Our experience working with companies in many different industries around the globe has shown us that the factors which determine correct wire straightener selection are often misunderstood. For instance, many process engineers are not aware when setting the roller positions in a straightening assembly that less wire deflection frequently yields better results than more deflection.
One of the most detrimental misunderstandings is the very common approach of choosing a straightener strictly on what had been in place previously or in another operation within the same facility. Simply put: many operations simply “go with what we know” instead of fully considering how quality and productivity could be improved by optimal straightener choice.
Here is a brief overview of the factors we look at when helping our customers achieve the greatest efficiency and productivity from their wire straightening operation.
First, we consider the incoming parameters of the wire:
Size — What is the wire diameter or shape dimensions? Is there a range of sizes?
Material type — Such as steel, aluminum, copper, etc.
Material shape — Is the material solid, tube or cable?
Material Tensile Strength — Ideally the yield strength should also be specified.
Surface Conditions — Are there any coatings or lubricants on the wire?
Next, we consider wire output parameters:
Desired Straightness — What output is desired? With roll straightening the best straightness is in the area on .015 to .020” per foot.
Desired Out-of-Straightness — What is the amount of cast or helix to be set?
Line Tension — Is there a requirement to add back tension in the process line?
Effect on Surface — Is marking or flattening of the wire acceptable?
Material Properties — Is a change in material strength desirable or detrimental?
Another important step that is sometimes overlooked are the broader process parameters (Many concerns with the wire straightening operation actually do not relate directly to the assembly):
Payoff Type — Is the payoff a rotating spool, rotating coil or carrier, or a stationary spool or coil with a flier arm?
Attitude of Wire — How is the curvature of the wire approaching the straightener; for instance: is the direction of wire travel left to right or right to left?
Line Speed — This is usually listed in feet per minute.
Line Temperature — Are high temperatures involved, above 150 degrees?
Line Tension — Are any special line tensions involved in the process?
Every operation has unique factors — Sjogren always takes the time to work with customers to select the optimal straightener and other components. Before you “go with what you know” when selecting a replacement or new straightener, contact us: we will help you get the best possible solution.