Lower operating costs are achieved by down gauging the film thickness and at the same time obtaining the optimum load stability. The Lachenmeier stretch units are developed to handle the thinner film without overstretching it and without destroying the holding forces of the film.
An interesting feature of the new stretch hood machine is the heavy-duty stretch unit, which is based on hydraulic stretching. Each gripper has a stretch force exceeding more than 1 tonne, which Lachenmeier claims is considerably more than the stretch force of electrical stretch units seen on other stretch hood machines in the market.
The new stretch units provide a controlled application of the stretch hood film as every step of the application procedure is fully controllable, from stretching the film to releasing the film under the pallet. A film hood with a smaller circumference than the load is wound up on four stretch units and stretched to a size matching the exact outer circumference of the load.
The top stretch film unwinding system means that a controlled amount of film is unwound during stretching. Thin and fragile film, especially around the corners of the product, is avoided.
Finally, the Lachenmeier film snapback system, where the film hood is released from the stretch units in a controlled manner, ensures a reliable hold between load and pallet, which the company claims means less product damage during transport.
Lachenmeier is a manufacturer of end-of-line packaging machinery. It has long thought of itself as an industry innovator - it introduced the shrink frame in 1971 as a replacement of the energy-heavy shrink ovens, the combined shrink machine in 1982, where hood application and shrinking take place in one unit, and the fully automatic stretch hood machine in 1988.
The latest stretch hood machine concept was developed in co-operation with ExxonMobil Chemical. The company is one of the largest producers of polyethylene as well as speciality copolymers and metallocene catalysed products.