Triple screw extruder design
Keimei Plastifizierung Technik introduced their range of high efficiency triple and twin screw extruders as well as their versatile system of blend reactors for challenging applications. The systems are all equipped with a three-start screw design, which are said to provide an optimised balance between plasticising effect, output and energy consumption.
One highlight introduced at the K show included Keimei’s triple screw extruder design. The processed materials are sheared three times per screw revolution. Additionally, the trefoil formation provides three cutting points between these three screws in the barrel, compared to only one in a conventional twin screw extruder. Keimei says that in-house tests proved that, due to the combined effects of three-start screw and the use of the triple screw design, the L/D ratio of the systems can be reduced to only one third of that required for a comparable standard twin screw extruder design to achieve the same plasticising effect. Hence, also, the retention time of the material inside the barrel is just one third. The systems are particularly suitable for polymer blending and grafting, compounding and dispersing of powder and polymer additives, and also for the continuous mastication of rubber.
PA crankshaft cover
DSM, together with its automotive component specialist partner Kaco, have developed a lightweight multi-functional crankshaft cover in biobased polyamide 410, EcoPaxx, which is derived from 70% natural resources. It will be used on Volkswagen’s new MDB modular diesel engine platform, implemented across its Audi, Seat, Škoda and VW brands.
In component production, Kaco uses a highly energy-efficient production cell to not only mould the crankshaft cover, but also integrate two separate seals: the first, in PTFE, is placed into the mould by a robot, and EcoPaxx is over-moulded onto it; the second, in LSR, is then moulded directly into the part using a 2K process. Fibre orientation, the number and position of gating points, and the design and integration of the various inserts of the crankshaft cover have all been optimised to minimise warpage and ensure tight seals between the cover and the engine block and oil sump. The cover also has to resist tightening of bolts fixing it to the engine block and the sump (each of which is built to different tolerances), as well as from tools used to fix the position of the FEAD (Front End Accessory Drive) belt.
Compared with covers made in aluminium, system costs for the EcoPaxx cover are said to be lower and lighter, since the PA grade is 45% less dense than aluminium.
Transparent biopolyamide for tubes
Ems-Grivory introduced its biobased extrusion grades Grilamid 1S XE 4281 and Grilamid 2S XE 4282 for flexible, transparent and impact resistant pneumatic tubes. Thanks to proprietary technology, the products are said to show properties such as flexibility, impact strength and transparency. In addition to the extrusion of transparent tubes, the products can also be used for coloured tubes, where the transparency of the base polymer is claimed to ensure intense colours and a good gloss finish frequently required in the pneumatic tube sector.
The polyamide PA1010 Grilamid 1S is based to nearly 100%, PA610 Grilamid 2S to 62% on renewable resources. The properties of Grilamid 1S are said to be close to those of polyamide 12 (PA12), the properties of Grilamid 2S are positioned between those of PA12 and PA66 or PA6.
Moulded auto parts with 20% density reduction
3M, manufacturer of high-strength glass bubbles, and Trexel, the exclusive provider of MuCell Microcellular Foam injection moulding technology, demonstrated the results of combining a variety of optimised polymer resin systems using 3M Glass Bubbles iM16K with Trexel’s MuCell foaming technology.
The combination is said to enable manufacturers to realise 20% density reduction of finished plastic parts with mechanical properties comparable to standard formulations. Manufacturers can also reap improvements in dimensional stability, process throughput and sustainability, according to the companies. The combined 3M and Trexel technology is also said to offer several benefits including lower cavity pressure resulting in reduced clamping tonnage, no sink marks and increased sustainability resulting from the use of less petrochemical feedstock.
As part of 3M’s line of high-strength glass bubbles, the company’s latest product in the family, iM16k, is especially relevant for automotive applications as it is designed as a high-strength injection moulding grade glass bubble for PP, PA and other polymer systems. It is intended to feature crush strength of >16,000 psi.
