Abstract: A resiliently flexible ring of dimensionally heat-recoverable polymeric material whose tubular length is less than its notional circular diameter, formed so that it inherently maintains a non-circular open configuration enabling it to grip resiliently an object around which it is placed in use prior to heat-recovery, the maximum transverse dimension of the said object being at least 2.5% less, preferably at least 5% less, than the notional circular diameter of the ring. The ring preferably has at least three "corners" of relatively small radius of curvature, preferably evenly spaced around its circumference. Use of the rings is described for damping the noise of chain-drive sprocket wheels and for connecting flexible hoses to supply outlets.

Abstract: An apparatus and method for producing an hydraulic hose having ends of different internal diameters. An uncured hose is produced by conventional extrusion. The uncured hose is placed upon a mandrel having a reduced diameter end. That end of the uncured hose proximate the reduced diameter of the mandrel is covered by a heat responsive shrink tube. The shrink tube is heated to mold the end of the hose about the mandrel. Thereafter, the hose is vulcanized.

Abstract: To improve the re-wrappability of the expander members used on balloon catheters subsequent to an initial inflation thereof, the balloon member is subjected to an annealing process in which the balloon member, in its wrapped configuration, is placed within a plastic sheath and it, together with the sheath, is then placed between the jaws of a clamping fixture where the jaws may be heated to a predetermined temperature. When the jaws are made to close on the sheath and the wrapped balloon contained within it, the wrapped balloon is subjected to a radial compressive pressure and a temperature approximately equal to or above the glass transition temperature for the balloon material utilized and then maintained at that temperature for a predetermined time interval. The annealing is found to introduce a memory component into the plastic of the balloon that causes it to assume a lower profile upon deflation than otherwise obtained.

Abstract: The method of making polystyrene foam for foam products which includes utilizing atmospheric gases as the blowing agents or preferably mixing one or more of these gases and a blending agent which is non-volatile at the extrusion temperatures, introducing the mixture to a molten thermoplastic polystyrene resin containing nucleating agents such as sodium bicarbonate and citric acid and extruding the thermoplastic in the form of a foam. The resultant foam has substantially no residual blowing agent, is dimensionally stable at ambient temperatures and when used with a non-volatile blending agent can be made with small amounts of blowing agent permitting cooling of the melt without high loading on the extruder. The foam may be coextruded with one or more layers of thermoplastic film so that the resultant product is adapted for use for plates, cups, food containers or packaging and for labels for containers such as glass and plastic containers and for labels that are shrunk in place on a container.

Abstract: A resin transfer molding process for making composite pipe. The method includes disposing a preform on a mandrel and jacketing a heat-shrinkable sleeve over the preform such that an annular gap is maintained between the sleeve and the preform to form a buffer chamber in the annular gap. A thermosetting resin is then filled into the buffer chamber. The resin is then leveled and settled in the resin in the buffer chamber to form a resin pool. The heat-shrinkable sleeve is thermally shrunk by heating the sleeve. The heating occurs in a heating zone having an upper portion and a lower portion. A first fastening ring is fastened on the sleeve adjacent to the upper portion of the heating zone, and a second fastening ring is fastened on the sleeve adjacent to the lower portion of the heating zone. The heating zone moves upwardly along the sleeve to thermally shrink the sleeve. The resin is heated and cured and the sleeve is removed to form a composite pipe.

Abstract: A simple and inexpensive method and apparatus for molding a peripheral frame around a sheet or grid of thermoplastic material to produce a framed panel. A peripheral frame, preferably of structural foam or the like, is injection molded about a thermoplastic sheet or grid of panel-forming material which has been previously drawn or stretched at a temperature which orients the molecules of the polymer, i.e., below the glass transition temperature of the polymer, T.sub.g. Either during the frame molding process, or subsequent thereto, the panel-forming material is heated sufficiently to cause the material to shrink or revert toward its prestretched condition so as to tension the panel-forming material within the frame. Elastomeric sealing means are disclosed for sealing the mold during injection of the frame-forming material and locator fingers are provided to position a grid-like panel-forming material prior to initiation of the molding process.

