JPS6224521B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a split yarn made of thermoplastic synthetic resin, having a large number of fluffs, and having a good texture and consisting of trunk fibers and branch fibers forming a continuous network structure. More specifically, a split yarn made of thermoplastic synthetic resin has a fineness of 500 to 10,000 denier and has a continuous network structure and has 20 or more fluffs per 1 cm of each of the main fibers or branch fibers of this network structure. In order to produce a split yarn with good texture, preferably having a fineness of 10 to 150 deniers for the main fibers constituting the network structure and 5 to 50 deniers for the branch fibers, a thermoplastic synthetic resin sheet or film is rolled or simulated. The present invention relates to a method for producing a split yarn, which comprises stretching the stretched film by uniaxial stretching, and then splitting the stretched film by appropriate means.

Conventionally, many split yarns obtained from thermoplastic synthetic resin sheets or films, including their production methods, are known, and these split yarns are made into nonwoven or woven fabrics and used as carpet base fabrics and backing materials, paper, films, etc. It is widely used in packaging materials pasted onto sheets, or cut into carpet fibers, cotton, etc.

However, with conventional split yarns, only products with a strong rough and stiff feel are obtained that do not have the texture and feel of natural fibers such as linen or cotton.
Various attempts have been made to improve this, such as arranging the network structure of the split yarn in a regular or irregular manner, but none of these attempts has yet produced products that have the texture and feel of natural fibers. We have not yet reached the point where we can obtain .

It is an object of the present invention to be extremely flexible, have the feel and feel of natural fibers, and maintain the above characteristics even when twisted or woven, so that it can be used as a material for carpet woven fabrics and other materials. The object of the present invention is to provide a method for inexpensively producing split yarn with good texture that can be used for various purposes.

Natural fibers, both twisted yarns and woven fabrics, have a large number of fine and long fluffs on their surfaces, and these fluffs are thought to give the texture and feel unique to natural fibers. On the other hand, with conventional split yarns made of thermoplastic synthetic resin, whether the network structure is regular or irregular as described above, many fine and minute fluffs like natural fibers are present. It is recognized that it cannot be obtained.

The present inventors have provided a method for producing a split yarn with good hand feel by overcoming the above-described drawbacks of the conventional split yarn.

That is, the fineness obtained by the method of the present invention is 500~
The 10,000 denier split yarn consists of main fibers 1 and branch fibers 2 that form a continuous network structure with a large number of fluffs 3 as shown in Fig. 1, and the fineness of the main fibers is preferably 10 to 150 deniers. , more preferably 30 to 90 deniers, the fineness of the branch fibers is preferably 5 to 50 deniers, more preferably 10 to 30 deniers, and the fluff is for each of the main fibers or branch fibers constituting the network structure. There are more than 20 fibers per 1 cm length. The preferred fineness of the main fibers and branch fibers is determined to be the most preferable range above, i.e., 30 to 90 deniers for the main fibers and 10 to 30 deniers for the branch fibers, taking into consideration the balance between texture or feel and mechanical strength. This is what I did.

FIG. 2 shows the state of fuzz 3 when the split yarn obtained by the method of the present invention is twisted, and it is clear that a large number of fuzz exists in the split yarn even in the twisted state.

Figure 3 shows a split yarn with a fineness of 1500 denier obtained by the method of the present invention with 10 warp threads per inch.
This figure shows the state of fuzz 3 when enlarging a woven fabric plain-woven with 10 wefts. This figure also shows that the split yarn of the present invention has a large number of fuzz intertwined between each lattice, resulting in texture and texture. In addition to improving feel, it has also been shown to increase adhesion when used as a carpet backing.

By the way, as an example, a split yarn obtained by the method of the present invention (1500 denier, number of fluffs 100
Carpet is made of a leno-woven fabric with 8 yarns per inch, 8 yarns per inch, and 2 flat yarns (400 denier) as the warp and 8 yarns per inch. When used as a backing material, the peel strength of the woven fabric using the split yarn obtained by the method of the present invention was compared with that of jute cloth at 4.8 kg/5 cm width, and that of the juute cloth was 4.4 kg/5 cm width (of the backing material). The peel test method was based on JISL-1021), and the fabric made of split yarn obtained by the method of the present invention was excellent in both feel and adhesive strength.

