Sheet Manufacturing Apparatus Airflow Classification Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sheet manufacturing apparatuses face challenges in producing high-quality sheets due to insufficient deinking processes, leading to spots and insufficient thickness, primarily caused by varying content rates of foreign substances in stock materials, which are difficult to measure and control.
Innovation Solution
A sheet manufacturing apparatus equipped with a measuring unit to assess the thickness and air permeability of defibration objects, a dry-defibrating unit, and a classifying unit that adjusts airflow velocity and pipe diameters to efficiently separate and remove foreign substances based on measured content rates, ensuring balanced removal and collection of fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a deinking process is performed to remove foreign substances, then the quality of the sheet is improved, but the collection rate of defibrated fibers decreases resulting in insufficient sheet thickness
Solution Approach 1:
The patent changes the operational parameters of the classifying unit based on the measured foreign substance content rate. When the foreign substance content rate is high, the classifying unit operates with higher airflow velocity to maximize foreign substance removal. When the content rate is low, the airflow velocity is reduced to preserve defibrated fibers, thus maintaining sheet thickness while still achieving acceptable sheet quality.
2Manufacturing precision
If the content rate of foreign substances in stock material is large, then deinking process becomes insufficient, but increasing deinking intensity removes too many defibrated fibers
Solution Approach 1:
The patent implements a feedback control system where the foreign substance content rate is first measured in the stock material, and this measurement feeds back to control the operation of the classifying unit. The classifying unit adjusts its airflow velocity based on the measured content rate, creating a closed-loop control system that optimizes deinking effectiveness while minimizing fiber loss.
Solution Approach 2:
The patent makes the classifying unit dynamic by allowing its operational characteristics (airflow velocity) to change based on the input material conditions. Instead of operating at a fixed setting, the classifying unit adapts its performance to match the actual foreign substance content, enabling optimal separation for each batch of stock material.
3Device complexity
If used paper is processed without measuring foreign substance content, then the process is simple, but spots and quality deterioration occur due to insufficient deinking control
Solution Approach 1:
The patent replaces complex manual measurement and judgment processes with an automated optical measurement system. The foreign substance content rate is measured objectively using light transmission or reflection principles, and this measurement automatically controls the classifying unit operation, substituting human decision-making with a precise instrumental system.
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 approach enhances production efficiency and quality by optimizing the removal of foreign substances and maintaining the collection rate of defibrated fibers, resulting in improved sheet quality with reduced spot patterns and consistent thickness.
Implementation Method 1
a classifying unit configured to separate and remove, by airflow classification, foreign substances other than the fibers from the defibrated material
Data Source
AI summary
A sheet manufacturing apparatus includes a measuring unit configured to measure thickness and air permeability of a defibration object containing fibers, a defibrating unit configured to dry-defibrate the defibration object, and a classifying unit configured to separate and remove, by airflow classification, foreign substances other than the fibers from the defibrated material defibrated at the defibrating unit.