KR101272041B1 - Method for processing end of monofilament - Google Patents

Abstract

The present invention is a) after producing a bundle of short fibers obtained by melt extrusion and stretching the synthetic resin composition comprising a polyester-based resin in a bundle (bundle), by sealing one end of the bundle to form a molten film, and then the opposite end Dipping in a processing tank containing a basic solution; b) immersing the closed molten film and one end of the bundle in contact with the closed molten film in a processing tank containing a basic solution to cool the molten first block; And c) re-immersing the cooled first block in a processing tank containing a basic solution to form a distal end by separating and removing the cooled first block. By providing a soft touch feeling can be obtained, it is widely applied to brush hair or industrial fields applied to the human body.

Description

Method for processing end of monofilament

The present invention relates to a method for processing the ends of the short fibers produced by melt extrusion and stretching the resin composition, and a short fiber produced by the above method, a brush comprising the same.

Brushes are generally used for industrial or domestic use, and the ends of the bristles in contact with the object exhibit different functions and effects depending on the shape. For example, in the case of bristles, the end directly touches the tooth, gum or periodontal to affect tartar removal or gums.

In order to make a fine bristles, there is a processing method of miniaturizing both sides of short fibers or a method of processing one surface to a round end after processing. The processing method of short fiber bundles is generally a method of heat treatment, mechanical polishing or mixing them to form a rounded end shape. These methods are chemically immersed methods used in micro hair and general toothbrush processing methods, and generalized methods of abrasion of the surface by rotating at a high speed in a polishing machine. In applications, the polished debris does not fall off and the tip is thinned due to the nature of abrasion or simple machining, resulting in the opposite result of a lasting irritation to the gums. Therefore, the conventional processing method of the short fiber end portion needs to be improved.

Therefore, the present invention was devised to overcome the disadvantages caused by the end formed by the conventional short fiber processing method, by changing the interface of the end of the short fiber can provide a wide surface of the end surface is reduced and softer The purpose is to have a touch. In addition, the present invention is to provide a short fiber end processing method that can be utilized in bristles including the bristles applied to the human body or a product used in the industrial field.

The present invention melt-extruded synthetic resin composition comprising a polyester-based resin, and then prepared and used as a bundle of short fibers obtained by stretching. One end of the bundle of short fibers thus prepared is sealed, and the closed end is immersed in a processing tank containing basic solution to be slowly hydrolyzed, and the block is rapidly cooled. At this time, the cooled block is immersed in a processing tank containing a basic solution and removed to provide a terminal processing method of short fibers which is processed into hemispherical ends.

Hereinafter, the present invention will be described more specifically.

End processing method of short fibers according to the present invention

a) manufacturing a short fiber obtained by melt extrusion and stretching a synthetic resin composition including a polyester resin into a bundle, and then sealing one end of the bundle to form a molten film;

b) immersing one end of the sealed molten film and the bundle in contact with the sealed molten film in a processing tank containing a basic solution to form a first block and then cooling it; And

and c) re-immersing the cooled first block in a processing tank containing a basic solution to separate and form an end portion.

The polyester resin may include at least one selected from polyethylene terephthalate (PET), polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PETE) or polylactic acid (PLA). . More preferably, the synthetic resin is preferably at least 400 cN in tensile strength and 10 to 40% in tensile elongation because of excellent durability.

In the present invention, a synthetic resin composition containing the polyester resin is used. In this case, the synthetic resin composition further includes any one or two or more selected from an elastomeric resin, a thermoplastic resin, and a silicone resin.

In addition, the resin composition may further include an inorganic additive as needed.

The inorganic additive is used to adjust the polyester properties such as strength and elasticity of the product, and to provide surface irregularities and antimicrobial properties for imparting functionalities of the processed surface after taper, and the amount thereof is 0.3 to 100 parts by weight of the polyester resin. It is preferable to include 40 parts by weight.

The elastomer-based resin is used to impart elasticity, and is propylene-α such as ethylene-α olefin elastomer, such as ethylene-hexene elastomer, ethylene-octene elastomer, propylene-hexene elastomer, propylene-octene elastomer, etc. Thermoplastic olefin elastomers including olefin elastomers, ethylene-propylene-diene elastomers, and the like, styrene-butadiene block copolymers, styrene-isoprene block copolymers, hydrogenated styrene-butadiene elastomers, styrene-butadiene-styrene elastomers, Thermoplastic styrene elastomers including styrene-ethylene-butylene-styrene-based elastomers, styrene-ethylene-propylene-styrene-based elastomers, and the like, and the like, and these may be used alone or as a mixture thereof.

