Calendering concepts
Excellent calendering solutions for all paper grades
One of the essential machines for the final quality of papers is the calender. Calendering means the deformation of paper or board under pressure and temperature; it is basically an embossing process. The surfaces of the nipforming rolls are embossed onto the surface of the paper web. Depending on the paper grade, different technical properties of the paper – above all, gloss and smoothness – are optimized in the calender. By passing through one or more roll nips in the calender, the surface of the paper can be further smoothed and calendered according to its intended use. In order to meet your individual requirements, our experienced experts will work with you to select the right calender configuration.
Portfolio of calendering concepts
Voith offers calendering solutions for every requirement: soft nip or hard nip calendering, with single or multiple nips, whether calendering on one or both paper sides. With Voith calendering concepts, you achieve the desired surface properties of your paper and board.
EcoCal Hard – Top seller for universal use
The EcoCal Hard calender increases the smoothness value and provides a constantly precise caliper, which may be required for subsequent process steps such as coating, etc. The EcoCal Hard calender consists of at least two rolls with a hard surface. A heated roll provides a uniform temperature profile. The mating roll is a deflection compensation roll for controllable line load in cross direction. The EcoCal Hard calender is used mostly for calibration of the paper web. EcoCal Hard calender achieves an improved quality.
Your benefits with EcoCal Hard
- Economical investment
- Reduced energy consumption due precise adjustment of nip load and surface temperature of the heated roll
- Reduced downtime because of easy and fast roll change
- High productivity due to long grinding intervals of rolls
EcoCal Soft – Best printability and runability
EcoCal Soft calenders provide a more uniform density compared to a hard nip calender. Visual characteristics such as gloss and smoothness but also the printability are positively influenced. The EcoCal Soft calender consists of at least two rolls. A heated roll provides a hot surface and a uniform temperature profile. The mating roll is a deflection compensation roll for controllable line load in cross direction and covered with a soft cover comprised of fiber-reinforced epoxy resins. EcoCal Soft calenders are the standard for a wide range of paper and board grades.
Your benefits with EcoCal Soft
- Best smooth and gloss level
- Excellent soft cover with long run time
- Easy operation and maintenance due to deep design knowledge
- Less downtime due to fast and easy roll change
- Reduced energy consumption due to exact control of line load and temperature
Janus – Premium calender for highest requirements
The Janus calender is our high-end product with multiple nips for achieving the highest smoothness, gloss and density values. The roll stack is arranged at an angle of 45 degrees, which is advantageous for stability, accessibility for roll change and best fit into the production flow. Multiple nips are formed with heated rolls and soft covered rolls. Automatic tail threading and advanced soft roll protection systems – such as the NipProtect system – ensure the highest availability of the Janus calender. The Janus calender can be operated in multiple, dual or single nip operation mode, thus providing high flexibility in regard to product properties. The Janus calender is used for the production of high-quality specialty paper grades such as release liner, SC paper, LWC paper and coated paper where it can be installed on-line or off-line.
Your benefits with Janus
- Highest smoothness and gloss level
- High productivity
- Excellent soft cover with long run time
- Easy operation and maintenance with 45° degree framing
- Less downtime due to fast and easy roll change
NipcoFlex calender – Minimal macro-roughness combined with bulk savings
The NipcoFlex calender is a soft calender characterized by a longer nip and therefore provides a long dwell time of the web in the nip. Due to its special design, the calendering process is gentler on the paper web so that a bulk saving effect is achieved at the same level of smoothness. On the other hand, it is possible to achieve a higher surface quality on a given bulk value. Furthermore, a significant improvement of the macro-roughness can be achieved. The NipcoFlex calender is mostly used for specialty paper and high quality board paper.
Your benefits with NipcoFlex calender
- Volume-preserving smoothing
- Best solution for thermal paper and high-quality packaging paper
- High safety standard
- Easy operation and maintenance
- Less downtime due to fast and easy roll change
Add-ons improve your calender performance
Bulk savings with EcoCal HiBulk
High-quality cardboard types should have as large a volume and stability as possible but at the same time enable good printability for advertising purposes. Thermal smoothing with the new EcoCal HiBulk calender reduces the mechanical pressure on the paper web. This gives the smoothed paper a higher specific volume and an improved surface structure. The special thermal smoothing of EcoCal HiBulk also enables raw material savings.
The machine calender used for pre-calendering makes use of the fact that surfaces can be smoothed more easily when moisturized and warm. To enable the steam to condense on the paper surface and give the board more stiffness, the paper web is cooled in a first step using an MCB cooler. Before the paper web enters the calender nip, the integrated OnQ ModuleSteam steam humidifier heats the paper web. This specifically enhances the volume-saving smoothing effect and printability. With its patented new technology, the EcoCal HiBulk calender from Voith achieves a bulk saving of up to 4 percent, which results in a significant reduction in fiber consumption.
The machine calender used for pre-calendering makes use of the fact that surfaces can be smoothed more easily when moisturized and warm. To enable the steam to condense on the paper surface and give the board more stiffness, the paper web is cooled in a first step using an MCB cooler. Before the paper web enters the calender nip, the integrated OnQ ModuleSteam steam humidifier heats the paper web. This specifically enhances the volume-saving smoothing effect and printability. With its patented new technology, the EcoCal HiBulk calender from Voith achieves a bulk saving of up to 4 percent, which results in a significant reduction in fiber consumption.
Optimal process control with Nipco roll systems
The EcoNip, Nipco and Nipcorrect rolls are used as deflection compensation rolls and for profiling the paper and board web in cross machine direction over the entire width.
The EcoNip rolls are specially designed swimming rolls for compensation of the deflection of the mating roll and thus provide an even line load distribution in the nip. The Nipco and Nipcorrect rolls are zone-controlled rolls where the roll shell is supported by individual pistons underneath. The pistons are bundled in various zones and supplied with pressurized oil for creating the line load in the nip. The oil pressure in the various zones automatically adjusts to maintain the required CD line load profile in the nip. The Voith grown compensation rolls are robust, reliable and easy to maintain.
Your contact - How can we help you?
Engineered for success
130
More than 130 Calender installed in the last 10 years
2200
Suitable for production speeds from 100 to 2200 m/min
11
Suitable for working widths from 2.0 to 11.0 m
4
Up to 4% bulk saving with EcoCal HiBulk
Calendering Technology Center
With the pilot calenders at the Heidenheim Calendering Technology Center, the best possible combination of nip pressure, temperature and roll surface for each grade can be determined for your products, whether they are board and packaging, specialty, or graphic papers. As a result of the trials, you will successfully reach your project goals and produce your target paper quality with the tailor-made calender concept.
Servolution. Service at the next level
At Voith, the success of the customer takes center stage. Service means delivering customized service solutions and utilizing our full expertise to help our customers reach their goals.
News
Explore other relevant products and solutions
Voith Paper Newsletter
Voith Paper Newsletter
Subscribe to our newsletter and stay informed about news in the world of Voith Paper
Always get the latest updates on new products and services, projects, campaigns and success stories as well as upcoming exhibitions and conferences – straight to your inbox.
Subscribe now