Method for high speed stranding of aramid yarns
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Solution Overview
Problem
The production speed of fiber optic cables is limited by the deformation of aramid yarn packages at high rotating speeds, leading to shifting of yarn layers and inability to take off the yarn, which restricts the operating speed of stranding servers to around 150 RPM due to insufficient package stability.
Innovation Solution
Applying a minor amount (0.05 to 0.95 wt%) of a specific organophosphorus compound finish to the aramid yarn, comprising compounds like mono- or dialkyl phosphate esters, improves the frictional behavior between yarn layers, enhancing package stability and allowing for higher stranding speeds without compromising quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the server rotation speed is increased to improve production speed, then productivity increases, but package stability deteriorates causing yarn layer shifting
Solution Approach 1:
The invention changes the chemical composition parameter of the yarn finish by applying an organophosphorus compound instead of conventional finishes. This chemical parameter change modifies the frictional behavior between yarn layers, enabling the package to maintain stability at higher rotation speeds (up to 300 RPM) that would otherwise cause layer shifting and production defects.
2Productivity
If the server rotation speed is increased beyond 150 RPM, then production efficiency improves, but yarn take-off becomes impossible due to package deformation
Solution Approach 1:
The invention modifies the frictional parameters between yarn layers through the organophosphorus compound finish. This parameter change prevents package deformation even at high rotation speeds, ensuring that yarn take-off remains reliable and continuous without interruption, thereby enabling sustained high-speed production.
3Stability of the object's composition
If standard organophosphorus compounds are used as finish, then frictional behavior improves, but the amount of finish required increases beyond acceptable limits
Solution Approach 1:
The invention changes the chemical structure parameters of the organophosphorus compound to achieve optimal frictional modification at minimal concentrations. By selecting specific compounds with appropriate molecular characteristics, the invention achieves the desired frictional behavior improvement while keeping the finish amount within the controlled range of 0.05 to 0.95 wt%, avoiding excessive finish application.
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 package stability enables aramid yarns to be stranded at higher speeds, significantly increasing the production speed of fiber optic cables while maintaining quality, and can be applied to standard servers in the industry.
Implementation Method 1
appliance of a minor amount, i.e., 0.05 to 0.95 wt%, based on the weight of the aramid, of a finish comprising a specific organophophorus compound on aramid yarn influences the frictional behavior between yarn-layers
Data Source
AI summary
The invention pertains to a method for stranding aramid yarn around an endless core, wherein the core is provided for a stranding step to a stranding apparatus comprising at least one yarn bobbin, wherein during operation the bobbin revolves around its own axis and the bobbin revolves around the core, and unwinding the yarn from the bobbin around the core to provide a core surrounded by the yarn, wherein the yarn is a continuous aramid yarn provided with 0.05 to 0.95 wt%, based on the weight of the aramid, of a finish comprising an organophosphorus compound, wherein the organophosphorus compound is a compound of the formula X1X2X3P=O, wherein X1, X2, and X3 are independently selected from Y1-, Y1-O-, and M-O, wherein Y1 is a branched or straight-chain C1-C20 alkyl, aryl or alkenyl, with M being selected from Li, Na, K, or ammonium, with the proviso that at least one of X1, X2, or X3 is selected from Y1- or Y1-O-, wherein the different types of Y1 may be the same or different. In one embodiment, the continuous aramid yarn is provided with 0.10 to 0.50 wt% of the finish. It has been found that the use of a relatively minor amount of a finish comprising a specific organophosphorus compound results in an improved package stability on a rotating server with a rolling yarn take-off. Consequently, packages of aramid yarns provided with this finish allow for high speed stranding of aramid yarn around an endless core.