Korea Institute of Science and Technology

Other

Korea Advanced Institute of Science and Technology

Han S Yoon

Tae W Son

Chul J Lee

Byung G Min

Jae W Cho

Byung C Kim

A hand drip coffee tumbler comprises: a container keeping coffee; a filter unit seated on the top of the container; a grinder unit separably coupled to the container over the filter unit to grind coffee beans; a cap separably coupled to the top of the container; and an auxiliary container having a space for keeping the grinder unit and separably coupled to the lower end portion of the container.

Hand drip coffee tumbler

The instant dental bridge is one used in surgical operations in areas of missing teeth between abutment teeth includes: an artificial tooth or teeth () formed with slots () in recessed parts near to the gum; a connecting body () which has through holes () formed in positions corresponding to the slots () and projections joined onto the abutment teeth, and of which the entire surface, except the surfaces (') in contact with the abutment teeth, is covered by the artificial tooth () or by the same material as the artificial tooth; and wires () for securing the abutment teeth and the connecting body () to each other, by being wound through gaps () neighboring the abutment teeth and through the slots () and the through holes ().

Instant dental bridge

A highly-oriented acrylic staple fiber prepared by simple extrusion of a PAN/H.sub.2 O melt in a gel crystalline state without spinning is provided. The acrylic fibers according to the present invention are characterized by the following properties: a degree of orientation between 80 and 97% observed by an X-ray diffraction; a length distribution ranging from 5 to 500 mm and a thickness distribution ranging from 5 to 500 .mu.m, a length to thickness ratio ranging from 100 to 100,000 determined by a scanning electromicroscope; a tensile strength of 10 to 70 kg/mm.sup.2 ; an initial tensile modulus of 300 to 1,500 kg/mm.sup.2 ; an elongation of 5 to 20%; and a specific surface area of 1 to 50 m.sup.2 /g.

Unspun acrylic staple fibers

Pulp-like short fibers prepared from liquid crystal polyesters capable of forming an anisotropic melt phase at a temperature of 200.degree. C. to 400.degree. C. and having a molecular weight of 2,000 to 100,000 are provided. These fibers consist of microfibrils and have the following highly-oriented fiber characteristics and properties:

Pulp-like short fibers from liquid crystal polyesters

A non-spun fiber of acrylic polymers, characterized by a pulp-like short fiber form of a thickness distribution of 0.1 to 100 .mu.m and a length distribution of 0.1 to 100 mm, and by irregular cross-sections in a plane taken perpendicular to the fiber axis and needle point-like ends similar to those of natural wood pulp fibers. The acrylic fiber of the present invention is made of an acrylonitrile homopolymer or copolymer consisting of a least 70% acrylonitrile (by weight) and at most 30% copolymerizable monomers (by weight) and having a viscosity average molecular weight between 10,000 to 600,000. The acrylic fiber according to the invention is further featured by the following physical properties: a degree of orientation of more than 80% based on X-ray diffraction pattern data, a tensile strength of 3 to 10 g/denier and an initial modulus of 30 to 100 g/denier, and absolutely no cylindrically-shaped filament trunks.

Non-spun, short, acrylic polymer, fibers

A new, pulp-like, acrylic short fiber having excellent heat- and chemical-resistance is provided. The fiber has a thickness distribution of 0.1 .mu.m to 50 .mu.m, a length distribution of 1 mm to 20 mm, and a thermal transition temperature (Tg) of above 200.degree. C. The fiber is produced by heating a mixture of polyacrylonitrile and water of about 5% to 100% by weight to temperatures above hydration-melting temperature under seal to an amorphous melt; cooling the resulting amorphous melt to temperatures between the melting and the solidifying temperatures of the melt to form a supercooled melt; extruding the resulting supercooled melt to give extrudates; heat-stabilizing the resulting extrudates at temperatures between 180.degree. C. and 300.degree. C. for 1 minute to 4 hours after drying and drawing; and cutting and beating the resulting heat-stabilized extrudates into an appropriate size.

