VARI-STEM contains the explosive energy within the rock mass where it belongs!
VARI-STEM Plugs work by creating a blocking effect within the drill hole by wedging the stemming material between the drill hole wall and our plug. Upon detonation of the explosives, the plug is forced upward into the stemming material and "locks up". The the plug locks up, the explosive gases and energy are prevented from traveling (venting) up through the drill hole, and instead are contained within the rock mass for milliseconds longer than non-plugged blasts!
Introduction to Varistem blasting plugs
Increased Fragmentation, Fracturing and Cap Rock Breakage. Reductions in Fly Rock, Air Blast, Stemming Ejection, Dust, Noise and Oversized Rock. These are all direct benefits and results of containing the blast energy within the rock mass for milliseconds longer than normal, simply by using VARI-STEM.
Vari-Stem plugs provide several benefits such as reduced fly rock, noise, stemming ejection and dust. These plugs are detonator cord friendly with the numerous vertical grooves. These grooves also provide structural strength to the plug.