Roof membranes: Laminating without heat or glue enhances quality

Roll goods of 6 feet width are being processed on ultrasonic calander. This new successful projects include calander application with ten ultrasonic stacks for roof membranes. Ultrasonic laminating offers advantages over heat laminating or gluing. Breathable roof membranes protect the roof against wind and moisture from the elements, but have to be permeable so condensation from inside the house can diffuse through the roofing material. The roof membrane is made of two nonwoven layers and one watertight, yet permeable membrane foil, sandwiched in the middle. The three layers pass between the embossing anvil drum and the sonotrodes in the calander, being laminated in precisely scattered bonding points over their entire width without heat or glue.

Ultrasonic technology has great paybacks

Age durability of the membranes determines the difference between a high quality product and a bargain. Compared to heat laminating or gluing, ultrasonic bonding induces much lower energy into the material, hence positively impacting age durability. Heat laminating has a potentially negative effect on the membranes which are susceptible to UV-ray. It also accelerates the process of turning porous over time. In a similar way gluing requires high levels of energy as well. The glue coating decreases permeability. Another advantage of ultrasonic technology is instant operational readiness. No heat-up time is required, parameters can be changed immediately and recipe management is simple. The patented Microgap Control by Herrmann Ultrasonics maintains a constant, precise micron gap between anvil drum and sonotrodes. This ensures reproducible and consistently high bonding quality.

Calanders at high speeds

"We see high potentials for ultrasonic calanders with much large widths and high speeds of up to 400 feet/minute", says Uwe Peregi of Herrmann Ultrasonics. There are many applications in the hygiene and medical field, i.e. filter products and elastic laminates, and anywhere roll goods need to be bonded at respective speeds.

In the technical competence center in Bartlett, IL Herrmann Ultrasonics has the capability to run speed trials up to 1,000 feet/minute and at the Headquarter in Germany up to 1,500 feet/minute.