Abstract: This invention pertains to a coated, bonded or non-woven abrasive article containing precisely shaped particles and a binder. These precisely shaped particles can contain abrasive grits, fillers, grinding aids and lubricants. The binder is preferably a mixture of a resole phenolic resin and a free radical curable resin, resulting in improved cutting and life span. Also disclosed is a method of forming the coated, bonded or non-woven abrasive article.

Abstract: An improved former assembly which can be used in the manufacture of plastic pipe with the former assembly comprising a plastic pipe former assembly having a housing, a center tube supported on the housing, and a plurality of rollers oriented about the center tube, with the improvement comprising a plurality of universal joint assemblies each having a first end and a second end, each of the first ends being connected to the housing and each of the second ends being connected to one of the rollers.

Abstract: An improved manifold calibration finger which can be used in conjunction with a die head in the extrusion of a plastic with the manifold calibration finger comprising a first section comprising an elongate tubular member having a grooved outer surface and an elongate central channel extending through the first section from one end of the first section to the other.

Abstract: An improved manifold assembly which can be used in the extrusion of a plastic with the manifold assembly having a die having a first end and a second end, with the die having a die head sectored at the second end, sets of a plurality of tubes located centrally of one another, each set positioned longitudinally within a respective die manifold tube with the outermost surface of each set of tubes spaced a first distance from the die manifold tube, each of the die manifold tubes extending through the die, at least two calibration fingers secured to the die, each of the calibration fingers having a proximal portion adjacent the die head, the proximal portion of each calibration finger being spaced a second distance from the die head, with the manifold assembly being vented to atmosphere by a venting channel, the venting channel extending from between the proximal tip and the die head to the first end of the die head with a portion of the venting channel being between the die manifold tube and the otuermost surfac

Abstract: An improved manifold assembly which can be used in conjunction with a die head in the extrusion of a plastic with the manifold assembly having a water inlet tube, a tube through which a vacuum is pulled, a water return tube, a calibration finger first section, and a calibration finger second section.

Abstract: A method for manufacturing plastic pipe such that the pipe has apertures formed therein when the pipe is viewed in cross-section, comprising the steps of having hot plastic flow through a die and subsequently be extruded through a die head to form an extruded wall component having first and second end wails, with the die head having formed therein a plurality of first sized gaps and a plurality of second sized gaps, with the second sized gaps having an aperture located inside each of said second sized gaps. The die is secured to a manifold assembly, with the manifold assembly comprising sets of tubes located centrally of one another, each set of tubes comprising a water inlet tube, a tube through which a vacuum is pulled, and a water return tube. Each set of tubes is positioned longitudinally within a respective die manifold tube with the outermost surface of each set of tubes spaced a first distance from the respective die manifold tube. Each of the respective die manifold tubes extends through the die.

Abstract: An improved pipe production line is provided having an improved manifold assembly component and an improved former component.

Abstract: A hydraulic structure is provided in the form of a flexible, flat, corrugated plastic tube having a relatively oblongated cross-section, with apertures associated with the grooves of the corrugation. The tube is enclosed in a geotextile sheath. The two relatively flat sides or panels of the tube are separated from each other by a plurality of pairs of cuspations, which project inwardly from the panel surface. Cuspations from the opposing panels are secured to one another thereby providing increased structural integrity.

Abstract: Apparatus and method for producing thermoplastic corrugated tubing having substantially uniform thickness throughout comprises extruder and step of forming hollow smooth-walled extrudate. Corrugating structure immediately adjacent extruder is arranged to receive extrudate and to form corrugations therein. Such structure includes continuously moving cooperating mold blocks configured to form alternating annular peak portions, valley portions and interconnecting side wall portions in extrudate when it is blown into intimate engagement with configured mold blocks. Thickness of extrudate being corrugated is controlled to provide relatively thin extrudate portions during formation of annular valley portions and relatively thick extrudate portions during formation of annular peak and interconnecting side wall portions.