KR101175634B1 - Biodegradable polylactic acid high strength filament yarn, manufacturing method thereof, manufacturing method of woven or knitted fabric using it and its use - Google Patents

Abstract

The present invention relates to a biodegradable polylactic acid high strength fiber yarn, a method for producing the same, a method for producing a woven fabric using the same, and a method for producing a woven fabric using a biodegradable yarn.

In the present invention, a method for producing a biodegradable polylactic acid (PLA) high strength fiber yarn which is uniformly stretched while increasing the draw ratio while repeating heating and cooling by adding a heating and cooling system to the multistage drawing apparatus in the drawing zone in melt spinning is presented. do.

According to the present invention, there is also provided a fabric for a banner and a knitted fabric for a protective film using biodegradable fiber yarn.

The outdoor display banner or construction protective film of the present invention using environmentally-friendly biodegradable fiber yarn is decomposed by microorganisms at the time of disposal after use, and thus does not cause environmental pollution problems.

Biodegradable, Polylactic Acid High Strength Fiber Yarn, PLA, Banner, Protective Film

Description

Biodegradable polylactic acid high strength filament yarn, manufacturing method according, manufacturing method of woven or knitted fabric using it and its use }

The present invention relates to a biodegradable polylactic acid high strength fiber yarn, a manufacturing method thereof, a method of manufacturing a woven fabric using the same, and a use of the woven fabric, and more specifically, it can be biodegraded upon disposal after use to solve environmental pollution problems. The present invention relates to a biodegradable polylactic acid high strength fiber yarn which can be usefully used for outdoor posts, banners, construction safety nets, and the like, a method for manufacturing the same, and a method for manufacturing the knitted fabric using the same.

Posted inside and outside of the building to protect people and material promotions, such as banners or construction works for the collection of falling objects at the construction site, etc. are made of ordinary synthetic fibers such as polyester, nylon, polypropylene and collected when finished After recycling, it is almost impossible to recycle.

Disposal by landfill in this process is impossible because it takes more than 200 years to decompose. In the incineration disposal process, many environmental hormones and dioxins are emitted due to the characteristics of PET materials, which are mainly used, causing serious damage to the environment.

In addition, such banners have to withstand the hard breakdown by ultraviolet rays and hydrolysis by moisture during the publication period for the promotion, and temporarily resists strong winds and external shocks, so that the used yarns may be general biodegradable yarns. It is preferable to be a high strength yarn, and because it must flexibly cope with and withstand changes in the external environment such as the wind, it is preferable that the tissue of the banner should be a tissue having excellent breathability and good tissue strength.

In detail, the fibers that are widely used as materials for banners and protective fabrics to date are high strength nylon and polyester in domestic and overseas.

However, in the case of high strength nylon, or polyester yarn mainly used at home and abroad, the energy consumption is high during the manufacturing process, and the carbon dioxide and environmental hormones are emitted at the time of disposal. They cannot be landfilled, recycled, or disposed of in combustion, but in the case of regeneration, they must go through physical and chemical treatment processes to remove the contaminants such as dust and oil and minerals such as cement powder that are attached outdoors or at construction sites. The cost of recovery and regeneration is high, and environmental pollutants must be used in the cleaning process, which causes environmental pollution problems.

The present invention attempts to use biodegradable resins to solve environmental problems in the prior art.

Commercially available biodegradable resins include PLA (Poly Lactic Acid, "PLA"), PBS (Poly Buthylene Succinate, "PBS"), PCL (Poly caprolactam, (P (HB-HV), Starch / PVA) There is this.

These biodegradable resins generally have a low melting point and low crystallinity, which is disadvantageous in melt spinning and poor in fiber formation, and thus are used in the form of a resin film or in the form of a long fiber nonwoven fabric (Korean Patent Publication No. 2001-12198). It was mainstream and only part of it is being developed as filament yarn.

The development of some filament yarns is also less powerful and brittle, making it difficult to use in knitted fabrics.

Due to these difficulties, it has not been recognized that biodegradable resins can be used in filament fibers, weaving, knitting, and processing for banners or protective films.

The inventors of the present invention have come to complete the present invention by solving the above problems of the prior art by devising a special spinning method and a woven fabric processing method.

