JP2005256197A - Polyamide monofilament fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyamide monofilament by finely dividing a thermally denaturated gel polymer which is not dispersed in a foreign material dispersion filtration layer to lower yarn breakage trouble in spinning and provide a polyamide monofilament having improved higher order processability and product quality. <P>SOLUTION: The polyamide monofilament fiber is produced by spinning with a melt-spinning spinneret pack containing at least a spinneret, a pressure plate, a metallic wire filter and a filtering material in a pack case in laminated state and having a sintered filter of metal short fibers having a nearly polygonal cross-section between the metallic wire filter and the sand filtering material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyamide monofilament having improved quality and having few nodes, and a method for producing the same.

  A woven fabric woven from monofilaments called a screen cocoon is widely used for screen cocoon printing and filter applications. In recent years, the weight reduction and thinning of the koji fabric has progressed, and the demand for the quality of the koji fabric has increased. Therefore, there is a demand for uniform monofilaments having no knitting yarns and fluff. As a means for producing monofilaments, for example, a melt spinning base pack described in Patent Document 1 is used. After the molten polymer is discharged through a filter, spinning is cooled, and then the oil is supplied and taken up by the first goderol, the heated first It is stretched between two goderols and wound up.

  In general melt spinning packs, a base for spinning yarn is arranged at the bottom, a pressure plate with one hole or many through holes is arranged on it, and fine mesh metal fibers are baked on the top. The thing of the structure which put the foreign material microfiltration filter comprised from the bound nonwoven fabric, and also arrange | positioned the foreign material dispersion | distribution filtration layer which consists of sand or metal powder on it is disclosed (for example, refer patent document 2).

  The function of the foreign substance dispersion filter layer is to remove coarse foreign substances in the molten polymer and coarse particles of added particles, and at the same time, effect of homogenization by subdividing the polymer flow and merging and mixing, and heat-denatured gel It is said that there is an effect of subdividing the polymerized polymer. In particular, if the heat-denatured gelled polymer has insufficient subdivision function, physical properties such as strength decrease occur during spinning, and yarn breakage is likely to occur, and defects such as fluff and knots occur during high-order processing. There was a problem to do.

Therefore, in order to improve the fragmentation function of the heat-denatured gelled polymer, attempts have been made to design a mesh layer that makes the mesh of the above-mentioned filtration layer finer, but in that case, the filtration pressure in the pack case is high. As a result, thread breakage increases, and the pack replacement cycle becomes faster.
JP 11-256420 A JP-A-7-090711

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and a polyamide that can reduce the spun yarn breakage rate by subdividing a heat-modified gelled polymer that could not be dispersed in a foreign matter-dispersed filtration layer. An object of the present invention is to provide a monofilament manufacturing method, a polyamide monofilament capable of improving high-order workability and product quality.

In order to achieve the above object, the following configuration is adopted.
(1) A spinning pack in which at least a base, a pressure plate, a metal wire filter, and a filter medium are laminated inside the pack case, and a metal having a substantially polygonal cross section between the metal wire filter and the sand filter medium. A method for producing a polyamide monofilament fiber, comprising spinning using a melt spinning die pack provided with a sintered filter of short fibers.
(2) The polyamide monofilament according to (1), wherein the sintered monofilament is spun using a spinneret pack having a filtration accuracy of 10 to 60 μ and an aspect ratio of short metal fibers of 10 to 100 A method for producing fibers.
(3) A polyamide monofilament fiber having a fineness of 8 to 66 dtex, a strength of 4.0 cN / dtex or more, an elongation of 30 to 50%, and a node of 10 pieces / 300 m or less.

According to the present invention, it is possible to subdivide the heat-denatured gelled polymer that could not be dispersed by the foreign substance dispersion filtration layer, to reduce the spinning yarn breakage rate, and to provide uniform polyamide monofilaments with no knitting yarns and fluff. It was.

  The present invention will be described in detail below.

  Polyamide fiber as referred to in the present invention includes polycapramide, polyhexamethylene adipamide, polydodecanoamide, polyhexamethylene azelamide, polyhexamethylene sebamide, polyhexamethylene dodecanoamide, polymetaxylylenadipamide, Examples include polyhexamethylene terephthalamide and polyhexamethylene isophthalamide. In particular, polycapramide (nylon 6) and polyhexamethylenadipamide (nylon 66) are preferable as the polyamide fiber for silk fabric.

  FIG. 1 is a longitudinal sectional view showing an example of a melt spinning base pack of the present invention. The melt spinning base pack includes an upper pack block 1 for introducing a molten polymer, an intermediate pack block 2 and a lower pack block 3 for spinning. It has the composition which consists of. The upper pack block 1 is provided with polymer introduction holes 4 for introducing the molten polymer into the pack. The intermediate pack block 2 is formed in a hollow cylindrical shape, and a filter medium 5 made of a powder fluid such as sand or metal powder called sand filter is provided in the hollow portion. The lower pack block 3 is provided with a projecting step portion 3a in a hollow cylindrical lower portion, and a base 8 having a plurality of polymer discharge holes 8a and a pressure plate 7 having a plurality of polymer passage holes 7a are mounted on the projecting step portion 3a. It has become the composition. The pressure plate 7 is disposed on the base 8 via a seal packing 10. A metal wire filter 6 is laminated on the pressure plate 7. The metal wire filter 6 is placed directly on the pressure plate 7.

