Preformed Bag Web Segmented Weakness Lines
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Solution Overview
Problem
Existing preformed bag webs are prone to tearing when opened by bagging machines due to the lines of weakness, which can lead to inefficiencies in packaging processes.
Innovation Solution
A web of preformed bags with parallel lines of weakness in both layers, featuring gaps with no perforations between the openings and transverse seals, which are designed to prevent tearing and facilitate smooth opening and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If continuous lines of weakness are provided in the web of bags, then the bags can be easily opened by bagging machines, but the lines of weakness are prone to tearing during the opening process
Solution Approach 1:
The continuous line of weakness is segmented into discrete perforations separated by gaps. Each perforation allows controlled opening while the gaps between them prevent tear propagation along the entire line, thus maintaining ease of opening while improving reliability
Solution Approach 2:
The line of weakness has non-uniform structure with perforated regions for opening and gap regions for tear prevention. The local quality varies along the line: perforations provide opening functionality where needed, while gaps provide structural integrity to prevent tearing, creating different local properties along the same line
2Ease of operation
If lines of weakness extend continuously across the web, then bag opening is facilitated, but the lines of weakness intersect with sealing points causing damage
Solution Approach 1:
The line of weakness is divided into discrete perforations with gaps between them, preventing continuous tear paths that would intersect with sealing points. The segmentation ensures that even if a tear starts at one perforation, it cannot propagate continuously to reach the sealing area
Solution Approach 2:
The gaps in the line of weakness preemptively block the propagation path of potential tears before they can reach the sealing points. By introducing these gap regions, the design anticipates and prevents the harmful interaction between line of weakness and sealing operations
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3A~3C
AI summary
An exemplary web of preformed bags includes first and second layers, first and second side, first and second side seals proximate the first and second edges, a plurality of transverse seals extending between the first and second side edges, an opening in the first layer, and a line of separation in the second layer, a first line of weakness in the first layer. The first line of weakness has a plurality of gaps having no perforations in a region between the plurality of openings in the first layer and the plurality of traverse seals.