound package parts. Results indicate that the data obtained by means of the newly developed system are more meaningful, practically usable and less prone to edge-effects, compared to those obtained according to the ASTM E2611 test procedure. In addition to this, the article compares also the results obtained by means of the new system with those obtained in a compact two-cabins facility commonly used for the evaluation of diffuse-field insertion loss following the ASTM E90 standard, a quantity customarily employed in the automotive industry for the assessment of the sound insulation of acoustic multilayers. Results indicate that the data obtained with the new system compare well with those obtained with the two-cabins facility, both quantitatively and qualitatively. This indicates that sound-insulation tests with the new system may be a valid alternative to much more resource-consuming tests in two-chamber facilities, in particular (but not only) when the sound insulation of moulded parts must be assessed.
For years the NVH community has known that openings in the dash sheet metal, such as holes to pass wire harnesses through, creates an acoustical weak point that limits the potential noise reduction of the dash insulation system. These pass-throughs can also be a source of water leaks into the vehicle’s interior. With internal combustion engines and now electric inverter power plants generating significant high frequency sound, the need to seal this area is vital. By molding a lightweight barrier that draws through the fiber/absorber interior decoupler and dash sheet metal which mates to a secondary seal molded into an outer engine dash decoupler, the two opposing molded barriers meet in the engine compartment and compress together forming a seal around the wire harness. This male/female molded seal replaces the conventional snap in grommet and eliminates noise/water leaks. The system Sound Transmission Loss (STL) is equivalent to similarly insulated sheet metal with no holes, increasing sound intelligibility/articulation index in the automotive interior, leading to new levels of occupant comfort and ease of communication. This technology can also be used anywhere in the vehicle where a hole is created in sheet metal and a wire is passed through it (e.g. electric side view mirrors).
Climate-neutral aviation requires resource-efficient composite manufacturing technologies and solutions for the reuse of carbon fibers (CF). In this context, thermoplastic composites (TPC) can make a strong contribution. Thermoforming of TPC is an efficient and established process for aerospace components. Its efficiency could be further increased by integration of joining processes, which would otherwise be separate processes requiring additional time and equipment. In this work, an integrative two-step thermoforming process for hollow box structures is presented. The starting point are two organosheets, i.e. fiber-reinforced thermoplastic sheets. First, one of the organosheets, intended for the bottom skin of the uplift structure, is thermoformed. After cooling, the press opens, the organosheet remains in the press and an infrared heater is pivoted in, to locally heat up just the joining area. Meanwhile, a second organosheet, intended for the top skin, is heated and thermoformed and simultaneously joined to the lower skin, thereby forming the box structure. The process can be referred to as co-consolidation with localized heating of the joining areas. The target of this study was to initially built up a test setup allowing to process single lap shear samples with this concept, test the shear strength (tensile test based on DIN 1465) and compare it with similar tests on samples joined via co-consolidation and resistance welding. The tests were based on organosheets processed from nonwovens made of polyamide 6 fibers and recycled carbon fiber. Resistance welding and co-consolidation gave similar shear strength of about 9 MPa, but the co-consolidation with localized heating reached only around 56 % of the shear strength (around 5.4 MPa). Optical observation shows adhesive failure, indicating that the contact time above temperatures allowing for healing was insufficient and requires further improvement.
The Electroimpact Automatic Fan Cowl Riveter uses two novel drill processes to control exit burr height and achieve the required hole quality in CRES (Corrosion-Resistant Steel, also called stainless steel) material stacks. Both processes use piloted cutters on the OML (Outer Mold Line, referring to the exterior surface of an airframe) side, and two different tools are used in a backside spindle on the IML (Inner Mold Line, referring to the inside surface of an airframe) side of the component. The first process uses a shallow-angle shave tool in the IML spindle to directly control the exit burr height after it is produced by the OML spindle and is called the “burr shave” technique. The second process uses a countersink tool in the IML spindle and produces an “intermediate countersink” after the pilot hole is drilled by the OML spindle, but before the final hole diameter is drilled. These drill processes were able to achieve the required hole quality in a challenging CRES material stack, which allows the machine to be qualified for one-up assembly of the component.
