Paper Feeding Roll Geometry for Paper Powder Discharge
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Solution Overview
Problem
Existing paper feeding rolls in electrophotographic devices suffer from paper powder adherence, which leads to reduced friction and increased paper jams due to wear and accumulation on the roll surface, despite previous designs focusing on improving grip and powder escape mechanisms.
Innovation Solution
A paper feeding roll design featuring convex parts with a forward inclined surface increasing along the paper passing direction, angled between 25° and 55°, and a nip area ratio of 0.2 to 0.6, combined with a reverse inclined surface and controlled hardness, to effectively discharge paper powder and maintain durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rubber is used to maintain friction with paper for transport, then paper transport function is improved, but paper powder adheres to the roll surface causing wear and reduced friction over time
Solution Approach 1:
The roll surface is segmented into convex parts (protruding strips) and groove parts, creating a non-uniform surface structure. This segmentation allows paper powder to escape into the groove parts while the convex parts maintain contact with paper for transport, resolving the contradiction between maintaining friction and preventing powder accumulation.
Solution Approach 2:
Different regions of the roll surface have different functions: convex parts provide friction for paper transport while groove parts provide escape paths for paper powder. This local differentiation of surface properties addresses both the need for maintained friction and the need to prevent powder accumulation that causes wear.
2Object-generated harmful factors
If convex strips are added to escape paper powder, then powder accumulation is suppressed, but roll surface wear increases
Solution Approach 1:
The angle of the forward inclined surface is optimized to 25°-55° to balance paper powder discharge efficiency with wear reduction. This parameter optimization ensures that paper powder is effectively removed while minimizing the shear force and wear on the roll surface material.
3Object-generated harmful factors
If forward inclined surface angle is increased to improve powder discharge, then powder removal efficiency is improved, but wear on the roll surface increases
Solution Approach 1:
The forward inclined surface angle is optimized to 25°-55° to balance paper powder discharge efficiency with wear reduction. This parameter optimization ensures that paper powder is effectively removed while minimizing the shear force and wear on the roll surface material.
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
The design effectively removes paper powder, reducing friction-related wear and preventing paper jams, ensuring reliable paper transport throughout the roll's service life.
Implementation Method 1
maintains the friction with paper by using the tackiness derived from rubber
Implementation Method 2
using the tackiness derived from rubber
Implementation Method 3
a forward inclined surface in which an inclination increases along a paper passing direction; An angle of the forward inclined surface is 25° or more and 55° or less
Data Source
AI summary
A paper delivery roll (12) includes: a shaft body (12a) and an elastic body layer (12b) formed on an outer peripheral surface of the shaft body (12a). A convex part (13) having a forward inclined surface (13a) whose inclination increases along a paper passing direction (Y) is provided on the outer peripheral surface of the elastic body layer (12b). An angle (θ1) of the forward inclined surface (13a) is 25° or more and 55° or less. A ratio of a nip area to a product of a nip width and a roll surface length at a load of 500 g is 0.2 or more and 0.6 or less.