It is an object of the present invention to provide a knitted fabric for a banner or a protective film using a biodegradable resin so as not to cause environmental pollution problems after disposal.

Another object of the present invention is to provide a high-strength biodegradable polylactic acid filament yarn which is particularly suitable for use in banners or protective films and the like and a method of manufacturing the same.

Still another object of the present invention is to provide a high strength biodegradable polylactic acid filament yarn woven fabric suitable for a protective film such as a banner or a construction because it is biodegradable and has high strength and weather resistance and flame retardancy.

The method of manufacturing the high strength biodegradable polylactic acid (PLA) fiber yarn of the present invention is performed by heating and cooling a system for repeating heating and cooling during multistage stretching in a drawing zone in a molten spinning of PLA resin. It is characterized by uniformity in the radial and longitudinal directions of the filament while increasing the draw ratio from 2.0 to 4.5 to 4.5.

The melt spinning method is preferably a multi-stage stretching spin draw method.

PLA resin used in the present invention is the L-type stereoisomer PLLA (Poly Laevo enantiomer Lactic Acid), the weight average molecular weight is preferably 10,000 to 200,000.

PLA resin used in the present invention may be added to the flame retardant 3 to 10% by weight in a master batch method to impart flame retardancy.

High-strength biodegradable PLA fiber yarn of the present invention is prepared by the above method, characterized in that the tensile strength of 4 to 8 g / d, elongation 20% to 50%.

Method for producing a fabric for a banner using the biodegradable yarn of the present invention is the inclination of the biodegradable filament yarn 50 to 800 denier and the biodegradable yarn or other biodegradable yarn as the weft, the warp density 50 to 120 T, weft density Weaving to 40 to 120T; Refining or dyeing the woven fabric in a conventional manner; Heat setting at a temperature of 100 to 130 ° C .; It is made by cutting by melt cutting using heat to an appropriate size.

According to another aspect of the present invention, a method of manufacturing a fabric for a placard using a biodegradable yarn is made using a slope of 50 to 800 denier of the PLA high strength biodegradable yarn, and a warp density using the PLA biodegradable yarn or another biodegradable yarn as a weft yarn. Weaving 50 to 120 T, weft density of 40 to 120 T; Refining or dyeing the woven fabric in a conventional manner; Heat setting at a temperature of 100 to 130 ° C .; It is made by cutting by melt cutting using heat to an appropriate size.

In the present invention, after the heat setting step may be coated with a biodegradable resin 10 to 100㎛ in order to improve the print quality and shape stability.

The method for producing a protective membrane knitted fabric using the biodegradable yarn of the present invention is characterized in that the length of the mesh is 1 to 8 cm using a biodegradable filament yarn, but using some of the plurality of beams as another high-strength yarn in raschel knitting.

According to another aspect of the present invention, there is provided a method of manufacturing a protective membrane knitted fabric using biodegradable yarns, wherein the high-strength biodegradable PLA filament yarn is used, but the length of the mesh is set to 1 to 8 cm using some of the plurality of beams as other high strength yarns. It is characteristic.

The other high strength yarn may be selected from the group consisting of PLA monofilament yarn, high strength nylon yarn, high strength PE yarn, high strength PET yarn, and high strength PP yarn.

According to the present invention, there is an effect of providing a biodegradable banner fabric or a fabric for a protective film that does not cause environmental pollution by being naturally decomposed upon disposal after use.

According to the present invention, there is an effect that the polylactic acid high strength biodegradable fiber yarn is provided.

According to the present invention, by using the high-strength biodegradable fiber yarn, there is an effect that the promotional banner that does not cause environmental pollution problem by being naturally decomposed upon disposal after use.

According to the present invention, by using a mixture of the high-strength biodegradable fiber yarns and high-strength yarns, there is an effect that there is provided a protective membrane for construction works civil engineering does not cause environmental pollution problems by being decomposed naturally when discarded after use with proper strength. .

Hereinafter, the present invention will be described in more detail.

The manufacturing method of the fabric for the banner using the biodegradable yarn of the present invention is the inclination of the biodegradable fiber yarn 50 to 800 denier and the biodegradable fiber yarn or other biodegradable yarn as the weft, the inclination density 50 to 120 T, weft Weaving the density to 40 to 120T; Refining or dyeing the woven fabric in a conventional manner; Heat setting at a temperature of 100 to 130 ° C .; It is made by cutting by melt cutting using heat to an appropriate size.