MuCell foaming technology uses the controlled use of gas to create a foamed part, resulting in high quality precision and engineered plastic components, while reducing production costs associated with lower material consumption, shorter moulding cycle times, and reduced machine clamping tonnage requirements. The process also leads to predictable and repeatable part geometry, allowing for the use of lower cost polyolefin resins without warpage or distortion.
Thermally conductive & glowing in the dark
High-performance fillers from HPF The Mineral Engineers, part of the Quarzwerke Group, are based on naturally occurring and synthetic minerals such as quartz, wollastonite, kaolin or mica and can impart distinctive functional or optical properties to plastics. Recent innovations include Silatherm, a filler which is said to substantially increase the heat conductivity of thermoplastics and thermosetting plastics, as well as Silglow, an after-glowing filler.
The use of Silatherm for boosting a product’s thermal conductivity is said to eliminate an undesirable side effect often associated with metallic fibres or powders employed for this purpose, and this means that compounds containing Silatherm retain their good electric insulating properties.
Another distinct functionality is provided by the Silglow filler, which features a special inorganic coating of high mechanical and thermal stability. Its fused silica grains absorb daytime sunlight or light from any other source and emit it in the dark. A lasting afterglow capability can thus be imparted to thermosetting plastics, paints and coatings.
Vehicle face using hot stamping
The Leonhard Kurz company showcased a chrome coated radiator grille with a diamond lattice look, produced in the hot stamping process. The requirement from the auto industry was to apply a partial metallic finish to a radiator grille. The plastic part consisted of a lattice structure with 288 individual pins protruding from the nodes on the external face. These pins, which form the visible face of the radiator, were required to be given a brilliant and high-quality chrome finish. The particular difficulty with this application was that the pins all had domed heads and varying shapes so as to produce a non-uniform refraction, and consequently a diamond-like sparkle, after the metallic coating has been applied. Full-surface galvanic chroming of the plastic part would have adversely affected the appearance of the individual pins. To individually galvanize the pins and then mount them would have required enormous effort. It was therefore decided to use the environmentally friendly and more economical hot stamping process. In this dry transfer process, the chrome layer, together with top lacquer and adhesive layers, are released from a carrier foil by means of a heated silicone die and permanently bonded to the plastic part.
Besides the pin geometry, a further challenging aspect is the size of the radiator grille because an injection moulded part of this size is required to meet part tolerances within 2mm. The particular challenge was to ensure that the silicone die, into which the curvature of each individual pin had been incorporated, would contact each pin precisely and transfer the chrome coating accurately and with clean edges. Baier, a member of the Kurz Group, developed a custom hot stamping machine especially for this application: a four-head hot stamping machine with four indexed part fixtures that divide the radiator grille into four segments that are coated consecutively.
Vehicle glazing made of Plexiglas
Evonik presented vehicle glazing options with PMMA with the MicroMax concept vehicle, among other features. “Since Plexiglas glazing offers great potential in vehicle construction, we are pursuing two development lines so as to offer our customers the widest possible range,” says Michael Träxler, Senior Vice President of the Evonik Acrylic Polymers Business Line. Evonik is therefore working on both monolithic and multilayer systems based on Plexiglas. Various monolithic systems with a scratch-resistant hard coating have already received ECE R 43 certification for side, rear and roof glazing, and are being used in a number of prototypes. These include the electric concept vehicle microMax, produced by Swiss think tank Rinspeed. The material was chosen because it can be formed more freely and fabricated more easily than glass by means of injection moulding and all other thermoforming processes. This allows for highly curved or pointed shapes. The combination of several functions is also possible, for example, non-movable windows that include a black pillar trim part and tail light all in one unit. At the same time, functional integration can help to reduce installation depth, thus saving weight. Also, PMMA glazing elements are said to be about 40 to 50% lighter than conventional glass window panes, but to be tough all the same.
