JP4441106B2 - Biodegradable bath towel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bath towel that can be suitably used with a soft feel for dirt and the like, and can be biodegraded after use with compost or the like and has excellent discardability.
[0002]
[Prior art]
Conventionally, bath towels are broadly divided into soft types that use spun yarns, mainly cotton yarn, and hard types that use long fibers of synthetic fibers such as nylon. Yes.
Among the above, the soft type has the advantage that the touch when washing the body is soft and does not damage the skin, but the friction with the skin is too little to remove fine dirt clogged in pores etc. In order to make it foam enough, it was uneconomical in that a large amount of detergent such as soap was consumed.
On the other hand, the hard type is easy to remove dirt on the skin, consumes less cleaning agent, and is excellent in durability, but the rigid intuition of the synthetic fiber that is the material used stimulates the skin excessively, It is avoided from people with sensitive skin and women, and the material itself does not decompose naturally, and the amount of heat generated during combustion is large and toxic gases are easily generated.
[0003]
[Problems to be solved by the invention]
The present invention eliminates the disadvantages of the conventional bath towels as described above, has an excellent detergency to remove dirt on the skin, is gentle to the skin, and has a property of decomposing naturally, and is therefore environmentally friendly when discarded. It is an object to provide a bath towel that does not give a load.
[0004]
[Means for solving the problems]
In order to solve the above problems, the present inventors have studied using various biodegradable fibers, and as a result, in order to prevent oblique deformation when knitted fabric, a crimp with less swirlability is used. It has been found that polylactic acid is suitable as a material to be knit / denited for that purpose, and further, a multifilament yarn of polylactic acid having such a crimp is warped. As a result, it was found that a rugged surface having elasticity was born on the surface, and a toweling cloth that gave an appropriate stimulus to the skin was obtained, and the present invention was completed.
[0005]
That is, the gist of the present invention is as follows.
1. A bath towel using a warp knitted fabric formed of yarns made of biodegradable fibers, wherein 50 to 100% by mass of the yarns made of biodegradable fibers has a boiling water shrinkage of 3% or less. A bath towel, characterized in that it is a multifilament yarn made of polylactic acid fiber, and the multifilament yarn made of polylactic acid fiber is a yarn having a crimped shape in the longitudinal direction by knit / denit processing .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
From the viewpoint of disposal after use, the bath towel of the present invention needs to be made of yarn made of biodegradable fibers (hereinafter sometimes abbreviated as biodegradable yarn). As biodegradable fibers, natural fibers such as cotton, cellulosic fibers such as rayon, and biodegradable thermoplastic resin fibers such as polylactic acid can be used. As the biodegradable thermoplastic resin, an aliphatic polyester resin that is biodegradable through hydrolysis is preferable, and among them, an aliphatic polymer synthesized from a diol component and a dicarboxylic acid component is particularly suitable. , Polyalkylene alkanoates, poly β-hydroxy alkanoates and copolymers thereof, and specifically, polylactic acid is most preferably used.
[0007]
The bath towel of the present invention is made using a warp knitted fabric, and the biodegradable yarn forming the warp knitted fabric includes a multifilament yarn made of polylactic acid fiber, and the yarn is in the longitudinal direction. It is necessary to have a crimp shape and to be non-swirl or weakly swivel. Since the yarn has a crimp shape in the longitudinal direction, an elastic undulation surface is formed on the surface of the warp knitted fabric formed using the yarn, thereby embodying a detergency that removes dirt on the skin. In addition, since the yarn is non-swirl or weakly swirl, the warp knitted fabric formed using the yarn does not cause skew deformation.
