On 2nd and 3rd April 2014 in Mannheim, Germany the Association of German Engineers (VDI) is hosting the international plastics conference Plastics in Automotive Engineering. In the form of strategic overview lectures from research and the market, topical technical reports from the passenger car and commercial vehicles sectors concerning plastics innovations and practical examples from plastics processing, the conference serves as a source of information about the state of the art in plastics technology and automotive applications.
A technical exhibition by plastics producers and machine manufacturers as also an accompanying auto show with the latest cars and commercial vehicles allow attendees to discuss technical points at the physical object itself.
Pre-dimensioning of direct fastenings
As support for design engineers and developers, Ejot offers a prognosis programme for the pre-dimensioning of direct fastening into thermoplastics. Depending on material and pilot hole dimension, the fastening parameters of the Delta PT screw can be calculated with this tool. It will help to reveal potential cost savings, particularly during the design stage of a component.
With the development of the Delta Calc prognosis programme, Ejot aims to offer a precise calculation tool, suitable for calculating the boss hole design, the clamp load oriented design (screw dimension and required tightening torque), the assembly parameters as well as a prognosis for the long-term performance of a screw joint.
Adhesive solutions for a carbon fibre BIW
Dow Automotive Systems provides OEM customers with customised adhesive solutions that enable bonding of all lightweight materials, including carbon fibre composites. Application areas include compartment solutions for compact electric cars as well as boot lids.
Adhesives offer an alternative to traditional mechanical and thermal processes, which cannot be applied to these lightweight materials, says Dow Automotive. Bonding solutions such as Betaforce structural adhesives are intended to enable a continuous bond line and cohesive joining of surfaces. Recent formulations of this adhesive offer a cycle time of around 1min and are currently being used for volume production. Open times can be adjusted to accommodate specific mounting requirements in the plant, such as a quicker curing time by infrared treatment. In addition, the initial adhesion requires no additional fixing tools.
Customised automotive interiors
Bayer MaterialScience is showing numerous variants of a decorative strip designed for automotive interiors. The concept components were created in close collaboration with Gerhardi Kunststofftechnik in Lüdenscheid, Germany. The processing specialist developed a mould concept in which a diverse range of surfaces and design variants can be efficiently produced. The performance spectrum of Bayer polycarbonate (PC) materials enables a single mould frame to be used for a wide range of decorating options. “These include matte and high-gloss structures, attractive shades with deep lustre and also coated, film-decorated and metallised surfaces,” says Dirk Kieslich, Head of Product and Process Development at Gerhardi. “This near-volume mould can be used to replicate the most common surface design techniques and thus produce a wide array of variants without further processing steps”.
One possibility is the production of three-dimensional laser-engraved graining with two different levels of gloss. The high flowability and processing temperature of the PC+ABS blend Bayblend HG allows for the precise reproduction of the graining, the structure is said to provide a natural form of scratch protection. The glossy surface can then be coated in a particular colour using coatings formulated with polyurethane (PU) raw materials.
The use of the metallisable product Bayblend T65 PG expands the spectrum of design possibilities. Chrome surfaces can be produced on the component by means of galvanic plating. Structures with matte or high-gloss designs can be produced using the StrukturChrom process, a decorating technology developed by Gerhardi. Components with integrated lighting provide a look at the plastic surface below. Three-dimensional laser engraving is also possible.
PC films such as Makrofol HF open up further prospects for the visual design of automotive interiors. These scratch-resistant, coated films are robust and thanks to new processing technologies can also be shaped three-dimensionally. The result is components with a customised appearance.
One interesting variant are surfaces with daytime/nighttime designs that are a good fit with the current infotainment trend. The optical display is only visible when switched on and is produced by means of LEDs behind the film. Otherwise the driver sees only an elegant, matte-black surface.
Processes for composite components
Lightweight design will be one of the focuses of Engel’s presentation. Special attention is given to the processing of semi-finished thermoplastic products (organic sheets and tapes) and to reactive technologies that use thermosetting and thermoplastic systems, such as HP-RTM and in-situ polymerisation. In cooperation with ZF Friedrichshafen, Engel launched at the K 2013 the first one-shot process for the production of composite brake pedals using the organomelt process. New efficiencies in composite processing will be presented at Mannheim as well.
Additionally, Engel will present its Dolphin and Varysoft technologies for soft touch surfaces for vehicle interiors. Compared with other technologies, the Varysoft process, developed at Georg Kaufmann Formenbau, is said to offer great softness while allowing undercuts in the mould design. During a recent “Varysoft Day” in Austria, Engel presented a highly-integrated and automated production cell that combines a decorative film with thermoplastic carrier and a PU foam layer in a single step.
About functional surfaces is the clearmelt technology. In this case, a thermoplastic carrier is injected and then immediately flooded with transparent PU. PU makes the surface scratch proof and gives it visual depth. At the same time, functionality can be added to components through smart electronics by inserting capacitive films into the mould. In this way, controls can be integrated into thin decorative trims – both visibly and invisibly.
Reinforcing agents and additives
Milliken will present its high performance reinforcing agent, Hyperform HPR-803i and its Hyperform HPN nucleating additives for polyolefins. New application examples will highlight the weight-reduction benefits.
The synthetic reinforcing agent Hyperform HPR-803i is intended to allow automotive designers to create parts that are up to 15% lighter without compromising performance. Hyperform HPR-803i is added at a lower addition rate than mineral fillers to polypropylene (PP) compounds, so the compounds have a lower density. Used alone or with talc, it helps automakers meet weight reduction targets and produce cars with reduced fuel consumption and lower vehicle emission.
