JPH0515814B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a cut pile carpet made of thermoplastic synthetic fiber intended for use in Persian carpets, curtains, etc. <Prior art> Persian rug using fine-count wool worsted yarn,
Dantsu carpets, Wilton carpets, etc. have very clean grains and firm textures, and together with their distinctive color patterns, they are ranked as the highest quality carpets. This is largely due to wool's high elasticity, special cross-sectional shape, curl-like crimpability, and blend of different deniers, and also due to the convergence due to the twist peculiar to worsted yarns and the pinpoint feel due to the use of fine count. However, everyone would like to realize the high quality inherent in these natural fibers in tufted carpet made from thermoplastic synthetic fibers, but in reality, there has been no attempt to do so because of the huge disparity between the two. . <Objective of the Invention> An object of the present invention is to provide a cut-pile carpet that can be substituted for conventional high-quality carpets with inexpensive thermoplastic synthetic fibers at a low cost. A further object of the present invention is to provide a worsted cut pile carpet that is rich in compression and recovery elasticity, has good durability, has fine pencil points, and is capable of expressing a clear printed pattern. <Structure of the Invention> According to the present invention, in a cut pile carpet made of thermoplastic synthetic fibers, the number of crimped threads of thermoplastic synthetic fibers that simultaneously satisfy the following conditions (a) to (b) as pile threads is reduced. A worsted carpet is provided which is characterized by a pile density of 10 piles per inch. (a) It has at least one hollow part in its cross section, and has a plurality of protrusions extending radially outward from the center of the fiber cross section. (b) Two to three crimped yarns with a single fiber denier of 5 to 25 de and a total denier of 400 to 1000 de are twisted together and heat-set with top and bottom twists of 200 T/m or more each. . The configuration of the present invention will be explained in detail. First, thermoplastic synthetic fibers include polyamide (nylon-6, nylon-66, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polypropylene, etc., but they are soft and durable for carpet yarn. Polyamides are particularly good. On the other hand, the cross section has at least one hollow space and at least two protrusions extending outward from the center of the cross section, a typical example of which is shown in FIG. In the figure, 1 is the main body part, 2 is a hollow part, and 3 is a lobe. In this case, the number of hollow parts 2 should be in the range of 1 to 5, but the total hollowness ratio is 5 to 40.
%, especially 10-25% is preferred. In addition, the number of protrusions may be 2 or more, preferably 3 to 5, and the size may be determined based on the degree of irregularity.
It should be around 1.1 to 3.0. As shown in Figure 2, the length of the protrusion can be quantitatively determined by the degree of irregularity determined by the ratio (R/r) of the diameter r of the inscribed circle of the main body and the diameter R of the circumscribed circle touching the tip of the protrusion. is shown. Moreover, three-dimensional random crimp is preferable as the crimp, and the crimp rate is preferably about 4% to 15%.
If the crimp rate is too low, the bulkiness will be lost, while if it is too high, the felt will be too felt and the quality will be lost. Here, the crimping process is performed by depositing yarn plasticized by heated fluid in a pad or wad shape in a heated fluid processing nozzle that has excellent high-speed processability. The method of applying the yarn (U.S. Pat. No. 4,188,691, U.S. Pat. No. 4,268,940, Japanese Patent Publication No. 56-37339), after taking out the yarn plasticized by heated fluid in the nozzle as a loop yarn and cooling it. Drafting and opening method (U.S. Pat. No. 3,186,155, U.S. Pat. No. 3,543,353) The yarn is plasticized by heated fluid in the nozzle and is buckled and deposited on an air-permeable collision surface. A method of cooling and then taking it out (U.S. Patent No.
