Strictly-Extrusion

Borealis, a leading supplier of innovative, value-creating plastics solutions, introduces a new grade of BorclearTM for high transparent polypropylene (PP) blown films used in food packaging. Borclear RB709CF now provides the food industry with packaging that has improved optics and sealing behaviour, and film converters and extruders with a product that provides cost-effective, environmentally-friendly processing.

Borclear RB709CF is a random copolymer PP characterised by brilliant clarity, outstanding sealing performance, high stiffness and good printability. The heat resistance of up to 100 degrees Celsius and low hexane levels fulfilling FDA requirements make it particularly attractive for food packaging. Potential applications include bread film, lamination film for dried pasta packaging and high gloss label films.

The unique combination of properties of Borclear RB709CF allows film packaging producers to fulfil food industry expectations regarding aesthetically-attractive packaging while at the same time enabling converters and extruders to reduce the amount of film required, thanks to the material’s high stiffness. The reduced material usage results in cost and environmental benefits throughout the food packaging value chain.

Additionally, RB709CF offers faster, more efficient processing. Its low sealing initiation temperature and broad sealing window reduces sealing cycle times, creating more seals per minute and increased line speed. Furthermore, film winding and the converting of the film is made easier.

Mr Kwakman from Kivo Plastic Verpakkingen, one of Europe’s largest producers of polyolefin packaging material, comments: “Borclear RB709CF offers a wide range of benefits that help us to deliver the packaging our customers need to differentiate their products. High gloss, high transparency and good sealing behaviour allow for aesthetically-attractive films with good performance. Plus, it adds flexibility both to our production process and to the finished applications for our films, thanks to the freezability of the material, its good blending possibilities and its processing advantages.”

Borealis has more than 40 years experience in providing advanced polyolefin solutions for industries using film, coating and thermoforming products. Through understanding of the value chain, Borealis continues to provide innovative, value creating PP and PE solutions for the film industry.

Xtrutech is a one-stop service centre for all users of co-rotating twin-screw extruders including APV, Leistritz, Theysohn, W&P, Maris, Baker Perkins, OMC, Berstorff, Clextral and Prism machines. What makes Xtrutech different: Graham Edwards, Managing Director and Richard Johnson, Sales Director with over 50 years of experience between them with Baker Perkins, APV Baker and Theysohn Maschinenbau have set Xtrutech apart by offering more than the OEM’s and more than copied parts manufacturers. Backed by process know-how and many years of experience in twin-screw extruder design, Xtrutech provide industry trained Service Engineers and spare parts including shafts, screw elements, barrel housings and liners, machine upgrades and refurbishments, re-configuration and process optimisation along with preventative maintenance programmes at competitive prices. The company manufactures its wear resistant screw elements to the highest standards to ensure compatibility with original parts. Screw elements and replacement barrels from Xtrutech coupled with advice on alternative screw profile designs can offer users improved performance, productivity and profits.

Just recently, ETA Kunststofftechnologie, Germany, has supplied four co-extrusion die heads for three-layer polyolefin pipes in the diameter range from 63 to 400 mm, two in Switzerland and two in Germany. Thus, ETA again has proved its technological leadership in developing and supplying high-tech coextrusion die systems for the plastic pipe industry. Even though ETA has supplied numerous dies for all kind of two- and three-layer products, all new systems are tailored to customers’ specifications. The die heads contain three concentric spiral mandrel manifolds and all flow channels are optimised by using computer simulation programmes developed in-house. All parts are made from high-quality tool steel — forged and ultrasonic test approved — and all wetted surfaces are high-gloss polished and chromeplated. The main extruder is connected centrally, and the systems have a side arrangement of the ancillary extruders for inner and outer layers. In case of one ancillary extruder for both inner and outer layer a branching adapter in front of the two side feed ports has a valve in each feed channel for either running three-layer products or two-layer pipes with inner or outer skin layer. Between the manifold system (base unit) and the die inserts coloured stripe markings (4 or 6 stripes) are applied from a small co-extruder. All ETA dies — including dies for blown film, pipe coatings and sheathing, extrusion blow moulding — are tailored to customers’ product specifications and production requirements. That is also true for peripheral equipment like heating/cooling units for better temperature control or a carriage with manually operated or motorised turning device for easy handling during die set change etc.

The UK poly(vinyl chloride) compounds producer Dugdale has launched two new nitrile poly(vinyl chloride) compounds under the trade name Ducaseal® PVC/NBR. These new materials that have been specially designed for co-extruded window sealing applications are said to offer a good balance of cost and performance. The first material suits for static applications while the second one is a dynamic compound designed to produce weatherproof door and window closure seals. Both compounds are easy to process and provide good adhesion to PVC and consistent surface finish.

Extrusion specialist Battenfeld Gloucester Engineering Co. has added a feature to the barrels of its ContraCool® extruders that increases throughput and polymer quality. Called light groove feed (LGF), it is a series of shallow grooves that improve the conveying efficiency of the screw by increasing the coefficient of friction in the barrel. The result is a plasticizing process in which resins, including soft materials like plastomers and nonlubricated grades of nylon, move down the barrel to the die in a steady, consistent flow.
Improved plasticizing and conveying of soft pellets occurs because the grooves in a LGF design are less aggressive to resins than those in conventional groove-feed extruders, where the grooves are much bigger, says Angelo Vissas, Blown Film Project Manager at Battenfeld Gloucester. ‘This broadens the spectrum of materials that can be processed in a LGF extruder,’ Vissas says. ‘Groove-feed extruders, by contrast, can only safely proc-ess high-molecular-weight polymers with hard pellets.’
Battenfeld Gloucester’s LGF barrels combine the benefits of smooth-bore and groove-feed design to achieve less shear along with steady conveying of resin and additives. In field tests producing agricultural stretch film, where resins with high vinyl acetate content and polyisobutylene were used, a 33% improvement in output stability was achieved over conventional smooth-bore extruders.
LGF barrels can use the same screw as smooth-bore extruders, do not require high-priced lubricated barrier resins and process fluff regrind. The option is available on ContraCool® extruders used in blown film lines, and is easily retrofittable.
Vissas says Battenfeld Gloucester sees potential for the technology in other applications.