Single-component spiral PBT (Polybutylece Terephthalate) antibacterial double-end rounding toothbrush filament and preparation method thereof

Abstract

The invention relates to the technical field of toothbrush filaments, in particular to a single-component spiral PBT antibacterial double-end rounding toothbrush filament and a preparation method thereof. The preparation method comprises the following steps: sequentially carrying out melt spinning, cooling and secondary water bath stretching on a brush wire material to obtain monofilament fibers, and then carrying out twisting shaping, balancing and rounding treatment on the monofilament fibers to obtain finished monofilaments. The prepared finished product monofilament is soft and endowed with tough lodging resistance, has excellent cleaning power of the spiral filament, has antibacterial and bacteriostatic functions, endows a double-end rounding technology, can assist the spiral filament to multiply the cleaning power compared with a sharpened filament, remarkably improves friction resistance with teeth, does not damage gingiva, and has the advantages of simple process and low cost. The massage effect, the soft feeling and the cleaning power on the gingiva are balanced and excellent.

Description

Technical Field

[0001] The invention relates to the technical field of toothbrush filaments, and in particular to a single-component spiral PBT antibacterial double-end rounded toothbrush filament and a preparation method thereof. Background Art

[0002] The product categories of PBT toothbrush filaments currently include single-component monofilaments, two-component skin-core structure monofilaments, two-component two-color spiral filaments, and three-component three-color spiral filaments. Single-component monofilaments account for about 80% of the market, and a wire drawing production line has a masterbatch metering system and a screw extruder. Two-component skin-core structure monofilaments account for about 10% of the market, and a wire drawing production line has two masterbatch metering systems and two screw extruders. Two-component two-color spiral filaments account for about 10% of the market, and a wire drawing production line has two masterbatch metering systems and two screw extruders, in addition to a single spindle winding system, twisting machine and shaping machine. Three-component three-color spiral filaments have just been launched on the market, and in terms of equipment, they have one more masterbatch metering system and one screw extruder than two-color spiral filaments.

[0003] In terms of the cleaning power of toothbrush filaments, there is no difference between single-component monofilaments and two-component skin-core monofilaments, and the cleaning power of spiral filaments is 20% higher than that of single-component round monofilaments. There is no difference in the cleaning power of two-color spiral filaments and three-color spiral filaments.

[0004] In terms of the cleaning power of toothbrush filaments, there is no difference between single-component monofilaments and two-component skin-core monofilaments, and the cleaning power of spiral filaments is 20% higher than that of single-component round monofilaments. There is no difference in the cleaning power between two-component two-color spiral filaments and three-component three-color spiral filaments.

[0005] From the perspective of the intrinsic quality and quality of toothbrush filaments, single-component monofilaments are easier to control to a relatively high level. The two-component skin-core structure and two-color spiral filaments are not as good as single-component monofilaments, and three-color spiral filaments are even more difficult to control to a relatively high level. This is because the existing spiral filaments are all two-color or three-color spiral filaments, and the other one or two colors come from another one or two screw extruders, melt pipes and metering pumps. In the spinning assembly, the melt of the other one or two components is added to the main component according to the principle of composite spinning, and its proportion is less than one-sixth of the total component, that is, each monofilament is not a uniform component, and it pursues a color and visual differentiation. In a series of process flows after the spinning assembly, it is impossible to ensure that the two or three components in the monofilament produce the same changes in intrinsic quality. More importantly, the existing two-color or three-color spiral filaments cannot produce toothbrush filaments with real antibacterial and antibacterial functions, because the antibacterial components cannot reach other composite components.

[0006] In summary, the market currently lacks a toothbrush filament that has both the excellent intrinsic quality of a single-component monofilament and the excellent cleaning power of a spiral filament. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a single-component spiral PBT antibacterial double-end rounded toothbrush filament, which is used to solve the technical problem that the existing toothbrush filaments cannot have both excellent intrinsic quality and outstanding cleaning power.

[0008] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a single-component spiral PBT antibacterial double-end rounded toothbrush filament comprises the following steps: S1: Feed the dried PBT granules, masterbatch granules and antibacterial granules into the screw extruder for melt spinning. The set temperatures of each zone of the screw extruder are 260±5℃, 265±5℃, 268±5℃, 270±5℃, 275±5℃, 275±5℃, 275±5℃ from front to back; the melt pressure is 100±10 bar; S2: The melt is extruded into spinning fibers through the spinneret assembly and then enters the cooling bath system for cooling. The cooled spinning fibers enter the traction system for primary and secondary water bath stretching to obtain monofilament fibers; S3: feeding the monofilament fiber into a twisting machine for double twisting to obtain a double twisted monofilament in a spiral shape with a twist of 300±10 twists / m, and then performing a fixed twisting process on the double twisted monofilament to obtain a single-component spiral yarn; S4: in an environment of constant temperature of 26±3°C and constant humidity of 75±3%, the twisted and shaped single-component spiral yarn is left to stand for 48-72 hours, and then the single-component spiral yarn is made into a yarn cake; S5: Immerse the two ends of the filament cake in the rounding liquid respectively, and after ultrasonic treatment at 75-125° C. for 2-15 minutes, take out the filament cake and wash and dry it to obtain the single-component spiral PBT antibacterial double-end rounded toothbrush filament.

