Disposable Pool Cleaner Filter Bag With Welded Divider Seam
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Solution Overview
Problem
Existing disposable filter bags for pool cleaners suffer from premature seam failure due to adhesive deterioration in swimming pool environments and exhibit reduced performance due to air entrapment issues, leading to inconsistent debris collection and increased buoyancy.
Innovation Solution
A disposable filter bag with a reinforced cuff and a divider seam defined by a spaced-apart array of welds, formed through direct welding without additional adhesive, to enhance strength and prevent tearing, while minimizing stress concentration points and air entrapment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If adhesive material is used to form seams in disposable filter bags, then the bag can be manufactured with simple processes, but the adhesive deteriorates in swimming pool environments causing premature seam failure
Solution Approach 1:
The patent replaces the chemical adhesive bonding system with a mechanical/thermal welding system. The weld seams are formed by heating and fusing the thermoplastic material layers together, eliminating the need for adhesive materials that deteriorate in pool environments. This substitution resolves the contradiction by providing durable, reliable seams that maintain strength throughout the disposable bag's service life.
Solution Approach 2:
The patent changes the bonding mechanism from chemical adhesion to thermal fusion. By controlling temperature and pressure parameters during the welding process, strong seams are created that are resistant to deterioration. The weld seams maintain their structural integrity under the environmental conditions (water exposure, chemicals, temperature variations) that would degrade adhesive materials.
2Device complexity
If continuous divider seams are used in filter bags, then the bag structure is simple, but stress concentration points increase leading to tearing
Solution Approach 1:
The patent segments the continuous divider seam into discrete, spaced-apart weld points or short weld segments. Instead of a single continuous line of welding that creates stress concentration along its entire length, the divider seam is broken into multiple isolated welding zones. This segmentation allows stress to be distributed across multiple points rather than concentrated in one continuous line, significantly improving tear resistance while maintaining the structural function of the divider seam.
Solution Approach 2:
The spaced-apart weld pattern in the divider seam acts as a stress-distributing structure that cushions against tearing forces. By positioning welds at intervals rather than continuously, the design anticipates and accommodates stress concentration that would occur in a continuous seam, preventing tear propagation before it can compromise the entire bag structure.
3Productivity
If disposable filter bags are used for single-use cycles, then debris collection efficiency is improved, but manufacturing cost increases due to additional welding processes
Solution Approach 1:
The patent embraces the disposable nature of the filter bag by designing it for single-use cycles. The bag is constructed from thermoplastic materials that can be efficiently welded using automated processes. Although welding adds a step compared to adhesive bonding, the disposable design eliminates the need for cleaning, maintenance, and replacement of reusable bags, improving overall productivity through consistent performance and reduced downtime.
Solution Approach 2:
The patent utilizes the phase transition properties of thermoplastic materials during the welding process. By applying heat, the material transitions from solid to a softened state, allowing fusion and bonding, then cools to form a strong seam. This phase transition enables efficient, automated welding processes that are well-suited for high-volume production of disposable bags, balancing manufacturing complexity with productivity benefits.
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 improved filter bag provides increased resistance to tearing and consistent performance by maintaining structural integrity and preventing air entrapment, ensuring efficient debris collection and easy disposal.
Implementation Method 1
the divider seam is defined by a spaced-apart array of welds to form a divider seam of increased strength and resultant increased tear resistance
Data Source
AI summary
An improved disposable filter bag for use with a pool cleaner of the type disclosed, for example, in U.S. Pat. Nos. 5,863,425; 4,558,479; and 3,822,754. The filter bag is formed from a porous filter material having marginal seams formed by direct welding to form a reinforced cuff defining an open bag mouth leading to a hollow bag interior. The cuff is configured for removable mounting on a pool cleaner suction mast, as by removable connection to a mounting collar as disclosed in U.S. Pat. Nos. 5,863,425; D409,341; and D468,067. A divider seam defined by a spaced-apart array of welds subdivides the bag interior into a primary flow chamber for receiving flow of water and water-entrained debris from the pool cleaner, and a secondary collection chamber for trapping and collecting the water-entrained debris.