JPS627300B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is easy to handle during finishing processing,
The present invention also relates to a polyester fiber knitted fabric that has a soft feel and good anti-pilling properties. Conventionally, knitted fabrics knitted using single spun yarns have been known to have serious problems during finishing, such as curling of the ends of the knitted fabric or skewed stitches due to the torque possessed by the yarn and the torque generated during knitting. It's summery. When a warp knitted fabric such as a half-tricot knitted fabric or a cylindrical circular knitted fabric is cut into a flat shape, the edges of the knitted fabric are rounded from the gray state, and this degree of curling is further promoted by scouring. Therefore, when going through a subsequent process such as heat setting, there are measures to improve workability, such as adding glue to the ends and making only those parts flat, and making the knitting work skewed. The work efficiency is significantly reduced because it takes a lot of effort for the worker to straighten the material and feed it to the heat setting process. In addition, when the blending ratio of polyester fibers is high and a particularly soft texture is desired, various complicated methods such as blending multiple polyester fibers to create bulk or mixing fibers with small fineness may be used. Efforts have been made. Furthermore, various anti-pilling measures have been taken during fiber manufacturing or at the post-processing stage, but most of them degrade other properties, and there are no anti-pilling measures that can improve other properties as well. Not many pill fibers are found. An object of the present invention is to provide a knitted fabric containing spontaneously extensible polyester fibers that is easy to handle during finishing, has a soft feel, and is less likely to cause pilling. That is, the present invention is a knitted fabric using spun yarn with a twist coefficient of 2.5 or more in the state of a single yarn, which is heated at a temperature of 180°C.
Spontaneous extensibility polyester fibers elongated by 4% or more by dry heat treatment, and the reduction rate of elongation at break due to the heat treatment is 10% to 50%.
A polyester fiber knitted fabric characterized by being knitted with spun yarn containing 80% by weight. However, the above twist coefficient is α: Twist coefficient T: Number of twists (turns/inch) Ne: Given by wire number. The present invention will be explained in detail below. The knitted fabric of the present invention is knitted using spun yarn with a twist coefficient of 2.5 or more. If the twist coefficient is less than 2.5, the texture of the knitted fabric will be poor and a satisfactory product cannot be obtained, and the yarn structure will be loose and pilling cannot be prevented. Therefore, knitted fabrics using spun yarn require yarn with a twist coefficient of 2.5 or more. Next, the spun yarn contains 40 to 80% of the total amount of spontaneously extensible polyester fibers. If the blending ratio of the spontaneously extensible polyester fibers is less than 40%, even in the case of gray fabrics, further scouring will make the fabric stronger and the ends of the knitted fabric will not be sufficiently prevented from curling. Furthermore, if the blending ratio exceeds 80%, the amount of spontaneously elongated fibers will increase, resulting in a knitted fabric with a stiff texture, which is not preferable. The above spontaneously extensible polyester fiber can be spontaneously elongated by 4% or more by heat treatment at a dry heat temperature of 180°C,
Moreover, the rate of decrease in elongation at break before and after the heat treatment is
It is necessary to be between 10% and 50%. In general, the structure and physical properties of spontaneously extensible fibers depend not only on the heat treatment temperature but also on the heat treatment time, so the above physical property values are based on the time required for the fiber structure to stabilize, i.e. 10 to 30 minutes. This is the value after processing. That is, this spontaneous elongation rate must be 4% or more due to heat treatment at 180°C, and if it is less than 4%, the effect of reducing the twisting torque due to spontaneous elongation cannot be obtained. However, the above-mentioned spontaneously extensible polyester fiber can be obtained, for example, by the following method. That is, the spontaneously extensible polyester fibers used in the present invention are generally obtained by subjecting fibers with potentially high shrinkage performance to a relaxation heat treatment to cause at least 20% shrinkage. An undrawn polyester fiber bundle having a ratio Δn of 0.02 to 0.08 is drawn at a temperature below [glass transition point +20° C.] at the following draw ratio (DR). 0.04/Δn+0.7≦DR≦0.04/Δn+1.1 Next, it can be obtained by performing a relaxation heat treatment at a temperature of 100°C to 140°C. The spontaneously extensible polyester fiber obtained by the above method has an irreversible elongation rate of 4% or more when subjected to heat treatment at a dry heat temperature of 180°C. Note that the production of the spontaneously extensible polyester fiber used in the present invention is not limited to the above method. Furthermore, the spontaneously extensible polyester fiber obtained here has its breaking elongation reduced by the above heat treatment.
This is a 10-50% decrease. Table 1 shows an example of spontaneously extensible polyester fibers obtained by the above method.

