Dispensing Urethanes and Primers to Seal Automotive Windows

A Success Story

Successful automotive window sealing applications are dependent on consistent dispensing of urethanes and sealants. Many of these applications require consistent bead or line widths dispensed within tight tolerances. Defects of any kind become costly scrap or rework. The reliable, low-maintenance design of Nordson EFD dispense valves meet the controlled, high-volume production requirements necessary in the automotive manufacturing industry.

Here are a few more details about these types of applications:

Fluids Used

Urethanes and Sealants

Application Requirements

• Specific bead / line fluid deposit widths
• Tight tolerances
• Consistent area of coverage
• Minimal defects / rework

Previous Process

The automotive manufacturer used a felt tip attached to a robot arm. The sealant was fed through tubing from pressurized tanks. This was the setup to apply 20 mm wide beads of a solvent-based primer to seal the edges of car windows – the rear windows that remain closed.

In another example, the manufacturer used a dispense valve and pump to dispense urethane in 4 mm wide beads on windshields and sunroofs.

Issues with Previous Process

Applying the expensive primer sealant with felt created a lot of excess fluid that required an operator to wipe it off after each application because they had no way to control the amount being dispensed. The felt method often led to rework. It also dripped, creating even more fluid waste. The cost of the fluid waste and rework led the manufacturer to seek a cleaner and more consistent process.

When dispensing the urethane, the manufacturer faced issues with clogging in the dispense valve they were using. The clogging created too much downtime for maintenance, which led the manufacturer to seek a better dispensing solution.

Solution

For Primer Sealant on Window Trim

• 752V-SS diaphragm valves with PTFE-coated dispensing tips
• ValveMate™ 8000 or 7100 controller
• Fluid reservoir tank with analog pressure regulator

For Urethane on Windshield / Sunroof

• 736HPA high pressure valves
• ValveMate 8000 or 7100 controller

Results

Primer Sealant on Window Trim

The goal was to lower the amount of primer usage and to also create a cleaner, higher quality finished product. Mounting the 752V valve to the robot arm versus a felt pad made the process far more accurate and repeatable. The automotive manufacturer saw a 50% reduction in primer usage, increased the number of finished parts completed per day, and found there was less clean-up after each application.

Urethane on Windshield / Sunroof

The automotive manufacturer started using the 736HPA valve and found that they had no more clogging when sealing windshields and sunroofs with the high-viscosity urethane. The EFD valve was not only less expensive than the valve they used previously, it also improved their dispensing process. The closed-system design worked great and reduced waste by minimizing premature curing of materials.

Related Dispensing Solution

Nordson EFD’s 725D piston valve consistently dispenses gasket sealant on automotive parts. Watch video.

Learn more about Nordson EFD fluid dispensing solutions in our Automotive Application Guide. Watch more dispensing videos in our Automotive Video Playlist.

Got a question about Nordson EFD’s automotive assembly equipment? Don’t hesitate to contact us at [email protected].