In addition, the non-turning property or weak turning property in the present invention is defined as follows. That is, as shown in FIG. 1, a loop 1 having a length of about 1 meter is folded in two to form a loop 1 having a closed end, and a weight 2 having a predetermined mass (number of decitex of the thread × 0.1 g) is hooked on the loop. The number of twists per 50 cm generated in this case (the number of twists is 2 in the case of FIG. 1) is defined as the turning index. And a thing with a turning index of 0 is called non-turning ability, and a thing with 1-15 is called weak turning ability. In a warp knitted fabric formed using a swirling yarn having a swirling index exceeding 15, the shape is liable to be damaged by skew deformation, and the handleability as a bath towel is deteriorated. Preference is given to using non-swivel yarns.
[0008]
Further, the filament cross section of the multifilament yarn made of polylactic acid or other biodegradable fibers is not particularly limited, and may be any cross sectional shape such as a round cross section, a multi-leaf cross section, a flat cross section, and a hollow cross section. A plurality of types having different cross-sectional shapes may be mixed.
[0009]
In the present invention, it is particularly important that the multifilament yarn having a crimp shape in the longitudinal direction and having non-swirl or weak swirl is made of polylactic acid fiber. Non-swivel crimps can be obtained by knit / denit processing, which will be described later, but depending on the type of fiber, crimping does not occur even if such processing is performed, or even if crimping occurs, it can be easily done by external force etc. This is because the crimps often disappear, and the melting point is low, so that it cannot be processed. As a result of studying various fibers, the present inventors have given that a polylactic acid fiber having a melting point of 120 ° C. or higher provides a continuous non-swirl crimp by a knit / denit process among biodegradable fibers. It has been found that it is the most suitable fiber to make it.
Another reason for using polylactic acid fiber is the moderate rigidity of polylactic acid. That is, by using polylactic acid, the elastic undulating surface formed on the warp knitted fabric surface described above has a cleaning power for removing dirt on the skin, and may cause excessive skin irritation and damage. Without giving a comfortable massage effect.
[0010]
In addition, the boiling water shrinkage of the multifilament yarn made of the polylactic acid fiber is preferably 3% or less, and more preferably 2% or less. When the bath towel of the present invention is used in a bathhouse, it may be immersed in hot water. However, when the boiling water shrinkage rate exceeds 3%, the yarn shrinks due to the action of hot water, and warp knitting. The space between the loops of the ground or between the filaments may be lost, and it is not preferable because the foaming property tends to deteriorate when soap or the like is foamed with a bath towel.
[0011]
Moreover, as a ratio for which the multifilament yarn which consists of said polylactic acid fiber among the biodegradable yarn which forms the bath towel of this invention, it is necessary to be 50-100 mass%, and 75- 100 mass% is preferable. If the ratio is less than 50%, the effect of using the yarn cannot be obtained.
In addition, the performance and biodegradability such as a feeling of use can be changed by mixing other biodegradable yarns other than the multifilament yarns composed of the polylactic acid fibers described above. For example, by using flat yarn, side-by-side conjugate yarn, interlaced entangled yarn that is not crimped, or spun yarn such as cotton and rayon as other biodegradable yarn, touch, foamability, detergency, etc. The practical performance can be changed.
[0012]
The polylactic acid fiber used in the present invention has biodegradability, but since it is a kind of polyester, it has a property of hydrolyzing, and as its decomposition behavior, hydrolysis proceeds to some extent. Is characterized in that biodegradation by microorganisms is accelerated and finally changes to water and carbon dioxide. That is, biodegradation is efficiently performed by allowing hydrolysis to proceed preferably in an environment of a temperature of 55 ° C. or higher and a humidity of 65% or higher.
Therefore, the bath towel of the present invention containing 50% by mass or more of polylactic acid fiber starts to hydrolyze polylactic acid when placed in a high-temperature and high-humidity environment, and biodegradation by microorganisms continues over time after a certain period of time. Proceed to.
When biodegradation is performed, it may be left in compost or soil where bacteria and the like are propagated. However, by using a composting machine in which temperature and humidity can be set, efficient treatment becomes possible.
[0013]
Next, a preferred method for producing the bath towel of the present invention will be described.