[Table] As explained above, the knitted fabric of the present invention uses spun yarn with a twist coefficient of 2.5 or more in a single yarn state,
This is a knitted fabric, but the spun yarn contains 20 to 80% by weight of the entire yarn of spontaneously extensible polyester fibers that elongate by 4% or more when subjected to dry heat treatment at a temperature of 180°C. Since it is possible to elongate the polyester fibers and thereby reduce the twisting torque of the spun yarn, it is possible to eliminate the curling up of the ends of the knitted fabric of the present invention. The fibers to be blended may be ordinary polyester fibers or any other fibers. Furthermore, in the above blended yarn, the structure of the spun yarn becomes loose due to the spontaneously elongated polyester fibers (that is, the structure of the spun yarn forming the knitted fabric becomes loose, and within the spun yarn, the single fibers become loose). (makes it easier to exercise). Therefore, a knitted fabric with a soft texture and fullness can be obtained without using high shrinkage fibers or conjugate fibers. Furthermore, even with such a loose structure, the pilling characteristics can be maintained to a level that is sufficient to withstand use by heat-treating the breaking elongation of the spontaneously extensible polyester fiber to reduce the elongation at break by 10 to 50%. We were able to improve this. The knitted fabric obtained according to the present invention is achieved by heat-treating the spun yarn or fabric, but the heat treatment conditions require a temperature that exhibits spontaneous elongation, and in wet heat, the temperature is 100°C or higher. , in dry heat
A temperature of 150℃ or higher is required. More preferably, moist heat
It is best to carry out at a temperature of 120°C or higher, dry heat 170°C or higher. The heat treatment process is most preferably carried out in the form of yarn, i.e., in the form of a cot in the spinning process or in the form of a cone or cheese in the winding process, but after knitting, The knitted fabric can also be partially heat-treated using an iron or the like. In the knitted fabric obtained in the above manner, once the spontaneously extensible polyester fibers are elongated by heat treatment and the twisting torque is eliminated, the structure of the fabric becomes stable and the phenomenon of the edges of the knitted fabric being curled up is eliminated. The texture is kept soft and the pin resistance is good. Table 2 shows that an Amagasa is knitted using spun yarn containing spontaneously extensible polyester fibers that has been heat-treated with steam at 120°C for 30 minutes in the form of a cheese, and is cut open at the center during finishing. The degree of curling of the ends of the knitted fabric, the texture after finishing, and the pilling characteristics were investigated. Experiment 1 is an example in which spontaneously extensible polyester fibers with a fineness of 1.5 denier are used, and Experiment 2 is an example in which spontaneously extensible polyester fibers with a fiber size of 3.0 denier are used. On the other hand, in Experiment 3, the reduction rate of elongation at break due to heat treatment was relatively small at 7%, and in this case, the curling of the cut-out knitted fabric ends was not large. It is not improved and the pilling characteristics are also poor. Experiment 4 was an example in which ordinary anti-pilling type polyester fibers and 100% spun yarn with a fineness of 1.5 denier were used for comparison, and although the pilling properties were good, the edges of the knitted fabric curled, and This made handling during finishing extremely complicated.

【table】

[Table] Instead of the jersey used in Table 2, a warp knitted half-tricot was knitted and evaluated in the same manner as in Table 2. In other words, spun yarn containing spontaneously extensible polyester fibers is processed into a cheese shape using steam at a temperature of 120°C.
A half tricot was knitted using this yarn after heat treatment for 30 minutes, and the state of the rolled ears was evaluated. Table 3 shows the results. Experiment 5 shows that the ears are rolled up;
Pilling was good in both cases, but those in Experiment 6 had poor pilling properties, and those in Experiment 7 had poor ear curling.

【table】

【table】

Claims (1)

[Claims] 1 A knitted fabric using spun yarn with a twist coefficient of 2.5 or more in the form of a single yarn, where the spun yarn is elongated by 4% or more by dry heat treatment at a temperature of 180°C, and the elongation at break is reduced by the heat treatment. A polyester fiber knitted fabric characterized by containing 40 to 80% by weight of the entire yarn of spontaneously extensible polyester fibers having a ratio of 10 to 50%.