For individual calender nips
Optimal process control in the calender NIPCO™ roll systems The timeline of an ingenious concept NIPCO™ The basic concept behind today’s NIPCO™ roller was born in Zurich in 1971. A short time later, the first version of this roll was operating in a paper machine. Thousands of delivered NIPCO™ rollers are testimony to the vast experience garnered from the most diverse sectors, including many outside of the paper industry. This know-how led to new, product-oriented technology solutions for a vast variety of requirements. The NIPCO™ rolls today solid, reliable and maintenance-friendly roller concepts, allow each and every user to adjust the production process according to their product requirements.
The NIPCO™ roll principle
A NIPCO™ roll has three key elements: - the stationary cross shaft - the rotating roll shell - the hydrostatic pistons Of these, the cross shaft is the element that supports the entire roll structure. It transmits force from the calender into the nip. The NIPCO™ shell rotates freely over the cross shaft. Either steel or highly flexible shells are selected, depending on the application case concerned. The surface temperature of the shell is controllable. Hydrostatic pistons individually installed in the cross shaft support the freely rotating roll shell against the load from outside. With the conventional NIPCO™ roll, these hydrostatic pistons are actuated zone-by-zone. This allows individual line load curves over the entire width of the nip – even with the smallest linear loads.
Reliability and experience spanning over 40 years The individual force distributed across the entire width of the nip, regardless of the total force or the deflection of the counter roll, creates enormous adaptation potentials for the user. Even operation with a uniform parallel working nip is possible. The individual force permits purposeful corrections, depending on the NIPCO™ roll design. The effective width can be adapted to suit specific requirements.
Tougher quality requirements, increasingly larger working widths and higher operating speeds call for market-oriented technologies that guarantee the best possible production reliability. The NIPCO™ roll systems satisfy these criteria and are individually tailored to meet the needs of our customers. And the field of applications goes way beyond the paper industry. From printing floor coverings or magazines to rolling steel plates or aluminum, from milling foodstuffs to finishing textiles and technical textiles. Likewise, these roll types are suitable for non-woven applications, such as thermal bonding. For flexible use in various calender systems, smoothing and printing presses, embossing calenders or with the thermal bonding calender, the ideally formed print curve also rules out the risk of local over-pressing. A NIPCO™ roll system can usually be retrofitted into an existing system without major conversion effort, creating an almost endless list of applications for this roll system.
The use of NIPCO™ roll systems allows the user to set individual forces in the nip. Consequently, the deflection curves of the shell can be adapted to suit the requirements concerned. Depending on the roll design, operation with parallel nip is possible, i.e. the deflection of the NIPCO™ roll precisely matches that of the counter roll. To generate this parallel nip, the NIPCO™ roll shell is mounted equidistant to the counter roll, and the shell is precisely bent to the calculated deflection of the coun-ter roll in a parabolic manner under the generated hydrostatic piston force. If the process demands that the force distribution is varied across the entire width, the hydrostatic pistons and/or hydro-static piston zones are controlled zone-by-zone. A different pressure is applied to each zone. In addition, the precise limits of the working width permits a gentle transition across the edge zones in case of different material widths. This significantly improves the process result and reduces wear on the cover. With calendering, embossing, laminating and coating in particular, the individual advantages of the NIPCO™ roll are key to a reproducible high product quality.
- Linear loads 20−15000N/mm
- Speeds 5 – 2.200 m/min
- Product widths 500 – 12.800 mm.
- Surface temperatures up to approx 300 °C
- Sleeves: GTP6 - TT3 - BiComponent - Steel - Rubber
- Width adjustment for different fabric widths
- Multiarea Pressure setting
- Counter pistons for sleeve retracting to prevent edges overheating