  Further, a sintered filter 9 in which short metal fibers having a substantially polygonal cross section as shown in FIG. 4 are sintered is provided between the metal wire filter 6 and the filter medium 5 described above. The filter medium 5 is filled and arranged so as to be stacked on the sintered filter 9 in a state of being filled in the hollow portion of the intermediate pack block 2.

  As described above, the three-stage pack blocks 1, 2, 3 containing the base 8, the pressure plate 7, the metal wire filter 6, the sintered filter 9, the filter medium 5 and the like are integrally tightened with bolts (not shown). Assembled as a base pack.

  The foreign substance dispersion filtration layer, which is a filter medium 5 composed of a powder fluid such as sand or metal powder, removes coarse foreign substances in the molten polymer and coarse particles added, and at the same time, subdivides the polymer flow and mixes and mixes them uniformly. Although it is said that there is an effect of heat treatment and a heat-denatured gelled polymer, the filtration accuracy varies widely. In the case of a 46 mesh sand filter, it is generally said that the filtration accuracy is 40 to 70 μm. Therefore, it is thought that the removal of coarse foreign substances in the molten polymer and coarse particles of added particles are performed evenly to some extent, but heat-denatured gelled polymers cannot be subdivided due to large variations in filtration accuracy. There will be cases. In such a case, the heat-denatured gelled polymer has insufficient subdivision function, and changes in physical properties such as a decrease in strength occur during spinning, and yarn breakage tends to occur, and fluff easily occurs during high-order processing.

  However, even in such a case, by disposing a sintered filter having a substantially polygonal cross section between the metal wire filter 6 and the filter medium 5, the metal short fiber having no variation in filtration accuracy is dispersed in the foreign matter dispersion filtration layer. By subdividing the heat-denatured gelled polymer that has not been cut with a sintered filter having a substantially polygonal cross section, it is possible to reduce the yarn breakage rate and to improve the high-order workability. Moreover, when the filtration accuracy of the sintered filter in which the short metal fibers have a substantially polygonal cross section exceeds 60 μm, the dispersion function of the heat-denatured gelled polymer is lowered and the effect of reducing the yarn breakage rate is lowered. On the other hand, if it is less than 10 μm, the heat-denatured gelled polymer can be subdivided, but the filtration pressure in the pack case becomes high, and the productivity due to shortening of the pack replacement period is inferior. ~ 60μ is preferred. The filtration accuracy of 10 μ means that 95% or more of foreign matters having a size of 10 μ or more are removed. The filtration accuracy of 60 μ means that 95% or more of foreign matters having a size of 60 μ or more are removed.

  Examples of the metal wire filter include a depth filtration filter obtained by sintering and compressing a web obtained by opening a cotton-like web using a stainless steel fiber NASRON of micron order in a high temperature controlled atmosphere.

  The sintered filter is a filter obtained by laminating and sintering substantially polygonal short metal fibers produced by the chatter vibration cutting method, and the aspect ratio (length L / diameter D) is composed of a group of 10 to 100 short metal fibers. Are preferred. When the aspect ratio is less than 10, the entanglement becomes insufficient, so that the dispersion resistance is weakened, and when the molten polymer is pressed into a drop, it moves under a fluid pressure and easily forms a recess. Because it becomes. If the aspect ratio exceeds 100, the entanglement is good, but it is not preferable because it becomes a lump and the density becomes non-uniform, or the rigidity becomes poor and a recessed portion is easily formed by fluid pressure. More preferably, the aspect ratio is 15 to 70.

The substantially polygonal shape may be any shape having an acute cross-sectional shape as shown in FIG. The heat-modified gelled polymer can be subdivided with an acute cross-sectional shape.
The polyamide monofilament fiber of the present invention needs to have a fineness of 8 to 66 dtex. When it is less than 8 dtex, the tearing strength in the case of a woven fabric is low and the durability for use becomes poor. On the other hand, when it exceeds 66 dtex, the yarn-making property is deteriorated due to insufficient cooling when spinning the polyamide monofilament. Preferably it is 8-44 dtex.

  The polyamide monofilament fiber of the present invention needs to have a strength of 4.0 cN / dtex or more. When it is less than 4.0 cN / dtex, the tear strength when it is made into a woven fabric is low, and the durability for use becomes poor. The polyamide monofilament of the present invention needs to have an elongation of 30 to 60%. When the elongation is less than 30%, there are many yarn breaks and the yarn-making property is deteriorated. When the elongation exceeds 60%, the strength becomes 4.0 cN / decitex or less, and the tear strength in the case of a woven fabric becomes low, resulting in poor use durability.

  The polyamide monofilament fiber of the present invention needs to have 10 nodes / 300 m or less. If the number of nodes exceeds 10 pcs / 300 m, for example, when used for printing, clear printing cannot be performed, and the quality at the time of selection does not satisfy the requirements.

