Abstract: An optical fiber arrangement method includes: preparing an intermittently connected optical fiber ribbon including optical fibers arranged side by side at a first pitch larger than a fiber diameter; holding a non-connecting region of the optical fiber ribbon with a holder, wherein connecting portions of the optical fiber ribbon intermittently connect the optical fibers extending out from the holder to each other; changing a width of the optical fiber ribbon in an interior of the holder; and arranging the optical fibers, extending out from the holder, with intervals of the optical fibers changed from the first pitch to a second pitch smaller than the first pitch by removing the connecting portions in a holding state where the holder is holding the optical fibers.

Abstract: An optical fiber arrangement method includes: preparing an intermittently connected optical fiber ribbon including optical fibers arranged side by side at a first pitch larger than a fiber diameter; holding a non-connecting region of the optical fiber ribbon with a holder, where connecting portions intermittently connect the optical fibers extending out from the holder to each other; changing a width of the optical fiber ribbon in an interior of the holder; and arranging the optical fibers, extending out from the holder, with intervals of the optical fibers changed from the first pitch to a second pitch smaller than the first pitch by removing the connecting portions in a state where the holder is holding the optical fibers.

Abstract: An optical fiber protective unit includes: a reticulated tube; and a tubular member that is inserted through the reticulated tube and that is configured to accommodate a plurality of optical fibers. The reticulated tube is disposed on an outer periphery of the tubular member in a state folded in a longitudinal direction. Both end parts of the reticulated tube are located on the outer periphery of the tubular member.

Abstract: A machining method for an optical fiber unit, includes: preparing an optical fiber unit in which a first optical fiber ribbon that intermittently connects a first plurality of optical fibers and a second optical fiber ribbon that intermittently connects a second plurality of optical fibers are layered and arranged, the first optical fiber ribbon and the second optical fiber ribbon are intermittently connected in a length direction by interlayer connection parts; opening up a separation part between the first optical fiber ribbon and the second optical fiber ribbon; and breaking the interlayer connection parts by inserting a finger or a division tool into the opened separation part.

Abstract: An optical fiber cable includes: optical fiber units each comprising optical fibers, and twisted together in an SZ shape; a wrapping tube that wraps around the optical fiber units; fillings disposed inside the wrapping tube, wherein the fillings include at least one first filling and at least one second filling that are located between two adjacent optical fiber units; and a sheath that covers the wrapping tube. The first filling is in contact with the wrapping tube. The second filling is located more radially inward than the first filling in a radial direction.

Abstract: An optical fiber unit includes: a first optical fiber ribbon that intermittently connects a first plurality of optical fibers; a second optical fiber ribbon that intermittently connects a second plurality of optical fibers; and interlayer connection parts that intermittently connect the first optical fiber ribbon and the second optical fiber ribbon in a length direction while the first optical fiber ribbon and the second optical fiber ribbon are layered and arranged. The first optical fiber ribbon and the second optical fiber ribbon are layered and arranged such that optical fibers having a same fiber number of the first optical fiber ribbon and the second optical fiber ribbon are aligned in a up-down direction perpendicular to the length direction.

Abstract: An optical fiber cable includes: optical fiber units each having optical fibers; a wrapping tube that wraps around the optical fiber units; a filling disposed inside the wrapping tube; and a sheath that covers the wrapping tube. The optical fiber units includes outer units that are disposed at an outermost layer of the optical fiber units. The outer units are twisted in an SZ shape around a cable central axis of the optical fiber cable. The filling is sandwiched between one of the outer units and the wrapping tube in a cross-sectional view.

Abstract: An optical fiber protective unit includes: a reticulated tube; and a tubular member that is inserted through the reticulated tube and that is configured to accommodate a plurality of optical fibers. The reticulated tube is disposed on an outer periphery of the tubular member in a state folded in a longitudinal direction. Both end parts of the reticulated tube are located on the outer periphery of the tubular member.