3255508, British Patent No. 1273797)
will be adopted. Further, the crimp rate (total crimp rate; TC) follows the definition below. A certain length of crimped thread is taken out, left in a free state, crimped in boiling water for 30 minutes, and then dehydrated.
Air dry for one day and night under standard conditions, then apply 0.1
Apply a load of g/de, measure the length l ₂ after 1 minute,
Next, after leaving it free for 3 minutes, the length l 3 after 1 minute was measured under a load of 2 mg/de, and the length l ₃ was calculated from these measured values using the following formula. Crimp ratio (TC)=l ₂ −l ₃ /l ₂ ×100 (%) The single fiber denier of this crimped yarn is preferably 5 to 25 de (preferably 5 to 20 de). If it is less than 5 de, the carpet will be too soft and lose its elasticity, while if it exceeds 25 de, the carpet will become coarse and hard and lose its texture as wool. In this case, a denier density yarn may be used, and in that case, the average denier should be in the range of 5 to 25 de. In addition, the total denier is 400 to 1000 de, especially 400 to 1000 de, to express the fine count high quality worsted feel.
Approximately 800 de is preferable. In addition, in order to create the same pencil point feel as worsted yarn, it is necessary to align two or three of the crimped yarns and apply top twist/first twist depending on the denier. For example, in the case of nylon 6 700de/56fil 2ply, it is necessary to apply at least 200Z/200S top/bottom twist, preferably 230~
Apply top/bottom twist of 290Z/230 to 270S. Further, the twist is sufficiently set using moist heat so that twisting torque and untwisting are eliminated. nylon 6
In this case, a suitable example can be achieved by heat setting for 5 minutes with saturated steam at 127°C. Such pile yarns may be made into carpets by looming or hand-weaving, but in order to produce them industrially at low cost, it is desirable to use a tufting machine. Especially in this case 1/
A fine gauge tufting machine of 10 gauge or less, preferably 5/64 gauge or less, is used to create a dense carpet. In other words, if the gauge of the tuft is rough, the grain surface will be rough and will not be close to the quality of a dantsu style carpet. Further, the pile yarn may be dyed with a solid color, but if a color pattern similar to that of a Persian carpet is applied using a computer jet dyeing machine, a more luxurious look will be created. <Operation of the Invention> The present invention is based on extensive research aimed at analyzing the causes of the high quality image and high texture of the above-mentioned dansu carpets, Persian carpets, Wilton carpets, etc., and replacing them with tufted carpets made of thermoplastic synthetic fibers. It was completed based on the results, and its functions are as follows. First of all, although wool worsted yarn has a high Young's modulus and convergence (pinpoint feeling) due to twisting, the pile has a swell, giving it a bulky and firm texture. It is very difficult to replace this with thermoplastic synthetic fibers, and even if you twist a simple ○ cross-section yarn, trilobal yarn (〓), or a simple hollow fiber (◎, 〓), it will not work if the cross-section is ○ or 〓. Although it gives a pinpoint feel, the pile lacks swelling and does not give a bulky or waist texture. On the other hand, if the trilobal cross section (〓) has a high degree of irregularity, it will have bulkiness, but the pile will be rough, lack pinpoint quality, and result in a low-quality carpet with a dirty surface. Therefore, it was extremely difficult to simultaneously satisfy pinpoint convergence, firm texture, and bulging pile. As a result of various studies, we found that by using hollow fibers, the bulkiness of the hollow part does not disappear even when a high number of twists are applied, and by making the fibers hollow, it is possible to improve the moment of inertia ( ), which increases bending hardness. It was found that the elasticity (EI) increased and a firm texture could be created.