The present invention relates to a method of manufacturing the above-mentioned split yarn. That is, the present invention provides a split yarn having a fineness of 500 to 10,000 deniers and consisting of a continuous network structure of thermoplastic synthetic resin, in which 20 or more fuzz fibers are formed per 1 cm length from each of the main fibers or branch fibers of the network structure. When manufacturing a thermoplastic synthetic resin sheet or film, the thermoplastic synthetic resin sheet or film is first stretched at a stretching ratio of 1.5 to 8 times by roll rolling or quasi-uniaxial stretching, and then the stretched film is stretched at a total stretching ratio (first Obtained by stretching under the conditions that the stretching ratio (stretching ratio x stretching ratio) is 5 to 12 times, and the ratio of the primary stretching ratio to the stretching ratio (primary stretching ratio / stretching ratio) is 0.18 to 5.4. , the width reduction rate is 5 compared to before the first elongation.
The present invention provides a method for producing a split yarn, which is characterized by splitting a stretched membrane by 50% to 50%.

The rolling method referred to in the present invention means that a synthetic resin film is passed between two heated rolls having a gap smaller than the thickness of the synthetic resin film, and compressed at a temperature lower than the softening (melting) point of the resin film. This is a method of increasing the length by the amount of the decrease. In addition, the quasi-uniaxial stretching method is a method in which a synthetic resin film is stretched by passing it between low-speed rolls and high-speed rolls (close rolls) with the roll gap as small as possible to suppress shrinkage in the width direction as much as possible. When the widths of the unstretched film and the uniaxially stretched film are W ₁ and W ₂ , respectively, and the stretching ratio is V, x=
1-1/〓VW ₁ /W ₂ , X is an index of uniaxiality of stretching, and the closer the value (≧0) is to 0, the more the width and thickness decrease at the same rate during uniaxial stretching, The closer it is to 1, the less the width decreases. In the present invention, the case where the value of X is ≧0.3 is referred to as pseudo-uniaxial stretching.

Conventionally, split yarns have been produced by orienting a thermoplastic synthetic resin sheet or film in the longitudinal direction using a conventional tensile stretching method, such as a hot oven stretching method or a hot roll stretching method. It is obtained by splitting the fibers at the base. Stretched sheets or stretched tapes produced by such conventional stretching methods tend to cause longitudinal cracks and are easily split into fibers, but do not generate a large amount of fuzz.

The present inventors have completed the present invention as a result of intensive research to overcome the drawbacks of conventional manufacturing methods. The method of the present invention will be explained in detail below.

The method of the present invention consists of the following three steps.

(1) A step of first stretching a thermoplastic synthetic resin sheet or film by a rolling method or a quasi-uniaxial stretching method; (2) A step of stretching the stretched film obtained in step (1) above by a tensile stretching method; ( 3) A step of splitting the stretched membrane obtained in step (2) above using a splitting tool to obtain a split yarn.

In step (1), the thermoplastic synthetic resin sheet or film is first stretched by the above-described rolling method or quasi-uniaxial stretching method, with the stretching ratio appropriately controlled in the range of 1.5 to 8 times. Therefore, it is possible to obtain an elongated film in which shrinkage in the width direction is minimized and the film is oriented in the width direction and the length direction.

In step (2), the above-mentioned stretched film is further stretched, but this is done by increasing the total stretching magnification (first stretching magnification x
Stretching ratio) is in the range of 5 to 12 times, and the ratio of the primary stretching ratio to the stretching ratio is 0.18 to 5.4, preferably 0.5 to 3.0.
This can be easily carried out by aligning the film so that the width reduction rate after stretching is 5 to 50% with respect to the width of the unoriented film.

In this step (2), by specifying the above-mentioned stretching ratio and width reduction rate, an oriented film that is resistant to vertical cracking can be obtained, and when splitting, a natural fiber with many fine and microlong fluffs is obtained. A split yarn with a feel and feel similar to that of the above can be easily obtained.

By the way, ordinary uniaxially oriented stretched tape has a large width reduction rate after orientation, and at a low stretching ratio of 4.
Even when the method is doubled, the width reduction rate is 50% or more, and uneven stretching occurs, making it difficult to put it to practical use, and a split yarn having fine and minute fuzz as obtained by the method of the present invention cannot be obtained. Further, at a generally used stretching ratio of 6 to 8 times, the width reduction rate is extremely large at 60% or more, and the film is oriented in the longitudinal direction. Furthermore, if the stretched film is oriented so that the width reduction rate is 5% or less, it will be difficult to split the resulting stretched film and the generation of fuzz will be insufficient. In this way, in order to obtain a split yarn like the one of the present invention, a balance between the longitudinal direction and the width direction is essential, and the range of width reduction rate of 5 to 50% of the present invention is the optimal condition for achieving the above objective. becomes.

