Tampable chub cartridge
AssigneeE. I. Du Pont de Nemours and Company
InventorsWalter John Simmons, Frank Marsden Willis
Life of this patent
Estimating the term…
Abstract
A chub cartridge containing a water-bearing blasting agent and having a film wrap of a cross-laminate of oriented film layers has at least one unlaminated zone in the film wrap in the longitudinal direction, or preferably is adapted to form a zone of multiple delaminations along said direction by virtue of scoring, the latter being the site of delamination when the cartridge has end-pressure applied to it with a tamping rod. The different layers fail in different directions along the unlaminated zone, affording a measure of integrity to the cartridge if roughly handled, as well as ease of rupture on tamping. The cartridge also has good abrasion and tear resistance, and dimensional stability.
Claims13
A blasting cartridge comprising a tube of plastic film gathered and closed at both ends and filled with a water-bearing blasting agent, said film comprising a cross-laminate of oriented film layers of like composition and pliability, said layers being adapted to fail in different directions along at least one unlaminated zone so as to rupture said cartridge upon the application of end pressure thereto in a borehole with a tamping rod, said unlaminated zone(s) being formed in said cross-laminate prior to or in conjunction with the application of end pressure to said cartridge.
A blasting cartridge comprising a tube of plastic film gathered and closed at both ends and filled with a water-bearing blasting agent, said film comprising a cross-laminate of two layers of oriented high-density polyethylene, and one of said layers having at least one scored zone along a major portion of the length of said cartridge and inclined to the orientation of the layer adjacent thereto.
In a method of continuously producing a series of chub cartridges by forming a web of film into a tube, longitudinally sealing the tube, feeding a water-bearing blasting agent into the tube, constricting the loaded tube at spaced intervals, applying a pair of encircling closure means to the constricted areas, and severing the tube between the pair of closure means, the improvement comprising continuously moving into a cylindrical tube-forming member a web of film comprised of a cross-laminate of two layers of oriented polyolefin of like composition and pliability, one layer of the cross-laminate film having at least one scored zone therein substantially in the direction of the web's motion as the web moves toward the tube-forming member, whereby a tube is formed from the cross-laminate film having at least one substantially longitudinal scored zone in one of the layers thereof inclined to the orientation of the other layer.
A blasting cartridge comprising a tube of plastic film gathered and closed at both ends and filled with a water-bearing blasting agent, said film comprising a cross-laminate of oriented film layers of like composition and pliability, and said cross-laminate having at least one unlaminated zone along a major portion of the length of said cartridge, whereby said layers fail in different directions along said unlaminated zone and said cartridge ruptures upon the application of end pressure thereto in a borehole with a tamping rod.
Dependencies are inferred from the claim text.