[Table] Same denier for both Hollow rate = 20%
However, this alone is not enough to create a wool-like texture. As a result of various studies on this point, I came up with the idea of adding protrusions on the outside of the cross section to correspond to the scale of wool, and after further consideration, I found that adding protrusions would also increase the moment of inertia ( ). It was also found that the bending stiffness (EI) also increased, making it bulkier and giving it a firmer texture. It has also been found that the hollow portion undergoes plastic deformation during twist setting to enhance the setting effect and to significantly improve pencil pointability. However, it has been found that increasing bulkiness by using only projections results in coarse hardness, poor pile convergence, and poor grain surface.

[Table] When we combined these methods and added protrusions as shown in Figure 1 to the hollow cross-section yarn, we found that even when twisted, the pile swelled much more than expected due to the synergistic effect of the hollow section and the protrusions. It was found for the first time that a carpet with a beautiful pin-point feel can be obtained because the point feeling due to the twist remains. In addition, due to the synergistic effect of the increase in the second moment of area due to the hollow space and the increase in the second moment of area due to the increased degree of irregularity due to the protrusion, the compressive elasticity of the carpet becomes very close to that of wool.
It was discovered that high quality carpet with a firm texture can be obtained. Even if either the protrusion or the hollow is missing, the above-mentioned special wool-like texture cannot be obtained. In other words, they discovered that wool's high Young's modulus, special cross section (〓), and scale can be replaced by a completely different combination of hollows and protrusions. The fiber itself used in the present invention has already been described in JP-A-62-45710 and JP-A-61-89314. However, these only disclose flat yarn (raw silk) with excellent bulk and antifouling properties, and do not disclose anything about the use of yarn [requirement (b)] or pile density as in the present invention. Not yet. <Effects of the invention> By optimizing the cross-sectional shape of the thermoplastic synthetic fiber by combining hollows and protrusions, and by combining the denier, number of single yarns, number of top/bottom twists, setting conditions, etc., efficient fine gauge can be achieved. By constructing the carpet using a tufting machine, a carpet similar to high-grade dantsu can be provided at a very low cost. <Example> Example 1 Nylon-6 having a cross section as shown in Table 1
The raw yarn was supplied to a crimping nozzle shown in Figure 1 of Japanese Patent Publication No. 56-37339 and subjected to heated fluid injection processing to obtain a crimped yarn with a crimp ratio of 12 to 13%. Next, each crimped yarn was twisted and set under the twisting and setting conditions shown in Table 2. Thereafter, the above-mentioned twisted yarn was tufted according to the tufting conditions shown in Table 3, and the quality of the cut pile carpet is listed in Table 1.

[Table] Things.
Table 2 Twisting - 2ply Number of twists (top twist/bottom twist) Comparative example 1 210Z/210S Comparative examples 2 to 5, inventions 1 to 2 250Z/250S Setting conditions - Setting temperature 127°C with super bass setting machine

[Table] As shown in the above examples, only the examples 1 and 2 of the present invention whose cross-sectional shape and denier satisfy the conditions of the present invention have the pencil point feel, bulk, elasticity, and durability required for high-grade carpets. It turns out that everything is satisfied. On the other hand, if a yarn having a cross section of only hollow portions or only protruding portions is used, a carpet of desired quality cannot be obtained. Example 2 The denier and number of twists of the raw yarn having the cross section of No. 2 (Example 1) of the present invention were changed as shown in Table 4, and tufting was performed with a 1/10 gauge tufting machine at a basis weight of 1250 g/m ² . When similar evaluations were made, it was found that those with a thick denier did not have a high-quality pencil paintability and were poor, and those with a twist number of 200 T/m or less did not have pencil point properties and were felt-like and were poor.

【table】 [Brief explanation of the drawing]

FIG. 1 shows a fiber cross section of the carpet yarn used in the present invention, and FIG. 2 is an explanatory diagram of the degree of irregularity. 1...Body portion, 2...Hollow portion, 3...Protrusion, r...Inscribed circle diameter in fiber cross section, R...
Circumscribed circle diameter in fiber cross section.

Claims (1)

[Claims] 1. In a cut pile carpet made of thermoplastic synthetic fibers, the following conditions (a) to
A worsted carpet characterized in that crimped thermoplastic synthetic fiber yarns satisfying (b) are arranged at a pile density of at least 10 yarns/inch. (a) It has at least one hollow part in its cross section, and has a plurality of protrusions extending radially outward from the center of the fiber cross section. (b) Two to three crimped yarns with a single fiber denier of 5 to 25 de and a total denier of 400 to 1000 de are twisted together and heat-set with top and bottom twists of 200 T/m or more each. .