Bonding with long dwell times and low pressures
The Klieverik belt calender can be used to bond individual fibres of a non-woven or to melt the added BiCo material only. Klieverik offers the belt calender as the most economical solution for technical applications.
Due to its long contact time of several seconds, the pressure required can remain low. Optimizing the parameters – contact time (speed), temperature and pressure, the desired effect like higher tensile strength, surface smoothness, hand and (calibrated) thickness can be obtained.
Advantages of thermobonding calenders
- Contact heat and dwell time
- Energy efficient and non-polluting process
- Accurate control of temperature, belt guide, tension and belt pressure
- Speeds up to 100 m/min possible
- Reproducible production process
- Very high uniformity of the temperature across the full width of the heating cylinder
- Special silicone belt resistant to high temperatures
- Special long life coating on heating drum
- Limited shrinkage during process (by belt tension on substrate)
Single side process
The non-woven enters the calender via the belt and is pushed against the heated drum. With a different pressure setting in this belt, the penetration of the heat can be influenced. A pressurized roller at the exit can add a nip pressure with its own independent setting. A calibrated thickness by setting this roller to a defined gap is possible as well.
Double sided treatment
In a line process as displayed below, two almost similar calenders are places in line of eachother. In this way, first the front side of the non-woven is being processed, and then the back side.
Double sided treatment with double drum
This calender is equiped with two drums, one above the other. The lower drum heats up the belt, which subsequently heats up the non-woven from its back side. The upper drum heats up the non-woven from its face side. In this way a dual side effect will be created.