Polymeric materials with improved resistance through untrasonic treatment and dental appliances and other articles formed thereby
AssigneeBay Materials, LLC
InventorsRay F. Stewart, John Lahlouh, Diyun Huang
Life of this patent
Estimating the term…
Abstract
A method of treating a polymeric material includes exposing the polymeric material to ultrasonic energy in a liquid medium at a temperature below a glass transition temperature of the polymeric material for a time sufficient to modify one or more properties, or to reduce surface or internal stress, of the polymeric material, the one or more properties including stress relaxation, shape recovery, glass transition temperature, and crystallinity.
Claims20
A method of treating a polymeric material comprising:
- exposing the polymeric material to ultrasonic energy in a liquid medium at a temperature below a glass transition temperature of the polymeric material for a time sufficient to modify one or more properties, or to reduce surface or internal stress, of the polymeric material, the one or more properties including stress relaxation, shape recovery, glass transition temperature, and crystallinity.
A method of reducing stress relaxation and/or creep in a polymeric article, the method comprising:
- adjusting a temperature of the polymeric article in a liquid medium to a temperature that is below a glass transition temperature of the polymeric material;
- and
- exposing the polymeric article to ultrasonic energy in the liquid medium at the temperature for a time sufficient to reduce stress relaxation of the polymeric article,
- wherein the exposing the polymeric article to ultrasonic energy reduces stress relaxation and/or creep resistance in the polymeric article by at least about 5% or 10% as compared to the stress relaxation and/or creep resistance of the polymeric article before the exposing.
A system for modifying the properties of a dental appliance, the system comprising:
- the dental appliance, wherein the dental appliance comprises a polymeric material;
- an ultrasonic treatment device comprising a fluid containing chamber, a heating (or cooling) element configured to heat the fluid containing chamber, and an ultrasonic transducer, wherein the treatment device is configured to adjust a temperature of the dental appliance in the fluid containing chamber to a temperature that is below a glass transition temperature of the polymeric material;
- and activate the ultrasonic transducer to subject the dental appliance to ultrasonic energy in the fluid containing chamber at the temperature for a time sufficient to reduce stress relaxation of the polymeric material.
Dependencies are inferred from the claim text.