In step (3), the stretched membrane obtained by the above method is split using a splitting tool to obtain a split yarn. Various known splitting tools can be used for this purpose, but examples of effective splitting tools include
The splitting tool shown in Figures A and B (grooves 4 are cut at regular intervals in the length direction on the surface of a round rod that can be rotated around the length direction, and grooves 4 are arranged in parallel in the length direction at a constant pitch). (with ridges 5 arranged along a spiral),
Alternatively, there are rotary rough surface splitting tools having a file-like surface, which are used to rub and scrape the stretched film to split the fibers. This method of applying friction and abrasion to the splitting tool generates frictional heat between the splitting tool and the stretched film, and this heat crimps the split yarn, producing the same effect.
This has the effect of not only generating a large number of fuzz in the split yarn, but also improving the texture of the yarn as a whole.

The thermoplastic synthetic resin sheet or film used in the present invention includes a narrow tape-like sheet or a synthetic resin film composed of multiple layers with different melting points, which is composed of one layer or multiple layers that can be oriented by rolling or stretching. Thermoplastic synthetic resin membranes are included.

On the other hand, the thermoplastic synthetic resin used in the present invention is
There is no particular limitation as long as it can be oriented by rolling or stretching, but in general, crystalline homopolymers of ethylene or propylene, crystalline copolymers containing these as main components, and crystalline copolymers containing these as main components are generally used. It refers to mixtures of polyolefins, nylon, polyester, polyvinyl alcohol resins, and mixtures containing one or more of these as main components.

It is also possible to add commonly used additives such as pigments, radiation absorbers, antioxidants, antistatic agents, lubricants, nucleating agents, and fillers.

As detailed above, the split yarn produced by the method of the present invention has a large number of fuzz, is extremely flexible, does not have the rough and stiff feeling seen in conventional split yarn, and has excellent texture and feel. It is. In particular, when the split yarn of the present invention is woven, it has countless fluffs, so there is no occurrence of mesh misalignment, and it is not only effective for carpet base fabrics and backing materials, but also for packaging materials or strings by pasting it with paper, film, etc. It can be used for such things. In particular, as a carpet backing material, it is comparable to jute cloth, which has been used conventionally, in terms of texture, touch, and adhesive strength. Furthermore, cut fibers obtained by cutting the split yarn of the present invention into short fibers have excellent texture and feel, and can be widely used as carpet fibers or cotton, or for mixing with paper.

Examples of the present invention are shown below.

Example 1 An unoriented film (width) of polypropylene resin (melt flow index 2.0, density 0.90 g/cm ³ )
A pair of rolling rolls (diameter 150mm, surface length 300mm,
Roll surface temperature 130℃), rolling speed 30
Rolled at m/min to twice the length of the original roll,
A rolled film with a width of 150 mm and a thickness of 49 μm with no width change was obtained. Next, this rolled film was cut into 15 mm width during the running process, and the length was kept at 140℃.
Using a 1.5 m heating curved plate for stretching, the rolled tape was slid onto it and further stretched to 4 times the length before stretching at a stretching speed of 120 m/min. The width of this stretched tape is 9.0mm, the thickness is 21μ, and the fineness is
It was 1500 denier. Next, the above-mentioned stretched tape was cut using a splitting tool (diameter 80 mmφ, length 300 mm) as shown in Figure 4 A and B.
The fibers were split by frictional rubbing at a rotational speed of 1300 rpm). The resulting split yarn has a network structure split into the shape shown in Figure 1, and the main fibers (30 to 40 deniers) of the network structure,
Approximately 130 fluffs of 1 to 6 denier were generated per 1 cm of length from each of the branch fibers (8 to 10 denier). The conditions and results of the example are shown in Table 1, and the split yarn of this example had a very good feel.

Example 2 Polyethylene resin (melt index 0.8,
Unoriented film (density 0.96 g/cm ³ ) (width 150 mm,
A split yarn (thickness: 93μ) was oriented and split in the same manner as in Example 1, except that the rolling roll surface temperature was 110°C and the heating curved plate temperature for drawing was 120°C. The conditions and results of this example are shown in Table 1.

Example 3 Polypropylene resin (melt flow index 2.0, density 0.90 g/cm ³ ) 90% by weight, polyethylene resin (melt flow index 1.0, density 0.96 g/cm 3 )
cm ³ ) with a composition of 10% by weight (width
150mm, thickness 96μ) was rolled to twice the original length in the same manner as in Example 1, then cut into widths of 15mm, and stretched and heated to a length of 1.5m while maintaining the temperature at 130°C. Using a curved plate, it was stretched to 5 times the length before stretching. Next, the fibers were split by rubbing with the splitting tool used in Example 1 at 1200 rpm to produce a split yarn. The conditions and results of this example are shown in Table 1.

