Gone are the days of only manually dispensing liquids using plungers. With the constantly evolving technologies, a horde of new and effective fluid dispensing techniques along with a wide variety of state-of-the-art fluid dispensers have been put out in the market for different types of applications. With all these available choices on hand, choosing the perfect equipment to suit the needs of a particular application can be very challenging.
This guide provides a list of current fluid dispensing tools that you can use for specific applications.
The Manual Syringe System
Although the manual dispense procedure using syringes is outdated, it is still a very efficient and cost-saving option for dispensing low volumes of liquids. This dispensing technique uses a plunger with a piston that pushes down the fluid in a syringe to be dispensed on a certain workpiece. This type of dispensing method is perfect for low volume, low repeatability, and low accuracy type of applications.
Time/Pressure Syringe System
Time/pressure dispensing is another technique in liquid dispensing that is faster and more accurate than the manual dispensing technique. As the term implies, time/pressure fluid dispensers make use of controlled pressure and timing mechanisms in addition to the manual dispensing elements to effectively regulate the dispensing process, which eventually results to less waste, less clutter, and less hazard to the user. With time/pressure dispensing, you can dispense a wide range of liquids and pastes such as adhesives, coatings, sealants, greases, oils, inks, and varnishes.
One of the cheapest time/pressure dispensing valve is the pinch tube valve. This disposable valve functions by automatically pinching (or opening and closing) a defined plastic tube containing the fluid. It is used in an “on and off” application, which means that you basically aim to start or stop the flow of liquid. It is highly suitable to dispense small dots of low-viscosity fluids like quick curing adhesives and epoxies.
If you do not want to regularly replace pinch tubes for some applications, then a diaphragm valve is a more desirable option. The diaphragm valve makes use of a sturdy diaphragm material to block the course of the fluid, perfect for efficient performance throughout millions of cycles. In this technique, air pressure is used to trigger the diaphragm in the fluid path to retreat and enable liquid flow. Stopping the air pressure leads the diaphragm into its closed position. This tool is best for low to medium viscosity fluids such as moisture-sensitive adhesives, UV-cured adhesives, and other coating applications.
When you are in need of tiny shot sizes that are as small as 0.0005 CC, then you might want to opt for a microshot needle fluid dispenser. Air pressure is used to hoist the needle upward away from the seat, which permits the fluid to flow. Need valves are greatly suitable to use for high-viscosity liquids like solvents, inks, primers, and oils, and can take up those with up to 100,000 cps. However, they are not for moisture-sensitive liquids and quick-curing pastes.
If you intend to use a dispensing tool to dispense high-viscosity liquids in high volumes, then the spool valve is the perfect choice. This fluid dispenser valve makes use of an air-regulated piston to allow or restrict the liquid flow. At the end of the cycle, the lifting of the piston acts as a natural suck-back state that is very helpful in avoiding splashes in dispensing high-viscosity liquids like silicones, sealants, and automotive greases.