Rheological measurement systems for use with systems including pressurized polymer melts and/or other viscous materials are described. In one embodiment, a rheometer is connected to an associated system with a bent, curved, or bendable tube to permit the rheometer to measure rheological properties in locations where the rheometer could not otherwise be located due to the presence of obstructions. Embodiments including rigid straight tubes for connecting a rheometer to an associated system are also described. In another embodiment, a flow-through rheometer is connected to an industry standard ½-20 thermowell aperture that is typically used for attaching temperature and pressure probes to a vessel containing a viscous material such as an extruder or injection molding system.

A method and system for adjusting melt pressure in an injection molding material that allows calculating a melt pressure of a molten plastic material to be injected and based on the calculated melt pressure and a desired melt pressure adjusting operation of an injection molding machine. This control of an injection molding cycle using the method and system of plastic melt pressure determination allows production of parts of increased quality and consistency.

In a method for operating an injection moulding machine in the absence of a backflow barrier, plastic melt is injected by a plasticising device into a cavity in a screw antechamber of a plasticising screw adapted to rotate about a longitudinal axis and to move translationally by a drive unit during an injection phase and a holding-pressure phase. A rotational drive of the drive unit is controlled such that a speed of the plasticising screw causes overlay of a backflow of the plastic melt from the screw antechamber back into screw threads of the plasticising screw by an opposing delivery flow as a result of a rotation of the plasticising screw due to a translational injection movement of the plasticising screw. A differential flow is established from the backflow and the opposing delivery flow and influenced at least during the injection phase by influencing the speed of the plasticising screw.

Disclosed are a system and method tuning PET raw material processing process by employing real time process management and machine learning steps and reactive addition of dosing of homogenizing composition for impregnating chain extenders and compatibilizing agents in thermoplastic resin using the liquid additive as a carrier into the process for modifying material performance. The properties of PET blend are no longer fixed once dry-blending and melting is complete.

A method of forming a urinary catheter is disclosed that includes injecting a polymer melt through a primary melt channel and into an elongated recess around an outer surface of a core; and controlling a first pressure of the polymer melt in a first secondary melt channel separately and individually from a second pressure of the polymer melt in a second secondary melt channel and reducing stress of the polymer melt along the elongated recess. Opening the mould and removing the core provides a moulded intermittent urinary catheter having an open distal end and a closed proximal tip.

Apparatus and methods for forming and printing hollow bodies from amorphous materials to form three-dimensional objects are provided. Apparatus provide a hollow body forming and printing machine, and methods for determining a desired amount of impact deformation for the hollow spheres, including calculating specific characteristics of the hollow spheres and the amorphous material, deriving a target viscosity range, adjusting the apparatus to satisfy the target viscosity range, and using the apparatus to form a plurality of hollow spheres with controlled deformation.

Systems and approaches for controlling an injection molding machine and a mold forming a mold cavity and being controlled according to an injection cycle. The systems and methods include analyzing a model of at least one of the injection molding machine, the mold, and a molten material to determine initial values for one or more control parameters of the injection molding machine, and executing a run of injection cycles at the injection molding machine; measuring operation of the injection molding machine during a particular injection cycle of the run of injection cycles; determining one or more operational parameters exceed a threshold; and upon determining that the one or more operational parameters exceed the threshold, adjusting the one or more control parameters for subsequent injection cycles of the run of injection cycles.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

Rheological measurement systems for use with systems including pressurized polymer melts and/or other viscous materials are described. In one embodiment, a rheometer is connected to an associated system with a bent, curved, or bendable tube to permit the rheometer to measure rheological properties in locations where the rheometer could not otherwise be located due to the presence of obstructions. Embodiments including rigid straight tubes for connecting a rheometer to an associated system are also described. In another embodiment, a flow-through rheometer is connected to an industry standard ?-20 thermowell aperture that is typically used for attaching temperature and pressure probes to a vessel containing a viscous material such as an extruder or injection molding system. The rheological measurement systems described can have improved tube resistance and thermal strength.

A molding method produces a molded part from a polymer starting material in a molding machine, in particular an injection-molding machine. In the method, the polymer starting material is plasticized and/or fused, and at least one monomer in the gaseous state is supplied to the polymer starting material.