The thermoplastic resin is used to improve flexibility, and polyethylene, polypropylene, or a copolymer thereof may be used.

The silicone resin may be used to increase compressive strength and wear resistance and maintain flexibility.

The inorganic additive may be used calcium carbonate, silica, silver nano powder, platinum nano powder, charcoal powder, TiO ₂ , TiON, fluorine, antibacterial agents, and the like.

Melting and extruding in step a) comprises extruding the synthetic resin composition using a nozzle having a plurality of holes (80 to 120) having a diameter of 0.2 to 0.8 mm in an extruder heated to 220 to 280 ° C, and then to 1.5 to Stretch it at 6 times the stretching ratio and wind it up to the take-up machine. The total draw ratio at the time of stretching is preferably drawn at 1.5 to 6 times, and if less than 1.5 times, there is a change in color, the strength is weak, and the elongation cannot be formed to form a constant taper. If it is more than 6 times, flexibility is very low and cutting occurs during drawing.

At this time, it is preferable to perform extending | stretching at 150-220 degreeC. More preferably cooling in a cooling water of 13 ° C. or lower and primary stretching at 150-220 ° C .; And repeating two or more steps of cooling in a low temperature water of 25 ° C. or lower and stretching at 150 to 220 ° C. two or more times.

Specifically, in the present invention, the stretching process is preferably performed 1 to 4 times, more preferably 4 times. In the case of stretching four times, after cooling with cooling water of 5 to 13 ° C, the primary drawing is performed at 150 to 220 ° C to 30 to 50% of the total drawing ratio, and after cooling it to low temperature water of 25 ° C or less, 150 Secondary stretching to 15 to 30% of the total stretching ratio at ~ 220 ℃, and then cooled again with cold water below 25 ℃, third stretching to 15 to 30% of the total stretching ratio at 150 ~ 220 ℃, again After cooling with low temperature water of 25 ° C or less, the fourth shrinkage is performed while reducing the stretching speed at 150 to 220 ° C. By repeating such cooling and shrinking, it is surprisingly possible to obtain a polyester-based short fiber with further improved strength.

In the present invention, the sealing in step a) is preferably performed by melting one surface having an orientation formed in the stretching process by immersing one surface in an oil bath at 220 to 280 ° C, and cooling water at 5 to 20 ° C. , More preferably, it is hardened in a cooling water of 8 ~ 16 ℃ to seal one surface. Specifically, the strand ends of the short fibers having the orientation due to the stretching are melted to form a melted layer of the polyester resin that loses the orientation.

The present invention may further comprise the step of forming a second block by immersing the opposite end of the molten membrane in the processing tank containing the basic solution in step a).

At this time, the processing tank containing the basic solution is characterized in that the temperature range of 100 ~ 140 ℃, the one end is immersed in the processing tank containing the basic solution of 30 ~ 60% concentration of the opposite end of the sealed bundle. At this time, the length of the melt can be adjusted according to the length to be immersed, and the present invention is substantially melted by the length of the immersion, since the basic solution does not rise between the fibers by capillary action. It is preferable to use caustic soda as the basic solution.

Next, one end of the closed molten membrane and the bundle in contact with it in step b) is immersed in a processing tank containing a basic solution to a predetermined length and melted. At this time, the length of the tip immersed in the processing tank is preferably 5 ~ 15mm. The temperature of the processing tank is 90 ~ 120 ℃, it is preferable to heat to a relatively lower temperature than in step a). By using the difference in the hydrolysis rate of polyester in short fibers and molten membranes with different crystallinity, the rate and amount of basic processing liquid penetrate into each short fiber are constant so that natural cracks are formed and separated from each other during instant cooling. To do this. At this time, the temperature deviation of the processing tank is preferably ± 2 ℃. If the temperature deviation is out of this range, it is desirable to maintain this error range, because even in bundles processed in the same processing tank, the difference between the blocks due to length and melting will be obtained.

Cooling of step b) in the present invention includes performing at 8 ~ 30 ℃. The cooling may be carried out in the temperature range for a predetermined time to change the interface to the first block formed by melting the end of the short fibers in the processing tank. The cooling time is preferably 1 to 30 minutes, more preferably 1 to 10 minutes. At this time, when the temperature is out of the range of time and temperature of the cooling process, the separation is not performed or only a partial separation occurs.