The biodegradable fiber yarn may be used PLA or PBS yarn.

The method for producing a protective membrane knitted fabric using the biodegradable fiber yarn of the present invention is characterized in that the length of the mesh is 1 to 8 cm by using a biodegradable filament yarn, but using some of the plurality of beams as another high-strength yarn in raschel knitting. to be.

The biodegradable fiber yarn may be used PLA or PBS yarn.

General biodegradable yarns that can be used in the present invention as above are commercially available products, and there is no particular limitation on the components thereof.

The method of manufacturing high-strength biodegradable PLA fiber yarn, which is one embodiment of the present invention, adds a heating / cooling device to a multistage stretching apparatus in a drawing zone in melt spinning so as to uniformly stretch while increasing the draw ratio while repeating heating and cooling during multistage stretching. There is a characteristic.

Looking at the polylactic acid (PLA) resin used in the present invention.

The polylactic acid (PLA) resin may be a commercially available resin and may be used as a production company (Cargill, Dow Polymers, Mitsui Chemical, Chronopol, or Dimadzu). Any kind may be used, regardless of). Used in the present invention It is preferable that the weight average molecular weights of PLA resin are 10,000-200,000.

Currently, PLA resin is one of a variety of biodegradable resins, and has been studied a lot in material engineering by adding substances that are not harmful to the human body, and are also used as scaffolds in tissue engineering. (Biomaterials. 2004 May; 25 (10): 1901-9., Avd Exp Med Biol, 2003; 534: 191-9., Ann NY Acad Sci. 2002 Oct; 974: 556-64). However, it is a biodegradable resin that possesses some characteristics from a general commercial point of view, not a special field such as medicine.

On the other hand, when looking at various biodegradable resins that are currently commercialized, PLA resins and aliphatic polyester resins (PBS, etc.) are most used, and polycaprolactam, P (HB-HV), and starch / PVA system are widely used. Biodegradable polymer resins have low melting point due to their chemical structure and are difficult to diversify their use due to their poor workability.

Table 1 shows the types and physical properties of various biodegradable resins.

Physical properties of various biodegradable resins Resin type and
Manufacturer PLA Aliphatic
polyester ε-caprolactam P (BH-HV) Starch / PVA system Nature works Digestive polymer Daicel Chemistry Geneca Japan Synthetic Chemistry importance g / cm ³ 1.27 1.26 1.14 1.23 1.28 Melting point ℃ 171 113 57 154 132 Exterior Transparency milk white milk white milk white milk white The tensile strength
Fracture
Flexural strength
Flexural modulus
Impact strength kg / cm ²
%
kg / cm ²
kg / cm ²
kgcm / cm 590
2
730
30,400
2.4 310
350
320
6,500
7.5 150
430
160
3,600
nb 240
7
250
9300
7.6 220
125
300
10,300
2.1

As shown in Table 1, PLA is characterized by its clear appearance, higher melting point than other resins, high tensile strength, and extremely low elongation at break. This feature is suitable for being used as a yarn for banners because it is made of high strength yarn.

Table 2 shows the chemical structure and thermal properties of these biodegradable fibers (PET is a general synthetic resin for comparison).

Thermal and Physical Properties of Various Biodegradable Resins Fiber name Primary structure Melting point crystallization
Temperature Glass transition temperature T _m Tc Tg PLA H- (OCH (CH ₃ ) CO) _n -OH 175 105 57 ε-caprolactam H- (O (CH ₂ ) CO) n-OH 60 22 -60 PBS H- (O (CH ₂ ) ₄ OOCC ₂ H ₄ CO) _n -OH 116 77 -32 PET H- (C ₂ H ₄ OOC (CH) ₆ CO) _n -OC ₂ H ₄ OH 256 170 69

As shown in Table 2, when compared to PET, which is currently used a lot of banners and yarns at home and abroad, it can be seen that PLA exhibits the physical and thermal properties closest to those of PET except for the melting point.

Therefore, in consideration of such physical and thermal properties, the present invention chose to develop a high strength yarn for banners based on PLA.

