Zone-Controlled Roll Smoothing Device for Paper Thickness
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Solution Overview
Problem
Existing paper production methods face challenges in achieving uniform paper thickness and strength properties, particularly with the increasing use of recovered paper fibers, as they require high energy consumption and additional space for separate calendering and coating units, leading to compromises in paper quality and production efficiency.
Innovation Solution
A smoothing device that combines pre-calendering and coating in a single unit with a non-contact application process, using a deflection-compensated and zone-controlled roll to apply treatment substances like starch, optimizing starch penetration and pressing power across the paper web to enhance strength properties without the need for separate units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate calendering and coating units are used, then paper thickness uniformity and strength properties can be improved, but energy consumption increases and production space is required
Solution Approach 1:
The patent combines the calendering function and coating function into a single integrated unit. The calendering unit includes at least one nip formed between two rolls, with at least one roll being a deflection-compensated and zone-controlled roll. The coating unit applies treatment substance to the paper web passing through the calendering unit. This integration allows simultaneous thickness control and coating application, eliminating the need for separate units and reducing energy consumption while maintaining manufacturing precision.
2Manufacturing precision
If separate calendering and coating units are used, then paper quality can be improved, but production space increases
Solution Approach 1:
The patent integrates calendering and coating functions into a single production line unit. The calendering unit with deflection-compensated rolls works in conjunction with the coating unit within the same physical space, allowing quality improvement without requiring additional separate production areas.
3Manufacturing precision
If high pressing power is applied in calendering, then paper thickness uniformity improves, but starch penetration and strength properties may be compromised
Solution Approach 1:
The patent applies the treatment substance (starch) to the paper web before it enters the calendering nip. The coating unit meters and applies the treatment substance in advance, allowing the substance to be positioned on the paper surface before the high pressing power is applied. This preliminary coating action ensures that the treatment substance is not compromised by the calendering pressure and can effectively contribute to paper strength properties while the calendering simultaneously achieves thickness uniformity.
4Ease of manufacture
If recovered paper fibers are used to reduce costs, then production cost decreases, but paper strength properties deteriorate
Solution Approach 1:
The patent uses a deflection-compensated and zone-controlled roll that can adjust pressing power parameters across different zones of the paper web. This allows optimization of the calendering process for papers containing recovered fibers, applying appropriate pressure distributions to achieve both cost-effectiveness and acceptable strength properties. The zone-controlled capability enables tailored processing parameters that accommodate the variable characteristics of recovered fiber papers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution achieves uniform paper strength and quality by matching starch application with pressing power, reducing energy consumption and space requirements, while improving paper strength and reducing starch usage, resulting in cost savings and increased flexibility in existing production lines.
Implementation Method 1
The roll has a roll shell (7) rotating about an axis of rotation, on the inner circumference of which supporting elements (5) exert a force. The supporting elements (5) form individual hydrostatic pressure elements.
Implementation Method 2
In the at least one nip (6), the material web (9) is smoothed by means of an adjustable line load profile when the material web (9) passes through the nip (6). Simultaneously with the exertion of a pressing pressure in the nip (6), a treatment substance or treatment medium (2) is placed into the material web (9).
Data Source
AI summary
Device for smoothing a paper or board web (9) with at least one nip (6) formed between two rolls (3, 4), wherein at least one of the rolls (3) for controlling a thickness transverse profile of the paper or board web (9) in the web transverse direction is a deflection-adjustable and zone-controlled roll (3) for setting a line load distribution over the roll width which can be selected in the at least one nip (6), wherein the at least one nip (6) is provided for smoothing the thickness transverse profile of the paper or board web (9) by means of an adjustable line load profile and simultaneously introducing a treatment medium (2) into the paper or board web (9), for which purpose at least one coater (1) having a delivery nozzle (8) for applying application medium (2), in particular starch, is arranged in such a way that the application of the treatment medium (2) to at least one of the two rolls (3, 4) of the nip (6) is provided and is designed for indirect application of the treatment medium (2) to at least one side of the running paper or board web (9) and the at least one coater (1) has at least one delivery nozzle (8) with a device (13) for cross-profile adjustment of a volume flow of the treatment medium (2) which can be adjusted zone by zone over the web width.