Chilled Knife Cutting System:
Installation & Maintenance

The Chilled Knife Cutting System was designed to be used on paddle wheel tape applicators for efficient application of closure tapes to disposable diapers. Unlike the traditional paddle wheel, window knife cut-off systems, this system incorporates a cooling unit which circulates cold ethylene glycol solution through the system to chill the stainless steel and tungsten carbide components. This prevents adhesive from accumulating and tape tabs from "hanging up" on the cutting surfaces. When installed and maintained properly, the system will perform throughout the production of 100,000,000 diapers, potentially 150 times longer than conventional, non-chilled systems.

Materials

The following parts are needed for installation of the system:
1. Cooling unit
2. Set of adapters, connectors, pipes and insulating hoses
3. Window knives   
   • Baby diaper applicators - 2 pieces   
   • Adult diaper applicators - 4 pieces
4. Cutting knives   
   • equivalent to the number of paddles

TOOLS
1. Set of Metric wrenches
2. Set of Metric Allen wrenches
3. Vice
4. Rubber Hammer
5. Knife

SUPPLIES
1. Rags or towels
2. 6mm Gasket (O-Ring material)
3. Cleaning Tank & Solvent
4. New bolts for all component
5. Teflon Thread Tape

Installation Instructions

COOLING UNIT
1. Location - The cooling unit should be installed as close as possible to the
    applicator, commonly under, behind, or on top of the line. Never install the
    cooling unit close to a heat source.
2. Electrical connection - Standard cooling units are 220 V - 50 Hz (see
    identification plate). The cabinet in front of the unit contains instructions
    for the electrical wiring.It is recommended that a qualified electrician perform
    the installation procedure.
3. Cooling fluid- The fluid supplied with the cooling unit is ethylene glycol,
    commonly known as antifreeze, which is used in frigid climates as an
    automobile non-freezing radiator fluid. Additional fluid should be obtainable
    from an automotive supply store. Warning: Prior to turning on the power, the
    brine tank must be filled to prevent damage to the circulation pump.

FILLING THE BRINE TANK
1. Install the inlet and outlet valves. Fill the brine tank 1/3 full with the supplied
    ethylene glycol concentrate.
    Baby line chiller (SC 1.4)- 3 bottles (1.5 liters / bottle)
    Adult line chiller (SC 2.0)- 6 bottles
2. Add water to brine tank until full.
3. Check to see that the fluid in the tank is completely covering the coils and
    examine the system for leaks.

Window Knife Removal

  1. Turn off Chiller
  2. Remove hoses from window knife legs.
  3. Drain coolant into containers.
  4. Unplug air line from side of window knife holder (If so equipped).
  5. Remove the window knife holder.
  6. Remove the side plate on one side of the knife holder.
  7. Remove the side plate on the other side of the knife holder.
  8. Remove spring assembly.
  9. Loosen spring assembly nut and back spring pressure out all the way.
10. Remove front knife plate holder.
11. Remove knife from holder, using the rubber mallet if necessary (when using
      rubber mallet always hit knife towards the top, never hit the legs of the knife).
12. Remove hose connectors from knife legs.
13. Wearing gloves and safety glasses, clean knife holder and other components.
14. Clean threads on hose connectors.

New Window Knife Assembly

  1. Replace all bolts with new ones.
  2. Place window knife holder in vice.
  3. Wrap a new piece of 6mm gasket (O-Ring) over one side of the window knife, 
      laying it in the grooves on the top of the knife. Place top of window knife with
      gasket into the knife holder. Using the rubber hammer, lightly tap the knife and
      gasket down through the holder until the knife is flush with other end of holder.
  4. Cut off extended pieces of gasket flush with the edge of the knife holder.
  5. Using new bolts replace side plate.
  6. Turn knife holder over in vice.
  7. Cut off extended pieces of gasket, flush with the edge of the knife holder.
  8. Using new bolts replace side plate.
  9. Install spring assembly (using new spring if necessary).
10. Using new bolts install front knife plate.
11. Apply Teflon tape to hose connectors.
12. Install hose connectors on window knife legs.
13. Check window knife flex. They should move easily.

