Abstract: The present invention provides an improved coextruded medical port tubing. The medical port tubing provides characteristics that are desirable in the medical industry and therefore can be used as a medical port tubing in, for example, renal therapy or blood donor tubes. To this end, the present invention provides a coextruded medical grade port tubing comprising: an outer layer comprising a blend of polypropylene copolymer and styrene-ethylene-butylene-styrene copolymer; a tie layer; and a core layer comprising polyvinyl chloride.

Abstract: The present invention provides an improved coextruded medical grade port tubing. The medical grade port tubing provides characteristics that are desirable in the medical industry and therefore can be used as a medical port tubing in, for example, renal therapy or blood donor tubes. To this end, the present invention provides a non-PVC coextruded medical grade port tubing including: an outer layer comprising a blend of polypropylene copolymer and styrene-ethylene-butylene-styrene copolymer; a tie layer; and a core layer including a blend of polyamide and ethylene vinyl acetate.

Abstract: An apparatus for sealing a web of film in a packaging machine. The apparatus includes a sealing bar for heating a web of film to a temperature sufficient to melt at least a portion of the web of film. The sealing bar includes a surface that directly contacts the web of film and does not include a release layer. The surface includes thereon a measuring member for measuring the temperature of the molten area of the film. The apparatus further includes a cooling member for cooling the melted portion of the film to its crystallization point during a cycle time of the packaging machine.

Abstract: An apparatus for sealing and severing a web of film is provided. The apparatus includes a sealing bar having a body portion including first and second sidewalls and a top portion for melting and severing a portion of a web of film. A backup member is provided located on an opposite side of the film from the sealing bar for urging the film against a portion of the sealing bar. The apparatus also includes a holder for holding the sealing bar, the holder includes a first side and a second side that define a center region for receiving at least a portion of the body of the sealing bar, and first and second sides having shoulders. The shoulders and top portion of the sealing bar are so constructed and arranged that they deflect a bead generated at a molten area of the film when the film is sealed and severed and substantially limit the creation of a resultant bead in a final cooled product.

Abstract: The loss modulus of a material is ascertained by subjecting a sample of the material to a mechanical vibration at the resonant frequency of the material. The dynamic driving force required to maintain the material in mechanical vibration at its resonant frequency is measured. Next, the static driving force required to displace the same material the same distance as when vibrating is measured. The quotient of the dynamic force divided by the static force is proportional to the tangent of the angle between elastic modulus and loss modulus of the material, or tan .delta.. Since the frequency of the material, when in vibration, is related to the elastic modulus of material, the loss modulus may be readily computed by multiplying the elastic modulus by tan .delta..An apparatus capable of performing this method includes a driving system that vibrates the sample material at its resonant frequency using a sinusoidal driving force which is 90.degree.

Abstract: The apparatus described includes a fixed plate and a movable plate mounted to vibrate relative to the fixed plate in a plane parallel to the plane of the fixed plate. The plates are spaced apart so that fluid can be placed therebetween. A drive system maintains the movable plate vibrating at its resonant frequency. The drive system uses a sinusoidal drive with a linear transducer to facilitate determination of viscosity simply by measuring the peak driving force.

Abstract: A heat flow type differential calorimeter uses a planar thermoelectric disc as its major heat flow path for transferring heat to the sample and reference capsules. To improve the reproducibility of the calorimeter, two small discs of a thermoelectric material capable of forming a thermocouple with the thermoelectric disc are attached thereto in face-to-face relationship. Next a thermocouple pair made of the same material as the small disc and a third material, capable of forming a thermocouple with the disc, is attached to the center of each of the small discs. This converts the usual point contact temperature sensor to a large surface area temperature sensor and hence improves the reproducibility of the thermal analyzer.

Abstract: An instrument for determining the complex mechanical response of samples incorporates two parallel sample arms each pivotally mounted at their central portion by flexure pivots of precisely known spring constants. The sample is mounted on one end of each. An electromechanical driver acts on the other end of one arm to maintain the arms and sample in mechanical oscillation about the pivots. A displacement transducer senses the mechanical motion. A feedback amplifier between the displacement transducer and the driver maintains the oscillation at a constant amplitude and at a resonant frequency determined primarily by the sample. With this arrangement the driver and displacement sensor are removed from the sample and its usual thermal chamber. This improves the stability of the instrument. At the same time the arms are dynamically balanced about the pivots and hence are relatively insensitive to vibrational upset.

Abstract: A thermomechanical analyzer is adapted to measure stress or strain in a sample material by the use of a flat, passive spring, having a known modulus of elasticity, in conjunction with an axially displaceable shaft which mechanically links the spring and the sample together. The linkage is such that the sample under test and the spring are mechanically connected in parallel, i.e., each undergo equal displacement. A transducer senses axial displacement of the shaft such that the magnitude of the shaft displacement is related to the stress in the sample. The sample may be subjected to temperature variations during the test cycle.