E.i. Dupont De Nemours and Company

Navs, LLC

Ashok H Shah

John Chu Chen

Arthur William Etchells

Edgar W Slocum

Don Mayo Coates

Sam Louis Samuels

Tom Edward Estep

Charles Wesley Starke

Robert E Albers

Joseph Daniel Gutmann, Jr

Robert B Bruce

A concrete mix for producing freeze-thaw durable concrete having enhanced strength properties, like compressive strength, abrasion resistance, impact strength, toughness, is disclosed. The novel concrete mix contains deformable solid elements in place of 4-8% entrained air for good durability of concrete under freeze-thaw cycles.

Durable concrete and method for producing the same

Disclosed is a variable vapor barrier for moisture control of buildings comprising or formed from a material having a moisture permeance of less than 0.1 perms (grains/h&#xb7;ft&#xb7;inches of Hg) at less than 50% average humidity, such as from 10 to 50% or 20 to 40%; and a moisture permeance greater than 4, or greater than 10 perms at greater than 60% average humidity, such as from 60 to 90%, or 70 to 80%. Also disclosed are articles comprising the variable vapor barrier and methods of their use.

Variable vapor barrier for moisture control in buildings

Disclosed is a composition comprising a neutralized acid copolymer or ionomer thereof, an organic acid, and optionally other polymers, having a ratio of wet cup permeance to dry cup permeance greater than 10. The composition is useful as a variable vapor barrier for moisture control of buildings. Also disclosed are articles comprising the variable vapor composition and methods of their use.

Variable vapor barrier for humidity control

The present invention relates to a gypsum board having a nonwoven liner and a gypsum core. The gypsum board of the present invention has a high work to break, resulting in a gypsum board product that has a high resistance to abuse in use. The gypsum board of the invention is also more flexible and more resistant to water and fire than paper-lined gypsum board, and does not contain nutrients that support mold growth.

Gypsum board having improved flexibility, toughness, abuse resistance, water resistance and fire resistance

This invention relates to mixing two substantially immiscible fluids having substantial viscosity differences into a single phase solution. The invention particular includes a mixer comprising a specially designed conveyor flights to provide shear mixing without differential conveying of the fluids or causing excessive back pressure or pressure drop on the solution.

Forming a solution of fluids having low miscibility and large-scale differences in viscosity

A mixing apparatus for continuously generating a homogeneous mixture of a polymer and a less viscous fluid is provided. The mixer includes means for continuously injecting a viscous polymer into a pressure vessel; means for continuously injecting a lower viscosity fluid into the pressure vessel; means for continuously injecting a plasticizing agent into the viscous polymer entering the pressure vessel; high shear centrifugal mixing means within the pressure vessel for mixing the polymer and the less viscous fluid; drive means for rotating the rotational mixing means; heating means for maintaining the temperature of the substances being mixed in the pressure vessel at a desired mixing temperature; and means for continuously discharging a homogeneous mixture of the polymer, the plasticizing agent, and the less viscous fluid from the mixer.

Process and apparatus for mechanically mixing polymers and lower

This invention relates to making backwindable rod shaped batts or logs from highly oriented flash-spun continuous fibers. The fibers are conducted from the exit of a spinneret through a tunnel and into a two stage diverging nozzle to slow down the fibers for an organized collection in the collection section. The invention further includes an inflatable bladder in a discharge section for initiating the formation of the log and a mesh screen in the collection section for reducing the occurrence of fiber blow out through the gas discharge ports.

Apparatus for making and collecting continuous fibers in the form of a

Process of making and collecting continuous fibers in the form of a

Process for making and collecting continuous fibers in the form of a

A method for making strong discrete fibers by flash spinning a polymer solution through a spinneret. A gaseous fluid is injected in parallel into the core of the polymer solution prior to passage through the spinneret. The high shear forces the gaseous fluid exerts on the polymer solution cause highly oriented, strong discrete fibers to be produced upon flashing through the spinneret rather than continuous fibers.

Method for making strong discrete fibers

An improved nonwoven-sheet-making apparatus includes an improved rotatable baffle which has a conical section that whose axis is displaced from the axis of rotation of the baffle. In preferred operation, the baffle deflects, spreads and oscillates a fiber stream as it advances from a spinneret to a moving receiver on which the stream fibers are deposited to form a ribbon which is overlapped with like-formed ribbons to form a sheet. The apparatus is particularly useful in making a less ropy more uniform sheet of flash-spun plexifilamentary strands.

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Chesterfield, VA, United States of America

Ashok H Shah