Example 4 An unoriented film (width 150 mm, thickness 143μ) made of the same resin composition as that used in Example 3 was prepared in the same manner as in Example 3 so that the length of the original film was four times as large. The tape was rolled with a rolling roll and then cut to a width of 15 mm. The tape was stretched three times using a heating curved plate for stretching, and then the number of revolutions was adjusted using the splitting tool used in Example 1.
Split yarn was produced by splitting at 1440 rpm. The conditions and results of this example are shown in Table 1.

Example 5 The same unoriented film as in Example 4 was rolled with a rolling roll in the same manner as in Example 4 so that the length of the original film became 1.5 times, and then the tape was cut into a width of 15 mm and used for stretching. After stretching 8 times using a heated curved plate,
The fibers were split using the splitting tool used in Example 1 at a rotational speed of 960 rpm to produce a split yarn. The conditions and results of this example are shown in Table 1.

Example 6 An unoriented film (width) of polypropylene resin (melt flow index 2.0, density 0.90 g/cm ³ )
150mm, thickness 133μ) using a stretching roll stretching machine (manufactured by Austrian Lenzing) with a roll gap of 2mm, the delivery roll speed was 11m/min, and the take-up roll speed was
By quasi-uniaxial stretching method (X = 0.43) at 50 m/min
The film was stretched 4.5 times to produce a stretched film with a width of 124 mm and a thickness of 36 μm. This film was cut into 10 pieces, further stretched to 2.4 times using the same device as in Example 1, and then split using a splitting tool at a rotational speed of 1300 rpm to form split yarns as shown in Table 1. Manufactured.

Comparative Example 1 The same unoriented film as in Example 1 was cut to a width of 15 mm, and the above tape was slid onto it using a 1.5 m long heated curved plate for stretching held at 140°C. The length was stretched to eight times the length before stretching. This stretched tape had a width of 5.3 mm and a thickness of 35 μm. Next, apply the above stretched tape to the splitting tool used in Example 1 at 1300 rpm.
A split yarn was produced by abrasion and splitting. This split yarn has a relatively regular network structure consisting of trunk fibers of 120 to 130 deniers and branch fibers of 55 to 60 deniers, and the occurrence of fuzz is small, with the occurrence of fuzz being 1 cm for each of the main fibers or branch fibers. There were 5 pieces per length.

[Brief explanation of the drawing]

Fig. 1 shows a developed schematic diagram of the split yarn obtained by the method of the present invention, Fig. 2 shows the state of fluff obtained by twisting the split yarn obtained by the method of the present invention, and Fig. 3 shows 10 warps per inch x weft. Fig. 4A shows the state of the fuzz when a woven fabric made of 10 plain weaves is enlarged, Fig. 4A shows a longitudinal cross-sectional view of an example of the splitting tool used in the present invention, and Fig. 4B shows the state of fluff in Fig. 4A. A sectional view taken along line A is shown. 1: Trunk fiber, 2: Branch fiber, 3: Fuzz, 4: Groove of splitting tool, 5: Ridge of splitting tool.

【table】

【table】

Claims (1)

[Scope of Claims] 1. Split yarn with a fineness of 500 to 10,000 deniers consisting of a continuous network structure of a thermoplastic synthetic resin, in which 20 or more fibers per 1 cm length are formed from each of the main fibers or branch fibers of the network structure. When manufacturing a product with fluff, a thermoplastic synthetic resin sheet or film is first stretched at a stretching ratio of 1.5 to 8 times by roll rolling or quasi-uniaxial stretching, and then the stretched film is stretched at a total stretching ratio (first It is obtained by tensile stretching under the conditions that the secondary stretching ratio x stretching ratio) is 5 to 12 times, and the ratio of the primary stretching ratio to the stretching ratio (primary stretching ratio/stretching ratio) is 0.18 to 5.4. In addition, the width reduction rate compared to before the first elongation was 5
A method for producing a split yarn, characterized by splitting a stretched film of 50% to 50%. 2. The method for producing a split yarn according to claim 1, wherein the stretched film is split by frictionally rubbing the stretched film with a splitting tool made of a rotary rough surface. 3. The method for producing a split yarn according to claim 1 or 2, wherein the thermoplastic synthetic resin sheet or film is made of polyolefin.