Abstract: A resin fiber formation nozzle 20 of the present invention is a nozzle configured to discharge a molten resin material into a fiber shape. The nozzle 20 includes: the internal flow path 21; an inlet 22 that allows the resin material to flow into the internal flow path 21; and an outlet 23 that allows the resin material to be discharged from the internal flow path 21 to an outside of the nozzle 20. The internal flow path 21 is shaped such that a diameter of the internal flow path 21 decreases continuously, in a section from a position A 5 mm upstream in the internal flow path 21 from the outlet 23 to a position B of the outlet 23, from the position A toward the position B.

Abstract: The present invention provides a fiber manufacturing method suitable for reducing the variation in outer diameter. The fiber manufacturing method of an embodiment of the present invention includes: discharging a softened linear body 1 through a nozzle 10; and winding the linear body 1 so that the linear body 1 passes through a cooling portion 20 supplied with a cooling fluid 50, thereby obtaining a fiber 5. The cooling portion 20 has a filter 40 configured to rectify the cooling fluid 50. The cooling fluid 50 in the cooling portion 20 has a temperature that is substantially constant in a moving direction of the linear body 1. According to the fiber manufacturing method of the embodiment, an index M determined by the following equation (I) is 1.52 or less.

Abstract: 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.

Abstract: A method for producing a coated optical fiber includes coating, using a coating die, a circumferential side surface of an optical fiber with a coating material by passing the optical fiber sequentially through an insertion hole portion, a_ liquid retaining chamber (21), and a_coating hole portion opposed to the insertion hole portion, while the coating material in the liquid retaining chamber is supplied under pressure to the coating hole portion, in which a pressure difference ?P (MPa) between a liquid pressure of the coating material in the liquid retaining chamber and a pressure outside the coating die, a viscosity µ (Pa·s) of the coating material in the liquid retaining chamber, and a length L (mm) of the coating hole portion in an extending direction satisfy a relationship of ?P/µL ? 0.15.

Abstract: A coating apparatus includes: a coating unit configured to form a coating film by applying a coating liquid containing a component to be solidified onto a sheet that is relatively moving and by solidifying the applied coating liquid; a liquid delivering unit configured to deliver the coating liquid to the coating unit; a measuring unit configured to measure a mass flow rate of the coating liquid and arranged between the liquid delivering unit and the coating unit; and a control unit storing a reference value of the mass flow rate and configured to change the mass flow rate of the coating liquid to be delivered by the liquid delivering unit on the basis of the reference value and a measurement result by the measuring unit.

Abstract: A filter unit including a filter and a housing, in which the filter has an opening on one end side and filters a coating liquid from the outside to the inside of the filter, the housing has, on one end side, an inlet port of the coating liquid, and has, on the other end side, an outlet port of the coating liquid filtered by the filter, the filter is attached to the other end side of the housing so that the opening and the outlet port communicate with each other, and the housing has a release hole through which air is released, the release hole being formed at the other end outside the filter.

Abstract: Provided is a shim member which is sandwiched between two die blocks provided in a die coater, and has the U shape formed by a base end portion which is arranged so as to extend in a longitudinal direction of the slot, and a pair of extending portions which extend toward a nose portion of the die from both ends in a longitudinal direction of the base end portion, wherein a first portion which is a nose portion of at least one extending portion or the whole of at least the one extending portion, out of the pair of the extending portions, and a second portion which is the remaining portion including at least the base end portion, are structured so as to be separable from each other.

Abstract: Provided is a shim member which is sandwiched between two die blocks provided in a the coater, and has the U shape formed by a base end portion which is arranged so as to extend in a longitudinal direction of the slot, and a pair of extending portions which extend toward a nose portion of the die from both ends in a longitudinal direction of the base end portion, wherein a first portion which is a nose portion of at least one extending portion or the whole of at least the one extending portion, out of the pair of the extending portions, and a second portion which is the remaining portion including at least the base end portion, are structured so as to be separable from each other.