The present invention provides an apparatus for manufacturing a plastic optical fiber suitable for adjusting a plastic optical fiber to be uniform in size while inhibiting the entry of a metal that causes an increase in transmission loss of the plastic optical fiber. The apparatus for manufacturing a plastic optical fiber of the present invention is provided with an extruding device and a gear pump. The extruding device has a containing portion that contains a resin composition, and introduces a gas into the containing portion to extrude the resin composition from the containing portion by means of the gas. The gear pump adjusts a flow rate of the resin composition extruded from the extruding device.

One or more embodiments of the present invention provide an apparatus for applying a mixture of a first compound and a second compound, the apparatus comprising a first extruder for processing a first compound and a second extruder for processing a second compound, wherein the outlet from the first extruder is in fluid communication with a first channel of a housing, and the outlet from the second extruder is in fluid communication with a second channel of the housing, wherein a gear pump is positioned in each channel, wherein a nozzle is in fluid communication with an outlet of the first channel and an outlet of the second channel, and a coextruded continuous strip is produced. The ratio of the first compound to the second compound may be adjusted instantaneously.

The smoothing device for plastic films comprises plastic-melt-producing means (1, 5), an adjustable slit die (10) and a roller smoothing unit (16) having cooled smoothing rollers (11, 12), which form an adjustable smoothing gap (13) between each other. Optionally, further rollers (15) are arranged downstream. A thickness gauge (23) measures the thickness of the plastic-film web (22). A controller (30) for controlling the thickness of the plastic-film web (22) may set a setpoint thickness (SD) of the plastic-film web (22) and the volumetric flow rate (SS) of the plastic melt or the line speed (LS). The controller (30) captures the current torques and rotational speeds of the rollers (11, 12, 15) and the current thickness (FD, FD1-FDn) of the plastic-film web (22).

The controller (30) sends setpoint rotational speed signals (C0S, C2S-CnS, CAS) calculated from the captured torques of the rollers (11, 12, 15) to the drives of the rollers and a smoothing-gap setpoint distance signal (GW) for adjusting the smoothing gap (13), and furthermore—in the case of a specified line speed (LS)—setpoint plastic-melt volumetric flow rate signals (SS) to the plastic-melt-producing means, or—in the case of a specified plastic-melt volumetric flow rate (SS)—setpoint line speed signals (LS) to the drives of the rollers (12).

Embodiments of an invention disclosed herein relate to devices, processes, and systems for processing polymers.

A cross-head die assembly for use with an extruder is described. The cross-head die assembly includes: an inlet section having an inlet for communicating flow from the extruder to one or more flow channels formed in a support block; and an outlet, a removably mounted die located at the outlet and in fluid communication with the one or more flow channels; said support block further comprising an interior slot extending from a first side of the support block to an outlet passageway; a removable cassette positioned in the interior slot, wherein the front end of the removable cassette is positioned to seal the outlet passageway of the slot so that the slot is isolated from the flow.

The present invention is directed to an apparatus for forming a multi-layer web formed from at least two polymeric film tubes in intimate contact with each other but not bonded to each other. The apparatus and method includes the use of a blown film extrusion die that extrudes two separate blown film polymeric tubes via two separate annular die lips. A fluid cooling system applies cooling fluid across a plurality of surfaces of the two blown film tubes. One of the die lips may be at a different height from the other die lip. The frost line of one blown film tube may be at a different height from the other blown film tube.

Techniques recycle plastics in multiple successive process steps. A polymer, preferably a recyclable material, is melted using a discharge extruder, filtered using a first filter device under a positive pressure atmosphere, filtered and degassed using a degassing device, and discharged using a discharge extruder. The degassing device has at least one filter element and a vacuum chamber with a negative pressure atmosphere for filtering and degassing purposes, wherein the plastic melt can be conducted into the negative pressure atmosphere of the vacuum chamber through the filter element.

A method for reducing gel in a polymer kneaded compound flowing in a polymer flow duct includes flowing a polymer kneaded compound in a polymer flow duct to a gel reduction mechanism including a gel reduction member having one or more through holes defining a squeezing flow path having a flow path cross-sectional area smaller than the polymer flow duct. The squeeze ratio S1/S2 of the squeezing flow path is 25 to 177.8, where S1 is a flow path cross-sectional area of the polymer flow duct and S2 is a sum total of flow path cross-sectional area of the squeezing flow path, to generate an extensional flow in the kneaded compound.

One or more embodiments of the present invention provide an apparatus for applying a mixture of a first compound and a second compound, the apparatus comprising a first extruder for processing a first compound and a second extruder for processing a second compound, wherein the outlet from the first extruder is in fluid communication with a first channel of a housing, and the outlet from the second extruder is in fluid communication with a second channel of the housing, wherein a gear pump is positioned in each channel, wherein a nozzle is in fluid communication with an outlet of the first channel and an outlet of the second channel, and a coextruded continuous strip is produced. The ratio of the first compound to the second compound may be adjusted instantaneously.

A continuous cycle system for moulding single objects from plastic material, including: an extruder including a cylinder extending along a longitudinal axis (L), a screw rotating inside the cylinder about the longitudinal axis (L), the screw having a core and a thread externally coupled to the core and heaters coupled to the cylinder; a moulding machine, configured to receive as input the flow of liquid plastic material from the extruder and including a plurality of moulds, each having a first and a second half mould movable relative to each other between an open position and a closed position.