Stretching Kit

Stretching kit is used for the stretching process of the wire.

Stretching kit increases the mechanical properties of the inlet material (which is rebar in coils) which should have the required chemical composition without adding any expensive micro-alloyed elements (vanadium and manganese) and without making a “water quenching” process (commonly called Termex or Tempcore).

The stretching process is performed by two stretching panels oriented at 90° one to each other that thanks to an alternate bending made by a series of rolls (tungsten carbide) on the entry material, apply the desired degree of stretching (that can varies from 1 to 7%) that increases the elongation of the wire, while the rib pattern have been already applied to the material surface in the hot rolling phase of its production). The stretched material that is obtained is essentially a hot rolled material with increased mechanical properties (tensile strength, yield strength and final elongation) and just like the other reinforcements wire exhibits an elevated ductility and ability to absorb unforeseen loads. Another advantage of this process are the wire dimensions that does not change significantly (the diameter remains practically the same) during the process.

With the stretching process you can produce the same quality of compact coils with the same mechanical properties and the same aesthetic characteristics of a spooler in a hot rolling mill but with a remarkable reducing of cost of investment and producing a cheaper material in the hot roll plant

The final product applications are normally reinforcing mesh, stirrups, cages and lattice girders for the civil and industrial construction, foundations and precast industry.

The stretching panels mentioned above are fixed to a metal structure that is completely closed by an external protection. Access is provided by means of a front operable door. This characteristic allows a remarkable reduction of noise and dust dispersion in the environment and increase the level of safety improving the working conditions for the operators.

On each stretching panels are mounted a series of idle rolls, whose position is adjustable through an electro-motor, and can be recorded creating a recipe that can be recall by the operators in the future for use the same setting.

All the rolls are made of tungsten carbide and mounted on idle wheel bearing supports that withstand high speed and harsh working conditions.

A centralized grease lubrication unit reaches all the roller supports and facilitates the automatic greasing of the same. A cooling water circuit flowing through the pins of the rolls eliminate the heat produced by the stretching process.

A local pulpit that is easily approached by the operator allows intervention during the wire insertion and adjustment phase.

An adequate outer covering and sufficient openings for wire insertion isolate all the hazardous parts in movement.

The stretching kit include also two (2) dedicated capstans for stretching process that have a hard metal coated V-shaped groove to assure an adequate pulling force necessary for the stretching process.

An arm with a pressing roll and a bypass pulley are added in the structure and complete the supply.

Stretching kit is designed and manufactured by Promostar working in collaboration with our partners using the latest technologies and best brands available in the market.