Polymer materials such as film and fabrics, woven, non-woven and meltblown, may be non-destructively surface treated to improve water wettability, wickability, and other characteristics by exposure to a glow discharge plasma sustained at substantially atmospheric pressure in air or modified gas atmospheres comprising helium or argon.
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a Continuation-In-Part of U.S. patent application Ser. No. 08/068,739, filed May 28, 1993.
Apparatus capable of sustained glow discharge at atmospheric pressure mounted along the web path in a web coating machine ahead of the point of coating application, for glow discharge treatment of the surface of a polymeric web shortly before coating. Latencies of treatment (the time between treatment and coating) approaching zero are possible, minimizing or preventing loss of treatment effect and maximizing adherence of a coated layer to the web surface. Elimination of one or more conventional subbing adhesion layers on the web surface is possible in some applications.
The invention is directed to methods for fabricating devices from polymer precursors, along with devices so fabricated. The methods of the invention include the steps of plasma treating a polymer based resin, paste, preform billet, or extrudate, and employing the treated polymer in the fabricated device. According to one embodiment, the fabricated device can include implantable prosthetics such as heart valves, sutures, vascular access devices, vascular grafts, shunts, catheters, single layered membranes, double layered membranes, and the like. Devices fabricated according to one embodiment of the invention include regions having selected porosity, permeability and/or chemistry characteristics.
A corona discharge apparatus 2 is provided as an ionized gas irradiation means above a plate 3 on which a textile product 2 is placed. The ionized gas E generated by the corona discharge apparatus 4 is irradiated to the textile product 2 and the textile product is activated. The ionized gas E penetrates into the textile product 2 from surface to back under the influence of the magnetic field generated by the plate 3. The textile product 2 is fully ionized from surface to back by this method and apparatus.
The invention is directed to a process for treating a photographic support in the form of a web, said process comprising providing a first grounded drum shaped electrically conductive electrode and at least one electrically conductive wire electrode of which the diameter varies between 60 and 1500 .mu.m facing said drum shaped electrode, establishing an AC voltage with a frequency range between 100 Hz to 300 kHz over said electrodes, moving the web at atmospheric pressure along said drum shaped electrode, thereby exposing it to atmospheric pressure glow discharge established between the said drum shaped and wire electrode.
Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.