A small extra with great effect – How to avoid snake heads

In many applications, one would like to avoid so-called “snake head applications”, whereby the beginning of the bead or spray pattern is slightly thickened and then continues to become narrower.  Such an application pattern occurs when the pressure at the start of the application is stronger and normalizes in the course of the application.

This pressure fluctuation takes place in fractions of a second. “Tame” the snake heads by means of a pneumatic bypass, which is built as an option into many gear-pump tank systems, such as our HB 4000 series: The pneumatic cylinder built into the bypass can be regulated by an external control, so that the delivery pressure can also be regulated during the application; for example little pressure at the beginning and higher pressure towards the end of an application. In this way, one achieves a uniform adhesive application from beginning to end without a “snake head” – an advantage that a simple mechanical bypass with pressure spring, usually standard in gear-pump tank systems, cannot offer.