First, the general process for obtaining a fibrous biodegradable PLA resin is as follows.

The PLA resin is divided into L-type and D-type stereoisomers as stereoisomers, and it is preferable to use L-type PLA resins (PLLA) having relatively good elongation (Orientation).

In the above process, the lactic acid (lactic acid) may be cyclized (cyclization), and then lactide is produced, and then ring-opened and polymerized to produce a polylaevo enantiomer lactic acid (PLLA).

The PLLA produced by ring-opening polymerization is a crystalline polymer, which is difficult to have a high draw ratio, but has a characteristic of excellent mechanical properties after stretching, and its melting point (Tm) is 180 ° C., which is higher than other biodegradable materials. It can be maintained, which is advantageous for industrial applications such as banners.

Looking at the spinning (Spinning) process for the fiberization of PLA resin according to the present invention.

For the fiberization of the polymer resin, the molten polymer is melted through an extruder, the fiber is melted through a spinneret, the fiber is cooled through a cooling airflow, the drawing roller is stretched to the fiber side, and the fiber is wound through a winder. Is completed.

Looking at the spinning (spinning) process for the PLA resin fiber fiber of the present invention in detail.

 1) Melt Resin in Extruder

As mentioned in the previous table, the melting temperature of PLA resin is 170-180 ℃. Therefore, in order to melt the PLA resin and make it into fiber, it is necessary to heat it to a temperature higher than this. In particular, in order to produce fine fine fibers, the melt viscosity must be lowered to improve the flowability of the melt resin. The temperature gradient in the extruder is important. In the present invention, according to the thermal properties of the PLA resin to have the following temperature gradient.

 <Temperature gradient in the extruder>

division Supply department
(feed zone) Melting part
(melting zone) Extrusion
(compress
zone) Weighing
(metering
zone) Temperature (℃) 180-220 200-230 210-240 220-250

2) Selection of Radiation Detention

In order to extrude the molten PLA polymer into a fibrous shape, it is necessary to select the hole size of the spinneret based on the fibrous monodenier to be mass-produced. Based on the calculation, spin draft should be calculated and this value should be designed by selecting a spinneret hole size of 80-200 level that can maintain stable fairness. If the spin tension value is designed lower than 80, the spin tension is low and the solid point is shaken to obtain a uniform uniform fiber. On the contrary, if it exceeds 200, it is overstretched due to too high spin tension during spinning. It is a cause of a decrease in physical properties, in particular a decrease in strength and elongation, and a strong fiber cannot be obtained.

  (1) Finding the radial tension

      Radiation Tension = V2 / V1

     V1: initial velocity of spin off of polymer

     V2: High speed 1 roller speed

  (2) initial speed of departure

     ρV₁A = Q

      Q: discharge per hole (den x spinning speed x DR / (9000x odd))

      ρ: PLA density (1.34 g / cm³)

      V₁: Detention rate of PLA polymer

      A: cross-sectional area of the detention hole (πr², r = radius of the detention hole)

3) Drawing and heat setting process of PLA fiber

The stretching process of the polymer fiber is a process for acquiring the fiber properties (strength, elongation) in the process of polymerizing the fiber. At this time, the stretching process is a one-step stretching process and a multi-stage stretching process of two or more stages. Because the orientation process is too much orientation, the fiber does not win the orientation process and is cut. On the contrary, if the orientation is not sufficient, the stretching process is very important to secure the fiber properties because the strength of the fiber is weak.

In the present invention, the stretching ratio optimization test was carried out to secure the properties of the PLA fiber (strength 4g / den or more, elongation 50% or less) and it can be seen that the best physical properties are secured at the stretching ratio between 2.0 and 4.5 times depending on the spinning speed. there was. In addition, in this process, when the draw ratio is appropriate, the fibers are oriented in the axial direction according to the draw ratio. This orientation causes shrinkage in the axial direction when the fibers are used for the purpose of clothing, and the like. Since it is crucial to the shape stabilization of the product, it is necessary to thermally set the oriented molecular chain, and for this purpose, heat setting is performed by applying heat during the orientation (stretching) process, in the present invention, the temperature range of 80-140 ℃ Stable thermal setting was achieved. Outside of the stretching ratio and the stretching temperature range, it is difficult to obtain a yarn property suitable for the purpose of the fiber of the present invention.