Abstract: A method for producing a squeezable, thin-walled tube container of orientable plastic material in which the container includes a mouth portion, a squeezable thin-walled tubular container body having an open bottom-forming portion and a connecting portion located between the mouth portion and the container body and in which the mouth portion and the connecting portion consists of non-oriented material includes forcing the non-oriented material in the tube portion, by mechanical means, through a gap with a gap width at most amounting to approximately half the wall thickness of the material in the tube portion for orientation of the material passing through the gap, thereby obtaining substantially monoaxial orientation of the material which forms the container body and the open bottom-forming portion of the thin-walled squeezable tube container.

Abstract: In a method for manufacturing a thermoplasic pipe a pipe-shaped blank having larger wall thickness and less diameter than the completed thermoplastic pipe is positioned in a cylindrical chamber. The blank is formed by being softened and expanded into engagement with the inner surface of the chamber. A sealing ring is then mounted in an end portion of the plastic pipe by positioning the sealing ring in the expanded blank and shrinking the blank around the sealing ring by heating the pipe end portion.

Abstract: A method for making air bag covers includes enclosing leather or other covering material in a mold, advancing a projection on a mold portion against a covering material to form a tear seam, and injecting moldable material behind the covering material to form a backing layer bonded to the material while forming an aligned groove in the backing layer. Embossing a desired pattern in the leather or covering material with a design in the mold cavity is also disclosed. A method for molding leather covered, resinous articles using a preformed, preshrunk leather piece, which articles optionally have designs, indicia or enhanced leather graining embossed during molding, is also disclosed.

Abstract: A method for improving the radial enlargeability and other properties of tape-reinforced tubular vascular graft formed of sintered fluoropolymer(s), such as expanded, sintered PTFE. Broadly, the method comprises the step of radially shrinking the reinforcement tape layer of the graft, or the entire tape-reinforced graft, after sintering thereof. Such radial shrinkage of the reinforcement tape layer, or of the entire graft, renders the graft subsequently radially enlargeable by more than 5%, without tearing or breaking of the reinforcement tape layer of the graft. Radially enlargeable grafts of the present invention may be combined with various types of stents or anchoring systems, to form endovascular graft devices which are transluminally insertable and implantable within the lumen of a host blood vessel.

Abstract: In this method of making a mold for molding an optical lens an annular closure sleeve is fitted around two molding shells and cooperates with them to define the required molding cavity. The closure sleeve is made from a heat shrinkable synthetic material and is heated to shrink it onto the molding shells. Applications of the method include molds for molding ophthalmic lenses.

Abstract: A process for the manufacture of a multilayer, cross-linked, heat shrinkable, polyolefin film, the film having at least one inner layer including a thermoplastic polymer sandwiched between two outer layers including a thermoplastic polymer different from the thermoplastic polymer of the inner layer, including the steps of coextruding the polymers into a tape; cross-linking the tape; and converting the cross-linked tape into a heat shrinkable film by orientation; wherein scrap material produced in the manufacture of the heat shrinkable film is incorporated by recycling the film into the coextrusion step in an amount up to 50% by weight of the total film weight.

Abstract: A method for producing catheter guidewire composed of a wire core whose distal end section is encased in a polymer sleeve, to increase the column strength of the core. Axially spaced grooves formed in the sleeve increase the flexibility of the core end section. The guidewire is advantageous for use with a small-diameter catheter in accessing body sites along a tortuous vessel pathway.

Abstract: This invention relates to polyester/plasticizer blends which are useful as heat-shrinkable films or sheet in low temperature shrink packaging applications. The plasticizer is injected into the melt of the polyester. The plasticizer lowers the glass transition temperature, on-set temperature and shrink rate of the polyester. Film or sheet produced by the polyester/plasticizer blends is clear.

Abstract: A thermoplastic pipe for installation in an existing conduit is manufactured in folded form and spooled for storage. The pipe is then reheated to make it pliable for installation and pulled into the conduit for lateral periods. Steam under pressure is used to round the installed pipe. The leading end of the replacement pipe may be restricted by an end clamp which enables hot fluid to pass completely through the pipe and heat the full length, or by an inflatable plug which is displaced to the leading end of the replacement pipe after installation. Methods and apparatus for the manufacturing of the pipe include extruding heated thermoplastic pipe material through a die to form a tubular shape, shaping the resulting hot tubular plastic material in the molten state to the folded form and cooling to provide a pipe with a memory for the folded form.