In 2014, Evonik is launching a new impact-modified moulding compound for glazing applications. This increases the variety of processing options – from currently thermoforming to now also injection and compression moulding.
The Grafe Group presented its luminescent masterbatches in a wide range of colours and for different processing technologies such as injection moulding, extrusion or staple fibres.
The group is also able to produce this product in all popular thermoplasts as well as to vary the duration and intensity of the luminescence individually in accordance with the wishes of its customers. One of the possible colour effects is the appeal of the night time starry sky. The result can be found across a large spectrum of applications ranging from the fashion and advertising industries through the toy industry to the production of safety equipment. In emergency situations in connection with power failures especially, a quick orientation and a targeted location of emergency exits can save lives. For example, a carpet with woven-in luminescent fibres which are normally not visible by daylight but appear only in the dark, is an example of such a useful, luminescent safety aid. The luminescent masterbatches have been well-known for years but are gaining new importance through their application in technical materials. Up until now, customary products have been available only in a green-yellow luminescent colour.
Wipers in multi-component technology
The French injection moulding machine manufacturer Billion, in collaboration with the mould and rotary units specialist Weber from Esslingen, Germany, showcased a new production item, a skimmer, which looks like the piece of equipment that is used for windscreen wiping. It consists of a PC/ABS Creablend-A45 and a TPE Thermoflex 65A1.2. Both materials were selected by Weber, together with Plastics-Technology-Service (PTS), Adelshofen, Germany, so as to enable the production of a perfect hrd/soft chemical compound in a mould. In this both the wiper skirt and the handle areas (fabricated so as to be slip-resistant) are made from the thermoplastic elastomer and one of the things this does is to ensure easy and secure handling.
The skimmer is manufactured on an all-electric Billion Select injection moulding machine. The Select H150/260-150 T D3 operates with a clamping force of 1,500kN. The second injection moulding machine is installed at an angle of 45° to the horizontal unit. Both units inject into the Weber mould through the fixed moulding plate.
In the case of the rotary unit, what we are looking at is a tried and tested, servo-electric drive indexing version (agitator-type technology), which enables the entire configuration to operate electrically and at the same time with maximum precision. If necessary, this rotary unit (optionally available as index or rotary table) can also be integrated in the mounting plates on the machine at the maximum installation height of the mould without restrictions. One of the things that makes this possible is by extending the side rails or machine framework. The component is designed by Weber. Rheological calculations are carried out prior to constructing the mould so as to enable smear-free cleaning of the surfaces by assurance of an absolutely flat wiper contour.
Ter Plastics Polymer Group introduced the new product series Terez GT3 for the first time, which was developed especially for high metal replacement requirements in the automotive industry, mechanical engineering and sanitary installations.
The Terez GT3 line complements high glass fibre reinforced PA6 und PA66 types and is based on a PA6T/6I/66 with partially aromatic parts. Because of the potential glass fibre content of up to 60%, high stiffness and strength are achieved that keep their good level of strength even after absorbing humidity. The company says that dimensional stability is also increased compared to conventional polyamides.
According to Ter Plastics mould wear can be reduced by using the new material, compared to zinc or aluminium die casting, so that the service life of the mould improves by a factor of five.
Molecor, a Spanish company specialised in PVC-O technology and PVC-O pipe production for water conveyance, presented its latest development: PVC-O fittings, including elbows, reducers, repairing couplers. The prototypes have been validated and during 2014 the industrial development will be finalised. The PVC-O fittings will be available for Molecor licensees at the beginning of 2015.
The molecular orientation process is a physical process that stretches the material and under certain conditions of pressure, temperature and speed, reorganises the polymer molecules achieving a laminar structure. The recently developed air process of molecular orientation now enables pressure pipes to be produced up to DN 800mm.
Latch locking units – now with DLC coating
Latch locking units are used primarily on injection moulds with multiple plate movements. They can be subject to particularly high loads as a function of the component dimensions and the size of the mould. With its extensive range of latch locking units, Hasco offers a variety of options for solving complex applications on a customised basis.
