Injection moulding
Apart from showcasing the latest developments in flexible, highly automated injection moulding technology along with special units for high-tech applications, K 2004 (www.k-online.de) once again presented the whole spectrum of innovative advances on the process engineering front. Visitors could inform themselves about combinations of special processes such as multi-component injection moulding with the gas-assist and water injection techniques, injection moulding of micro-cellular foams and various in-mould decoration processes.

On the machinery side, drive technology is now playing an increasingly important role in injection moulding. Energy- saving electrical drives today are no longer just found in all-electric machines, but also in machines with a modular drive technology. All-electric machines – which account for the majority of the market in Asia and just under a quarter of the market in North America – are making comparably slow progress in Europe. Another key topic at the fair were direct drives with high torque that manage without a reducing gear unit and thus reduce the risk of failure and amount of maintenance. These are now gradually making inroads into injection moulding machine construction.

Extrusion
Manufacturers of extruders and extrusion lines also are now opting mainly for high-torque direct drives. They are easier to handle and maintain, reduce the footprint and bring double-digit energy savings. Many machinery manufacturers now offer standardised extruders with good value for money. Often sporting a “plug-and-play” label, these machines are available with short delivery times, are quick to start up and easy to operate. At the same time, they also have the advantage of flexibility. The entire range of these standard extruders was on show at K 2004.

Film manufacture
For film extrusion, machinery manufacturers not only have raised outputs in blown film and cast film extrusion, they also have made polypropylene a standard product for blown film. With three-layer film having become the accepted standard, new five-layer films now offer improved properties and bring significant cost savings on the raw materials side through even thinner sealing layers, fewer additives and a more uniform distribution of the individual layer thicknesses.

Blow moulding
For large-sized blow-moulded containers, the multi-layer technology is gaining increasing popularity. PET stretch blow moulding, for example, is constantly growing. The specific output per cavity has been rising continuously, while the weight of the moulded parts has fallen. From 2000 to 2002 alone, the average weight of a 1.5 litre bottle, produced on a modern large two-stage machines with an output of 1,500 to 1,600 bottles per hour/cavity, fell by around 10 %. Exhibitors at K 2004 demonstrated the latest increases in productivity.

Thermoforming
In the thermoforming of vehicle interior parts, female forming is gradually gaining in importance. The grain is produced by the thermoforming tool. The advantage is the very uniform reproduction of the grain on the finished part, regardless of radii, corners and edges, and is a useful alternative to male forms. In the field of thermoformed packaging, PET- based materials are becoming increasingly popular due, among other things, to their brilliance and microwave compatibility. On show at this year´s exhibition were a wide range of complex machinery and equipment designed to provide users with a reliable, fully automatic production process that guarantees 100% quality control of the finished parts.

Rubber
The rubber industry also showcased its new products at K 2004. Silica compounds, for example, are being used increasingly for the production of tyre treads to improve rolling resistance and anti-noise properties. They are extremely abrasive and necessitate modifications to the mixing and extrusion units, with particularly hardwearing, thermally controllable process elements. For rubber extrusion, mathematical programmes have been developed for calculating the process of continuous vulcanisation. Gear pumps for rubber processing on its own or in combination with extruders (for example, for the production of preforms for rubber mouldings) are constantly finding new fields of application. In building and automotive applications, manufacturers are turning increasingly to heat-resistant and flame-resistant materials, which make corresponding demands on the design of the screw and the heat control system of the extruders.

Polymer materials
The chances of anyone coming up with a material made of a completely new polymer are very slim indeed, so most producers are concentrating on ways to provide existing materials with improved properties and customised property profiles. New colouring concepts and systems for improving the flame resistance of plastics are keeping many people busy in the chemical industry´s applied technology departments.

At K 2004, a number of advanced concepts and the possibilities for applying them to other types of plastic were on display. Such advances in process technology consistently are opening the door to the production of plastic grades with brand-new property profiles. With polyolefins for packaging, for example, the future will see grades with a new combination of toughness and rigidity, transparency and processing properties, predicts the organiser of K 2004, Messe Düsseldorf (D-40001 Düsseldorf; www.k-online.de).