Laminated Communication Cable Structure for High-Temperature Water Blocking
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Solution Overview
Problem
Conventional communication cables experience inadequate water-stopping performance at high temperatures due to softening of the resin layer and improper joining of the laminated tape, leading to reduced strength and water ingress, especially when bent or twisted.
Innovation Solution
A cable design featuring a laminated tape with a resin layer made from medium-density or high-density polyethylene with grafted maleic anhydride, wrapped around a cable core and covered with an outer jacket of high-density polyethylene, where the resin layer is thicker at overlapped parts and joined continuously with the outer jacket, and optionally injected with waterproofing resin to ensure secure bonding and enhanced water-shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional resin layer is used in the laminated tape, then the cable can be manufactured with standard materials, but the resin layer softens at high temperatures causing adhesive failure and reduced water-stopping performance
Solution Approach 1:
The patent changes the chemical composition parameters of the resin layer by incorporating polyethylene with grafted maleic anhydride and specific additives (wax, slip agents, crosslinking agents) to raise the softening temperature and maintain structural integrity at high temperatures up to 75°C or higher, while preserving water-stopping performance
Solution Approach 2:
The patent creates a composite resin material by combining polyethylene base resin with grafted maleic anhydride, wax components, slip agents, and crosslinking agents to achieve both high-temperature resistance and effective water sealing properties that single materials cannot provide
2Reliability
If the laminated tape is wrapped with overlapped parts to ensure water stopping, then water-stopping performance is improved, but the overlapped parts may not be properly joined at high temperatures
Solution Approach 1:
The patent introduces an intermediary substance (waterproofing resin or adhesive composition containing crosslinking agents) at the overlapped parts to mediate the bonding between tape sections, ensuring strong joining and sealing at high temperatures where conventional adhesives would fail
Solution Approach 2:
The patent applies waterproofing resin or adhesive composition to the overlapped parts before final assembly and heating, allowing preliminary bonding and sealing to occur before the cable undergoes thermal processing or service at high temperatures
3Volume of moving object
If the resin layer is made thinner to reduce cable diameter, then cable size is reduced, but water-stopping performance and bond strength are compromised
Solution Approach 1:
The patent changes the density and compositional parameters of the resin layer by incorporating wax and slip agents that allow for thinner sections while maintaining effective water barrier properties, enabling reduced cable diameter without sacrificing water-stopping performance
4Strength
If high-density polyethylene is used for the outer jacket to improve durability, then mechanical strength is improved, but flexibility and ease of installation are reduced
Solution Approach 1:
The patent adjusts the density parameter of the outer jacket polyethylene to be greater than or equal to medium-density polyethylene (MDPE) rather than using full high-density polyethylene (HDPE), and incorporates slip agents to reduce friction, achieving a balance between mechanical strength and flexibility for easier installation
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 design ensures excellent water-stopping performance at high temperatures, maintaining bond integrity and preventing water ingress even under bending or twisting, while maintaining manufacturability and flexibility without requiring changes to existing manufacturing facilities.
Implementation Method 1
the fusion resin layer melts due to heat used for forming the cable, and the end parts of the fusion layer overlapping each other are solidified, bonded, and joined
Data Source
AI summary
A metallic cable includes, in order from an inner side thereof, a plurality of coated conduction wires, a press winding tape, a laminated tape, and an outer jacket. The outer jacket is provided on an outer circumference of the laminated tape and such that it covers the outer circumference of the laminated tape. The outer jacket is made of polyethylene having a density greater than or equal to that of medium-density polyethylene (MDPE) (≥930 kg/m3), and more preferably made of high-density polyethylene (≥942 kg/m3). If polyethylene having a density that is equal to or greater than that of MDPE is used to form the outer jacket, the temperature that is appropriate for extruding MDPE approaches a bonding temperature range of the resin layer of the laminated tape. The resin layer and the metal layer can be bonded and joined together at an overlapped part, tightly enclosing a cable core.