Latch locking units Z170/…, Z171/… and Z174/… which now have a DLC coating on their functional surfaces, are said to keep friction and wear down to a minimum. They are especially suited to use in the food and medical sectors, since production can be run without lubricants, making it compatible to a clean room environment.
According to Hasco, the coating does not lead to any dimensional changes in the functional surfaces, hence the new latch locking units can be fitted 1:1 to existing systems. The Hasco latch locking units show good slip properties, due to the low coefficients of friction, and show high corrosion protection.
Twin screw plastic compounding services
Intertek presented new lab scale twin screw compounding services for the polymer industry. Innovation in new product and materials development for next generation applications is essential to retain a competitive edge and market share in today’s economy. To optimise efficiency and reduce development cost, companies implement materials characterisation programs in the earliest phases of the development process in order to evaluate the likelihood of success and re-direct the development effort accordingly. Time to-market can be reduced when off-spec materials or products are adjusted or eliminated at the earliest stage of the development process. Companies involved in polymer development and processing rely on obtaining this type of data from independent, expert polymer compounding facilities.
Intertek’s Senior Vice President Dr Andrew Swift said: “Our investment in twin screw compounding capabilities is in response to increasing demand we have seen from the industry for independent advanced compounding services. Very few independent commercial test laboratories offer these services coupled with full chemical and materials characterisation capability which plays such an important role in polymer development programs. Companies developing innovative polymer based products often prefer to seek external expert support in materials evaluation to save time and to preserve their own capital for core needs.”
Gear pump technology
With the launch of Maag Pump Systems 6th generation gear pumps, first unveiled at the show, Maag has redesigned every single component featured in its pump portfolio, from gears and shafts through to bearings and seals, fine-tuning how all components interact, culminating in a system with a new industry-leading price/performance ratio. According to Maag, customers will mostly benefit in terms of productivity and process security in a variety of ways.
The portfolio is comprised of multiple sizes covering throughput ranges from a few kg/h up to 100t/h, with application-optimised design options. Sizes 250 and above will be available at launch, while others will be introduced in the course of 2014.
New BOYs at K
Dr. Boy presented six new machine types with a maximum clamping force of 1,000kN and the new EconPlast. The Boy 60 E and Boy 100 E, which have been presented for the first time at K 2013, each achieved a Euromap 60.1 classification of 9+. With the development of the EconPlast units, Boy claims to make the melting and processing of plastics more efficient.
A Boy handling unit was presented at the fair for the first time. The complete removal automation system, which was CE compliant, was demonstrated on the Boy 60 E. Now, in addition to injection moulding machines, Boy offers customised automation systems and the required protective housings as a total package.
Attractive applications like the production of Altbeer glasses on the new Boy 60 E that included a subsequent, local filling station attracted many visitors. The independent insertion and over moulding of blanks for hexagonal socket screw keys was impressive as well. Every visitor could produce his own tool kit on the new Boy 25 E VH.
By the company’s own account, high-gloss delicacy dishes, which were produced on the new Boy 25 E, were popular with the fair visitors. The production-related still pre-heated dishes were in great demand.
Greiner Extrusion presented a wide variety of new efficiency enhancements to its products – from the Red.Line system to advanced development of “flow.control pro” through to the new tooling system. One highlight was the live presentation of the new cutter, Red.Cut. The good cutting quality and exactness of profile separation impressed visitors to the booth shared by Greiner Extrusion Technology and Greiner Tech.Profile. Easy and tool-less changing of the knives demonstrated savings of time and resources. PLC length measurement featured ten preselection modes available from the touch panel. It was also shown that variable adjustment of the cutting speed can be controlled from the touch panel. Accurate cutting-to-length repeatability and its PLC knife heating system were further benefits of the Red.Cut system.