4) Devise a device to increase the strength of yarn in PLA fiber

The stable use of PLA fiber has to solve the problem of strength degradation of the biodegradable fiber polymer.

However, PLA has a problem in order to increase the strength of the yarn. In general, the high strength of the synthetic fiber is increased by high magnification (multistage stretching) in several stages, and thus the degree of crystallization due to the orientation crystallization. In order to increase the thermal energy of the yarn must be supplied.

 This will be described in more detail as follows.

The most effective method of increasing the strength of yarn in the fiberization process of the polymer material is high orientation of the molecular chain in the polymer in the fiber axis direction.

This is because in the case of all synthetic polymers, the crystalline and amorphous regions are repeatedly formed in the process of fiberization, thereby imparting physical properties to the fibers. The ratio between these crystal parts and amorphous parts Depending on the degree of orientation, physical properties, such as strength, elongation, shrinkage, and the like, vary.

 That is, the strength of the yarn increases as the fraction of the relatively strong crystal region in the yarn increases. These results can be seen by measuring the degree of crystallinity in the yarn by X-ray diffraction, but the strength of the yarn with high crystallinity is high.

 In other words, when the fiber polymer is spun and stretched in the direction of the fiber axis, the nuclei formed during the spinning process grow into crystals as they are stretched. When the draw ratio is increased, the molecular chains around the nucleus are bound together. At the same time, they form a folded chain, and as these chains increase, they grow into crystals and the crystallinity increases as the process continues.

The process of increasing the strength in the fiber can be achieved by this method of increasing the crystallinity.

However, it is not possible to increase the draw ratio unconditionally to increase the strength of the yarn. The molecular chains present in the synthetic polymers are randomly aligned, and the stretching process to orient them in the direction of the fiber axis requires a temperature above the glass transition temperature to cause the partial chain to move in the direction of the fiber axis. The provision of requires a supply of energy from the outside.

In other words, by supplying heat energy from the outside to increase the internal energy of the molecular chain, the increase of the internal energy increases the mobility (mobillity) of the molecular chain can be free movement of the molecular chain.

Accordingly, the present invention has led to the introduction of a heating & cooling system in the multistage extension zone of the radiator as such an external energy source.

However, since high magnification stretching, which can obtain high strength of yarn, is made by forcibly supplying energy to increase free mobility of the partial chain, more energy than the energy supplied in the yarn manufacturing process is input during the post-process use after manufacturing the yarn. In this case, the free movement of the molecular chains in the yarn occurs and the orientation is disturbed, resulting in a higher shrinkage of the yarn.

That is, when high-oriented yarns are manufactured to realize high strength, yarns of high shrinkability are inevitably manufactured.

Therefore, in order to prevent this, high temperature heat setting is performed at the last step during the high-strength yarn manufacturing process, in order to prevent the yarn orientation from being dispersed even if a lot of energy is applied in the later process.

 The heating and cooling system proposed in the present invention is a system designed to maintain uniform shrinkage between monofilaments and stable shrinkage after stretching in a highly oriented stretching process of multifilament yarns. In the case of a godet roller, the filament is stretched at high speed to provide heat to help the drawing process of the yarn.If the yarn is in contact with these high rollers and is multifilament, the filament is stretched without contact with the filament in contact with the hot drawing roller. There is a problem in that the supply energy non-uniformity between the liver and the filament, which is given little energy, does not endure the high magnification draw ratio in the high magnification drawing process and is cut. Therefore, even if you want to perform a high magnification stretching through the energy supply in the fiber, due to the cutting of the filament that does not receive enough energy, there is a limit to select and draw a lower draw ratio. This limits the yield of high strength yarns.

Theoretically, this is as follows.

The temperature gradient between the filaments changes the elastic stress inside the yarn. The mechanism is as follows.

In general, dv / dx is regarded as a constant in the radial drawing process, so σ has a value proportional to η _e .

However, _e can be expressed as

In Equation 4, η _e and E are inherent physical properties of the polymer, so it can be seen from Equations 3 and 4 that η _e and σ are inversely proportional to temperature.

That is, in the orientation crystallization of the yarn it can be seen that the elastic stress (tensile stress) changes with temperature.

