Crescent Former Shoe Press Configuration for Tissue Bulk Control
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Solution Overview
Problem
Existing tissue paper manufacturing systems struggle to produce a wide range of tissue grades efficiently and cost-effectively, as they often result in either high bulk or low bulk paper, with additional drying components being large, inefficient, and inflexible.
Innovation Solution
A crescent former paper machine with a double felted shoe press and suction felt roll, allowing two configurations: one with and one without the shoe press section, enabling flexible production of different paper grades by rerouting the paper web, and utilizing a suction box and air blade for efficient water management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a pre-heating section is added to dry the paper web before the Yankee cylinder, then the bulkiness increases and drying energy decreases, but the machine size increases and cannot be uninstalled efficiently
Solution Approach 1:
The patent applies a dynamic configuration where the shoe press can be positioned in different locations along the paper machine (upstream, mid-position, or downstream) depending on the desired tissue grade. This dynamic positioning allows the same equipment to serve multiple functions and resolve the contradiction between energy efficiency and machine complexity by adapting the press location to specific production requirements.
Solution Approach 2:
The shoe press is designed as a multi-functional component that can operate in different configurations to produce various tissue grades (high bulk or low bulk). By making the press position adjustable and integrating it with the existing Yankee cylinder system, the invention achieves energy efficiency without requiring separate dedicated drying sections, thus avoiding increased machine complexity.
2Productivity
If a shoe press is used to dewater the paper web mechanically before the dryer, then the bulk characteristics increase, but the product will always have high bulk which is not desirable for all tissue products
Solution Approach 1:
The patent implements a dynamic system where the shoe press position can be adjusted along the paper machine to control the degree of dewatering. By positioning the press upstream, mid-position, or downstream, the system can produce different bulk characteristics suitable for various tissue grades, thus resolving the contradiction between productivity and adaptability.
Solution Approach 2:
The invention changes the operational parameters by varying the press position and configuration to achieve different dewatering intensities. This allows the same shoe press equipment to produce both high bulk products (when positioned for maximum dewatering) and low bulk products (when positioned for minimal dewatering), thereby achieving product grade flexibility.
3Device complexity
If the shoe press is used in direct contact to the Yankee cylinder, then the configuration is compact, but water conveying problems occur and drying efficiency decreases
Solution Approach 1:
The patent introduces an intermediary felt layer between the shoe press and the Yankee cylinder. This felt acts as a mediator that facilitates water conveyance from the press to the dryer while preventing direct contact that would cause water conveying problems. The felt transfers water gradually, maintaining drying efficiency while preserving the compact configuration.
4Productivity
If additional drying components are added to the paper machine, then the drying capacity increases, but the components are large in size and cannot be uninstalled efficiently
Solution Approach 1:
The patent merges the shoe press functionality with the existing Yankee cylinder system by positioning the press at different locations along the paper path. This integration allows the press to work in conjunction with the existing drying components rather than adding separate large-scale drying sections, thereby increasing drying capacity while avoiding the installation and uninstallation problems of large independent components.
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
Enables the production of a wide range of tissue grades with reduced energy and cost, achieving high bulk for products like paper towels and low bulk for facial tissues, while maintaining efficient drainage and energy savings.
Implementation Method 1
A crescent former paper machine with a double felted shoe press and suction felt roll
Implementation Method 2
using a shoe press to dewater the paper web mechanically before being brought to the dryer
Implementation Method 3
The paper web is then loaded onto a dryer to be dried
Data Source
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AI summary
A crescent former paper machine comprising: a double felted shoe press (1) using a top felt (2) and a bottom felt (6); a suction felt roll (4) located upstream of the double felted shoe press (1); and a dryer section (3) located downstream of the double felted shoe press (1); wherein the crescent former paper machine has a first configuration and a second configuration: a)in which in the first configuration, the top felt (2) carries a paper web from the suction felt roll (4) to the double felted shoe press (1), the paper web contacting the bottom felt (6) at the double felted shoe press (1), and the top felt (2) carries the paper web from the double felted shoe press (1) to the dryer section (3), and b) in which in the second configuration, the top felt (2) carries the web from the suction felt roll (4) to the dryer section (3), bypassing the double felted shoe press (1).