Minnesota Mining and Manufacturing Company

Louis A Errede

Donald F Hagen

Craig G Markell

William V Balsimo

James D Stoesz

Steven J St Mary

George R Hunt

George D Winter, Deceased

Peter W Carr

Robert A Sinclair

Buren R Ree

Patricia M Ronning

Carol E Hendrickson

Dale R Anderson

Bruce A Langager

Gary B Jefson

Jenny Upton

A composite marine structure comprises a marine substrate having adhered to at least a portion of its surface a layer of a water-permeable composite article comprising a non-woven fibrous web having entrapped therein active particulate to provide said marine substrate with protection against at least one of fouling and corrosion. Underwater surfaces such as ship hulls, buoys, docks, intake pipes, etc., can be protected against marine growth and corrosion by adhering thereto the composite sheet article of the invention.

Antifouling/anticorrosive composite marine structure

A composite article having controlled void volume and mean pore size comprises:

Separation method using controlled pore composite

Controlled pore composite polytetrafluoroethylene article

Method of making a controlled pore composite polytetrafluoroethylene

A composite chromatographic sheet-like article is prepared by the steps comprising blending one or more non-swellable sorptive hydrophobic particulate materials in the presence of an amount of polar organic masking agent sufficient to allow rapid wetting of the surface of the particulate and in the presence of sufficient lubricant water to exceed the sorptive capacity of the particulate, provided that the volume ratio of water to masking agent does not exceed 3:1, adding with stirring an aqueous emulsion of polytetrafluoroethylene so that the resulting mass has a dough-like consistency, mixing the mass in an intensive mixer at a temperature between 50 C. and 100 C. for a time sufficient to cause fibrillation of the polytetrafluoroethylene particles, biaxially calendering the mass, while maintaining water at a level near the absorptive capacity of the particulate, between a gap in the calendering rolls maintained at about 50 C. to about 100 C. to cause additional fibrillation and consolidation of the polytetrafluoroethylene particles while closing the gap with each successive calendering operation, for a time sufficient to produce a composite chromatographic article having a net surface energy in the range of 20 to 300 milliNewtons per meter, and drying the resultant sheet.

Method of preparing composite chromatographic article

Articles which are composite structure are prepared which comprise a fibrillated polytetrafluoroethylene (PTFE) matrix containing enmeshed and immobilized therein viable cells capable of their usual and continuous biochemical and biological performances. The viable cells cells can be animal, bacterial, fungal or yeast. Almost all cells entrapped within said matrix are separated from each other and are unbound within said matrix such that when said matrix is cut the cells of the cut edge are free to escape from the matrix.

Immobilization of biological cells in polytetrafluoroethylene matrix

A composite chromatographic article comprising:

Composite chromatographic article

A polytetrafluoroethylene (PTFE) fibril matrix is prepared containing entrapped viable cells such as animal, bacterial, fungal or yeast cells. Cells are blended with surfactant and soap-free PTFE in aqueous dispersion to form a damp paste. Water is added to the paste and a resultant stiff dough is biaxially calendered between calendering rolls to cause fibrillation and form the PTFE fibril matrix. Calendering is preferably carried out at a temperature of 5.degree. to 70.degree. C. and a pressure of 1000 to 3000 MPa. The fibril matrix may be dried.

A method of preparing a tear-resistant composite sheet material having hydrophilic, absorptive particles enmeshed in a network of interlaced microfibrous polytetrafluoroethylene forming a fibril matrix, the hydrophilic absorptive particles having absorptive particles with absorptive capacity greater than 1.0 gram of water per gram of dry particle, wherein the method comprises:

Method for making water-swellable composite sheet

A composite sheet material is highly absorbent toward aqueous fluids including blood and exudate and comprises a polytetrafluoroethylene fibril matrix and hydrophilic absorptive particles enmeshed in the matrix. The composite sheet material is useful as a wound dressing, as a drying material for non-aqueous solvents, and as a chromatographic material.

Water-swellable composite sheet of microfibers of PTFE and hydrophilic

A composite wound dressing, optionally having controlled permeability, is highly absorbent toward blood and exudate and comprises a polytetrafluoroethylene fibril matrix, hydrophilic absorptive particles enmeshed in the matrix, and, optionally, a partially occlusive film coated on one surface of the matrix.

Composite wound dressing

A plant nourishment delivery device having a variable flux capability and comprising a water-permeable membrane having a conditioned flux capability in the range of about 0.005 to 10 cubic centimeters per minute per square centimeter at an applied hydrostatic pressure of about 1 atmosphere, and an exaltation of said conditioned flux capability in the range of about 30% to 10,000%.

Plant nourishment delivery device

A polytetrafluoroethylene composite sheet having a tensile strength of at least one megapascal and comprising particulate material distributed in a matrix of interentangled polytetrafluoroethylene fibrils. The composite sheet is prepared by blending the particulate material with polytetrafluoroethylene aqueous dispersion in the presence of sufficient lubricant water to exceed the absorptive capacity of the solids yet maintain a putty-like consistency, subjecting the putty-like mass to intensive mixing at a temperature between 50.degree. C. and 100.degree. C. to cause initial fibrillation of the polytetrafluoroethylene particles, biaxially calendering the putty-like mass to cause additional fibrillation of the polytetrafluoroethylene particles while maintaining the same water content and drying the resultant sheet.

Method of making polytetrafluoroethylene composite sheet

A black sorbent thermoset foam which has been prepared by the pyrolysis of a composition comprising at least one aromatic nitrogen-containing compound having the general formula:

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North Oaks, MN, United States of America

Louis A Errede