Extrusion International 6-2022

60 Extrusion International 6/2022 RECYCLING – CASE STUDY Cast film extruders have a higher capacity and faster run - ning speed that their blown film counterparts, so they need a higher power corona treater to achieve the best results. This typically means a single-sided treater with an extended shaft, which can bemotorised, and has a nip roller to prevent treatment to the reverse of theweb. Usually, the corona unit is used as a pull station. Cast Polypropylene, normally called CPP and different to stretch film, is used for a wide range of packaging, and normally requires corona treatment. The right way It is a definite need for specialist knowledge to ensure the best results are obtained. As substrates become more com- plex to meet new packaging and safety criteria, the need for a detailed understanding of the surface treatment process and what it can offer becomes ever more important. With more than 70 years of experience and research data, Vetaphone is in its ability to advise, educate and assist production personnel at every stage where surface treat- ment technology is required. It is a process that if managed correctly pays dividends throughout downstream process- ing from the moment of extrusion. Vetaphone A/S Fabriksvej 11, DK-6000 Kolding, Denmark www.vetaphone.com More Autonomy Through Clothes Hanger Recycling The Colombian company Plásticos Ojara is located in the idyllic south of the city of Medellin. The company is well known in the region as one of the leading manufacturers of plastic clothes hangers. Thanks to the use of a WLK 4 single-shaft shredder, it is possible to recycle rejected products on-site and return the material to the production process. In this way, waste can be effectively avoided, the purchase of raw materials can be reduced, and previously unused residual plastic is given a second life. For more than 40 years, Plásticos Ojara, which now employs around 200 people, has been an important supplier of hangers to the local textile industry. About 90% of the hangers produced are used by Colombian companies. The other 10% is exported to Ecuador, Panama, El Salvador, Guatemala, and the Dominican Republic. A lways concerned about sustain- ability, the Latin American com- pany was looking for a way to fur- ther optimize production and at the same time make it even more envi- ronmentally friendly. Those respon- sible at Plásticos Ojara decided not to dump rejects in the future, but instead to reintegrate the raw mate- rial into the manufacturing process. The cycle begins with an industrial shredder. Following recommendations from partner companies, the choice finally fell in favor of WEIMA's proven Ger- man mechanical engineering. Installa- tion and commissioningwent smooth- ly. Thanks to the comparatively short delivery time, the WLK 4 shredder was soon able to start work – and excelled with high throughput rates. The WLK 4 single-shaft shredder has a working width of 600 mm and an electromechanical drive with WEI- MA's own WAP gearbox in combina- tion with a V-rotor and a generously dimensioned hopper in logspacer de- sign. This prevents feed material from forming bridges. As a rule, it is oper- ated with a throughput of approx. 350 kilograms per hour, but a higher throughput is also possible with con- tinuous feeding. The rotor cutting blades can be flipped several times when worn, which drastically reduces Sorting of broken plastic hangers