Cylinder Fabrication System Welds and Planishes
Galvanized CRS and Stainless Steel

When quick, reliable and formable welds are required to manufacture your product, resistance mash seam welding and planishing should be a prime consideration.
This system, built by Weldmation, includes a combination destacker and launch table to receive either a galvanized steel or stainless steel blank from an existing decoiler, straightener and cutoff system, a cylinder forming and welding machine, and a cylinder finishing line. The cylinder finishing line provides wire brushing, planishing and nipping operations to complete the cylinder fabrication.

LAUNCH TABLE AND MASH SEAM WELDER

An entry feed table has side guides and an end stop to position the sheet at an approximate location. Once rough positioned, a bank of vacuum cups lowers, grips, and lifts the sheet to the launch table position. Side rollers pivot into place to support the sheet and establish proper alignment for roll forming. In forming position, an air-operated pusher advances the sheet across the launch table and starts it into the roll-forming station.

The roll-forming station has three (3) driven rolls, spring-actuated pressure, and an adjustable third roll for adjustment of final cylinder diameter. As the sheet is roll-formed it is guided around a lower mandrel. After roll-forming, crowder nests pivot into place, positioning the weld joint edges of the cylinder into a “z” shaped edge alignment locator. This locator sets the material overlap for the resistance mash seam weld operation. An air-operated pusher advances the cylinder along the “z” bar into a “nose piece” locator adjacent to the welding wheels. Upper and lower skew rolls provide the force necessary to maintain the joint edges against the nose piece during welding.

The resistance seam welding station features a heavy-duty welding ram with hardened machine ways and air follow-up cylinder that deliver the welding force. The ram includes take-ups to insure proper alignment of upper and lower welding equipment. The 200 KVA direct current (DC) resistance welding transformer provides power to weld galvanized steel and non-magnetic stainless steel up to .026 inches thick at speeds approaching fifteen (15) feet per minute.

FINISHING LINE

After mash seam welding, an automatic unloader transfers the cylinder from the welding equipment into an automated six (6) station cylinder finishing line. Finishing line operations include:

• Station #1 – Load
• Station #2 – Wire brush joint (optional)
• Station #3 – Planish
• Station #4 – Wire brush joint (optional)
• Station #5 – Nipper seam extrusions
• Station #6 – Automatic unload

The cylinders are transferred between stations using an electrically driven, shuttle-type transfer. The programmable transfer drive provides a smooth acceleration and deceleration motion resulting in a controlled transfer of the workpiece. Independent, air-operated lifters in each station are used to elevate the workpiece to the overhead tooling.

The optional wire brush equipment at station #2 and station #4 can be used to clean the welded joint before and after planishing. This is especially useful in removing surface impurities resulting from welding of galvanized material.

The planishing operation at station #3 reduces the welded joint build-up to near original material thickness. Planishing also smoothes the weld surface to minimize snags. The planishing station uses air pressure and mechanical leverage to deliver up to 20,000 pounds of force to the weld area. This high force exceeds the yield strength of the steel and causes the thickness reduction.

The ends of the welded seam where the weld and planish wheels have extruded small amounts of material are nipped in station #5. This forms a square edge, flush with the cylinder edge and removes weld seam discontinuity which normally occurs at each end of the cylinder.

The cylinder is automatically unloaded at station #6 and  placed on a discharge conveying system.

The welding machine and finishing line include separate programmable controllers housed in NEMA 12 enclosures.  Man Machine Interface (MMI) panels with screen displays and membrane touch buttons are provided for manual operation and setup purposes.

Mash seam welding offers the ability to weld at speeds greater then competing arc welding processes, while planishing, (a flattening operation) provides the ability to reduce the welded joint buildup to less then 10% over original parent metal thickness for carbon steels and less then 15% for stainless steels.