Therefore, a uniform temperature gradient between the filaments gives the same elastic stress in the orientation crystallization process of the yarn, which enables uniform stretching.

In order to achieve a uniform temperature gradient, the present invention designs a multi-stage heat supply device to increase the probability of contacting the heat supply device between the filaments and to supply heat in multiple stages, thereby increasing the time of exposure to the same temperature, thereby realizing a uniform temperature gradient. Through this, it was possible to achieve uniform temperature gradient between filaments in multifilament.

By the way, when the heat supply device is unidirectionally heated, a temperature gradient between the contact surface and the non-contact surface may occur, and thus, a cooling zone is set in the middle to reduce the temperature gradient deviation.

In addition, in the last step, the heat setting is performed while passing through the heat setting rollers of the two stages, and it is designed to have a stable shrinkage rate.

In the present invention, a heating and cooling system was devised in the multistage hot drawing apparatus as described above and shown in FIGS. 1 and 2.

Figure 1 shows a radiator with a heating cooling system of the present invention, Figure 2 is an enlarged view of the heating cooling system of the present invention, the structure of the spinning machine with a multi-stretch drawing spindle for producing a general yarn is heated in the multi-stage drawing zone It is designed to increase the draw ratio by attaching a cooling device.

1 and 2, in the present invention, the radiated PLA spinning yarn (multifilament yarn) 102 is introduced into the heating cooling system 110 through a multi-stage stretching apparatus by a series of multi-stage stretching rollers. In the heating cooling system 110 to achieve uniform polymer orientation in the longitudinal direction or the circumferential direction while alternately passing through the cooling rollers 113 and the heating rollers 111, spinning and knit knitting processability and fiber formability To improve. The temperature of the cooling rollers is 15 to 50 ℃, it is preferable that the temperature of the heating rollers is 90 to 140 ℃.

Outside the temperature range, the properties of the spun yarn do not meet the target or the processability is poor.

The heating cooling system as described above is provided with high-temperature rollers 112 and 113 for heat setting at the end to heat set at a temperature of 80 to 140 ° C. while the yarn passing through the heating cooling rollers passes.

In this way, the yarn having passed through the heating cooling system is wound around the winding device 123 via the known heating or cooling rollers 121 and 122.

In the present invention, a series of machining devices (air interlace, etc.) may be provided between the heating and cooling rollers 121 and 122.

5) False twist, Draw texteuring

The biggest disadvantage of the polymer synthetic fibers is that the bulkiness is bad compared to the natural fibers and the surface is smooth and the touch is degraded. In order to overcome this problem, the existing synthetic fibers are used to cover the shortcomings of synthetic fibers through the after-processing process, the most typical of which is twisting, false twisting, or ATY (Air texturing yarn) processing.

 In the present invention, a method for increasing the sensitivity of the fabric was carried out by performing the twisting, twisting and ATY processing as a four-step method for increasing the sensitivity of PLA fiber.

Double-burning processing is the most commonly used emotional enhancement processing method, and PLA fiber must satisfy significantly different conditions from existing synthetic fibers in order to proceed stably in the combustion process. In other words, PLA fiber has a much lower melting point than conventional synthetic fibers, so it must be processed at low temperatures, and has a lot of differences in stretching ratio and D / Y ratio (disk rotation ratio / spin ratio).

In the flammability processing, the draw ratio is a factor that stably causes flammable yarn without passing through the yarn passing through the flammable unit, but is 1.14 to 2.5 in the present invention.

If the draw ratio is more than 2.5, the badness caused by cutting is severe, and the workability is poor. If the draw ratio is lower than 1.14, the yarn is not twisted and decomposed properly, resulting in poor bulkiness.

In addition, the combustion temperature was 80 to 135 ℃ to ensure the most stable physical properties and fairness.

The most important thing to save the yarn's sensitivity in the combustible processing is the D / Y ratio, which is the ratio of the twist of the yarn and the loose smoke released, which is correlated with the draw ratio to influence the bulkiness of the yarn.

In the present invention, in the case of PLA fiber is 1.5 to 2.7, the sensitivity is not good beyond this range. Here, the term "sensibility" may be understood as a general term for the good properties of the fiber, such as fibrousness, touch, and shape stability.