CAUTION: BLADES ARE EXTREMELY SHARP

Fly Knife Removal and Assembly

REMOVAL
  1. Remove fly knife holder from paddle wheel applicator.
  2. After removing holder, use the air hose to clean out bracket and
      vacuum holes.
      "ALWAYS WEAR EYE PROTECTION WHEN USING AN AIR HOSE"
  3. Check condition of cam follower bearings by rotating back and forth. If it
      moves. This step is crucial to getting minimal blade
      contact and maximum blade life.
  4. Remove the three bolts holding the knife in the holder.
  5. Clean the knife holder (Wear gloves and safety glasses)

ASSEMBLY
  1. Using new bolts install new fly knife on holder.

On-Line Installation

  1. Install air line on window knife holder.
  2. Install the window knife holder onto the frame making sure the top of the knife
      holder is flush with the top of the frame. This may need adjustment later to
      obtain minimum contact.
  3. Install hoses onto the legs of the window knives making sure hoses
      do not kink.   
  4. Re-Fill the chiller with the Anti-freeze / Water solution (50/50).
  5. Turn on the chiller.
  6. Using new bolts, install fly knife holder as far back from window knife as
      possible. Snug up top bolts. Do not tighten at this time.
  7. Rotate knife assembly so fly knife is in line with cutting edge of window knife.
  8. With thumb pressure only move fly knife block in until it touches window knife.
  9. Snug up top bolts a little tighter, not all the way.
10. Using back set screws, move one side of the knife block in until no light shows
      between fly and window knives slowly move other side set screw until it also
      shows no light.
11. When fly knife is in the proper position tighten up top bolts to lock holder
      in position.
12. Contact between fly knife and window knife needs to be 1/2" / (13mm) or less.
      This can be seen by the lack of frost at contact point.
13. Contact has to be even on both sides of the window knife.
14. Thread tape through window knife and rotate fly knife until tape is cut.
15. Check to make sure clean cut was obtained.
16. If clean cut was not obtained repeat steps 6-15.

Chilled Knife Maintenance Guidelines

1. Keep chiller clean and free of dust.
2. Keep Anti-Freeze / Water solution at 50/50 and tank full at all times.
3. Maintain proper chiller temperature. (Typically -4° C to -7 ° C )
4. Make sure all hose connections are tight and not leaking.
5. Check cam follower and cam for worn bearings and play.
6. Maintain ice layer on window knife. If too much ice is generated,
    increase set point temperature.
7. Do not try to obtain better cutting by adjusting spring pressure;
    re-adjust knives instead.
8. Match Tungsten Carbide window and fly knives, DO NOT mix with D-2 steel.

Chilled Knife Troubleshooting Guide

PROBLEM: To much ice on window knife.
ACTION:
1. Increase set point on chiller one degree at time until proper level
    is obtained.

PROBLEM: Not enough ice on window knife.
ACTION:
1. Check for kinks or leaks in hoses.
2. Inspect connections at window knife legs, chiller and splitters.
3. Check cleanliness of chiller. (Filter)
4. Inspect pump.
5. Check knife alignment; fly knife may be scrapping frost off
    in too large of an area.
6. Lastly, decrease Chiller set point by one degree at a time.

PROBLEM: Tapes not cutting properly.
ACTION:
1. Check cam follower bearings for wear.
2. Check window and fly knife for sharpness.
3. Check window and fly knife alignment.
4. Check tightness of fly knife holder bolts.
5. Check unwind stand tensions and tracking.

PROBLEM: Knives hitting too hard.
ACTION:
1. Check for excessive wear.
2. Replace or re-align as needed.
3. Check if knife is Tungsten carbide or D-2, replace with Tungsten
    if necessary.

Adjustment /Alignment of the Knives



The unit must be on for approximately 15 minutes for ice to form on the knives before beginning adjustment. Check the pressure of the spring on the backside of the window knife, THIS MUST BE VERY LOW. To prevent damage to the knives, the cutting knife should NEVER start touching the window knife underneath the hard metal. Adjust the cutting knife so that it just touches the window knife legs equally about 6mm (1/4") below the cutting position. Move the paddle wheel upward. Take note of where the cutting knife scrapes off the ice from the window knife. If adjusted properly, the total contact length should not exceed 16mm (5/8"). A contact length of *13mm (1/2") (see fig.1) is recommended for optimal durability. This corresponds to movement of the window knife of 0.2mm (.005"). After proper alignment is achieved, tighten cutting knife and holder.