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ANDRITZ CellCal - Electrode manufacturing by innovative calendering

With more than 75 years of experience in calender technology for various industries, ANDRITZ has also developed an innovative calender for electrode manufacturing for batteries: the ANDRITZ CellCal calender.

ANDRITZ has become synonymous with high-quality calendering. For many decades, we have been providing the technology that enables various industries to refine their materials with our calendering technology and prepare them for further production steps. Very specific requirements are needed in the field of battery manufacturing for the production of electrodes. ANDRITZ can deliver here with its innovative concept.

Current production set-up

A calender is an essential part of the wet coating process for the production of electrodes for batteries. Within this process a uniform product thickness and stable quality are of utmost importance. For coating and drying, a product width of 1,400 mm is state-of-the-art. However, a calender of this width cannot meet the technical product requirements yet.

Thus, an acceptable thickness deviation cannot be reached with one calender only. This is why a center slit and two calenders in small product widths are needed for the current process. In addition, conventional calenders, create a so called W-profile, by activating roll bending in the second step. This profile is acceptable for narrow working widths. For larger widths, the product thickness deviation is out of tolerance.

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Conventional calender with overloaded edges

Conventional calender with W-profile at quarter points

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ANDRITZ calender concept with even load distribution with Double-S-shape

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ANDRITZ CellCal 3D model in housing cover

New production set-up with ANDRITZ

ANDRITZ has developed a new calendering concept to overcome the current process limitations. The new calender offers an even load distribution at the calender nip resulting in very good thickness evenness in the product at a width of up to 2,000 mm. This can be achieved through adding an axial roll displacement. Both rolls are ground to get a special Double-S-shape, which influences the quarter points of the W-shaped profile, created by the roll bending and crowned grinding.

Comparison: Conventional and ANDRITZ production set-up

Example of current production set-up
Coater and dryer 1,400 mm	Center slit	Calender 1 700 mm Calender 2 700 mm	Slitter 1 700 mm Slitter 2 700 mm
Example of ANDRITZ production set-up
Coater and dryer 1,400 mm	ANDRITZ CellCal calender 1,400 mm	Slitter 1,400 mm

TECHNICAL FEATURES:

Product width up to 2,000 mm
Speed up to 120 m/min
Line force up to 3,500 N/min (higher on request)
Roll surface temperature up to 160°C
Thickness uniformity, length direction: ± 1,5 μm
Thickness uniformity, cross direction: ± 3,0 μm

BENEFITS:

Even load distribution over the full width
Stable product quality due to repeatable production conditions and product settings
Implemented anti-wrinkling solutions
Gap control by control loop with thickness scanner
Easy and quick roll change for higher uptimes
Self-aligning roll bending cylinder design
Improved temperature distribution for higher product quality and thickness evenness