JP3453229B2 - Manufacturing method of polyester fiber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyester fibers having extremely large single-filament fineness with high productivity by a high-speed spinning method. [0002] It is known that when a polyester is melt-spun at a high take-off speed of 4500 m / min or more, a fiber having practically sufficient properties can be obtained without mechanical stretching. Such a high-speed spinning method is a spinning method that has high productivity and has advantages such as elimination of steps and reduction of energy costs. However, in such a high-speed spinning method, it is difficult to cool and solidify the yarn discharged from the spinneret in the case of an extremely thick fiber having a single yarn fineness exceeding 20 deniers. There is a problem in that the yarn is greatly reduced and severe yarn swaying occurs, and single yarn breakage and unevenness in fineness frequently occur. Conventionally, such problems of insufficient cooling of the yarn are caused by an increase in the amount of cooling air, a temperature adjustment of the cooling air, or a method disclosed in Japanese Patent Publication No. Sho 63-63.
A solution has been attempted by means of cooling efficiency improving means such as a method in which cooling air is passed through the yarn in a rectified state as described in JP-A-14540, but a single-fiber fineness of 20 denier or more and a fine fineness fiber In such a case, the solution was difficult with these cooling means. On the other hand, JP-A-64-14314 and JP-A-5-230713 disclose that high-speed spinning of polyester is performed at a high draft, but the purpose is different from that of the present invention. It is aimed at clothing fibers having a small single-fiber fineness, and does not describe high-speed spinning of large fineness fibers having a large single-fiber fineness. An object of the present invention is to provide a method for producing a large-sized polyester fiber having a large single-filament fineness by industrially extremely stable and high operability by a high-speed spinning method. It is. Means for Solving the Problems The inventors of the present invention have intensively studied to achieve the above object, and as a result, by making the spinning draft extremely large, even if the spinning speed is 4500 m / min or more, the polyester fiber has a large fineness. Was found to be able to be stably spun, and the present invention was reached. That is, according to the present invention, the single yarn fineness is 2
The present invention provides a method for producing a polyester fiber, characterized in that a spinning speed is set at 4500 to 6000 m / min and a spinning draft is set at 2500 to 45000 when melt-spinning 0 to 30 denier polyester fiber. DETAILED DESCRIPTION OF THE INVENTION The polyester referred to in the present invention is a polyester having an ethylene terephthalate unit as a main repeating unit, and is mainly intended for polyethylene terephthalate. May be a copolyester obtained by copolymerizing the third component. Examples of the third component include dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid, and naphthalene-2,6-dicarboxylic acid, oxyacids such as p-oxybenzoic acid, propylene glycol, butylene glycol, and polyoxyalkylene. And diols such as glycol. The degree of polymerization of the polyester may be appropriately selected depending on the kind of the polyester and the intended use of the obtained fiber. In general, polyethylene terephthalate has an intrinsic viscosity (measured in an orthochlorophenol solution at 35 ° C.) of 0. .
Those within the range of 55 to 0.75 are suitable. Further, these polyesters may contain additives such as matting agents, stabilizers, coloring agents, flame retardants, and surface modifiers. In the present invention, the above-mentioned polyester is melted at about 270 to 290 ° C. according to a conventional method and discharged from a spinneret. The discharged yarn is cooled and solidified by applying a cooling air, and then taken out to obtain a single yarn. The fibers have a fineness of 20 to 30 deniers. In this case, it is necessary to perform melt spinning at a take-up speed (spinning speed) of 4500 to 6000 m / min. If the single yarn fineness after take-up is less than 20 denier, the problem due to insufficient cooling hardly occurs, and therefore, it is out of the scope of the present invention. Conversely, if it exceeds 30 denier, the present invention is stable. Can not be spun. On the other hand, when the spinning speed is less than 4500 m / min, the problem of insufficient cooling hardly occurs, but the object of the present invention of industrially producing fibers with high productivity cannot be achieved. Also,
When it exceeds 6000 m / min, the problem of insufficient cooling cannot be solved even if the spinning draft described later is increased,
It is not preferable because spinning cannot be performed stably. It is preferable that the cooled and solidified yarn be cooled as soon as possible in order to suppress the crystallinity of the obtained polyester fiber (undrawn yarn). For example, an oiling roller is provided at a position where the yarns do not fuse with each other and It is preferable that the yarn be provided as high as possible above the spinning line and that the yarn be rapidly cooled in order to apply an oil agent. The undrawn yarn thus obtained is subjected to drawing false twisting to form a crimped yarn having a soft feeling. Can be. In the present invention, in addition to the above conditions,
The spinning draft is 2500-45000, preferably 10
It is important to be within the range of 000 to 30,000.
When the spinning draft is less than 2500, the spinning speed is 4
In the high-speed spinning region of 500 m / min or more, since the cooling of the yarn is insufficient, single yarn breakage and unevenness of fineness frequently occur,
The object of the present invention cannot be achieved. On the other hand, the spinning draft is 4
When it exceeds 5,000, the balance between the separation of the molten polymer discharged from the spinneret from the spinneret surface and the spinning tension is lost, and not only a unique long-period fineness unevenness in the fiber axis direction occurs, but also a single yarn. Is also not preferred because it also tends to occur. According to the production method of the present invention described above, the detailed reason is unknown, but the single yarn fineness is 20.
Even at denier or more, a decrease in high-speed spinning property due to insufficient cooling is eliminated, and high-speed spinning in an industrially extremely stable operation state can be performed. In addition, the fiber obtained by such a method, as it is, monofilament yarn for applications such as printing and shielding,
Further, it can be suitably used as a raw yarn for crimped monofilament subjected to false twisting. The present invention will be described in more detail with reference to the following examples. [Example 1] A polyethylene terephthalate chip having an intrinsic viscosity of 0.65 was melted at a melting temperature of 290 ° C, and then discharged from a spinneret having six discharge holes having the hole diameters shown in Table 1. The discharged yarn is blown in a spinning cylinder having a length of 1.0 m across a yarn at a temperature of 20 ° C. and a cooling air having a blowing speed of 1.4 m / sec to be cooled and solidified. Distance 2.
The oil agent is applied with an oiling roller installed at a position of 8 m, the oil is applied through a pair of Goded rollers at the take-up speed shown in Table 1, and 240 denier / 12 filaments or 3
A multifilament of 60 denier / 12 filaments (two ply yarns) was obtained. Table 1 shows the physical properties and the spinning properties of the obtained filaments. In the table, the sway of the yarn is indicated by ○ when hardly recognized, Δ when slightly observed, X by XX (strongly observed XX), and yarn breakage of 8 hours. In the spinning, those that were not recognized at all were indicated by 、, those that were slightly observed were indicated by Δ, and those that were frequently observed were indicated by X. [Table 1]

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-56-31011 (JP, A) JP-A-58-76516 (JP, A) JP-A-54-27024 (JP, A) JP-A-1- 132849 (JP, A) JP-A-1-14314 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6/62

Claims (1)

(57) [Claims 1] When melt-spinning a polyester fiber having a single yarn fineness of 20 to 30 denier, the spinning speed is set to 4500.
~ 6000m / min, spinning draft 2500 ~ 4500
A method for producing a polyester fiber, which is set to 0.