3m Innovative Properties Company

Patrick J Sager

James C Breister

William P Klinzing

Andrew W Chen

Andrew R Fox

Stanley C Erickson

Michael G Schwartz

Scott A Jerde

Bradley K Kucera

Douglas C Sundet

Matthew S Linabery

Marvin E Jones

Seth M Kirk

Steven John Pachuta

A method of making a fluorinated fibrous web, which method includes providing a nonwoven webthat contains polymeric fibers, creating a plasma that contains fluorine atoms at a first location, and contacting the nonwoven web with products from the plasma at a second locationremote from the first location. The method avoids exposure of the web to the plasma and hence expands the manufacturing processing window. Webs so fluorinated have a different CFHto CFratio when compared to locally fluorinated webs having similar levels of surface fluorination. The remote fluorinated webs can be subsequently charged electrically to provide a good performing electret filtersuitable for use in an air purifying respirator. Webs fluorinated in accordance with this invention also may exhibit good performance even after being 'aged' at high temperatures.

Remote fluorination of fibrous filter webs

Apparatus and methods for delivering a heated fluid. The apparatus includes at least a preheat zone, an expansion zone, and an expanded zone comprising a plurality of trim heaters, at least one fluid flow-distribution sheet, and an outlet. The apparatus may be used for delivering the heated fluid onto a moving fluid-permeable substrate.

Apparatus and methods for delivering a heated fluid

Methods and apparatus for meltblowing utilize an auxiliary manifold to dispense a fluid between an orifice of a die that is expelling polymeric fibers and an exit of a duct that is dispensing a secondary flow of gas onto the fibers. The fluid dispensed from the auxiliary manifold reduces a recirculation zone of the secondary flow between the exit and the orifice that, absent the fluid from the manifold, results in errant fibers that are blown back into the face of the die by the recirculating secondary flow.

Methods and apparatus for meltblowing of polymeric material utilizing fluid flow from an auxiliary manifold

Manifolds are designed to deliver fluid through multiple orifices of the manifold such that for a given inlet fluid pressure the fluid being output from the multiple orifices has a desired mass flow profile. The desired mass flow profile includes a desired mass flow rate and a desired direction and distribution of flow in three-dimensional space. The manifold is first modeled as a two-dimensional representation to determine manifold parameters necessary to achieve the desired mass flow profile within the two dimensions. Then, the manifold is modeled as a three-dimensional representation based on the parameters previously determined for the two-dimensional representation to determine manifold parameters of the third dimension that are necessary to achieve the desired mass flow profile within the three dimensions.

Manifolds for delivering fluids having a desired mass flow profile and methods for designing the same

Melt blown or spun bond nonwoven webs are formed by flowing fiber-forming material through a die cavity having a substantially uniform residence time and then through a plurality of orifices to form filaments, using air or other fluid to attenuate the filaments into fibers and collecting the attenuated fibers as a nonwoven web. Each die orifice receives a fiber-forming material stream having a similar thermal history. The physical or chemical properties of the nonwoven web fibers such as their average molecular weight and polydispersity can be made more uniform. Wide nonwoven webs can be formed by arranging a plurality of such die cavities in a side-by-side relationship. Thicker or multilayered nonwoven webs can be formed by arranging a plurality of such die cavities atop one another.

Nonwoven web forming apparatus

Method for making a nonwoven web

Melt blown nonwoven webs are formed by supplying fiber-forming material to a planetary gear metering pump having a plurality of outlets, flowing fiber-forming material from the pump outlets through a plurality of inlets in one or more die cavities, and meltblowing the fiber-forming material. Each die cavity inlet receives a fiber-forming material stream having a similar thermal history. The physical or chemical properties of the nonwoven web fibers such as their average molecular weight and polydispersity can be made more uniform. Wide nonwoven webs can be formed by arranging a plurality of such die cavities in a side-by-side relationship. Thicker or multilayered nonwoven webs can be formed by arranging a plurality of such die cavities atop one another.

Growing community of inventors

Hastings, MN, United States of America

Patrick J Sager