Abstract: A thermoplastic liner for installation in an existing conduit is manufactured in folded form and spooled for storage. The liner is then reheated to make it pliable for installation and pulled into the conduit. Steam under pressure is used to round the installed pipe. The leading end of the liner may be restricted by an end clamp which enables hot fluid to pass completely through the pipe and heat the full length, or by an inflatable plug which is displaced to the leading end of the liner after installation. Methods and apparatus for the manufacturing of the liner include extruding heated thermoplastic pipe material through a die to form a tubular shape, shaping the extruded tubular plastic material to the folded form and cooling to provide a liner with a memory for the folded form.

Abstract: A method and apparatus for identifying cast parts. A master is provided at least partially formed in the shape of a part to be cast. A slot is then milled into the master, the slot having a mouth and a base, and the slot having a "dovetail" cross-section so that the slot is wider at the base than at the mouth. An expandable plastic tag is inserted into the slot. The tag includes an identification surface with indicia formed thereon. Finally, the master and tag are heated, causing expansion of the tag within the slot to secure the tag within the slot. The tag includes a pair of tabs extending laterally therefrom to secure the tag in the slot prior to heat expansion of the tag.

Abstract: Methods for producing intraocular lenses which can be non-surgically repositioned after being placed in an eye. Such methods include providing a lens blank at least a portion of which is a polymeric material having a glass transition temperature of at least about 40.degree. C., and forming from the lens blank an intraocular lens including an optic and a fixation member so that at least a portion of the fixation member is made of the polymeric material. The position of the optic in the eye can be changed by heating the fixation member to a temperature above the glass transition temperature.

Abstract: In a process of manufacturing shaped elements from synthetic thermoplastics, particularly polyolefins, such as polyethylene and polypropylene, wherein the plastic material is heated to a temperature above its softening temperature and is shaped in that state to form the shaped element and is subsequently cooled to a temperature below its softening temperature, the shaped elements are shaped in a hot state to form intermediate products having a certain oversize over the desired final dimensions and after they have been cooled are caused by a material-compacting pressing operation to assume the desired final dimensions, in which they are dimensionally stable.

Abstract: A method for securing a boss to a thermoplastic liner of a pressure vessel are disclosed. A preferred method of forming the vessel includes inserting a thermoplastic projection of the liner into a mounting aperture located in the boss. The projection, which is rigidly attached to the liner, mechanically prevents rotation of the boss about a pressure chamber orifice relative to the liner. The method further includes melting and compressing the thermoplastic projection to conform it to a locking chamber in the mounting aperture. A composite case is then constructed over the thermoplastic projection, the liner, and the boss, using the liner as a mandrel. The thermoplastic liner and projection are integrally formed by blow-molding thermoplastic material into a die without any substantial use of injection-molding. A vessel constructed according to the method is also disclosed.

Abstract: A method of making tooth belts by formation thereof about the outer peripheral surface of a building drum having a generally cylindrical configuration and a surface defining a series of parallel, tooth-shaped grooves. The belts are formed by wrapping a fabric circumferentially around the building drum and winding a cord of tensile material helically about the fabric. A layer of thermoplastic material is formed about the cord of tensile material, and a cord of shrink material is wrapped helically about the layer of thermoplastic material. The shrink material has a higher softening temperature than the thermoplastic material and will shrink at a temperature below its softening temperature. Pressurized steam is applied to the shrink material at a temperature below its softening temperature and between the softening temperature and the melting temperature of the thermoplastic material.

Abstract: The invention is an improved hose clamp of the type formed of a band of heat shrinkable polymer having a diameter reducing released temperature, an inside band surface and an outside band surface. It is improved by the inclusion of a heating indicator.

Abstract: Methods for forming a strip of thermoplastic material by punch clamping are described.

Abstract: A polymeric article and method for making a polymeric article, such as a catheter, are disclosed wherein the article is contacted with a swelling agent, such as a solvent, and a plasticizer to make the polymeric material softer and/or more pliable or flexible. The contacting may be carried our sequentially or simultaneously, using a solution containing a plasticizer and a solvent.

