PRA Jan-Feb 2012 IMA Moulds

Injection Moulding Asia Largest MuCell system

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erman machine maker KraussMaffei, US-based Trexel and mould maker Mürdter Werkzeug-und Formenbau are applying MuCell microcellular foaming technology in the largest injection moulding machine at Mürdter’s factory in Mutlangen, Germany.

The machine is an MC 5400-17200 with 5,400-tonne clamping force.

Mürdter makes large moulds for automotive parts such as instrument panels and door panels and has large injection moulding machines for trials and small production in its nearby mould unit.

The companies say that MuCell technology allows the moulding of large components with shorter cycle times, lower clamping force, material savings and weight reduction.

Erodible material extends tool life

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ermany-based Leroxid has introduced Dimacer erodible ceramic material for tools for injection moulding, extrusion dies and other parts such as gears and threaded components. Said to achieve a longer life-span, it won EuroMold’s gold award at the show that was held late last year.

The ceramic has a degree of electrical conductivity that enables the ceramic mould parts to be produced using the spark erosion process. In addition, it’s co-efficient of thermal expansion and thermal conductivity values are close to steel, plus the material is said to outperform steel with its improved abrasion

resistance. This is useful in mould gates when injection moulding glass fibrereinforced plastics as well as in micromoulding.

Dimacer is also suited to ceramic injection moulding (CIM) and powder metal injection moulding (MIM) for sharp-edged parts, where mould wear becomes apparent after a low number of shots.

The material is prepared as a ceramic suspension containing a low 24% (by volume) of titanium carbide conductive content and meta-stabile tetragonal zirconium dioxide to prevent brittleness. It is then spray dried and sintered into blanks for spark erosion. The process is used to ensure that the conductive additive does not compromise the ceramic’s strength and toughness.

displayed in the new Fina chair from Brunner.

While the conventional way would be to use complex rotary table or stack moulds with painting required for an aesthetic surface, Deckerform says the GF-PP core serves as a barrier layer preventing sink marks from forming in outer layers. The process also boasts 40% lower material costs, is less expensive and has a faster cycle time, according to the mould maker.

Moulds as HDPE and PBT is vital to manufacturers as they can increase their production rates and gain a higher profit by filling a polymer with glass. Since glass cools faster, it reduces the time that the polymer needs to stay in the mould, allowing a faster output rate for products.

Integrated assembly for cost efficiency

Kit for testing pvT

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cientists at the UKbased National Physical Laboratory (NPL) research centre have introduced a pressure-volumetemperature (pvT) and thermal conductivity test kit. Based on nine years of research, the kit measures the thermo-physical properties of polymers and can help improve the injection moulding process by allowing designers to find the exact pvT and shrinkage properties of a material.

The pvT instrument operates at pressures ranging from 200-2,500 bar and is said to be the only equipment in the world that can test materials at ultra fast cooling rates of up to 280°C/minute and down to temperatures approaching -100°C. NPL says that at higher pressures, polymers can conduct heat up to 20% more efficiently, leading to faster cooling rates and shorter cycle times.

A thermal conductivity measurement feature is also incorporated in the instrument. Research on the thermal conductivity properties of polymers such

Mono-sandwich process improved

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nother winning entry (winning the Silver award) at the show came from mould maker Deckerform Technologies’s three component monosandwich process for one or two-colour parts that are subjected to high static loads.

The company says that glass fibre-reinforced nylon can be substituted with the use of inexpensive unreinforced PP in the outer/edge and 50% glass fibre-reinforced PP as the core material. The second colour together with a third component is injected in the same process cycle as a fourth boundary layer on the mono-sandwich part.

The layer structure provides stability and hardness for example to a spring seat, as

The lightweight closure was shown at Fakuma

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t the recent Fakuma show in Germany, the total integrated manufacturing or TIM principle, developed by Germany-headquartered mould maker Zahoransky, was displayed on a KraussMaffei machine.

The swivel-platen CXW 200-380/160 SpinForm machine was moulding a lightweight, three-part plastic closure made of PP. The parts came out of the machine ready to be assembled. This system was designed by the two companies to allow for a higher productivity on a small footprint.

The two-platen clamp of the CX series offers easy accessibility to the mould and has ample space for the integrated assembly stations.

The two injection units are positioned centrally opposite each other, making

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Injection Moulding Asia Moulds it possible to use simple hot-runner systems with natural balancing and short flow paths. This reduces the volumes of melt in the hot runners, making for simpler process management and consistent part quality, say the companies.

This new concept is not only cheaper than traditional injection assembly solutions, but it is also more effective due to lower mould investment, said Zahoransky.

Laser polishing of tools a reality

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urrently, components used in tool and die making are hand polished.

But German Fraunhofer Institute for Laser Technology Institute (ILT) recently developed a machine tool that uses laser polishing to give complex 3D surfaces a high-gloss finish, up to ten times faster than hand polishing. It has been developed in collaboration with Maschinenfabrik Arnold and S&F Systemtechnik.

While conventional methods remove material from the surface to even it out, ILT’s method uses a laser to melt a thin surface layer roughly 20 to 100 microns deep. Surface tension – a property that applies to all liquids – ensures that the layer of liquid metal solidifies evenly.

Depending on the material, it is able to produce surfaces with an average roughness (Ra) of between 0.1 and 0.4 microns. Though ILT says hand polishing can still get better results than that, in many applications a medium-quality surface is

In addition to SLM, Fraunhofer ILT is also promoting the use of Laser Material Deposition (LMD).

The difference between SLM and LMD is that in SLM, the process produces close contour mould inserts out of highly conductive copper alloy, which was previously not possible as copper alloy powders have lower laser light absorption and higher heat dissipation than steel-based powders because of the higher thermal conductivity. This interrupts the melt track and small molten metal balls form, which create pores and lead to lowdensity parts.

