RF System Maintenance: A Step-by-Step Guide

Nothing is more important for the proper functioning of RF welding and sealing equipment than preventive maintenance. Just as an auto owner never ignores the need for routine oil changes, preventive maintenance must be part of the ownership of RF welding and sealing equipment. Moreover, failure to properly maintain equipment could result in the delivery of faulty or sub-par products to your customers, potentially damaging valuable business relationships at worst and requiring costly replacement orders to be fulfilled at best. 

Thermex-Thermatron understands that during busy production times, routine maintenance easily can become anything but routine. Operators may be inclined to postpone small steps until a malfunction or breakdown occurs. When that happens, expensive repair costs can result and customer deadlines may be missed. That’s why Thermex-Thermatron has produced a series of guides to help operators better understand and execute scheduled maintenance. Below are three simple, easy-to-follow checklists for daily, weekly, and monthly maintenance.

DAILY MAINTENANCE CHECK-LIST

Before turning the equipment at the beginning of each work shift, the operator should make a visual inspection of the equipment. At no time should the operator reach under the press or into the equipment enclosure nor insert any object into it. If any of the conditions listed below are found, the operator should report them to the supervisor or designated person.

The operator should:

  • Visually inspect for damaged, broken, cracked or burnt parts in the generator cabinet, press, shuttle and on the main control panel.
  • Clean the die, nest, and loading tray surface from any arcing, contamination or material residue.
  • Check for loose or dangling components, wires or hoses.
  • Check for any physical damage (dents) to the press coax, ground straps, and shielding.
  • Check for accurate indexing of shuttle stations and mating of tool and nest, if applicable. 
  • Check the air pressure at the FilterRegulator-Lubricator (FRL) for the correct pressure and ensure that there is sufficient oil in the lubricator. If a self-draining filter is provided, check for proper operation. If it is not operating properly, replace it. If a manual drain filter is provided or is used to replace the self-draining filter, check and drain, if necessary. 
  • Before turning on the electrical power, turn on the air pressure and listen around the cylinders for leaks. 
  • During operation, observe the press to ensure that the platen rises and lowers evenly and smoothly.

WEEKLY MAINTENANCE CHECK-LIST

Supervisors should designate at least one day a week for the following items:

  • Clean the equipment once a week or more often if plant conditions require it. The single biggest factor in maintaining continuous operation of the equipment is keeping it clean. Dirt and corrosion can cause relay contacts to become inoperative and lead to deteriorated insulation, poor cooling, etc. 
  • If the blower wheel becomes coated with grease or dirt, it should be cleaned. It otherwise will become unbalanced and cause vibration and bearing wear. 
  • Check for leaks in the pneumatic system at all permanent connections, valves, gauges, sensors, and quick connects. Repair immediately, if leaking.
  • Clean all of the door contacts and check for correct contact between the doors and the door frames to insure that no RF energy escapes into the environment.

MONTHLY MAINTENANCE CHECK-LIST

Finally, at the start of each month or when it’s otherwise convenient, it is important to perform additional minor maintenance checks that need to be done less frequently. 

  • Check and tighten any nuts or bolts that may have become loose. 
  • Check for good metal-to-metal contact between all high-frequency components and between removable covers, shield contacts, and base plate.
  • Relays and contactors should be checked for freedom of operation. Manually operate each relay (power off) to determine if it is mechanically free. 
  • Keep the applicator (press) in good operating condition. Check the press leveling and support bolts and tighten if they become loose. 
  • The electrode should be thoroughly examined. The entire surface should be clean and smooth to reduce the possibility of arcing. The press guides should be lightly greased. 
  • Lastly, the insulator assembly between the hot electrode and upper platen should be thoroughly examined and cleaned. Carbon tracks are indicative of arcing and should be thoroughly removed. The probability of future arcs is greatly increased after a carbon track has been formed or dirt has accumulated.

CONCLUSION

It can seem like it is never a good time to perform routine maintenance checks as described above. However, the inconvenient break in productivity will seem minor against the time required to perform larger repairs. Begin following these recommended maintenance checklists immediately. If you identify any issues during the inspection that can’t be solved using our recommended tips, call our Service Department at (502) 493-1299 x207 or email us at [email protected]

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