Rotary Bag Machine Heated Perforator Seal Integration
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Solution Overview
Problem
Existing bag making machines face challenges in accurately placing perforations close to seals, leading to waste and inefficiency due to difficulties in sensing seals and mechanical knife adjustments, especially in high-speed continuous motion machines.
Innovation Solution
A rotary bag machine with a heated perforator and independently controlled sealing zones, including a nickel chromium resistance wire and glass mica insert, allows for precise formation of a weakening zone between seals, reducing waste by minimizing the distance between side seals and enabling consistent perforation placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a downstream rotary knife is registered to perforate between two seals, then perforation can be created, but seal cutting occurs due to variations in tension, film gauge, and machine settings
Solution Approach 1:
The patent performs the perforation action at the seal location itself rather than downstream, creating the perforation as part of the sealing process. This preliminary action eliminates the timing and positioning variations that occur with downstream perforation, preventing seal cutting while ensuring accurate perforation placement.
Solution Approach 2:
The patent combines the sealing and perforation functions into a single integrated process at the seal location. By merging these two previously separate operations, the system eliminates the registration and timing issues between seal formation and downstream perforation, ensuring both seal integrity and precise perforation placement.
2Loss of substance
If seals are placed close together to reduce waste, then material efficiency improves, but perforation placement becomes more difficult and seals may be cut off
Solution Approach 1:
The perforation is created at the seal location itself during the sealing process, rather than downstream. This allows perforations to be placed immediately adjacent to seals without the registration errors that prevent close spacing, thereby minimizing web waste while maintaining precise perforation placement.
3Productivity
If mechanical knives are used for perforation, then perforation can be created, but frequent adjustments are required due to tension and film variations
Solution Approach 1:
The patent replaces the mechanical downstream rotary knife system with a sealing-based perforation system that creates perforations at the seal location. This substitution eliminates the need for mechanical knife adjustments by using the seal bar and blanket interface to create controlled perforations, thereby improving operational continuity and reducing maintenance requirements.
4Manufacturing precision
If sensors are used to detect seals for perforation registration, then perforation placement can be improved, but sensing difficulty reduces measurement precision
Solution Approach 1:
The patent extracts the perforation function from the downstream registration system and places it directly at the seal location. By removing the need for seal detection and registration, the system eliminates the measurement and detection difficulties associated with sensing seals, while still achieving precise perforation placement through the integrated sealing-perforation process.
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 solution enhances the accuracy of perforation placement next to seals, reduces waste, and eliminates the need for frequent mechanical knife adjustments, maintaining high production speeds and efficiency in bag making.
Implementation Method 1
a heated perforator... including a nickel chromium resistance wire
Implementation Method 2
including a nickel chromium resistance wire and glass mica insert
Data Source
Figure 1
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AI summary
A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section The rotary drum includes at least one seal bar, having a first sealing zone and an adjacent weakening zone The weakening zone may be a heated perforator, includes a heating wire, or be disposed to create an auxiliary sealed area The heating wire can have collected thereto, a source of power that is at an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop The heating wire may be NiCr wire and make intermittent contact with the web and be disposed in an insert The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone, or includes a heat film toothed blade, row of pins, source of air, or a source of vacuum.