7-Wire PC Strand and the Wrapping Machine

PC steel wire, or prestressed concrete steel wire, is a high-quality steel wire commonly used as an internal reinforcement material for concrete. It is made of steel that is tightly alloyed with carbon. PC steel wire is known for its large diameter and is usually drawn after descaling and accumulation of a phosphate-type reactive surface coating. The process involves repeated heating and stretching of cold-drawn high-carbon steel wire to obtain a finished product with significantly reduced load relaxation and greatly increased yield stress.

The role of PC steel wire is to balance the tensile stress caused by bending loads, and it also helps to ensure the bearing capacity of concrete structures. PC steel wire is widely used in the construction field to manufacture prestressed steel structures such as long-span bridges, coal mine geotechnical anchoring projects, overhead crane beams, multi-story frames, dams, etc. Due to its consistent mechanical properties, excellent corrosion resistance and minimal relaxation, PC steel wire tends to provide uniform compressive strength to concrete.

Common sizes of 7-strand PC strands:

7-strand uncoated or galvanized PC steel strand is the most commonly used product for prestressed or post-tensioned concrete structures. There are two types of uncoated PC steel strands: the first is low relaxation and normal stress release. Galvanized PC strands have a corrosion-resistant zinc coating and are mainly used in mining and cable-stayed bridge construction.

PC strand rolls are packed by HDPE film to protect the material from rust and dust. The packaging process of 7-filament PC strands uses large coil packing machines or so-called coil wrapping machines. The machine wraps the big coils and rolls with wrapping material going through the core, making the coils fully wrapped and sealed. The wrapped coils are well protected to against dust, vapor and other types of corrosion.