ILT overcame the restrictions by using a more powerful 1,000W laser instead of the conventional 200W SLM lasers used with aluminium, cobaltchrome, titanium and steels. The firm optimised the process by choosing a particularly even beam profile and changing the inert gas control system and mechanical equipment.

By contrast, in LMD, the components are produced by laser melting powder material projected by a nozzle onto specific areas of the component. SLM is capable of generating the finely detailed structures of complex components while LMD is more suited to the manufacture of largearea components and for repairs.

The 3D SLM method is said to reduce production costs, with no costly tool modifications required to produce undercuts, internal cooling channels or complex support structures, for example. ILT says SLM is now ready for industrial use as it has achieved workpiece density of 99.9%.

all that is needed.

The system consists of a five-axis gantry plus an additional three-axis laser scanner, a design that enables it to be accessed from all sides. Mirrors deflect the laser beam to allow feed rates (the speed at which the laser beam moves along the workpiece within a specified time frame) in excess of 1 m/ second, even on small surfaces. An end-to-end CAM NC data chain has also been developed, which draws on a 3D CAD model of the component to be polished. The beam path data is calculated on the basis of this model.

Rapid prototyping made easier with SLM

Component removal at the end of the SLM process

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raunhofer Institute for Laser Technology (ILT) has also been driving forward additive manufacturing technologies. Its latest is Selective Laser Melting (SLM) that enables customised components, such as medical implants or parts for machine tools, to be manufactured costeffectively and rapidly in small batches using 3D CAD data, following the just-in-time principle. The firm says that with this, a metal-based prototype can be presented in a shorter time compared to the time it used to take previously.

3D multi-cycle software

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erman software provider Sigma Engineering’s latest Sigmasoft multi-cycle analysis is said to be a new benchmark for 3D injection moulding process simulation.

While in conventional software, a fixed mould temperature is defined and the simulation is undertaken assuming that this value remains constant over time, in reality, a complex thermal process is taking place in the mould.

As the steel is cooled with a tempering system, the mould is heated when the hot melt enters the cavity and there is loss of thermal energy in the surrounding environment. All these are governed by the heat transfer properties of the materials present in the system, like the melt, runner system, inserts, mould and isolation materials.

Hence, the firm says that only when these complex interactions are considered will the real production conditions be reproduced in the simulation. The 3D approach allows the mould components, including all the individual thermal and physical properties, to be exactly reproduced.

The firm says this allows the heat transfer process to be accurately calculated between each one of the components.

The simulation attempts to exactly reproduce the heat-up during machine start-up, when the mould is heated from room temperature to its production conditions. It also includes the warm-up produced by the hot melt over several consecutive

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Injection Moulding Asia pre-production cycles.

With this, Sigmasoft is able to simulate the thermal evolution of the mould over multiple consecutive production cycles.

This calculation is said to be able to predict the real temperature in each location of the mould during production, with conditions that Sigma says are more realistic. This allows the software to predict how long the polymer remains in a fluid condition so that post-pressure can be applied or where thermally induced deformation could most likely compromise part quality.

Multi-cycle simulation also allows the calculation of the number of production cycles required for the mould to achieve cyclic equilibrium, allowing a comparison of the efficiency of different tempering systems to understand how to achieve equilibrium more quickly and consume less energy.

Ball valve to meet tighter water laws

and warehouse areas at the Kottingbrunn facility by 3,000 sq m. This is to meet increasing orders for its large machine MacroPower.

First introduced in 2010, the model, available in clamping forces from 5001,100 tonnes is continuing to witness a “positive order situation and strong demand.” The company also says its facility was utilised to full capacity last year.

The assembly capacity will be increased by 1,600 sq m with a new building while the pre-assembly and warehouse capacity has already been expanded by 1,400 sq m through remodeling of existing buildings.

The extension of the assembly space will be implemented by adding a new bay to the existing assembly hall to cater specifically to producing the large machines. The new hall is expected to be completed by the end of September 2012.

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hinese component manufacturer for plumbing and heating systems Link-Tech has developed what is said to be the industry’s first modular ball valve that features several thermoplastic components including the ball, ball valve housing and several connector components.

The PolyBrass ball valve incorporates thermoplastic parts made of Acudel modified polyphenylsulfone (PPSU) resin from US-based Solvay Specialty Polymers, for prolonged resistance to hot chlorinated water and tight tolerance moulding.

Link-Tech is targeting its PolyBrass ball valve for the US market where new legislation to be enacted in 2014 will require lead-free systems for potable water and heating applications for residential and commercial use.

Modular construction allows versatility for the ball valve, thereby permitting use with a range of fittings including threaded screws, pushes and crimps. All three parts are injection moulded including the ball, which serves as a flow control device. Acudel modified

Industry News

Large machine orders boost expansion

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erman machine maker Wittmann Battenfeld is expanding its production

Wittmann Battenfeld is expanding its facility to meet the demand for its machines

The all-new ball valve features plastics in most of its components

PPSU allows tight tolerance moulding of the ball, previously made of metal, thus eliminating machining and post-treatment operations. All three parts are manually assembled.

China to lead in machine uptake

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new study from Freedonia Group forecasts global demand for plastics processing machinery is expected to increase by 6% a year until 2015. The “World Plastics Processing Machinery” report says that demand will reach to US$28.9 billion by 2015, with China to account for 40% of all additional global demand until 2015.

The US company also says that amongst the types of machinery, extrusion equipment will have the highest growth due to infrastructure development.

Meanwhile, injection moulding machinery will still remain the largest segment of the industry, accounting for 40% of demand in 2015.

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