What is the working principle of New Solar PV Round Wire Machine

      The New Solar PV Round Wire Machine is a continuous integrated precision forming equipment, specially designed for the production of tin coated photovoltaic round copper wire (round wire welding strip) for HJT, TOPCon, BC battery 0BB non main grid technology. Using oxygen free copper wire as the substrate, relying on multiple continuous processes, drawing, online annealing, surface purification, uniform tin coating, online detection, and precision winding are completed under a constant tension system; The core relies on servo linkage closed-loop tension control to ensure the stability of wire roundness, wire diameter tolerance, and tin layer thickness throughout the entire process, producing finished products directly for interconnection of photovoltaic module cells.

Complete workflow and segmentation principle

1. Constant tension unwinding unit

      The copper wire mother coil is smoothly laid out, and the tension swing rod and servo motor adjust the laying speed in real time to eliminate wire shaking and stretching deformation, ensuring that the wire entering the next process runs smoothly and avoiding fluctuations in thickness.

2. Precision wire drawing forming (optional integrated wire drawing module)

      The coarse copper wire continuously passes through a multi-stage diamond drawing die and gradually shrinks to the target finished product diameter through cold drawing plastic deformation; The equipment is equipped with a circulating lubrication system to reduce the pulling friction, ensure a smooth surface and a round cross-section of the wire, and control the micrometer level tolerance of the wire diameter.

3. Online continuous induction annealing (core process unit)

      Using resistance/induction rapid annealing process, copper wire forms a current loop through electrode wheel, and utilizes Joule effect for instantaneous heating; Rapid heating and synchronous cooling.

      Function: Eliminate internal stress caused by cold drawing, improve copper wire elongation and flexibility, reduce electrical resistivity, adapt to welding deformation of subsequent components, and prevent hidden cracking of battery cells.

      The servo speed of the entire line is synchronized to prevent the wire from being stretched and becoming thinner during the annealing process.

4. Surface cleaning and activation treatment

      Remove oil stains and oxide scales on the surface of copper wire through acid washing, pure water cleaning, and hot air drying; Re immerse the soldering flux, activate the surface of the copper substrate, ensure a tight bond between the tin layer and the copper substrate, and prevent defects such as desoldering and missed plating.

5. Thermostatic Tin Coating System (Hot Dip Tin Plating)

      The tin furnace maintains a constant melting temperature and uniformly pulls the round wire vertically through the tin solution; Equipped with an air flow tin blowing device, excess tin material is scraped off by uniform air pressure, and the thickness of the circumferential tin layer is precisely controlled to achieve uniform coating around the entire wire.

      Differentiate flat solder strips: Round wires require 360 ° balanced tin blowing to prevent uneven thickness of the upper and lower plating layers.

6. Cooling and online detection

      After tin coating, air cooling is used to shape and stabilize the structure of the tin layer; Combined with online appearance monitoring, it can identify defects such as scratches, missed plating, and tin nodules, and some models integrate real-time monitoring of wire diameter.

7. Storage buffer and precision winding

      Buffer start stop speed difference of storage line mechanism; Double station servo winding, with a constant reciprocating arrangement of the wire setter to ensure neat winding of the wire, avoiding squeezing deformation and mutual scratching of the wire.