Urethane Cable Tape Air Permeability Void Prevention
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Solution Overview
Problem
The formation of voids in urethane-based resin sheaths during cable manufacturing due to moisture absorption and evaporation, which affects the workability and reliability of cables and harnesses.
Innovation Solution
A cable design featuring a tape member made of nonwoven fabrics like polyester, polypropylene, aramid fiber, nylon, or glass fiber with air permeability greater than 30 cc/cm2/sec, wrapped around electric wires and covered with a urethane-based resin jacket, preventing void formation by minimizing moisture absorption and air trapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a tape member is wound around electric wires to enable easy separation from the sheath, then workability is improved, but moisture absorption by the tape member causes void formation in the urethane-based resin sheath
Solution Approach 1:
The invention changes the material parameters of the tape member by specifying nonwoven fabrics with particular properties (air permeability of at least 30 cc/cm²/sec, moisture absorption characteristics). This parameter change allows the tape member to maintain its separation function while preventing moisture-related void formation in the urethane sheath during manufacturing.
Solution Approach 2:
The invention uses composite material construction by combining the tape member (made from specific nonwoven fabrics like polyester, polypropylene, aramid fiber, nylon, acrylic fiber, or glass fiber) with the urethane-based resin sheath. This composite structure enables the tape to provide separation functionality while its specific material properties prevent moisture absorption that would cause voids in the sheath.
2Ease of operation
If a tape member is used to separate electric wires from the sheath, then ease of separation is improved, but air trapping by the tape member causes foaming in the urethane-based resin sheath during extrusion
Solution Approach 1:
The invention changes the physical parameters of the tape member by selecting nonwoven fabrics with specific air permeability (at least 30 cc/cm²/sec). This parameter ensures that air can pass through the tape member during the extrusion process, preventing air trapping and subsequent foaming in the urethane-based resin sheath while maintaining the separation function.
Solution Approach 2:
The invention employs a composite material system where the tape member (composed of specific nonwoven fabrics) is integrated with the urethane-based resin sheath. The specific material properties of the nonwoven fabric allow it to function as a separation layer while its air permeability prevents foaming during the extrusion manufacturing 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
Prevents void formation in the urethane-based resin sheath, enhancing the workability and reliability of cables and harnesses by maintaining structural integrity and flexibility.
Implementation Method 1
the water is evaporated by heat during the extrusion so as to cause the voids to be formed in the sheath
Implementation Method 2
the tape member absorbing moisture from the air is covered with the urethane-based resin sheath by extrusion etc.
Data Source
AI summary
A cable includes a plurality of electric wires, a tape member wound around the plurality of electric wires, and a jacket that covers an outer periphery of the tape member and includes an urethane-based resin. The tape member includes a nonwoven fabric including one of a polyester, a polypropylene, an aramid fiber, a nylon, an acrylic fiber and a glass fiber. An air permeability of the nonwoven fabric is not less than 30 cc/cm2/sec.