In addition to the flammable processing, soft drawing or ATY processing can be performed by a known method.

In addition, in the present invention, in order to meet the flame retardancy required in the field installation of the banner, it is possible to impart a flame retardant to the PLA resin in the master batch form.

That is, since the basic PLA resin is not flame retardant, it is preferable to add 3-10% by weight of the phosphorus-based flame retardant to the PLA resin.

The phosphorus-based flame retardant is to impart the flame retardancy required when using the yarn, the organic (mainly halogen-based compound) flame retardant is excellent flame retardant performance, but in the process of refraining from use due to suspected carcinogens, in the present invention mainly phosphorus inorganic flame retardant (P) type flame retardant was used.

If the phosphorus-based flame retardant is used at less than 3% by weight, the oxygen limit index (LOI) value is 22 or less, which is not suitable for the application of fiber yarns, and when it exceeds 10% by weight, the LOI 26 or more can be achieved. However, high yield cannot be guaranteed because yarn yield is lowered during the yarn manufacturing process, resulting in a decrease in yarn performance.

Method for producing a fabric for a placard using the high strength biodegradable PLA filament yarn of the present invention inclined 50 to 800 denier PLA biodegradable fiber yarn prepared as described above and the PLA biodegradable fiber yarn or other biodegradable yarn as a weft By weaving the warp density to 50 to 120T and the weft density to 40 to 120T; Refining or dyeing the woven fabric in a conventional manner; Heat setting at a temperature of 100 to 130 ° C .; It is made by cutting by melt cutting using heat to an appropriate size.

In order to manufacture indoor and outdoor display fabrics, both plain weave and twill weave are available. In the case of plain weave yarns, weaving can be made using biodegradable fibrous yarns of 50 to 800 days, and the density of the fabric is 50 to 120T. In the weft direction, the density of 40 to 120T is preferable because there is no fear of damage or damage caused by wind or the like in an indoor or outdoor environment in terms of breathability. Twill weave does not differ significantly in the thickness and density of yarn.

In order to obtain this kind of fabric, it can be manufactured in all kinds of looms. For example, weaving can be made with the yarn specifications and densities described above in water jet looms and rapier looms, drum looms, air jet looms and the like. However, since the elastic force of the yarn is lower than that of general chemical fibers due to the characteristics of the biodegradable yarn, it is desirable to lower the initial inclination tension during initial machine operation. As a method for lowering the initial tension in the inclined direction, it is possible to lower the guide roller angle of the inclined portion to lower the tension applied when the inclined portion enters the jet room.

The fabric thus produced is obtained through the steps of refining, dyeing, coating, and cutting to look at each process as follows.

Refining refers to attaching spin-finish oil so that the yarn injected into the fabric manufacturing process has a lubricating property during yarn manufacturing and lowers the friction during post-processing. It is a process to remove dye before dyeing because it can show dyed spots.

 In general, the land value dyeing machine and the rapid dyeing machine consists of a pretreatment process before dyeing, and the progress is made of a process of washing with water in boiling water at 100 ° C.

 Refined fabrics are dyed with disperse dyes in paper or rapid dyeing machines. The dyeing conditions are white with acid dyes and reactive dyes at 100 ℃ in the case of paper dyeing machines and white at 130 ℃ under high pressure in the rapid dyeing machines. You will get a dyed paper fabric. Such dyeing process will be easily understood by those skilled in the art as a conventional synthetic fiber dyeing process.

This dyed fabric is finally manufactured through heat setting (heat setting, tentering process) and finished product. At this time, the temperature normally used for manufacturing chemical fiber in heat setting process is 160-200 ℃, which is normal biodegradation. Low heat setting is essential because most biodegradable polymers melt at temperatures above the melting point (Tm) of the raw materials. In the present invention, it is preferable to do at 100-130 ° C. and outside the above range, the shape of the fabric is unstable and the handling is poor.

The fabric thus manufactured can be used in the form of dyed paper, but it is desirable to coat it with a thin film in order to increase the print quality of the fabric and to ensure the shape stability of the fabric. The material used as the coating material is also a biodegradable raw material ( It is preferable to coat thinly using biodegradable resin such as PLA, PBS, PBAT, PCL, and starch.

