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AssigneeTicona LLC
InventorsSherri M. Nelson, David W. Eastep, Timothy L. Tibor, Timothy A. Regan, Michael L. Wesley, Richard Stiehm
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A composite rod for use in various applications, such as electrical cables (e.g., high voltage transmission cables), power umbilicals, tethers, ropes, and a wide variety of other structural members, is provided. The rod includes a core that is formed from a plurality of unidirectionally aligned fiber rovings embedded within a thermoplastic polymer matrix. The present inventors have discovered that the degree to which the rovings are impregnated with the thermoplastic polymer matrix can be significantly improved through selective control over the impregnation process, and also through control over the degree of compression imparted to the rovings during formation and shaping of the rod, as well as the calibration of the final rod geometry. Such a well impregnated rod has a very small void fraction, which leads to excellent strength properties. Notably, the desired strength properties may be achieved without the need for different fiber types in the rod.
A composite rod extending in a longitudinal direction, wherein the rod contains a core comprising a plurality of thermoplastic impregnated rovings, the rovings containing continuous fibers oriented in the longitudinal direction and a thermoplastic matrix that embeds the fibers, the fibers having a ratio of ultimate tensile strength to mass per unit length of greater than 1,000 Megapascals per gram per meter, wherein the continuous fibers constitute from 25 wt. % to 80 wt % of the core and the thermoplastic matrix constitutes from 20 wt. % to 75 wt. % of the core, and wherein the rovings are distributed generally symmetrically about a longitudinal center of the core, wherein the core has a void fraction of 3% or less, and wherein the rod has a minimum flexural modulus of 10 Gigapascals, a bend radius of less than 40 times the outer diameter of the rod, and a minimum ultimate tensile strength of 300 Megapascals.
A method for forming a composite rod extending in a longitudinal direction, wherein the method comprises:
A composite rod extending in a longitudinal direction, wherein the rod contains a core comprising a plurality of thermoplastic impregnated rovings, the rovings containing continuous fibers oriented in the longitudinal direction and a thermoplastic matrix that embeds the fibers, the fibers having a ratio of ultimate tensile strength to mass per unit length of greater than about 1,000 Megapascals per gram per meter, wherein the continuous fibers constitute from about 25 wt. % to about 80 wt % of the core and the thermoplastic matrix constitutes from about 20 wt. % to about 75 wt. % of the core, wherein the core has a void fraction of 3% or less, and wherein the rod has a minimum flexural modulus of about 10 Gigapascals, a bend radius of less than 40 times the outer diameter of the rod, and a minimum ultimate tensile strength of 300 Megapascals.
Dependencies are inferred from the claim text.