Rotating Folding Rollers Prevent Ink Smearing
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Solution Overview
Problem
Existing folding devices tend to smear printing ink or toner on freshly printed or digitally printed sheets when forming the folding line due to the sliding action under the folding blade.
Innovation Solution
The folding device employs rotatably mounted folding rollers that match the sheet throughput speed, ensuring no smearing, and includes a circulating conveyor belt and transport rollers to support the sheet and guide it evenly, with a funnel folding device for open folding and precise edge formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed folding blade is used to form the folding line, then the folding structure is simple, but the printing ink or toner is smeared on freshly printed sheets
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed folding blade with rotatable folding rollers. These rollers can rotate in the direction of sheet travel, creating a dynamic system that adapts to the sheet movement. The rotation speed of the rollers is synchronized with the sheet throughput speed, eliminating relative motion that causes smearing while maintaining a relatively simple folding structure.
Solution Approach 2:
The patent changes the operational parameter of the folding mechanism from static (fixed blade) to dynamic (rotating rollers with controllable speed). By adjusting the rotation speed of the folding rollers to match the sheet throughput speed, the system eliminates the harmful sliding action that causes ink smearing, while preserving structural simplicity.
2Productivity
If the sheet slides along the folding blade to form the fold line, then the folding process is efficient, but the printing ink or toner is smeared
Solution Approach 1:
The patent transforms the static sliding action into a dynamic rolling motion. The folding rollers rotate in the direction of sheet travel, creating a synchronized movement that eliminates relative motion between the folding mechanism and the sheet surface. This dynamic approach maintains folding efficiency while preventing ink smearing.
Solution Approach 2:
The rotating folding rollers act as an intermediary between the fixed folding blade and the moving sheet. Instead of the sheet sliding directly against a stationary blade, the rotating rollers provide a moving contact surface that matches the sheet's velocity, eliminating the harmful sliding friction that causes smearing.
3Object-affected harmful factors
If rotatably mounted folding rollers are used to match sheet throughput speed, then ink or toner smearing is prevented, but the device complexity increases
Solution Approach 1:
The patent introduces dynamic elements (rotatable rollers with speed control) to prevent ink smearing. While this increases device complexity compared to a fixed blade, the complexity is concentrated in the drive mechanism, while the overall folding structure remains relatively simple and maintainable.
Solution Approach 2:
The patent changes the operational state from static to dynamic, requiring speed control mechanisms. The complexity increase is offset by the elimination of smearing problems, which would otherwise require more complex solutions such as heated blades or specialized coating applications.
4Manufacturing precision
If transport rollers are added to guide the sheet on both sides of the folding blade, then sheet guiding is improved, but the device complexity increases
Solution Approach 1:
The patent divides the sheet guidance function into multiple independent transport rollers positioned on both sides of the folding mechanism. Each roller can be independently controlled to guide the sheet edges, ensuring precise alignment and even fold lines while distributing the complexity across multiple simple components rather than one complex mechanism.
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
Prevents smearing of printing ink or toner while ensuring a precise and even fold line, allowing for the collection of folded sheets without smudging, and facilitating efficient folding and collation.
Implementation Method 1
The fold line is formed in the sheet by folding rollers (30), which are mounted so as to be rotatable and which form the fold line in the sheet by rotating upon contact with the sheet while the sheet is being passed under the folding blade (5).
Data Source
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AI summary
Device for folding paper sheets (22) comprises a sheet conveyor and a folding sword (26) with a series of folding rollers (30) that are arranged one after another in the machine direction and rotate about an axis (50) perpendicular to the machine direction.