[0009] The single-component spiral PBT antibacterial double-end rounded toothbrush filament prepared by the present invention has a soft and tough anti-lodging property. While having the excellent cleaning power of the spiral filament, it has antibacterial and antifungal functions. The double-end rounding technology can help double the cleaning power of the spiral filament compared to the sharpened filament, significantly improve the friction resistance with the teeth, will not damage the gums, and has a balanced and excellent massage effect, softness and cleaning power on the gums.

[0010] The present invention uses a spiral twisting process to make spiral brush filaments, and then after a fixed twisting process, a shiny appearance effect is produced due to refraction, and countless edges and corners are generated after the spiral, which brings about a significant improvement in cleaning power.

[0011] The double-end chemical rounding technology of the present invention is a revolution for PBT two-color spiral wire and three-color spiral wire, because the PBT spiral wires popular in the market are all sharpened wires, which is the conventional treatment method for PBT toothbrush wires for brush heads. However, the present invention believes that sharpening the spiral wire destroys the "cleaning power" of the spiral wire and deviates from the product positioning of the spiral wire.

[0012] Furthermore, in step S1, the moisture content of the dried PBT particles and masterbatch particles is no more than 30 PPM.

[0013] Further, in step S2, the cooling temperature of the cooling bath system is set to 20±5°C.

[0014] Further, in step S2, the temperature of the primary water bath is 85±5°C, and the temperature of the secondary water bath is 95±5°C.

[0015] Furthermore, in step S4, the double-twisted monofilament is subjected to a twisting process at a heat setting temperature of 180±5°C.

[0016] Furthermore, in step S5, the rounding liquid is a mixed aqueous solution of sodium hydroxide and potassium hydroxide, and its concentration is 25-45wt%.

[0017] Another object of the present invention is to provide a single-component spiral PBT antibacterial double-end rounded toothbrush filament prepared by the above preparation method.

[0018] Preferably, the cross-sectional shape of the single-component spiral PBT antibacterial double-end rounded toothbrush filament is a regular hexagon, a quadrilateral, a regular triangle or a circle.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the single-component spiral PBT antibacterial double-end rounded toothbrush filaments prepared by the present invention are soft and tough and anti-lodging, and while having the excellent cleaning power of spiral filaments, they are endowed with antibacterial and antifungal functions, and the double-end rounding technology can help double the cleaning power of spiral filaments compared to sharpened filaments, significantly improve the friction resistance with teeth, will not damage the gums, and have a balanced and excellent massage effect, softness and cleaning power on the gums. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Example 1

[0021] A method for preparing a single-component spiral PBT antibacterial double-end rounded toothbrush filament comprises the following steps: S1: Wire drawing process: The dried PBT granules, masterbatch granules, and antibacterial granules (containing zinc antibacterial agent) are fed into a single screw extruder at a mass ratio of 92:3:5 for melt spinning. The set temperatures of each zone of the screw extruder are 260°C, 265°C, 268°C, 270°C, 275°C, 275°C, and 275°C from front to back; the melt pressure is 100 bar; the above temperature tolerance is ±5°C, and the melt pressure tolerance is ±10 bar; wherein, the vacuum drying system is used to dry the PBT granules and masterbatch granules for 2-3 hours, so that the moisture content of each is not higher than 30PPM.

[0022] S2: Cooling and pulling process: After the melt is extruded into spinning fibers through the spinneret assembly, it enters the cooling bath system for cooling. The cooling temperature is 20°C and the temperature tolerance is ±5°C. This ensures that the water bath liquid level is stable, the water temperature is stable, and there is no turbulence, ensuring that the nascent fibers are uniformly cooled and shaped. The above process conditions create favorable conditions for achieving a high level of nominal wire diameter deviation rate.

[0023] The cooled spinning enters the traction system and undergoes primary water bath stretching at 85°C and secondary water bath stretching at 95°C, with the temperature tolerance controlled at ±5°C, to obtain monofilament fibers with a diameter of 0.15-0.18mm; high-temperature water bath stretching can fully control the boiling water shrinkage of the monofilament, creating favorable conditions for subsequent twisting, shaping and high-temperature chemical rounding; effective and reasonable stretching gives the monofilament fibers a good mechanical level, creating favorable conditions for the final presentation of perfect cleaning power and flexibility; the above process conditions lay the foundation for obtaining toothbrush filaments with a high level of intrinsic quality.

