Sheet and Method of Making Sheet for Support Structures and Tires

A method of forming a planar sheet, comprising the steps of:

• (a) providing a plurality of polyamide yarns having a yarn modulus of from 3.7 to 6.8 N/dtex, an elongation to break of from 2.9 to 4.7% and a denier of from 130 to 15,000,
• (b) optionally twisting a plurality of polyamide yarns into a cabled yarn,
• (c) providing a plurality of steel wires having a major cross sectional dimension of from 0.04 to 1.10 mm and a composition comprising a minimum carbon content of from 0.60 to 1.10%, a manganese content ranging from 0.20% to 0.90%, and a silicon content ranging from 0.10% to 0.90%,
• (d) determining the desired pitch, amplitude and planar arrangement of crimps to be applied to the steel wire such that the crimps lie in two planes that are at least 20° different from each other and the steel wire has an elongation to break no greater than 20% different from that of the polyamide yarn,
• (e) crimping the steel wire in accordance with the crimp parameters determined in step (d),
• (f) optionally twisting a plurality of steels wires into a cabled wire, and
• (g) combining the desired number of steel wires and/or steel cords, and the desired number of polyamide yarns and/or polyamide cords in a planar arrangement such that all the yarns, wires and cords are oriented parallel to each other.

A method of forming a planar sheet, comprising the steps of:

• (a) providing a plurality of polyamide yarns having a yarn modulus of from 3.7 to 6.8 N/dtex, an elongation to break of from 2.9 to 4.7% and a denier of from 130 to 15,000,
• (b) providing a plurality of steel wires having a major cross sectional dimension of from 0.04 to 1.10 mm and a composition comprising a minimum carbon content of from 0.60 to 1.10%, a manganese content ranging from 0.20% to 0.90%, and a silicon content ranging from 0.10% to 0.90%,
• (c) determining the desired pitch, amplitude and planar arrangement of crimps to be applied to the steel wire such that the crimps lie in two planes that are at least 20° different from each other and the steel wire has an elongation to break no greater than 20% different from that of the polyamide yarn,
• (d) crimping the steel wire in accordance with the crimp parameters determined in step (c),
• (e) twisting at least one crimped steel wire with at least one polyamide yarn to form a composite hybrid steel-polyamide cord into a steel cord, and
• (g) combining the desired number of steel wires or cords, polyamide yarns or cords and composite hybrid steel-polyamide cords in a planar arrangement such that all the yarns, wires and cords are oriented parallel to each other.