Excessive Scrap Problems In Rollforming Equipments

By Author: Joe Piegat
Total Articles: 2
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Roll forming machineries are used to bend metal for future use for construction, car industry and metal bending. These machines are needed by large industries to assist them have the bent metal they needed in their production, but it is unavoidable fact that large companies providing rollforming Valparaiso, Indiana experienced problem with their machineries having a scrap rate over 5%, where technically speaking, a roll forming machinery have a scrap rate or dump rate of 0 – 5percent. If you are experiencing the same problem, read this article and take your time to investigate and causes to take actions about it.

What is Roll Forming?
Roll forming is a continuous bending operation where a long strip of coiled steel is passed through sets of rolls mounted on consecutive stands. The sheet would go through a roll bending where the metal sheet would go through a roll stand and used to modify it shape. It is ideal for producing constant-profile arts with long lengths in large qualities. This is commonly used for bending roofs, car industry and construction.

The main causes of the scrap problems
• Equipment ...
... problems
• Improper set up procedures
• Improper tooling design
• Material quality issues
Causes for excessive scrap
Incoming Material Problem
Excessive camber, oil-canning, cross-break, or damaged edges in the coiled material could affect the consistency of the roll form production line, particularly to the roll formed cross section. Material defects are one of the reasons for problems in the post processing of the steel. Make sure to ask your personnel to make basic visual inspection and basic measuring of the incoming coils and standards that work for the specific roll set and products. Incoming material will always have one or more abnormalities and a good tooling design combined with definite setup procedures for each defect scenario will result in to acceptable parts and scrap rates while avoiding the defects by rejecting the material before it is fed.
Problems in Tooling set
The quality of the incoming steel is important, the setup and condition of the roll set contributes greatly to the amount of scrap produced. Scrap produced from a typical tool set is due from the lack of using documented setup charts and settings. One of the contributors in scrap problems are from secondary adjustments made by operators’ on-the-fly after the initial setup does not work. If the amount of scrap is occurring due to the tooling, a process of elimination is needed to determine the corrections needed to minimize it.
Variation in Scrap rates from different shifts
This is one of the most common issues all the time and some said that it is a simple problem to fix, this is one is the most common problems existing in many companies. It comes into three main causes
• Lack of documented setup procedures.
• Difference between shift operator techniques.
• Operator’s skill level.
Mill related Problems
One of the problem-provider during the process of roll forming is the alignment and maintenance of the rolling mill. Common problems such as spindle shoulder misalignment, spindle deflection and bent spindles cause numerous product defects that are difficult to trace and could result in inconsistent setups from one run to the next. A tooling set is machined to specific tolerance and if the machine is not properly aligned, the rolls cannot operate as designed. Bent spindles and deflection is a common problem and related to excessive for being applied to material to achieve a proper bend.

If you are experiencing excessive scrap and would like further details, or have existing roll forming production problems, consult a coil processing specialist to train your staffs and repair your coil processing materials.