Next, in step c), the surface of the cooled and separated first block is immersed in a processing tank containing basic solution to completely remove and remove the first block in which cracks are formed due to the interfacial change, to form a clean surface, and to process the end. . The re-immersion step is carried out by immersing in a processing tank containing a basic solution in the temperature range of 100 ~ 140 ℃.

In the present invention, the processing method of the end formed while the first block is separated and removed is a stage having an orientation due to stretching by immersing the closed molten membrane of step b) and one end of the bundle in contact with it by melting in a processing bath containing a basic solution The fiber ends form blocks such as, for example, white solid masses, which are cooled and re-immersed so that the ends have a hemispherical shape, which is different from the polishing process of leaving a resin residue. The invention may further comprise a step of washing with water after the process.

In the present invention, the hemispherical shape is defined as the diameter of the cross section in which the diameter of the short fiber is constant is smaller than the diameter of the sphere in contact with the end. This is characterized in that the shape of the distal end is wider and rounder than the polished or heat treated.

1 is a short fiber end portion manufactured by the manufacturing method according to the present invention, the short fiber end portion has a hemispherical shape, for example, compared to the short fiber end portion prepared by the polishing and heat treatment method as shown in FIG. In this case, a softer touch can be exhibited.

3 to 6 illustrate a process of separating the melt surface and one end of the bundle adjacent thereto from the manufacturing method according to the present invention. FIG. 3 is a photograph of the melt surface formed in the bundle to make the physical properties of the resin unoriented. 4 is a photograph of a state in which the processing liquid penetrates and partially hydrolyzes inside while immersing in a processing tank at 90 to 120 ° C. to warm up. 5 is a photograph of a state in which cracks are formed on the hemispherical filament cross section by rapid cooling at a low temperature and start to fall off. Fig. 6 is a photograph immediately before completion of a complete hemispherical filament and is immersed in the processing liquid to complete the complete surface.

The present invention provides a short fiber manufactured by the short fiber end processing method as described above. In addition, it is possible to provide a product that can be applied to a toothbrush or brush comprising the short fibers.

The short fiber end processing method according to the present invention can provide a distal end having a large surface reduced by changing the interface of the end of the short fiber to obtain a softer touch feeling, in the case of bristles, continuous stimulation of the gum It can reduce and increase the removal effect of tartar, and can be widely applied to the bristles or industrial fields applied to the human body, including such bristles have a very high utilization advantage.

Figure 1 shows a short fiber end portion produced by the manufacturing method according to the present invention.
Figure 2 shows a short fiber end portion prepared by the polishing and heat treatment method according to Comparative Example 2.
3 to 6 illustrate a process of separating the melting surface and one end of the bundle adjacent thereto in the manufacturing method according to the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples in order to explain the present invention. However, the present invention is not limited to the following Examples.

Example 1

Polybutylene terephthalate resin (Toraycon 1100) was melted at 250 ° C. and extruded to a thickness of 0.8 mm.

After cooling the extruded yarn with cold water at 10 ° C., the primary drawing is performed at 40 ° C. of the total draw ratio at 180 ° C., the second drawing is carried out at 30 ° C. at 30% of the total drawing ratio at 180 ° C., and the total drawing is made at 180 ° C. Third stretching was performed at 30% of the magnification, fourth stretching was performed at 180 ° C, and stretching was performed so that the total stretching ratio was four times. The thickness of the prepared short fibers was 0.2 mm, which was cut into 30 mm lengths after preparing a bundle having a diameter of 40 mm. One end of the bundle was immersed in an oil bath at 230 ° C. for 5 mm, and after 10 minutes, closed at the same time as cooling to form a molten film. The molten membrane and one end of the bundle adjacent thereto were immersed in a processing tank containing caustic soda at 90 ° C. for 1 hour and 30 minutes to slowly melt the molten membrane and its adjacent interface so that the processing liquid penetrated. This was allowed to stand for 10 minutes in cold water at 8 ° C. for cooling, and then immersed in a 120 ° C. processing tank for 30 seconds to obtain a hemispherical surface having a broad and clean short fiber end.

[Example 2]

Polybutylene terephthalate resin (Toraycon 1100) was melted at 250 ° C. and extruded to a thickness of 0.8 mm.