Abstract: A process to increase resistance to tearing in a heat-resettable material involves extruding a polymer of a specified crosslinking density to produce a plastic web. After cooling the plastic web is heated by creating a temperature decreasing towards its core and stretched at core temperature below crystalline melting temperature of partially crystalline and crystalline polymers resulting in a distribution of orientation over the full section of the plastic web. Resistance to tearing will be essentially increased in this manner based on a simple, low-cost production process.

Abstract: A hollow, heat-recoverable article 1, for enclosing objects such as electronic components etc. has a thermoplastic lining on its interior surface and includes a fusion bonded portion 2 in which different parts of the article have been brought together and bonded by fusion of the lining with substantially no welding of the heat-recoverable material forming the wall. The lining has a melting point that is higher than the recovery temperature of the article, thereby enabling subsequent recovery of the article without rupture of the bonded portion.

Abstract: The invention proposes a process for manufacturing a transmission shaft made of a composite material comprising at least one step for producing an external layer comprising reinforcing fibers impregnated with a heat-curable resin, characterized in that a peripheral sheath made of a knitted article is installed over the external layer prior to the curing of the resin during the polymerization cycle.

Abstract: A method for forming a surgical clip and fixture for use therein includes molding a polymeric clip body, the clip body having hinged legs, the polymer of the clip body being substantially amorphous. The clip body can then be moved to a desired configuration while being subjected to a temperature above the glass transition temperature. The molded clip body is then heated to a temperature within the crystallization range for a period of time sufficient to impart at least 20% crystallinity thereto to impart a spring back property. Also disclosed herein is a fixture for forming a surgical clip in accordance with this method.

Abstract: A process for continuously producing a phase retarder film or sheet comprising continuously supplying a stretched thermoplastic resin film or sheet to a heating zone in parallel with the stretching direction of the film or sheet and heating the film or sheet to a temperature not lower than the glass transition temperature of the resin while applying pressure to the surface of the film or sheet passing through the heating zone, thereby continuously subjecting the film or sheet to thermal relaxation while suppressing the expansion of the film or sheet in a direction parallel to the surface of the film or sheet and perpendicular to the stretching axis. According to the present invention, a phase retarder film or sheet having a low angular dependence of retardation can be produced continuously. By using the phase retarder film(s) or sheet(s) thus obtained as optical compensator(s), the viewing angle characteristics of liquid crystal display devices can remarkably be improved.

Abstract: A process for producing a phase retarder film, which comprises laminating a heat-shrinkable film on at least one side of a uniaxially stretched thermoplastic resin film so that the heat shrinkage axis direction of said heat-shrinkable film becomes perpendicular to the stretching axis direction of said uniaxially stretched thermoplastic resin film, subjecting the resulting laminate to heat shrinkage, and then peeling and removing the heat-shrinkable film. An object of the present invention is to provide a process for providing a phase retarder film having a desired R.sub.40 /R.sub.0 value and a desired retardation value, easily and at a high efficiency.

Abstract: A novel process and novel apparatus for producing prestretched plastic film is presented. The method and apparatus are capable of forming a film from molten material and cooling the film to a non-molten condition so the film can be stretched. The cooled film is engaged and passed through a primary nip and second nip to plasticly and elastically stretch the cooled film to cold orient the film such that the film is stretched beyond the material's yield point. The cooled film is engaged with a plurality of idler rollers at a relatively low tension over a distance sufficient to allow the cooled film to relax to recover a major portion of its elastic deformation. Thereafter, the film is formed into a roll prior to being affixed to a unit.

Abstract: A thermoplastic pipe in a reduced shape having a memory for the reduced shape is heated to make it pliable for installation in an existing conduit to be lined. The pipe is then expanded by passing a heated fluid into a pipe, or by the use of an inflatable plug or rounding device. The length of pipe which has been installed can be removed by heating to a pliable state to cause the pipe to return at least partially to its reduced form and remove. This ability to remove an installed length of replacement pipe allows for removal of a replacement pipe which is damaged.

