Discrete Web Perforators for Vibration-Free Patterned Tissue
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Solution Overview
Problem
Conventional methods for perforating web materials, such as paper towels and bath tissue, face issues with reliability, manufacturing costs, flexibility, and perforation quality due to vibrations between moving blades and stationary anvils, leading to inferior product quality, increased waste, and lengthy changeover times.
Innovation Solution
The use of a discrete web perforator and additional web perforators positioned to form perforations in both the cross and machine directions, allowing for selected perforation designs, embossing, or printing patterns, and the application of liquid weakeners to enhance perforation quality and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a moving blade and stationary anvil are used to perforate the web, then the perforation can be formed continuously, but vibrations occur at high speeds that adversely affect perforation quality and may cause web breaks or equipment malfunctions
Solution Approach 1:
The perforation system is divided into multiple independent discrete perforators positioned at different locations across the web width. Each perforator operates independently, eliminating the vibration transmission path present in conventional single-line blade-anvil systems while maintaining continuous perforation capability across the entire web.
Solution Approach 2:
The invention transitions from a single-line perforation approach (one dimension) to a multi-line distributed perforation arrangement (two-dimensional distribution across web width). This spatial redistribution eliminates constructive interference of vibrations while preserving continuous production operation.
2Ease of manufacture
If conventional perforating equipment is used, then perforations can be formed, but the moving blade teeth become dull or broken after a period of use, requiring shutdowns to replace the blade and discard inferior product
Solution Approach 1:
The system employs disposable or easily replaceable discrete perforating elements rather than a single expensive, wear-prone moving blade. When individual perforators wear or break, only that specific element needs replacement, not the entire blade assembly, minimizing production downtime and waste.
Solution Approach 2:
The perforation function is segmented into multiple independent elements distributed across the web. This segmentation means that wear or failure of one element does not affect the others, allowing continuous operation with selective replacement of only the worn component.
3Ease of manufacture
If conventional equipment is used, then perforations can be produced, but changing from one perforation pattern format to another requires shutdown for at least several hours, leading to increased manufacturing costs
Solution Approach 1:
The discrete perforators are designed with adjustable positioning capabilities, allowing the perforation pattern to be dynamically changed during operation. Each perforator can be independently repositioned to create different patterns without requiring equipment shutdown, enabling flexible product variation and rapid changeovers.
Solution Approach 2:
The system allows pre-programming or pre-configuration of different perforation patterns on the discrete perforators. When a pattern change is needed, the new pattern can be loaded in advance, and the transition can be executed during operation, eliminating the need for lengthy shutdowns.
4Device complexity
If conventional single-direction perforation is used, then the process is simple, but flexibility to produce products with enhanced consumer desirability (linear and nonlinear perforations in both cross and machine directions) is limited
Solution Approach 1:
The discrete perforators are designed as multi-functional elements that can create various perforation types (linear, nonlinear, cross-direction, machine-direction) by adjusting their positioning and orientation. A single perforator can perform multiple functions, eliminating the need for separate specialized equipment for different perforation patterns while maintaining process simplicity.
Data Source
AI summary
Methods for perforating web products are disclosed that include forming selected perforation designs and patterns. The perforation designs and patterns can be formed in linear or nonlinear fashion, can extend in the cross direction or the machine direction and can be formed to complement or match an embossed or printed design on the web. The perforation designs and patterns can be formed utilizing various mechanical perforating techniques.