Peelable Laminated Woven Plastic Bag Seals for Leak-Free Opening

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Solution Overview

Problem

Conventional woven plastic bags used for bulk materials face challenges such as slow sewing production lines, aesthetically unpleasing ends, difficulty in opening without tools, and susceptibility to leakage, breakage, and infestation, especially in high-speed filling operations.

Innovation Solution

The development of woven plastic bags with laminated layers and controlled peel strength seals, featuring easy open features like weakened areas and sealing tapes, and angled or curved cuts to reduce leakage and infestation, ensuring strong and durable bags that can be opened by hand without tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional woven plastic bags are used for bulk materials, then they provide basic packaging functionality, but they cannot be printed with high end graphics and are too rudimentary for consumer type packaging

Engineering Contradiction:
Improveprinting capabilityVSAvoidbag structure
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines woven polypropylene material with laminated film layers to create a composite bag structure. This allows the bag to maintain the strength and durability of woven material while adding the smooth surface and printability of laminated films, enabling high-end graphics for consumer packaging.

Inventive Principle:
Principle #40Composite materials

2Productivity

If conventional LWS bags are sewn shut on both ends, then they provide a strong structure, but the sewing production lines are slower than filling operations and create aesthetically unpleasing ends

Engineering Contradiction:
Improveclosing speedVSAvoidend appearance
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent replaces the mechanical sewing process with heat sealing technology. The sealed ends are created through thermal bonding of the laminated layers, which can be performed at high speeds integrated with filling operations, eliminating the bottleneck of sewing while creating clean, aesthetically pleasing end surfaces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If sewn bags are used, then they provide closure functionality, but they require puncturing the plastic bags resulting in reduced shelf-life and possible infestation

Engineering Contradiction:
Improveseal integrityVSAvoidinfestation risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical puncturing and sewing with heat sealing that fuses the laminated layers together. This creates a continuous, intact seal that maintains bag integrity, prevents infestation, and extends shelf-life while still providing secure closure functionality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of operation

If pinch bottom laminated woven sacks are used, then they provide improved filling and closing operations, but they do not include an easy open feature requiring scissors or knives

Engineering Contradiction:
Improveopening easeVSAvoidbag structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the sealed end structure into distinct functional zones: a sealed portion for maintaining integrity and a weakened portion with perforations for easy opening. This segmentation allows the bag to provide both secure sealing and consumer-friendly opening without requiring external tools.

Inventive Principle:
Principle #1Segmentation

5Reliability

If conventional bags are used, then they provide basic sealing, but they are susceptible to leakage, breakage, and infestation during handling

Engineering Contradiction:
Improveseal strengthVSAvoidleakage and breakage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses laminated films bonded to woven polypropylene to create a composite structure that combines the strength and tear-resistance of woven material with the sealability and leak-proof properties of laminated films. This provides superior protection against leakage, breakage, and infestation during handling and storage.

Inventive Principle:
Principle #40Composite materials

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 bags provide a strong, durable, and aesthetically appealing solution that remains sealed, is easy to open, and withstands rigorous handling conditions while preventing leakage and infestation, maintaining integrity during filling, shipment, and storage.

Implementation Method 1

the sealed closure comprises a peel strength, wherein at least a portion of a surface of the front wall or the back wall is adapted to be separable from the sealed closure with a lower peel strength than the remaining portion of said sealed closure

Methodology Applied
Scientific EffectPeel strength: Adhesive

Implementation Method 2

the difference in treatment comprises a difference in ionization of a portion of the one or more surfaces, wherein the portion of the one or more surfaces comprises a treatment of one or more of a polyurethane ink, a polyamide ink, a nitrocellulose ink

Methodology Applied
Scientific EffectIonization: Ionisation

Data Source

PatentEP3585699B1Peelable easy open plastic bag and method of making a bag
Publication Date: 2026.04.01 POLYTEX FIBERS LLC
  • EP3585699B1 patent drawingFigure 1~2
  • EP3585699B1 patent drawingFigure 3~6
  • EP3585699B1 patent drawingFigure 7~8

AI summary

A woven laminated plastic bag having features that prevent leakage of contents out of the bag, or infestation of organisms into the contents of the bag is provided. In various aspects the bag can be fabricated from woven polypropylene and/or polyethylene layer which can be laminated with a film layer, can form a pinch bottom bag, and can have one or both sides include graphics and/or printing. The bag can also provide a top end and/or a bottom end either or both of which provide a discrete area which may contain discrete graphics and/or printing. The bag can also include a sealed closure that at least a portion of which can be easily peeled open with less force than the remainder of the sealed closure.