Production process of prestressed concrete strand
The wire rod is descaled as a way to eliminate the mill scale present on its surface by way of a chemical descaling system(Pickling) and then it's pre-lined with service coating to facilitate the adherence of lubricant in the course of the wire drawing procedure.
The wire rod is cold drawn by dry drawing machines equipped with a series of 9/11 lubricated dies that reduce its cross-sectional area and allow it to achieve the desired mechanical properties.
3.WINDING OF DRAWN WIRE INTO SPOOLS
The cold drawn wire is wound onto spools.
The set of 2 or 3 spools are positioned into stranding machines to be synchronously unwound and stranded.
The stranding machines wind the drawn wires into a 7-wire strand which includes a primary wire around which are helical spin six-wire, in a single layer and with uniform pitch.
The drawn wire is subjected to a thermos. mechanical process wherein the wire is continuously heated even as beneath anxiety in order to relieve the residual drawing stresses and slash losses.
7.WINDING OF STRING INTO MASTER COIL
The strand is wound right into a master coil.
8.MASTER COIL REWINDING AND COOLING
The master coil is rewound into single finish coils of the strand of desired size and packaging.