Heat- and chemical-resistant acrylic short fibers without spinning

A process for the production of pulp-like short fibers having a highly-oriented fibril structure without spinning is provided. This process comprises heating a mixture of water and an acrylonitrile homopolymer or copolymer to a temperature above the melting temperature of the mixture under enclosed conditions to form an amorphous melt; cooling the resulting amorphous melt to a temperature below the melting temperature to obtain a supercooled melt phase; extruding the resulting supercooled melt phase through a slit die at a temperature between the melting and the solidifying temperatures of the melt phase into an external atmosphere to give extrudates; and subjecting the resulting extrudates to drawing and heat treatment followed by beating mechanically.

Process for the production of acrylic short fibers without spinning

Novel wholly aromatic polyamides and copolyamides of the formula: ##STR1## are provided. The aromatic polyamides and copolyamides are prepared by condensation polymerizing an aromatic diamine selected from 3,5-diaminobenzophenone and a mixture of 3,5-diaminobenzophenone and m-phenylenediamine with an aromatic dibasic acid chloride in a chemical equivalent amount. The polymers of the invention can be easily dissolved in an organic solvent to give a molding solution suitable for use in the film casting. The film resulted from the polyamides of the invention has excellent physiochemical properties such as durability, chemical resistance, flexibility, compactness, tenacity, transparency and electric insulation.

Wholly aromatic polyamides and copolyamides, and process therefor

Ultrahigh tenacity, ultrahigh modulus fibers are provided. The fibers are prepared by dissolving a mixture of poly(phenyleneterephthalamide) polymer with an inherent viscosity of at least 5 and a regularly ordered aromatic-aliphatic copolymer with an inherent viscosity of at least 2 in concentrated sulfuric acid to form a spinning solution, which solution is subsequently subject to extrusion by a known per se dry-jet spinning process.

Polymer alloy fiber and process therefor

High oriented poly(p-phenylenetetraphthalamide) short fibers having an inherent viscosity of at least 5.0 and a dimension of 2-12 .mu.m in diameter and 1000-5000 .mu.m in length are provided. These fibers have a physical form of irregular cross-sections and needle point-like ends similar to those of natural wood pulp fibers, and crystalline properties such as a crystallinity of more then 50%, an orientation angle of less than 25.degree. and an apparent crystallite size of more that 50 .ANG. as determined from an X-ray diffractogram scan, and a cross-section with four extinction positions through 360.degree. rotation when observed under a polarizing microscope. These fibers are prepared, without spinning steps, by subjecting the molecular chains of poly(p-phenyleneterephthalamide) to mechanical parallelization during the growth of the chains in a polymerization system therefor containing a pyridine/amide-based solvent.

Highly oriented aromatic polyamide short fiber

The present invention provides a removable attachment for a partial denture having assembly with body member which is to be the connector body therein and a slider member. The assembly is provided with the body member including a slot having a relatively wide and a relatively narrow slot or recess, in which a corresponding portion of slider member can be slid, and a neck portion of slot, which has a major axis which is horizontal and at a right angle to the row of teeth, a slider member including a lock rod and a protruding member suitable for being retained in a notch of the body member and has an aperture which may be engaged by the lock rod. The slider member is retained in position by two protruders of which both have the function as a rigid latch when the wearer or user masticates any foods and another function as a spring loaded rod when the user pushes out the slider member with his fingertip, and of which one is integrally formed on the individual movable member having one surface corresponding to a portion of the mastication surface of a natural tooth, and the other one is fixed to said individual movable member by a suitable method, for example, such as welding, soldering and etc. and is spring-loaded about the body of the slider member, and by the hemisphere detents to receive two protruders.

Removable attachment for partial denture

The present invention provides a removable attachment for a partial denture with a sliding locking assembly. The locking assembly is provided with a relatively wide slot and narrower sliding slot or recess which has a major axis which is horizontal and at a right angle to the row of teeth, a locking member including a lock pin and a protruding member suitable for being retained in a recess of the denture and has a hole which may be engaged by the lock pin. The lock member is retained in position by a spring loaded pin and detent to receive the pin. The attachment may be easily operated by a fingertip without injury to the finger and no sudden separation of the partial denture is experienced. It may be used in cases where only the canine teeth of both sides exist as well as in cases where bilateral and/or unilateral teeth are missing. General dental instruments can be adapted for use with this attachment and no special instruments are necessary. The attachment can be fabricated from various standard dental materials and is reasonably economical.

Growing community of inventors

Seoul, South Korea

Han S Yoon