k-show-news - November 20, 2018

Higher unwinding and winding speeds

PRA November 20, 2018

US extrusion machinery maker Davis-Standard will exhibit a high-speed unwind during K2016 that is engineered for splice speeds up to 800 m/minute for sensitive, thin webs.

This unwind features pneumatic splice-unit control for improved processing and functionality. It is uniquely engineered for extrusion coating applications involving aluminium foil and PE films.

The two-position, shaftless, phantom-axis turret design offers several advantages:

Driven idler rolls on the turret
Direct spindle drive using a timing belt without backlash
Cross-cut knives on the turret between two driven idler rolls
Lightweight carbon fibre knife holder
Inverter controlled turret drive
Precision turret control with an absolute encoder
Continual gap mode between the bumper roller and reel during the unwinding process
Automatic air inflation for pneumatic chucks with pressure control
Tension control via a long-stroke dancer roll
Ultrasonic sensor measurement for the incoming roll diameter
Automatic edge guide control

The unwind is capable of roll diameters from 300 to 1,000 mm with a maximum diameter of 800 mm for aluminium foil, and a maximum roll weight of 1,800 kg. It is ideal for aluminium foil webs ranging from 6 to 20 µm and PE films from 30 to 100 µm.

The unwind is typically used as an auxiliary unwind for aseptic packaging lines to maintain consistent high- speed operation. However, it can also be used as the primary unwind for flexible packaging lines that process a wide range of substrates, including paper up to 150 gsm.