Abstract: An intermittently connected optical fiber ribbon includes optical fibers, disposed side by side in a width direction of the optical fibers, and connecting portions that each intermittently connect two adjacent ones of the optical fibers. A center-to-center distance between any of the two adjacent ones of the optical fibers is greater than a diameter of the individual optical fibers. A total volume shrinkage per meter per 1° C. of the connecting portions of a single one of the optical fibers is 0.00070 mm3/m·° C. or lower.

Abstract: A reticulated tube includes: a plurality of openings that are reticulately formed; peripheral parts that form the openings; and a branch part that is formed in a boundary of three or more openings. The branch part includes three or more peripheral parts extending from the branch part. The reticulated tube is configured to accommodate a plurality of optical fibers inserted through the reticulated tube. The peripheral parts are restricted by the branch part and are bendable.

Abstract: An optical fiber arrangement method includes: preparing an intermittently connected optical fiber ribbon including optical fibers arranged side by side at a first pitch larger than a fiber diameter; holding a non-connecting region of the optical fiber ribbon with a holder, where connecting portions intermittently connect the optical fibers extending out from the holder to each other; changing a width of the optical fiber ribbon in an interior of the holder; and arranging the optical fibers, extending out from the holder, with intervals of the optical fibers changed from the first pitch to a second pitch smaller than the first pitch by removing the connecting portions in a state where the holder is holding the optical fibers.

Abstract: An elongated-object drum includes: a drum on which an elongated object is wound; and a management module that is attached to the drum and comprises: an acceleration sensor that detects acceleration of the drum, a computation device that performs computation based on a detection result from the acceleration sensor, and a storage device that stores a computation result obtained by the computation device based on the detection result from the acceleration sensor.

Abstract: An intermittently connected optical fiber ribbon includes optical fibers, disposed side by side in a width direction of the optical fibers, and connecting portions that each intermittently connect two adjacent ones of the optical fibers. A center-to-center distance between any of the two adjacent ones of the optical fibers is greater than a diameter of the individual optical fibers. A total volume shrinkage per meter per 1° C. of the connecting portions of a single one of the optical fibers is 0.00070 mm3/m·° C. or lower.

Abstract: An optical fiber unit includes: a first optical fiber ribbon that intermittently connects a first plurality of optical fibers; a second optical fiber ribbon that intermittently connects a second plurality of optical fibers; and interlayer connection parts that intermittently connect the first optical fiber ribbon and the second optical fiber ribbon in a length direction while the first optical fiber ribbon and the second optical fiber ribbon are layered and arranged. The first optical fiber ribbon and the second optical fiber ribbon are layered and arranged such that optical fibers having a same fiber number of the first optical fiber ribbon and the second optical fiber ribbon are aligned in a up-down direction perpendicular to the length direction.

Abstract: A reticulated tube includes: a plurality of openings that are reticulately formed; peripheral parts that form the openings; and a branch part that is formed in a boundary of three or more openings. The branch part includes three or more peripheral parts extending from the branch part. The reticulated tube is configured to accommodate a plurality of optical fibers inserted through the reticulated tube. The peripheral parts are restricted by the branch part and are bendable.

Abstract: An optical fiber cable includes: optical fiber units each having optical fibers; a wrapping tube that wraps around the optical fiber units; a filling disposed inside the wrapping tube; and a sheath that covers the wrapping tube. The optical fiber units includes outer units that are disposed at an outermost layer of the optical fiber units. The outer units are twisted in an SZ shape around a cable central axis of the optical fiber cable. The filling is sandwiched between one of the outer units and the wrapping tube in a cross-sectional view.

Abstract: A frozen urethane premix coating material is prepared by mixing together an isocyanate, a hydroxy terminated aliphatic polyol, and an organic solvent in an amount of at least 75 percent by weight of the total weight of the premix, and then freezing the mixture. The storage life of the mixture is several months, after which it is thawed and used as a coating material. In one form, the premix includes 4,4'-diphenyl methane diisocyanate as the isocyanate and a mixture of toluene and methyl ethyl ketone as the solvent.