In automated manufacturing, dispensing technology is widely used across electronics, automotive, optics, and medical industries. Among various types, the time-pressure dispensing system is one of the most commonly used due to its simplicity, low cost, and ease of operation. This article provides a concise explanation of its working principle, key components, control logic, and application characteristics.
1. Basic Working Principle
The time-pressure dispensing system uses compressed air and timed control to dispense precise amounts of fluid. The core idea is: compressed air is applied to a sealed reservoir containing the adhesive. When the solenoid valve opens, the air pressure forces the fluid through the tube and dispensing needle. The controller determines the duration the valve remains open, directly controlling the dispensing volume.
2. System Components and Functions
Fluid Reservoir
Typically a syringe or pressure tank. It must be well-sealed to prevent air leakage or contamination.
Pressure Regulator
Compressed air is regulated (usually between 0.1–0.6 MPa). Higher pressure results in faster flow rate.
Solenoid Valve
Controls air flow on/off. It is the core actuator for enabling timed dispensing control.
Dispensing Controller
Digital controller that allows users to set dispensing time with 0.01-second precision, controlling the solenoid valve.
Needles and Tubing
The adhesive flows through the needle. Different diameters affect bead size and shape.
3. Control Focus
Dispensing Volume Adjustment: Controlled by two parameters—air pressure and time. Higher pressure or longer open time increases volume.
Stability Factors: Pressure fluctuation, fluid viscosity changes, and needle clogging can affect accuracy.
Drip Control: Low-viscosity fluids typically stop naturally. For higher viscosity, a suck-back valve or anti-drip mechanism is recommended to avoid tailing or dripping.
4. Advantages and Limitations
Advantages:
Low cost, simple setup;
Easy to operate and adjust;
Compatible with most low-viscosity adhesives;
Fast response and easy to integrate into automation lines.
Limitations:
Accuracy affected by air pressure stability and fluid consistency;
Not suitable for high-viscosity or two-component materials;
Cannot perform complex motion paths or mixing ratios.
5. Suitable Applications
Time-pressure dispensing is ideal for small, consistent dispensing tasks involving low to medium-viscosity fluids, such as:
UV glue, water-based adhesives, red glue;
Low-viscosity epoxy resins;
Conformal coatings, fluxes, and conductive pastes.
Commonly used in electronic component packaging, LED dotting, part fixing, and coating processes.
6. Conclusion
While time-pressure systems are relatively basic, their ease of use and flexibility make them a popular choice in many industries. For processes requiring fast setup and consistent output with low-viscosity fluids, this method offers excellent cost-performance. For high-precision applications or those involving high-viscosity or complex motion control, alternatives like screw dispensing, jet dispensing, or two-part mixing systems should be considered.