company news about Application of UV lamps in dispensing machines: core technology of curing process

The use of UV lamps (particularly UV-LED light sources) in dispensing machines is a key technology for achieving fast, high-precision bonding and sealing in modern precision manufacturing. By combining the precision of fluid dispensing with the instantaneous nature of photochemical reactions, they significantly improve the efficiency and product quality of automated production lines.

1. Dispensing: A precision dispenser (such as a jet valve or screw valve) applies liquid UV adhesive to the surfaces to be bonded or sealed, following a predetermined path and volume.
2. Activation by irradiation: After application, a high-intensity UV lamp (typically in the UV-A region with a wavelength of 320 nm to 400 nm) irradiates the adhesive with a high-intensity beam.
3. Curing by polymerization: The photoinitiator absorbs the energy of the UV light and decomposes to produce free radicals or ions. These active substances rapidly trigger a cross-linking polymerization reaction between monomers and oligomers in the adhesive, transforming the adhesive from liquid to solid within seconds or even milliseconds.

UV lamps can be integrated into dispensing machines in various ways, depending on the dispensing process requirements:

• Spot Curing: Suitable for spot curing, small areas, or deep curing, such as bonding medical devices (needles) and fiber optic positioning. The light beam is transmitted through optical fibers, concentrating the energy and achieving high-intensity, precise irradiation of small areas. This unit is typically a separate unit located next to the dispensing machine head.
• Line Curing: Suitable for continuous curing of linear or elongated areas, such as sealing mobile phone camera modules and dispensing screen bezels. This strip-shaped light source is often mounted at the end or side of the dispensing path, enabling simultaneous curing as the dispensing machine moves.
• Area Curing: Suitable for curing large areas, such as rapid surface curing of conformal coatings. The light source covers the entire work area, providing high curing uniformity, and is often integrated with a conveyor system.

When selecting a suitable UV curing system for a dispensing machine, the following points should be considered comprehensively:

• Wavelength Matching: Ensure that the UV lamp's dominant emission wavelength (e.g., 365 nm) precisely matches the optimal absorption wavelength of the selected UV adhesive. Mismatches can result in incomplete curing.
• Irradiance Intensity (mW/cm²): Curing intensity determines the speed and depth of cure. High intensity can shorten cure time, but be mindful of its effects on heat-sensitive materials.
• Uniformity: Especially for line and surface light sources, ensure uniform light intensity across the entire irradiation area to avoid performance defects caused by uneven curing.
• Automation Interface: A superior UV lamp system must have a robust communication interface (e.g., I/O or RS-232) that can communicate with the dispensing machine and production line PLC, ensuring precise synchronization of dispensing completion and UV lamp on/off.

In summary, the use of UV lamps in dispensing machines is an indispensable component of modern automated manufacturing, representing the trend toward efficient, environmentally friendly, and high-quality industrial assembly.