Abstract: A method for producing a high strength multi-layered film excellent in heat resistance, shrinkability and stretchability and usable for wrapping of various articles which comprises at least five layers comprising a surface layer (S layer) mainly composed of at least one polymer selected from (A), (B), etc. and as inner layers at least one base layer (SBC layer) containing mainly a mixed composition comprising a combination such as (A)+(B)+(C), at least one core layer (H layer) containing mainly a polymer selected from (C), and at least one auxiliary layer (R layer) containing mainly at least one polymer selected from (A) and (B), with a proviso that when the R layer is placed-adjacent to the S layer, the R layer comprises the resin different from that of the S layer, said (A) being a low-density polyethylene or a copolymer of ethylene with a specific monomer, said (B) being a soft thermoplastic elastomer having a Vicat softening point of 80.degree. C.

Abstract: A temperature- and/or polar fluid-sensitive device which comprises a mechanically strained semi-crystalline hydrophilic polymer.

Abstract: A polymeric tube is extruded; one or more strands are wrapped around the tube, the strands having a polymeric core and a high strength helical fiber cover; a second tube extruded thereon; at least one of the tubes is cross linked; subsequently the composite tube wall is heated, expanded and cooled in the expanded state; the tube may be cut longitudinally before or after the heating/cooling.

Abstract: A process for making decorative articles. The process includes heating a polymeric substance up to its glass transition temperature and stretching in at least one direction from a first size to a second size. The substance is allowed to cool in the stretched condition. The stretched polymeric substance is thereafter heated locally at an intensity until surface cracks appear therein to a desired depth. The interior area of the cracks in the polymeric substance is then treated in various ways. Finally, the polymeric substance is heated further until the polymeric substance begins to retreat to its original dimensions and the cracks close.

Abstract: This method for forming a measuring diaphragm which measures the volume of a passing gas with high accuracy and has a prolonged service life because the diaphragm moves completely in the same way to both sides of the measuring vessel in which it is fixed. The measuring diaphragm when produced in quantity has an undulating structure of high uniformity and variation in quality of the diaphragm is small.

Abstract: An environmentally protected electrical socket and plug assembly retains environmental security throughout repeated connections and disconnections. The socket and plug assembly includes a socket containing an electrical conductor and adapted to insertably receive a plug, an environmental sealant at least partially filling the socket so that the sealant is at least partially displaced from the socket when the plug is inserted into the socket, and an elastomeric containment means for containing displaced sealant when the plug is inserted into the socket and for urging the sealant back into the socket when the plug is removed.

Abstract: A wraparound heat shrinkable sheet for covering pipes or cables is positioned therearound so its longitudinal edges overlap. A first patch is then positioned over the lapped edges, and a second patch, which is wider than the first patch, positioned over the first patch and secured to the underlying wrapped sheet. Heat is then applied, preferably by hot mastic. The heat acts to shrink the sheet which tensions the second patch, thereby directing a radial force downward onto the first patch.

Abstract: A method for installing plastic liners in pipes includes the steps of providing a plurality of cylindrical tubular liners of plastic material of predetermined diameters. Ribs extend radially between the liners. The liners are deformed or collapsed to reduced overall diameters. The liners are introduced into the pipe. The cylindrical shapes of the liners in the pipe are then restored with the ribs spacing the liners one from the other.

Abstract: Process crystallizes at least a portion of a molecularly oriented thermoplastic container by heat treating at least portions thereof at temperatures suitable to crystallize the portions, including the steps of heating at a first temperature for at least 5 seconds below a final crystallization temperature to heat set the container, followed by heating at a second temperature for at least 10 seconds at a final temperature to obtain crystallinity above 40%, wherein each of the heating steps is accompanied by shrinkage and distortion of the container; and sizing said crystallized container to a final shape.

Abstract: A container is produced from a preform which is formed by expansion in the axial and/or radial direction of a hollow blank of originally substantially amorphous material. In the production, the circumference of the preform is reduced by heating of material in the preform body, at least one material portion of the container body being displaced, by means of a mechanical forming device (30), in a direction towards the centre of the preform for forming an outer bounding surface of the container comprising material portions whose distance to the centre axis of the container is less than the distance of corresponding material portions to the centre axis (26) of the preform. An apparatus for producing the container includes the mechanical forming device which, during reforming of the preform into the container, abuts against material in the preform.

