Weima helps Inoplast Kunststoff GmbH process airbags

Inoplast Kunststoff GmbH, headquartered in Windischeschenbach, Germany, can shred technically demanding raw materials for recycling using two WLK 15 Jumbo single-shaft shredders manufactured by Weima Maschinenbau GmbH, Ilsfeld, Germany.

Throughout the past 10 years, the owner-managed Inoplast Kunststoff has specialized in recycling a wide range of plastics, purchasing and selling plastic scrap, regranulate and regrind as well as contract processing. At the end of June 2019, the operation was significantly expanded to add a production hall, warehouses and an office building.

Before the actual recycling process, plastic scrap delivered to the plant is checked for impurities and, if necessary, presorted according to type so the company can guarantee the purity and high quality of its reprocessed material.

The materials Inoplast recycles reflect almost the entire spectrum of plastics. For example, polyethylenes, such as high-density polyethylene and low-density polyethylene, polypropylene and polyamide (PA, or nylon) polyester-based fibers and textiles in various shapes and sizes.

© Weima

The F-rotor was specially developed
for shredding films and fibers.

In the past, PA airbag laminate posed a great challenge at Inoplast. To protect vehicle occupants in accidents, the material is extremely tear-resistant and, therefore, difficult to shred. With Weima, Inoplast found a solution for this technically demanding application with the equipment manufacturer's testing and development capabilities. After joint test trials in the Weima showroom, a solution was developed. Two specially manufactured Weima WLK 15 Jumbo single-shaft shredders have expanded the fleet of machines used by Inoplast.

The WLK 15 Jumbo is available with two different drive variants: an electromechanical drive or a flexible hydraulic drive. After extensive material tests, the company ultimately selected the high-throughput hydraulic drive. Weima says the machine is particularly insensitive to foreign materials and provides high torque without currency peaks and can be used in adjustable speed ranges.

In cooperation with Inoplast, the shredder was modified and optimally adapted to the application, the equipment maker says. With a working width of 1,500 millimeters and a rotor diameter of 500 millimeters, the WLK 15 Jumbo easily shreds not only airbags but also all kinds of plastic scrap. The shredding of PA airbag laminate requires a particularly precise cutting gap, Weima says. The F rotor, specially developed for shredding films and fibers, ensures optimum cutting geometry with maximum throughput and energy efficiency.

The raw material is fed into the hopper via a tilting system. After shredding, a conveyor belt with an integrated magnetic drum for ferrous impurity separation discharges the shredded material from the machine onto the feed belt for the extrusion line, The material is melted, homogenized and, if necessary, degassed. The melted plastic is cooled in strands in a water bath, cut into the desired granule size and then dried before being returned to the manufacturing cycle.