Pneumatic paste dispensers (applicators) can increase production and improve cost with consistent results. Two of the many great things about using a paste dispenser are the ease of use and quick changeover. What can be little difficult about using a paste dispenser is getting started and setting up for your application process. It can be especially difficult when using thinner, low viscosity materials. In this article I've outlined just a few quick tips and key points to help you get started.
Finding the right size gauge and I.D. tip can save on material cost, and provide more accurate results. You can always adjust shot time and pressure to control the dispense amount. Begin with the largest possible tip gauge for the shot size and work your way down from there.
Sometimes tip clogging can occur with materials that dry very quickly, like solvent-based varnishes or thinner adhesive material. Try using a tip with a higher material capacity and an inert material like a smooth flow poly tapered tip.
After some use, you may notice that the deposits are starting to become smaller and smaller. Your first instinct is to increase the pressure, but the material may be curing in the tip and reducing the flow. Instead use a new tip. This will save time and improve your accuracy because you will not be constantly resetting the pressure.
When changing a tip on a dispenser always detach the barrel adapter hose from the controller with the simple quick disconnect fitting. This will prevent any accidental hitting the foot pedal or finger trigger activation during this process. You can simply engage the safety clip on the hose before making any necessary changeovers.
Make sure your dispensing unit is supplied with dry clean air. Moisture in the air lines can do damage to the internal mechanics of your dispenser. Additionally, this can effect the adhesion and curing properties of the materials you are using and lead to contamination. If you can not supply your unit with clean air you should use a regulator with a 5 micron filter and a water trap.
Dispensing controls are inexpensive but effective way to improve the dispensing process. Choosing the proper tip size, air pressure, and shot time can help achieve the the perfect bead shot size.
When dispensing medium to low viscosity fluids and liquids the use of a polyethylene piston will improve on barrel pressure and decrease dripping. The piston will help keep the pressure more consistent.
Sometimes accidental back flow into the controller can occur which may cause major damage. Having an inline filter on the airline from the barrel is a useful addition and can protect the dispenser from fluid damage. Always be sure to place your dispensing barrel tip facing down into the barrel stand when not in use, and position your dispensing unit at a higher level than your working area.
As an added feature some units come equipped with a "vacuum pull back" option. This feature is ideal when using low viscosity materials and greatly reduces any dripping waste and potential messes that might incur. To set it properly start with little vacuum pressure so that the material is dripping from the tip. Then, gradually increase the vacuum pressure until the dripping stops. You shouldn't have to increase it any further. If you use too much vacuum the material may be sucked back into the dispenser. You will know that you have too much vacuum when the material starts bubbling in the syringe.
When you dispense the material you should hold the tip at a 45° angle. Once the deposit is made, lift the barrel vertically and away from the deposit to avoid contact with it.
There you go, you are now ready to get started on dispensing low to medium viscosity materials with your paste dispenser. After some use you should have the confidence and experience to dispense like a pro and complete all your dispensing projects in no time.
