Hot, cold, dusty or humid: These are only few of the challenges faced by the bag forming, filling and sealing machines of Hastamat Verpackungstechnik GmbH in Lahnau near Giessen during the packaging of the most varied products. For this purpose, they must be simple to operate and clean. The demands on the mounted machine elements are correspondingly high. Maintenance-free plastic bearing defy all outer influences and provides for the required service life.
Continuous operation without operators, quick to retrofit, simple to clean are essential components of the machine concept. Here the self-lubricating and maintenance-free plastic plain bearing system is a component of the overall concept. Aligned on top of each other, they can be easily mounted. They defy the most severe weather conditions, have absolute freedom from maintenance and there is no chance of a product contamination through lubricants.
To further reduce the production costs, complete systems of the "drylin®" technology are increasingly used, which are constructed according to customer specifications.
Adverse ambient conditions are the order of the day in the daily routine of machines. "Dust, powder deposits and moisture are normal during the packaging process; after the production, the machine is roughly cleaned or just blown with compressed air. "Constructively there are only two possibilities. Either the entire system should be elaborately sealed up, or use machine elements that can deal with this dirt accumulation without breaking down early. And here we have the best experiences with the maintenance-free polymer bearings. " Moreover there is the important topic, freedom from external lubrication. "Our customers mainly work in the food industry," clarifies Rainer Haus. "As the components need not be serviced, no accumulations of bacteria and dirt take place that require elaborate cleaning. “
In the guide of the cross seal jaws, extreme demands are posed on the bearing mechanism. "Here there is real action with 80 cycles per minute," says Rainer Haus. In this bearing assembly of the sealing bar, maintenance-free linear liners are used in combination with hard anodized aluminum shafts. They are composed of a wear-resistant "iglide®" material. The tribologically optimized high performance polymer is predestined for applications in which the bearing elements should attain maximum service lives. The self-lubricating machine elements are based on extremely wear-resistant plastic compounds specially developed for the linear technology. The dimensions are compatible with standard ball bearings. The special geometry guarantees ruggedness even in extreme environments. "Even wash-down applications pose no problems at all," clarifies the designer.
In the area of the long seal unit, four "drylin® Easy Tube" linear units are used for adjustment functions. "Thereby we offer two possibilities to our customers. You can manually adjust the adjustment carriage using "drylin® W" clamping units in the format adjustment, or do it automatically through the "drylin® Easy Tube" positioning device. In the format adjustment, the user always finds the accurate position. Adjustment errors are thus avoided," affirms Markus Schmachtel of Hastamat.