[0024] S3: Twisting and shaping process: The monofilament fiber is fed into the twisting machine for doubling to obtain a spiral-shaped double-twisted monofilament with a twist of 300±10 twists / m. The double-twisted monofilament is then subjected to a fixed twisting process at a heat-setting temperature of 180°C (temperature tolerance is ±5°C) to ensure that the twist is fixed at 300±10 twists / m, thereby obtaining a single-component spiral yarn.

[0025] S4: Balancing process: In an environment of constant temperature of 26±3℃ and constant humidity of 75±3%, the twisted and shaped single-component spiral yarn is left to stand for 48-72 hours, so that the internal stress of the fiber yarn is balanced and the internal quality is further improved; then the single-component spiral yarn is made into a silk cake.

[0026] S5: Rounding process: immerse the two ends of the wire cake in the rounding liquid (a mixed aqueous solution of sodium hydroxide and potassium hydroxide, with a mass concentration of 40wt%) respectively, and after ultrasonic treatment at 95-105°C for 8-10min, take out the wire cake and wash and dry it to obtain the single-component spiral PBT antibacterial double-end rounded toothbrush wire.

[0027] Comparative Example 1 A method for preparing toothbrush filaments, which differs from Example 1 in that, in step S2, the spun yarn after cooling enters the traction system and is not subjected to secondary water bath stretching, but to secondary stretching at room temperature.

[0028] Comparative Example 2 A method for preparing toothbrush filaments, which differs from Example 1 in that the twisting and shaping step S3 is not performed, that is, the monofilament fiber prepared in step S2 is subjected to subsequent steps S4 and S5.

[0029] Comparative Example 3 A method for preparing toothbrush filaments, which differs from Example 1 in that the balancing process of step S4 is not performed, that is, the single-component spiral filaments prepared in step S3 are subjected to the subsequent step S5.

[0030] Comparative Example 4 A method for preparing toothbrush filaments, which differs from Example 1 in that the rounding process of step S5 is not performed.

[0031] Comparative Example 5 A method for preparing toothbrush filaments, which differs from Example 1 in that the rounding process of step S5 is not performed, but the filaments are sharpened according to a conventional process.

[0032] In order to characterize the anti-lodging performance of the toothbrush filaments prepared in the above embodiments and comparative examples, the prepared brush filaments were prepared into a standard toothbrush head, which was mounted on an electric toothbrush handle. The brush was brushed back and forth on a ceramic sheet with a pressing force of 3N and a frequency of one reciprocation per 2 seconds for 90 minutes (simulating brushing one tooth). The anti-lodging effect of the brush filaments was determined based on the bending of the lodged brush filaments. The results are shown in Table 1.

[0033] Table 1 Test results of anti-lodging performance of toothbrush filaments Group Anti-lodging performance Example 1 The toothbrush wire can basically remain upright, with only slight bending and can recover quickly, and has good anti-lodging performance Comparative Example 1 Most of the toothbrush filaments can remain upright, but the bent parts take a long time to recover and have poor anti-lodging performance Comparative Example 2 A small part of the toothbrush wire can remain upright, but the bent part cannot recover for a long time, and the anti-lodging performance is poor Comparative Example 3 The toothbrush wire part can remain upright, and the bent part can recover for a long time but slower than Example 1, and the anti-lodging performance is poor Comparative Example 4 The toothbrush wire can basically remain upright, with only slight bending and can recover quickly, and has good anti-lodging performance Comparative Example 5 The toothbrush wire can basically remain upright, with only slight bending and can recover quickly, and has good anti-lodging performance In order to characterize the cleaning effect of the toothbrush filaments prepared in the above embodiments and comparative examples, the prepared brush filaments were prepared into a standard toothbrush head, which was mounted on an electric toothbrush handle and brushed back and forth on a denture model at a pressing force of 3N and a frequency of about one back and forth movement every 2 seconds for 30 seconds; wherein the gap width of the denture model was about 1 mm, and fine sand (simulating food residues in the gaps between teeth) was filled in the gaps. The cleaning effect of the brush filaments was determined according to the amount of fine sand remaining in the gaps, and the results are shown in Table 2.