Abstract: A heat-shrinkable polyester tube, which is a tube having heat shrinkability imparted by subjecting an unstretched tube made of a thermoplastic polyester resin to tubular stretching, and which has a crystallinity of not higher than 20% and a shrinkage of more than 5% and not more than 26% in the longitudinal direction (MD) and a shrinkage of at least 25% in the radial direction (TD).

Abstract: A method of lining a pipeline 24 intended to carry gas, oil, water, sewage or chemicals in which a cross-linked polymeric liner pipe 10, which has been reduced from its original diameter to a lesser diameter or to a shape of reduced maximum dimension, is pulled through the pipeline 24. The lesser diameter is less than the least inner diameter of the pipeline 24. After the liner pipe 10 has been fully pulled through, the pipe liner 10 is heated by means of a source 60 of visible or infrared radiation forming part of a pig assembly 50 to cause it to revert to the pipeline. The pig assembly or assemblies are stationary at zones 70 where service connections are to be made. Subsequently, the remaining liner pipe 10 is reverted by pulling the source 60 through the liner pipe 10.

Abstract: A thin, flexible tubular membrane provides a heat containment tube for inserting into and inflation within an underground conduit to be repaired. Folded rigid thermoplastic pipe is inserted into the tube while not and flexible. The tubular membrane is pressurized to exclude unwanted fluids from within the existing conduit. Hot steam is injected into the tube to heat the pipe full-length externally and internally until flexible. The pipe is then rounded and expanded against the walls of the conduit with the tube therebetween. The rounding and expanding of the pipe is carried out progressively by moving a plug through the pipe and by injecting hot steam under pressure behind the plug.

Abstract: A process for producing a phase retarder film or sheet, which comprises subjecting a stretched thermoplastic resin film or sheet to thermal relaxation at a temperature not lower than the glass transition temperature of the thermoplastic resin to shrink the film or sheet in the stretching axis direction while suppressing the expansion of the film or sheet in a direction parallel to the film or sheet surface and perpendicular to the stretching axis.

Abstract: A process for treating a film comprising a liquid crystal polymer capable of forming an optically anisotropic melt phase, which comprises passing the film between press rolls at a temperature in a range of from 80.degree. C. below the melting point of the liquid crystal polymer to 5.degree. C. below the same melting point and under a linear pressure of 20 to 400 kg/cm.

Abstract: A method of forming a heat-recoverable article including the steps of profile extruding polymeric material into a predetermined shape, irradiating the polymeric material and then deforming the polymeric material into a generally planar configuration. Also disclosed is a heat-recoverable article including a generally planar layer of polymeric material which is in the heat unstable condition. Opposed surfaces of the polymeric material have a latent recovery stress, however opposite in sense, so that the article upon recovering towards a predetermined shape, exhibits substantially no residual stress. Further disclosed is a heat-recoverable article made by the method.

Abstract: A method of manufacture of a fiberscopic catheter having a tightly fitted optical glass fiber bundle received within an internal lumen of the catheter. The lumen for receiving the optical glass fiber bundle is heated and expanded under internal fluid pressure. The catheter and lumen are then cooled with the lumen still under the internal fluid pressure. After cooling, the fluid pressure is released and the lumen retains its expanded condition. An optical glass fiber bundle is inserted into the expanded lumen to a predetermined position within the catheter. The catheter and lumen are reheated to contract the expanded diameter of the lumen about the optical glass fiber bundle to provide a fiberscopic catheter having a tightly fitted fiber optic bundle within the catheter.

Abstract: A method of producing a blow-molded PET container suitable for hot-filling includes the steps of injection molding a preform, blow-molding the preform into a primary molded article larger than the desired final container, heating the primary article in a series of oven chambers while its mouth is sealed so that pressure builds within the article to thereby control shrinkage, and blow-molding the shrunken article into the desired container. The two molds are preferably heated, and the mold contact time is as long as allowed by the manufacturing process to help remove internal stresses in the article. An apparatus for carrying out the method includes a first machine having an injection station, a thermal conditioning station, a primary blow-molding station, and an exit station. A second machine includes the oven chambers and a final blow-molding station.