Fluid Dispensing is Challenging
There are many techniques for dispensing adhesives, sealants, primers and other fluids. With manual dispensing, an operator controls the operation speed, material flow rate and volume dispensed using a squeeze bottle or other handheld applicator.
Semiautomatic dispensing uses dispensing equipment to select the material volume and flow rate, while an operator controls the operation speed, material dispensing and placement.
Robotic or fully automated dispensing is completely machine controlled and integrated. A robot or other automated device controls the dispensing equipment, depositing the fluid through the applicator using an end-of-arm tool.
Each method presents different challenges. We’ve compiled a few of the most common issues our customers face, and how we help solve them.
Low-Viscosity Flow Control
Understanding fluid viscosity is a critical part of the application process. A fluid with a high viscosity will appear thick and resist flowing, while a low-viscosity fluid flows quickly and easily.
Dripping and wicking are two problems manufacturers face when manually dispensing low-viscosity fluids, but both can be resolved easily with the correct dispensing applicator, process and system. Also known as capillary action, wicking occurs when a fluid flows into a narrow space without the assistance of any external forces.
In small-diameter fluid applicators, the combination of surface tension and adhesive forces between the fluid and container wall move the fluid inside the applicator and cause inaccuracies. Restricting this movement of low-viscosity fluids helps you better control the dispensing process.
In semi or fully automated fluid application systems, a remote-triggered pump panel is used to deliver fluid to the applicator. It ensures that the feed rate is consistent. Snuff-back technology provides sharp, clean cutoff to avoid dripping, even on high-speed production lines. That reliable, repeatable dispensing helps optimize adhesive while improving product quality.
Applicator Dry Out & Degradation
The viscosity of a fluid depends on the fluid’s properties. For example, the base chemical within a primer is designed to flash off quickly on the surface of a part. As that base chemical flashes off, the viscosity of the fluid increases. Air movement, temperature and moisture can also impact fluid viscosity. Understanding the factors that cause viscosity to change is critical to avoid applicator dry out and ensure consistent application quality.
To protect the applicator from drying out, you can integrate docking stations to facilitate the applicator tip wet-out process. After filling the docking station with the chemical or base solvent to be dispensed, the bottle is filled and the applicator is mounted. The operator holds the bottle upside down and squeezes until fluid flows through the applicator and completely wets the tip. The applicator is then placed head-down in the docking station where it’s shielded from damage.
With a Designetics pump panel, you can select a specific wet-out duration for an applicator in the docking station. This will ensure the applicator is always ready for its next application. We provide the docking station as a standard accessory with both the Handheld Remote and Applicator Track, or you can order it individually.
Inspection Cost Control
While automated fluid application systems can increase productivity and promote safety, quality control is still often performed manually. Inspecting the size, location and fluid path visually can lead to inconsistency, false rejections, missed defects and excess scrap. Although automated off-line inspection systems exist, they require operators to move products from the production line to an inspection area, adding to the overall process time and risking additional damage.
Real-World Example
A Designetics customer applying fluid to automotive glass sent the coated parts to a secondary quality inspection area where a camera-based system checked the part for any defects. The existing inspection system was easily influenced by ambient light, leading to false failures, unnecessary scrap and excess costs.
We introduced the Ce360 quality inspection path scanner to alleviate that customer’s problem. The automated inspection system combines technology by Coherix with the automated fluid application you expect from Designetics. Rather than relying on cameras, the Ce360 uses four high-speed lasers to track and inspect fluid application at an industry-leading speed of 1,600 samples per second. It tracks in any direction without blind corners!
Unlike a traditional inspection system, the Ce360 provides more than just a “no/no-go” signal. It allows our customer to specify both a width tolerance and marginal failure point, providing full control over what passed inspection and what triggered an alert.
Employee Safety
Your application processes or systems may require the use of fluids that – if not handled properly – could be harmful to your employees, the environment or the substrate. Even ancillary fluid application tasks, such as bottle filling, may pose potential hazards.
Workflow automation improves safety by removing personnel from dangerous or repetitive tasks, while eliminating accidents and reducing waste. The Horizontal dp3 uses an automatic flow dispenser and horizontally oriented fixture that lets operators quickly coat or prime parts in a “hands off” way. Because it’s pneumatically operated, there is no flash source, making it safe for the application of flammable chemicals. A drip tray positioned below the part and applicator catches any waste fluid and prevents accidental exposure until disposal.
Better Technology Lowers Costs
Upgrading your fluid dispensing technology normally increases improvement costs but resolves production-level issues and lowers total part cost. It’s important to account for the return on investment of new dispensing equipment and application techniques for your process to define total part cost. You may be surprised by how much money you can save with more sophisticated dispensing equipment.
The Designetics team works with you every step of the way to create an optimal fluid application process based on your specific needs. Whether you’re looking for manual fluid applicators or a closed-loop, end-to-end system, we have the solution for you. Get in touch with us today.