Bartell Machinery

Roll Form Strander System

The Roll Form Stranding process combines the advantages of two highly productive processes, namely: Roll Forming and Single Twist or Double Twist Stranding. These two systems are forged together to create a high-speed continuous manufacturing cell to produce Unilay concentric circular or shaped conductors with fill factors between 76% and 97%.

The Roll Form Strander program includes equipment designed to accommodate reels up to 2240mm (84in) and can produce a variety of products which include:

What is Roll Form Stranding?

This innovative process uses Single Input Wire (SIW) diameter and represents a strand design and manufacturing methodology that effectively reduces the conversion cost from rod to strand without compromising conductor performance. This concept is achieved by replacing the traditional stranding of wires using different wire diameters with stranding of wires using the same wire diameter for a wide range of cross sections. Through the shaping each wire in a layer the process then creates bunched conductors to compact strand with fill factors between 76% and 97% with unmatched productivity.

What is Roll Form Stranding?

By incorporating a Single Input Wire diameter program into the strand design, significant savings can be achieved:

  • Higher productivity at stranding machine
  • Lower drawn wire scrap
  • Lower insulating Costs
  • Improved return on investment
  • Quicker set-up
  • Reduced work in process
  • Shorter cycle times
  • Smaller input wire storage area


Single Input Wire (SIW) diameter meets the acceptance of the world’s major conductor standards such as IEC 60228, HD 383 and the ASTM standards.

What Equipment Does It Consist of?

Roll Form Strander System consists of the following equipment:

Double Twist machine: The machine is an “outside/in” configuration with bow, capstan, take-up, traverse and loading platform. The machine is a side loading unit and is equipped with a standard floor loader designed to load and unload the take-up reel with minimum operator effort.

OR

Single Twist machine: The machine is a closed cradle design consisting of bow, capstan, take-up, traverse and loading platform. The machine is a side loading unit and is equipped with a standard floor loader designed to load and unload the take-up reel with minimum operator effort.

Roll Forming Stand: 

Diagram of a Roll Forming Stand


The objective of this system is to shape individual wire and present to the strander the material in the optimum format depending on the desired strand construction.

The scope of the strand design determines the application configuration.

Available Configurations

Depending on the strand construction and stranding machine following line configurations are available:

  • Up to 37 wires (4 layers) of roll forming strand with Double Twist process. In this execution, each roll stand is driven individually allowing slight changes in speed to be made at each position to compensate for the variances in the spiral length. It further allows more precise distributions of wire tension in each layer optimizing the straightness of the resulting conductor.
  • Up to 61 wires (5 layers) of roll forming strand with Single Twist process. In this execution, each roll stand allows precise distributions of wire tension in each layer optimizing the straightness of the resulting conductor.


Different designs are available for each layer:

  • Roll forming of the input wires. This is achieved with a roll stand shaping each wire in a layer.
  • Round wire layers where a number of round wires are closed without any change in section. The “S” roll metering system is used in this instance.


The line is suitable to produce:

  • Unilay round Aluminum & Copper conductors
  • Unilay compressed Aluminum & Copper conductors
  • Unilay compact Aluminum & Copper conductors
  • ACSR conductors
  • Sector shaped Aluminum & Copper conductors
  • All Aluminum and Aluminum Alloy conductors (AAC & AAAC)


Machine parameters are digitally monitored and controlled via a Programmable Logic Controller (PLC) and a menu driven touch screen so that at each stage the operator is guided to obtain the desired machine operation.

Features & Benefits - Strander

Feature Benefit
Lower Capital Investment Compared To Tubular & Rigid Stranders
Improved Return On Investment
Higher Productivity Than Tubular & Rigid Stranders
Improved Return On Investment
Stem Package Pay-Off System
Longer Run Time, Reduce Downtime
Minimum Strander Pay-Off Change Over
Reduced Downtime
Continuous Input Wire Feeding Potential
Reduced Scrap, Reduced Downtime
Reduced Floor Space Requirement
Reduced Investment
Reduced Manning Levels
Labor Saving
Greater Control of Finished Product Parameters (Weight, Diameter, Resistance)
Improved Product Quality
Pre-Wire Interconnection Cable
Reduced Installation & Start Up Time
Simple Machine Set Up
Reduced Downtime
Roll Form Quick Change System
Reduced Downtime
Greater Level of Automation
Minimize Operator Error

Features & Benefits - SIW

Feature Benefit
Increased Wire Drawing Output
Improved Product Margins
Reduced Wire Drawing Die Inventory
Reduced Costs, Improve Product Margins
Reduced Conductor Material Scrap
Reduced Costs, Improve Product Margins
Reduced Work In Progress (Inventory)
Reduced Floor Space
Higher Productivity At Strander Machine
Improved Product Margins

Options
  • Single Twist/Double Twist pay-off for ACSR  conductors
  • Stem Pay-off with or without automatic change over
  • Dancer/Accumulator
  • Servo drive for Roll Former gap adjustment
Specifications - Double Twist

Roll Form Strander Double Twist Specifications

Specifications - Single Twist

Roll Form Strander Single Twist Specifications

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