E.i. Dupont De Nemours and Company

E. I. Du Pont Nemours and Co.

James E Geary, Jr

Gregory Paul Weeks

Wesley Memeger, Jr

Stephan Claude De La Veaux

Roland T Brierre

Michael L Trancynger

Kenneth Wayne Leffew

Daniel Gregory Tynan

David R Schiff

Richard D Mules

Thomas F Mistretta, Jr

Keith S Haight, Jr

An apparatus for treating a medium in situ includes counter-rotating shafts and intermeshed blades arranged on the shafts in a helical array to define mixing zones along the length of the shafts. Reagent supply conduits are disposed in a housing surrounding the upper ends of the shafts for introducing reagents into the mixing zones. The housing is attached to a mobile excavator which moves the shafts horizontally and vertically. The shafts are lowered into the medium by the excavator and are counter-rotated to cause the blades to pump the medium and the reagents along the shafts. Once at the desired operating depth, the shafts are moved below the surface of the medium in the horizontal direction generally perpendicular to the plane of the axes of the shafts to define a volume in the medium. The medium and the reagent are mixed vertically and laterally in the mixing zones and are further mixed horizontally as the mixing zones traverse the medium in the horizontal direction, thereby mixing the reagent and the medium in the volume in both the vertical and the horizontal direction to stabilize and homogenize the medium. The shafts are then withdrawn from the medium and the process is repeated for a second volume disposed adjacent the first volume. The apparatus and the method associated with operating the apparatus result in very uniform stabilization and homogenization of a medium at a rapid rate and a low cost.

Apparatus and method for in-situ treatment of a medium

A method for producing para-aramid pulp includes forming a liquid, actively-polymerizing solution and subjecting the solution to orienting flow which produces an optically anisotropic liquid solution with polymer chains oriented in the direction of the flow. When the solution has a viscosity sufficient to maintain the orientation of the polymer chains, the solution is incubated until it gels. The gel is cut transversely at intervals and para-aramid pulp is isolated from the gel. Para-aramid pulp produced by the process can be used similarly to pulp produced from spun fiber.

Method and apparatus for producing para-aramid pulp and pulp produced

A method of preparing porous fiber reinforced polymer composite sheets has been developed to allow a more efficient preheating of the sheel prior to molding and includes the steps of blending reinforcing fibers with resin matrix forming fibers to form a web. This web is then heated to a temperature wherein the resin matrix forming fibers melt and envelope the reinforcing fibers, tacking them together at crossover points. The resultant web can then be directly heated very efficiently for molding. This web is highly porous allowing rapid heating at moderate pressure differentials during subsequent preheat steps. The microstructure created when the resin matrix forming fibers are initially melted further enhances heating capability because the structure retains porosity during the subsequent heating step required for molding. Because the resin matrix forming fibers initially were uniformly blended, a highly uniform distribution of polymeric material within the reinforcing fiber matrix yields molded parts with very uniform properties.

Method of making fiber reinforced porous sheets

A method of preparing porous fiber reinforced polymer composite sheets has been developed to allow a more efficient preheating of the sheet prior to molding and includes the steps of blending reinforcing fibers with resin matrix forming fibers to form a web. This web is then heated to a temperature wherein the resin matrix forming fibers melt and envelope the reinforcing fibers, taking them together at crossover points. The resultant web can then be directly heated very efficiently for molding. This web is highly porous allowing rapid heating at moderate pressure differentials during subsequent preheat steps. The microstructure created when the resin matrix forming fibers are initially melted further enhances heating capability because the structure retains porosity during the subsequent heating step required for molding. Because the resin matrix forming fibers initially were uniformly blended, a highly uniform distribution of polymeric material within the reinforcing fiber matrix yields molded parts with very uniform properties.

Fiber reinforced porous sheets

Method for producing para-aramid pulp

Method for free surface casting an annular layer of film-forming liquid onto a substrate in a single pass by means of laminar flow through a slot die while the substrate and slot die are undergoing rotation relative to each other.

Free surface casting method

Growing community of inventors

Boothwyn, PA, United States of America

James E Geary, Jr