[0034] Table 2 Cleaning power test results of toothbrush filaments Group Cleaning effect Example 1 Most of the fine sand is removed, indicating that the toothbrush filaments can penetrate deep into the gaps for cleaning and have good cleaning power. Comparative Example 1 Most of the fine sand is removed, indicating that the toothbrush filaments can penetrate deep into the gaps for cleaning and have good cleaning power. Comparative Example 2 There is still a lot of fine sand in the gap, which means that the toothbrush filaments cannot penetrate into the gap to clean, and the cleaning power is poor. Comparative Example 3 The fine sand still remaining in the gap is more than that in Example 1 and less than that in Comparative Example 2, indicating that the toothbrush filaments can penetrate the gaps well for cleaning and have better cleaning power. Comparative Example 4 The fine sand still remaining in the gap is more than that in Example 3, but less than that in Example 2, indicating that the toothbrush filaments failed to penetrate the gaps well for cleaning, and the cleaning power was poor. Comparative Example 5 The fine sand still remaining in the gap is more than that in Example 1, but less than that in Comparative Example 3, indicating that the toothbrush filaments cannot penetrate the gap well for cleaning, and the cleaning power is slightly poor. In order to characterize the antibacterial effect of the toothbrush filaments prepared in the above examples and comparative examples, 1 g of each prepared toothbrush filament was added into a sterilized physiological saline tube, and then sterilized at 120°C for 20 minutes. 7cfu / mL of bacterial solution (Staphylococcus aureus and Streptococcus mutans) was added for 7 hours at 25°C, and the liquid (0.5 mL) was taken out for pouring culture for 24 hours to count the live bacteria (commercially available ordinary toothbrush filaments were used as controls), and the bactericidal rate (0 month) was calculated. The antibacterial rate was calculated as follows: bactericidal rate = (colony count of the control group - colony count of the experimental group) / colony count of the control group * 100%. In addition, the toothbrush bristles were soaked in a sucrose solution with a mass concentration of 10% for three minutes every day, and then rinsed with tap water for 1 minute. After one month of such treatment, 1 g of toothbrush bristles was taken for the above-mentioned 7-hour bactericidal rate statistics. The results are shown in Table 3.

[0035] Table 3 Antibacterial effect of toothbrush filaments

[0036] From Tables 1 to 3, it can be seen that the single-component spiral PBT antibacterial double-end rounded toothbrush filaments prepared by the present invention are soft and tough and anti-lodging. While having the excellent cleaning power of spiral filaments, they are also endowed with antibacterial and antifungal functions. The double-end rounding technology can help double the cleaning power of spiral filaments compared to sharpened filaments, significantly improve the friction resistance with teeth, will not damage the gums, and have a balanced and excellent massage effect, softness and cleaning power on the gums.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a single-component spiral PBT antibacterial double-end rounded toothbrush filament, characterized in that , including the following steps: S1: Feed the dried PBT granules, masterbatch granules and antibacterial granules into the screw extruder for melt spinning. The set temperatures of each zone of the screw extruder are 260±5℃, 265±5℃, 268±5℃, 270±5℃, 275±5℃, 275±5℃, 275±5℃ from front to back; the melt pressure is 100±10 bar; S2: The melt is extruded into spinning fibers through the spinneret assembly and then enters the cooling bath system for cooling. The cooled spinning fibers enter the traction system for primary and secondary water bath stretching to obtain monofilament fibers; S3: feeding the monofilament fiber into a twisting machine for double twisting to obtain a double twisted monofilament in a spiral shape with a twist of 300±10 twists / m, and then performing a fixed twisting process on the double twisted monofilament to obtain a single-component spiral yarn; S4: in an environment of constant temperature of 26±3°C and constant humidity of 75±3%, the twisted and shaped single-component spiral yarn is left to stand for 48-72 hours, and then the single-component spiral yarn is made into a yarn cake; S5: Immerse the two ends of the filament cake in the rounding liquid respectively, and after ultrasonic treatment at 75-125° C. for 2-15 minutes, take out the filament cake and wash and dry it to obtain the single-component spiral PBT antibacterial double-end rounded toothbrush filament.

2. The preparation method according to claim 1, characterized in that , In step S1, the moisture content of the dried PBT particles and masterbatch particles is no more than 30 PPM.

3. The preparation method according to claim 1, characterized in that ,In step S2, the cooling temperature of the cooling bath system is set to 20±5℃.

4. The preparation method according to claim 3, characterized in that ,In step S2, the temperature of the primary water bath is 85±5℃, and the temperature of the secondary water bath is 95±5℃.

5. The preparation method according to claim 1, characterized in that: In step S4, the double-twisted monofilaments are subjected to a twist setting process at a heat setting temperature of 180±5°C.

6. The preparation method according to claim 1, characterized in that In step S5, the rounding liquid is a mixed aqueous solution of sodium hydroxide and potassium hydroxide, and its concentration is 25-45wt%.

7. A single-component spiral PBT antibacterial double-end rounded toothbrush filament, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 6.

8. The single-component spiral PBT antibacterial double-end rounded toothbrush filament according to claim 7, characterized in that: The cross-sectional shape of the single-component spiral PBT antibacterial double-end rounded toothbrush filament is a regular hexagon, a quadrilateral, a regular triangle or a circle.

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