  The production method of the polyamide monofilament fiber of the present invention is not particularly limited, for example, by providing a polyamide for a melt spinning pack and providing a sintered filter in which short metal fibers have a substantially polygonal cross section inside the pack, After heat-denatured gelled polymer that could not be dispersed in the foreign material dispersion filtration layer was subdivided with a sintered filter having a substantially polygonal cross section, it was melt-spun from the nozzle hole, cooled, and in a sufficiently cooled position After applying the oil agent, after being taken up by the take-up roll (first godele roll), wound around the heated drawing roll (second godele roll) and stretched between the first godele roll and the second godele roll, and subjected to heat treatment, A one-step method that is wound up as a drum package is common. Alternatively, the polyamide may be applied to a melt spinning pack, melt spun from a die hole, cooled, and after applying an oil agent at a sufficiently cooled position, it may be wound once and then stretched.

  Although the use of the polyamide monofilament of the present invention is not particularly limited, the koji fabric woven from monofilaments called screen koji is used for screen koji printing applications, filter applications, speaker filter applications, and the like.

Next, the present invention will be specifically described with reference to examples. In addition, the measurement of the characteristic value in an Example was performed as follows.
A. Spin yarn breakage The number of yarn breakage during spinning per t was counted.
B. Yarn spots were measured using a Worcester thread spot measuring device (USTER TESTERI, manufactured by ZELLWGER), and judged according to the following criteria. The yarn unevenness was measured normally at a yarn speed of 200 m, and the number of whisker-like fluctuations more than 4 times the average value was counted on a chart per 1000 m of yarn length, and judged according to the following criteria. ○: No whisker-like variation, Δ: Whisker-like variation 0 to 2 pieces, ×: Whistle-like variation 3 or more Examples 1 to 5, Comparative Examples 1 and
In the spinneret pack of the present invention shown in FIG. 1, the short metal fibers have a substantially polygonal cross section, and the filtration accuracy of the sintered filter 9 having an aspect ratio of 30 is 8 μ (Example 1), 10 μ (Example). 16) 16 packs each having 2), 40 μ (Example 3), 60 μ (Example 4), and 70 μ (Example 5) were prepared. That is, 16 packs with different filtration accuracy were prepared for each level, and the filtration accuracy was changed by replacing the packs. In the conventional melt spinning pack shown in FIG. 2, the short metal fibers have a substantially polygonal cross section and the sintered filter 9 is not used (Comparative Example 1). Sixteen packs (Comparative Example 2) each provided with a sintered filter 9 in which short metal fibers having an accuracy of 40 μ and having a substantially polygonal cross section were prepared. In addition, the filtration accuracy of the metal wire filter 6 used for each was decided to be 10 μm.

  Using these melt spinning die packs, 98% sulfuric acid relative viscosity 2.8 nylon 66 containing 0.3% by weight of titanium oxide was melted at 290 ° C. and then used in the melt spinning die pack. It was discharged, cooled, stretched at 4.6 times, heat treated at 170 ° C., and wound as a drum-shaped package at a winding speed of 1500 m / min to obtain 44 dtex nylon 66 monofilament fiber.

  Table 1 shows the results of evaluating spun yarn breakage and yarn unevenness for the obtained fibers.

表１から明らかなように、本発明の製造方法から得られるナイロン６６モノフィラメント繊維は、糸切れが少なく、品位も良好であった。

As is clear from Table 1, the nylon 66 monofilament fiber obtained from the production method of the present invention had little yarn breakage and good quality.

It is a longitudinal cross-sectional view which shows the nozzle pack for melt spinning of this invention. It is a longitudinal cross-sectional view which shows the conventional die cap for melt spinning. It is a longitudinal cross-sectional view which shows the nozzle pack for melt spinning using the baffle plate as a filter medium. It is sectional drawing of a short metal fiber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Upper pack block 2: Intermediate pack block 3: Lower pack block 3a: Protruding step part 4: Polymer introduction hole 5: Filter medium 6: Metal wire filter 7: Pressure plate 7a: Pressure plate polymer passage hole 8: Base 8a: Base Discharge hole 9: Sintered filter in which short metal fibers have a substantially polygonal cross section 10: Packing

Claims (3)

A spinning pack in which at least a base, a pressure plate, a metal wire filter, and a filter medium are stacked inside the pack case, and a metal short fiber having a substantially polygonal cross section between the metal wire filter and the sand filter medium. A method for producing a polyamide monofilament fiber, comprising spinning using a spinneret pack provided with a sintered filter. 2. The method for producing a polyamide monofilament fiber according to claim 1, wherein spinning is performed using a melt spinning base pack in which the filtration accuracy of the sintered filter is 10 to 60 [mu] and the aspect ratio of the short metal fiber is 10 to 100. . A polyamide monofilament fiber having a fineness of 8 to 66 dtex, a strength of 4.0 cN / dtex or more, an elongation of 30 to 50%, and a node of 10 pieces / 300 m or less.

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