First, in order to obtain a multifilament yarn made of polylactic acid fiber, having a crimp shape in the longitudinal direction and having non-swirl properties, knit / denit processing is performed. That is, a multifilament yarn made of polylactic acid fibers is continuously knitted into a tubular shape, and this tubular knitted fabric is treated with hot water at about 100 ° C., then dried and then knitted. As a result, a non-swivel crimp is formed as a yarn formed in the longitudinal direction (hereinafter abbreviated as knit / denit processed yarn). At this time, in order to set the boiling water shrinkage of the knitted / denited yarn to 3% or less, the knitting density at the time of knitting into a cylindrical shape is increased to increase the shrinkage during the hot water treatment. preferable.
[0014]
Subsequently, a warp knitted fabric is knitted by a known method using the above-described knit / denit processed yarn and, if necessary, other yarns, and the resulting towel is sewn appropriately to obtain the bath towel of the present invention. .
In addition, as a method of dyeing the bath towel of the present invention, in the case of using 100% polylactic acid fiber, it can be dyed at a temperature of 90 to 110 ° C. using a disperse dye, and includes other biodegradable fibers. In this case, one bath or a plurality of baths may be dyed together with a dye suitable for the fiber.
[0015]
【Example】
Next, an Example is given and this invention is demonstrated concretely.
Example 1
Polylactic acid (melting point: 172 ° C., average molecular weight: 140,000) containing 99.3% of poly-L lactic acid is melt-spun by a conventional method, followed by drawing to obtain a multifilament yarn made of polylactic acid (560 Decitex / 96 filament). Using this multifilament yarn, a continuous tubular knitted fabric was knitted by a tubular knitting machine (cylinder diameter 10.16 cm, number of needles 120). Next, the knitted fabric was hydrothermally treated in hot water at 95 ° C. for 30 minutes, dried and then subjected to deknitting and knitting to obtain a knit / denit processed yarn having a boiling water shrinkage of 1.2%. .
Using the above knitted and knitted yarns, a net-shaped warp knitted fabric (25 cm wide) is produced by combining chain knitting and inlay knitting using an 8-gauge double-sheet raschel knitting machine. After cutting, the end in the longitudinal direction was sewn to produce the bath towel of the present invention.
When the bath towel of the present invention obtained as described above was used, creamy and abundant foaming was obtained even when the amount of soap and body shampoo used was small, and moderate slipping between the skin and the skin There was a feeling and was comfortable, and it was also excellent in the scouring effect.
Furthermore, although it was used for 1 month as a bath, it was able to be used comfortably with no particular deterioration in performance. When the material used for one month was put into a composting machine (set temperature 58 ° C., set humidity 70%) using soil fungi, 90% decomposed and disappeared in about 10 days.
[0016]
【The invention's effect】
The bath towel of the present invention has a feature that it has a comfortable elasticity to remove dirt on the skin and does not excessively irritate the skin because it has an uneven surface with moderate elasticity. In addition, it is a bath towel excellent in practicality that can provide abundant creamy foaming only by using a small amount of soap or the like.
In addition, when it is discarded after the end of its service life, even if it is decomposed into harmless substances in the soil or in a composting machine or incinerated, the calorific value is small and almost no harmful gas is generated. Therefore, the load on the environment is extremely small.
Moreover, according to the manufacturing method of this invention, such a bath towel can be manufactured simply.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a method for examining the presence / absence of turning of a yarn used in the present invention.
[Explanation of symbols]
1. Yarn loop 2. Weight 3. hook

Claims (1)

A bath towel using a warp knitted fabric formed of yarns made of biodegradable fibers, wherein 50 to 100% by mass of the yarns made of biodegradable fibers has a boiling water shrinkage of 3% or less. A bath towel, characterized in that it is a multifilament yarn made of polylactic acid fiber, and the multifilament yarn made of polylactic acid fiber is a yarn having a crimped shape in the longitudinal direction by knit / denit processing .

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