Hyperform HPR-803i compounds are suitable for injection moulding operations originally designed for talc-filled compounds, simplifying testing requirements and reducing implementation costs. PP compounds reinforced with HPR-803i are said to maintain their mechanical properties even after multiple recycling and compounding operations. Part surface appearance can also be improved, and HPR-803i lets processors reduce pigment usage while still meeting colour requirements. Scratch appearance is improved, which can allow for further formulation optimisation.
Achieving the desired weight with hollow microglass spheres
The 3M company has carried further developments to its hollow microglass sphere technology over the past few years and brought out a hollow microglass sphere in the form of the “iM16k”. This features an isostatic compressive strength of 1,100bar alongside a low density of 0.46g/cm³. This hollow microglass sphere enables the manufacture of plastic compounds with low density which, when processed using standard injection moulding or extrusion techniques, give a reduction in weight of 10% or more. In Mannheim, 3M are demonstrating ways in which these hollow microglass spheres can be used in lightweight construction. Some examples of applications are bumpers and boot lids.
A further focal point is the “two-component project”. This is the name given to a combination material based on Stanyl polyamide 46 und 3M Dyneon Fluorelastomer which has been developed jointly with DSM Engineering Plastics. This two-component material has been developed as an alternative to metal and metal elastomer composites, in particular for high temperature applications for the automotive industry.
Norilux DC is a formable, abrasion resistant Dual-Cure screen printing lacquer by Proell. It can be used as protection lacquer or hard coat on PC and PMMA films and is said to be ideally suited for first surface coating/protection of products manufactured in IMD/FIM technology. The glossy version of the Dual-Cure lacquer can be printed on textured film surfaces to produce abrasion resistant and transparent display windows. The matte version of Norilux DC can be printed on uncured transparent hard coat films such as Makrofol HF 278 or 312 to create matte and high gloss effects in one item. Besides the high glossy Norilux DC-5 lacquer, various matte grades, anti-microbial, UV-stabilised versions are available as well. The Dual-Cure screen printing lacquer can be used for overprinting silicone-free UV, solvent and water-based screen printing inks (pre-tests required). Norilux DC dries by evaporation of the solvents in jet dryers. Before further processing of the printed films, it is necessary to remove nearly all solvent residues from the layer of lacquer and substrate.
Films decorated with Norilux DC can be 3D formed after box oven drying, for instance by high pressure forming or thermo forming. Afterwards, the formed films must be UV cured. Depending on the thickness of the lacquer layer, UV doses of 1,200-2,000mJ/cm2 are necessary (Kühnast UV-Integrator, UV 250 to 410nm, max 365nm). The cured lacquer layer is said to show good resistances to abrasion, chemicals and cleaning agents and passes various creme tests of the automobile industry.
Surfaces and interior components
Recticel will exhibit its next generation of polyurethane (PU) moulded skin, in volume production since the end of 2013. Colo-Sense Lite, with its average density of 750kg/m?, is said to provide a solution in the search for overall weight reduction in today’s car industry. Its aliphatic top layer is intended to ensure durability over life time, its aromatic foamed back layer provides low density at high dimensional stability. Colo-Sense Lite can be used in traditional back foaming and airbag scoring processes.
For reducing the vehicle’s parts weight, Recticel will exhibit its CompoLite solution. Compared to conventional substrates, CompoLite substrates are more lightweight while keeping comparable mechanical properties and crash behaviour, and thus contribute to an effective reduction of car weight, according to the company.
This lightweight substrate may be combined with a variety of decorative materials. Small radii, contoured undercuts, as well as dynamic cross sections are possible with nearly no restrictions, says Recticel. The high dimensional stability and the CompoLite production process enable a direct integration of attachment features and functional parts.
Compounds based o styrenics chemistry
A new family of Sarlink thermoplastic elastomers (TPEs) from Teknor Apex expands the range of alternatives available to manufacturers of sealing systems and other automotive components by providing similar and in some cases improved performance compared with thermoplastic vulcanisates (TPVs).
The new compounds are the first Sarlink products to be based on styrenic TPE (TPE-S) chemistry. TPE-S compounds are said to exhibit strength and elasticity comparable to TPVs. They provide smoother part surfaces and equivalent or better long-term UV stability than TPVs and exhibit a broader processing window in injection moulding. While standard TPVs are restricted in colour to natural and black, TPE-S compounds are available in a variety of custom-matched colours. Unlike TPVs, they generally do not require pre-drying. On the other hand, TPVs exhibit better resistance to hydrocarbon fluids such as oil and grease and have a higher service temperature – 115 ºC as against 100 ºC for TPE-S compounds./p>
The four series of Sarlink TPE-S compounds being introduced for automotive applications are: high-performance extrusion compounds for functional parts such as sealing systems; general-purpose extrusion compounds for non-functional parts such as semi-rigid supporting components for sealing system backbones; high-performance injection moulding compounds for window encapsulation and exterior trim; and general-purpose injection moulding compounds for under-the-bonnet and interior components.
Styron Automotive will be highlighting several examples of their most recent commercial successes and their ability to overcome industry challenges through collaboration, specifically in regards to the Pulse GX50, GX70, and GX90 solutions. Styron will exhibit several parts of the following car models:
- Mercedes Benz C-class: pillars and door panels
- BMW i3 series: door sill trim, mid console parts and glove box
- Audi Q3: A-pillars