The initial powder used for the manufacturing of NdFeB permanent magnets is usually prepared through rapid cooling, either by melt spinning or strip casting. The powders produced by these two methods are suitable for different applications: while melt-spun powder is a good initial material for bonded and hot-deformed magnets, strip-cast powder is normally used for sintered magnets. To investigate the suitability of using strip-cast powder to manufacture hot-deformed magnets, NdFeB powder prepared by strip casting was hot pressed (without particle alignment) and compared with melt-spun powder prepared under the same conditions (700 °C, 45 MPa, 90 min). Although the processing parameters are the same (pressed in the same mold), the magnetic properties of the magnets made from the two powders are significantly different. Surprisingly, the magnet made from the strip-cast powder (after ball milling) shows comparable magnetic properties to those of isotropic magnets, with coercivity (HcJ) of 1270 kA/m and remanence (Br) of 0.7 T, while that made from the melt-spun powder exhibits much lower properties: HcJ = 480 kA/m, Br = 0.5 T, although the melt-spun powder initially shows much better magnetic properties than the strip-cast powder. Possible reasons for such a difference in magnetic properties are discussed. It was shown that the particle size of the initial powder plays an important role in determining the final magnetic properties of the hot-pressed magnets.
The present research explores the potential of high-performance thermoplastics, Polymethyl Methacrylate and Polyurethane, to enhance the passive safety of automotive instrument panels. The purpose is to evaluate and compare the passive safety of these two materials through the conduct of the Charpy Impact Test, Tensile Strength Test, and Crush Test —. For this, five samples were prepared in the case of each material via injection moulding, which enabled reliability, and consistency of the findings. As a result, it was found that in the case of the Charpy Impact Test, the average impact resistance varies with PMMA exhibiting a level of 15.08 kJ/m2 as opposed to the value of 12.16 kJ/m2 for PU. The Tensile Strength Test produced the average tensile strength of 50.16 for PMMA and 48.2 for PU, which implied superior structural integrity under tension for the first type of thermoplastic. Finally, the Crush Test showed that PMMA is more resistant to crushes on average than PU with the measures of 18.5 and 16.2 KN. In this way, the results of the research allow concluding that PMMA has the capacity to absorb energy and support the development of forces better than PU, and is, therefore, more suitable for the purposes of improving passive safety in terms of automotive applications. The findings suggest that PMMA offers better protection for vehicle occupants by reducing the severity of injuries during collisions, especially automotive instrument panels.
Bemis Manufacturing and BASF collaborated to develop a lighter-weight and lower-cost hydraulic tank for compact excavators that was recognized with a lightweighting award traditionally reserved for automotive innovations. Receiving an honorable mention in the Enabling Technology category of this year's Altair Enlighten Awards, the development team leveraged a combination of injection molding and vibration welding techniques to lower costs by approximately 20% and reduce mass by about 5% compared to the traditional roto-molding process. The solution also is more eco-efficient, delivering both environmental savings (reductions in lifecycle CO2 emissions) and reducing lifecycle costs.
Aitiip is a leading Spanish research and development institute and serves companies in the aeronautics, automation, industrial, and packaging sectors. The institute possesses strong platforms for the characterization of materials and processes and is known as a powerful integrator of technologies, which is constantly on the lookout for the next transformative technology. A year ago, Aitiip implemented an NXE 400 industrial resin 3D printer platform from Nexa3D to explore integrations of additive manufacturing and injection molding. Nexa3D is the Ventura, California-based provider of high-speed industrial printing technologies whose portfolio continues to grow, reflected in its acquisition of Essentium, one of the world's most well-known providers of extrusion 3D printing, earlier this year. Liebherr is one of the world's largest providers of a variety of industrial goods, services and products. Aerospace and transportation systems is one of 13 different product segments supplied by the multinational Liebherr Group. Liebherr-Aerospace & Transportation, based in Toulouse, France, produces a wide variety of systems and components for the aerospace industry across five global locations. The aerospace product segment develops and manufactures flight control and actuation systems, gearboxes and travel mechanisms, air management and cooling systems, as well as electronics among other systems and components.
The experimental investigation aims to improve natural composite materials aligned with feasible development principles. These composites can be exploited across several industries, including the automobile and biomedical sectors. This research employs date seed powder and neem gum powder as reinforcing agents, along with polyester resin as the base material. The fabrication route comprises compression moulding, causing the production of the natural composite material. This study focuses extensively on mechanical characteristics such as tensile strength, flexural strength, hardness, and impact resistance to undergo comprehensive testing. Furthermore, the chemical properties of the composites are examined using the FTIR test to gain understanding by integrating different proportions of date seed powder (5%, 10%, 15%, and 20%) and neem gum powder (0%, 3%, 6%, and 9%) in the matrix phase. These investigation goals are to evaluate the strength and performance of the fabricated composite materials. The results acquired from these evaluations contribute to identifying the finest loading situations that can be efficiently applied in real-time applications.
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