A system for manufacturing a catheter includes at least first and second controllable rate material feeders that feed at least first and second materials into a temperature-controlled mixer to form a compound material that varies in flexibility and/or strength with the respective first and second materials and material feed rates. An extruder extrudes the compound material onto a rotating and translating mandrel to thereby form a variable stiffness profile along a length of the catheter that depends on respective rates of rotation and translation of the mandrel.

It discloses a lignin enhanced wood-plastic composite, belonging to the field of polymer based composites. The wood-plastic composite is composed of one or more of plant fiber, lignin, a recycled thermoplastic plastic, mineral powder and a processing aid, and is processed by a screw granulating extrusion process. Compared with the prior art, the mechanical properties, heat stability and aging resistance of a wood-plastic material are improved by adding lignin into the wood-plastic material according to the present invention.

A method and a device for the online determination of the viscosity of a polymer in pasty to liquid form undergoing processing, such as extrusion is disclosed. It is provided that for the online determination of the viscosity of the polymer, at least a portion of the polymer undergoing processing is diverted and conveyed to the measurement volume of a measuring module, a predetermined volume of the respective batch is expelled from the measurement volume through a measurement nozzle by subjecting the batch to a predetermined pressure, the time required for expelling the predetermined volume of the batch is measured, the measured values are used for calculating the viscosity of the polymer, and prior to the filling of the measurement volume with the polymer to be measured, the measurement volume is flushed at least once with a quantity of the polymer being processed.

An improved control apparatus for producing plastic films and an associated improved method are distinguished, inter alia, by the following features: the control apparatus has two stages or at least two stages, the control apparatus comprises, for this purpose, a sensor module and/or a sensor model and a process module and/or a process model, the machine-dependent sensor module and/or sensor model and the production-dependent process module and/or process model are linked or can be linked to one another via production variables, adjustable machine variables are connected or linked to plant production variables via the sensor module and/or the sensor model.

The present disclosure includes a method for determining a melt strength includes extruding one or more polymers to form the polymer film, passing the polymer film at least partially around a measurement roll coupled to a force measuring device, at least partially around a chill roll downstream of the measurement roll, and through a nip defined between two nip rolls, and measuring a force exerted on the measurement roll by the polymer film using the force measuring device. The polymer film is at least partially molten when contacting the measurement roll. A system includes an extruder, a measurement roll couple to one or more load cells, a chill roll coupled to a drive motor, at least two nip rolls downstream of the chill roll, and a take-up roll downstream of the nip rolls. The load cells measure a force exerted by the molten polymer film on the measurement roll.

Method for regulating an extrusion device for the manufacture of a continuous strip of profiled product (P) made of an elastomeric compound, comprising a screw rotationally driven in a fixed barrel the outlet of which comprises an extrusion die and at least one rotationally driven cylindrical roller, the rotational speed of the screw (.sub.screw) being directly connected to the rotational speed of the roller (.sub.roller) by a proportionality coefficient, including: for a given elastomeric compound and a given profiled product (P), determining a setpoint value Ks of the proportionality coefficient, measuring the thickness (e) of the profiled product (P) leaving the extrusion die at each instant and correcting the value of the proportionality coefficient to Ks, correcting the rotational speed of the screw taking account of the corrected value Ks of the proportionality coefficient, such that .sub.screw=Ks*.sub.roller The roller speed is adjusted as a function of the corrected value Ks of the proportionality coefficient.

A method of manufacturing a pneumatic tire has a winding step of forming a rubber ribbon winding body constructing a tread rubber by spirally winding a rubber ribbon obtained by co-extruding a first rubber and a second rubber which are different in hardness. The first rubber is mainly arranged in a first area by making a cross sectional area ratio of the first rubber greater than that of the second rubber. The second rubber is mainly arranged in a second area by making the cross sectional area ratio of the first rubber smaller than that of the second rubber. The cross sectional area ratio of the first rubber becomes progressively smaller in a part of the first area as the second area approaches. The rubber ribbon retains an interface boundary between the first rubber and the second rubber to at least a part of the second area.

A method of manufacturing a polymer film includes melting a resin, extruding the melted resin through a die to produce a polymer film, shaping the polymer film, cooling the polymer film, capturing an image of a test pattern through the polymer film, calculating a modulation transfer function value from the image, and adjusting a process parameter of the melting, the extruding, the shaping, or the cooling based on the calculated modulation transfer function value.

A process to manufacture a solution of aramid includes: i) combining a solvent and a base to result in a solvent-base mixture, ii) adding aramid material to the solvent-base mixture to obtain a composition, and iii) mixing the composition to obtain a solution of aramid, wherein at least 1 Mol of base per liter of solvent is added to obtain the solvent-base mixture. An aramid solution, processes to further process the solution, and a continuous aramid fiber with high elongation.

The extrusion apparatus includes a screw in a fixed barrel. The barrel has a feed inlet and an outlet with an extrusion nozzle which discharges into the nip between first and second rotary rolls that can rotate in opposite directions. The apparatus also has a first means for rotating and a first control means that are able to synchronize the speed of rotation of the first roll and the screw and has a second means that is able to rotate the second screw at a different speed of rotation than the first roll. The first control means can regulate the speed of rotation of the screw depending on the width of the strip, and a second control means can regulate the speed of rotation of the second roll depending on the thickness of the strip.