Does staged heating (the method of operating the melter at lower temperature than the hoses and heads) effectively reduce the amount of char in a hot melt system?

No. Polymer adhesives are poor conductors of heat. Because of their laminar flow tendencies, little mixing occurs during the transfer through hoses and applicators. Staged heating cannot significantly raise the adhesive temperature in the hoses and applicators, and generally results in the application of adhesive at lower-than-desired temperatures.

What is the most effective way to reduce char in a hot melt system?

Keep the tank full, operate the system at the recommended application temperature of the adhesive, and reduce the system temperature during long periods of inactivity.

How often should hot melt system filters be changed?

Hot melt filters should be changed on a regularly scheduled basis at a frequency sufficient to keep the filter from ever being completely blocked by contaminants. The frequency of filter changes can be minimized by using the Nordson reverse flush filter, which traps contaminants inside the filter and permits flushing and cleaning without filter removal.

Do melters using cast-in heaters require more time to service than similar components using cartridge heaters?

No. Properly designed cast-in heaters will far outlive the useful life of an adhesive melter. With more than 30 years of experience using cast-in heaters in tanks, grids and other components, the use of Nordson cast-in heaters virtually eliminates the need for heater maintenance.

As a filter screen becomes partially covered with contaminants, will adhesive output decrease?

Not if the system is using high-efficiency positive-displacement gear pumps, such as those used in Nordson hot melt systems.

Which application method is better, spray or contact?

The choice of delivery equipment depends on the substrate and end use. There is sometimes a concern about heat from a contact die distorting sensitive materials; however, contact is linear and in contact with the web a short time on a moving substrate.

What coating coverage is possible?

Coverage ranges from 0.5 to 100 grams per square meter for slot applications and up to 1,000 grams per square meter for contact.

What are the minimum and maximum speed capabilities?

Advanced Nordson web coating systems handle speeds from 600 to 1,000 meters per minute.