After cooling the extruded yarn with cold water at 10 ° C., the primary drawing is performed at 40 ° C. of the total draw ratio at 180 ° C., the second drawing is carried out at 30 ° C. at 30% of the total drawing ratio at 180 ° C., and the total drawing is made at 180 ° C. Third stretching was performed at 30% of the magnification, fourth stretching was performed at 180 ° C, and stretching was performed so that the total stretching ratio was four times. The thickness of the prepared short fibers was 0.2 mm, which was cut into 30 mm lengths after preparing a bundle having a diameter of 40 mm. One end of the bundle was immersed in an oil bath at 230 ° C. for 5 mm, and after 10 minutes, closed at the same time as cooling to form a molten film.

The unsealed end of the bundle was immersed for 15 hours in a processing bath containing caustic soda at 120 ° C. for 2 hours. On the immersed portion, a white mass was produced in which the resin was hydrolyzed. The white mass was cooled at 20 ° C. for 1 hour. Thereafter, the molten membrane and one end of the bundle adjacent thereto were immersed in a processing tank containing caustic soda at 90 ° C. for 1 hour and 30 minutes to slowly melt the molten membrane and its adjacent interface so that the processing liquid penetrated. This was allowed to stand for 10 minutes in cold water at 8 ° C. for cooling, and then immersed in a 120 ° C. processing tank for 30 seconds to obtain a hemispherical surface having a broad and clean short fiber end.

[Example 3]

Except for immersing the molten membrane and one end of the bundle adjacent thereto in a processing tank containing 120 ° C caustic soda it was carried out in the same manner as in Example 1 it was possible to obtain a short fiber end with a wide and clean hemispherical surface .

Example 4

Except that the cooling temperature was 30 ℃ was carried out in the same manner as in Example 1 it was possible to obtain a short fiber end with a hemispherical surface was wide and clean.

Comparative Example 1

The short fiber ends were processed in the same manner as in Example 1 except that one end of the bundle was not sealed.

Comparative Example 2

Polybutylene terephthalate resin (Toraycon 1100) was melted at 250 ° C. and extruded to a thickness of 0.8 mm. After cooling the extruded yarn with cold water at 10 ° C., the primary drawing is performed at 40 ° C. of the total draw ratio at 180 ° C., the second drawing is carried out at 30 ° C. at 30% of the total drawing ratio at 180 ° C., and the total drawing is made at 180 ° C. Third stretching was performed at 30% of the magnification, fourth stretching was performed at 180 ° C, and stretching was performed so that the total stretching ratio was four times. The thickness of the prepared short fibers was 0.2 mm, which was cut into 30 mm lengths after preparing a bundle having a diameter of 40 mm. The cut surface was polished sequentially using the 600, 800 and 1200 stones. The ends of the short fibers, which have been polished, were removed by using an air gun.

The inner and outer filaments of the polished bundles were sharp and pointed on the outer side and unpolished on the inner side, and had large differences in shape. The ends of the short fibers produced in this manner were at a very urgent angle to the friction surface. It is sharp enough to be sharp or poke.

Claims (8)

a) manufacturing a short fiber obtained by melt extrusion and stretching a synthetic resin composition including a polyester resin into a bundle, and then sealing one end of the bundle to form a molten film;
b) immersing one end of the sealed molten film and the bundle in contact with the sealed molten film in a processing tank containing a basic solution to form a first block and then cooling it; And
c) re-immersing the cooled first block in a processing tank containing a basic solution to remove and form an end portion.
The method of claim 1,
And a step of forming a second block by dipping the opposite end of the molten membrane in a processing tank containing a basic solution in the step a).
The method of claim 1,
The processing tank containing the basic solution in step b) is the end processing method of short fibers, characterized in that the temperature range of 90 ~ 120 ℃.
The method of claim 1,
Cooling in step b) is the end of the short fiber processing method comprising performing at 8 ~ 30 ℃.
The method of claim 1,
Re-immersion in step c) characterized in that the end of the short fiber processing method characterized in that the temperature range of 100 ~ 140 ℃.
The method of claim 1,
Stretching in the step a) is the first step of cooling at 150 ~ 220 ℃ and cooling in cooling water of 13 ℃ or less; And repeating two or more steps of cooling at a temperature of 25 ° C. or lower and stretching at 150 to 220 ° C. two or more times.
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