Adhesive Systems Technology meter, mix and dispense systems

START-UP

Make sure "A" and "B" supply valves under containers are open.
Check level of materials in containers, making sure level is always over 1/3 filled. Use diverter plates (tunnel down center of material) if void in material develops.
Clean off applicator dispense head with plastic mixer nozzle removed. Trigger applicator into waste container to verify smooth, air-free flow of both materials. Wipe head clean and coat head with compatible lubricant.
Place new plastic mixer nozzle on applicator block and secure with retainer nut. NOTE: For some high pressure and high flow rate systems, a mixer retaining housing may be required to avoid cracking plastic mixers.

SHUT-DOWN

Turn off main air supply or disconnect it.
Remove plastic mixer nozzle.
Trigger applicator to relieve any pressure in lines or system. Materials may ooze out of the applicator or, open "A" and "B" valves below pressure gauges.
Clean head of applicator and coat with compatible lubricant.
Two zerks may be provided on each side of the dispense manifold, where the static mixer is attached to the applicator. These are provided so that the operator can remove the mixer and fill the ports of the manifold with a compatible lubricant. This helps prevent problems with material hardening in the manifold, and should be done when the unit is left unused for any period of time.

Daily Maintenance

Clean and lubricate exposed pump rods.
- Remove and clean any material residue or film with compatible solvent (damp pad only - do not pour solvent)
- Fill lube chambers with compatible materials (petrolatum grease, for example).
- If leakage appears at rear rod seal, tighten and refill lube chamber. If leak continues, the pump should be rebuilt and inspected for wear or damage (NOTE: Some material film on shaft is normal).
Check that air supply and air filter are clean, and drain moisture separator.
Ratio Check Test
- Remove the retainer cap or mixer nozzle.
- Trigger applicator; two separate beads of material will appear; compare for correct volume.

Weekly Maintenance

Seal/Pump Check Test
- Turn air pressure to 20-25 psi.
- Place a waste container or drop cloth under the purge valve (ball valve below gauge) and open the valve opposite the pump To be checked. EXAMPLE: to check "A" open "B".
- Disconnect the air line, (black or clear 5/32" tube) coming from the unidirectional (gray) valve, at the tube fitting on the 4-way valve the tube connects to. Plug or pinch off the tube. This will prevent the automatic dispense valve from opening. This air line should be marked for later reference.
- Trigger or actuate the unit and slowly turn the pressure up until the drive bar moves out and stalls against pressure (pressure gauge on "A" side should read 300-500 psi; "B" gauge should read "0" psi).
- If it stalls and pressure registers, the pressure seal is good. If not and it takes a long cycle or an additional cycle, there is either air trapped in the pressure tube, the pressure seal is bad, or material is not being supplied.
- Release signal; cylinder will move back and pressure should hold on gauge. If pressure drops, outlet check valve is failing. Rebuild or replace the check valve.
- Repeat sequence on other side closing "B" and opening "A" valve. This will check other side.
Check Pump Phasing: To "Phase" your system, simply watch the outlet gauges while dispensing material with the static mixer attached. Phasing is correct when both pressure gauges start to rise at the same time during the dispense stroke. Adjust the pump connecting rods in or out slightly to ensure that this occurs. Please note:
- The actual gauge pressures may differ due to material properties
- Excessive rod adjustment probably indicates air entrapment in one side of the pump or a malfunctioning component (pressure seal or check valve).
- The coupling between the (black) drive bar and the pump connecting rods has 2 large washers on either side of the drive bar. At least one of these washers must remain loose enough to spin, this will allow rods to float and not side load the seals. The entire coupling can be rotated on the pump connecting rod to adjust phasing.

Daily Maintenance

Never permit either material tank to get below approximately 1/3 full.
The most common cause of "cross-over" (materials hardening inside the applicator and hoses) is air in one or both materials. Damage and cost from cross-over is NOT covered under AST Corporation Warranty.
Diverter discs and follower plates are a means of avoiding air entering materials. If high viscosity materials are being used, the operator must become informed in the use of these items prior to the starting of the system
If gauges exhibit pressures that "peg" the gauge dial, immediately reduce air pressure at the systems air regulator.
Do NOT install a disposable mixer nozzle to the applicator until positive air-free flow is achieved from both outlets of the applicator block tip.
Air can be trapped in hoses during the filling of a new system at the time of hose replacement. To avoid trapping air, arrange the hose to obtain a continuous, gradual upward slope of the hose from the system hose fitting to the applicator while the system is cycling. Point the applicator tip upward to let the material push all the air out.

Questions?? Call us! If you're with the machine, we can walk you through the procedure for start-up and shut-down. Ask for Technical Assistance at 763-592-2060.

The following basic points can be checked for troubleshooting the metering pumps.

Is there sufficient air supply?
Is there sufficient material supply?
Is air regulator set at desired pressure?

To determine if there is a problem in the air control, air drive, fluid pump, or outlet hose and nozzle gun:

Disconnect outlet hose, turn air pressure down and trigger pump: If it cycles and pumps, your hose or gun is plugged. If not, remove outlet check valve, trigger pump, check for movement of pump; if no movement check for plugged pump or air motor problem.
If pump doesn't run, but pressure from drive cylinder can be seen, the problem is in the pump section. The fluid pump can be rebuilt with repair kit, or replaced if damaged.
Check phasing. Is one material flowing before the other?
If problem is in hose and gun:
- Hose: plugged or kinked hose; it should be replaced.
- Gun: if plugged, it can be disassembled and cleaned.

Seal Check / Check Valve Diagnostic Procedure:

Reduce air pressure all the way.
Close outlet of material, this can be done by disconnecting the air line From the uni-directionally operated roller valve to prevent the outlet or dispense valve from receiving an "opening" air signal. (For auto valves only)
- Manually Trigger Pump: Pump should move in and stall out and hold pressure. If unit continues to move, the pressure seal or o-ring at pressure seal adapter to rod is leaking -- replace it.
- If it moves forward and stalls after 3-4 inches of movement, either air is trapped in pump or air is in material.
- Release pump to "home" or "off" position. There will be no pressure from pump. The outlet check valve should hold pressure. If pressure drops to 0, outlet check valve is defective or blocked open. Rebuild or replace the check valve.

NOTE: OUTLET GAUGE SHOULD BE PLACED DOWN STREAM OF OUTLET CHECK VALVE. The outlet volumes of each pump cycle should be repeatable if properly working. A simple volume check in field is a quick check for operator.

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