 The thickness of the coating can generally be on the order of 10-100 μm. Outside the thickness range of the coating, printing is poor or the shape stability of the fabric is lowered.

Finally, the fabrics are subjected to a cutting process. The standard fabrics for banners are used in various sizes, such as 60 cm, 90 cm, and 120 cm. Problems such as loosening, sagging edges, and wrinkles may occur, so it is advantageous to melt-cut using heat when cutting the fabric. Laser cutting, high frequency cutting, ultrasonic cutting, hot knife, etc. can be used for the cutting method using such heat.

The method for producing a protective membrane knitted fabric using the high-strength biodegradable PLA fiber yarn of the present invention, in the Raschel knitting, using the high-strength biodegradable PLA fiber yarn of the present invention, but a part of the plurality of beams to a high strength yarn to the length of the mesh It is characterized by setting it as 1-8 cm.

The high strength yarn may be selected from the group consisting of PLA monofilament yarn, high strength nylon yarn, high strength PE yarn, high strength PET yarn, and high strength PP yarn.

In general, a Raschel knitting machine can manufacture a net using 7 kinds of yarns.The net is manufactured when the falling weight falls on a protective film due to heavy falling impacts or labor, and the impact of the net is stretched. As a form of the present invention, a PLA high-strength yarn was applied to six bars of the Raschel netting structure in which seven bars were used, and more strength was applied to the other one bar to reinforce the strength of the mesh. High PLA monofilament yarn, high strength nylon yarn, high strength PE yarn, high strength PET yarn and high strength PP yarn were applied.

In the present invention, it will be readily understood by those skilled in the art that the number of bars to which the biodegradable yarns in the Raschel knitting machine or the number of bars to which the high-strength yarns are applied is not necessarily limited.

The net structure of the Raschel structure of the present invention can be freely adjusted in a knitting machine, but in the present invention, the length of the mesh is preferably in the range of 1 to 8 cm in consideration of the stable collection of falling objects and the impact absorption strength of the protective film. More preferably, the range of 2-6 cm is good. If the length of the mesh exceeds 8 cm, the tensile strength and impact strength will be reduced, and heavy falling objects cannot be collected. If the length of the mesh is too short, less than 1 cm, the input of the yarn will be high, resulting in a high cost of manufacturing the banner, resulting in economic efficiency. do.

Hereinafter, preferred embodiments of the present invention will be described.

The following examples are illustrative only and should not be understood as limiting the scope of the invention.

Example

&Lt; Example 1 >

Using a general biodegradable yarn commercially available or melt spinning equipment as shown in Figure 1 by beaming a high strength PLA biodegradable fiber yarn of strength 5g / den or more produced by spinning a PLA resin having a molecular weight of 120,000 Six beams were prepared, doubled to form a warp weaving beam, and a weaving support for banner was made of plain weave with a weft density of 58T (T = density per inch) and a warp density of 85T in a waterjet loom.

In order to use the prepared bio-support stage as a banner, white dyeing was performed after refining in a rapid dyeing machine, and then a coating solution made of a biodegradable polymer (starch system) was 30 μm thick in order to obtain a toughness of a fabric suitable for a fabric for a banner. It was applied to prepare a high strength biodegradable fabric of the present invention.

The tensile strength was measured by the following method in order to find out whether the fabric for banners can withstand strong winds. The specimen of the banner was used to cut the part constituting the fabric, the tensile test speed was 20 cm / min (test section: 15-30m / min) in Instron. The average value measured was 35 kgf using normal biodegradable yarns and 40 kgf using newly prepared high strength polylactic acid fiber yarns. Such tensile strength is usually one having sufficient tensile strength that can be used for banners installed for indoor and outdoor timekeeping.

As a result of measuring the air permeability of the manufactured fabric for banner, it showed the same level as the banner fabric of the conventional PET material.

<Example 2>

Six filament beams were made using the PLA high-strength fiber yarn manufactured as in Example 1, and the warp yarn density was prepared as in Example 1 using a strong PBS fiber (strength of 5 g / den) after doubling them to prepare a warp beam. After manufacturing the fabric for the banner to the 85, 58T, as in Example 1 to prepare a banner fabric that is installed horizontally through the process of refining, dyeing, coating. Tensile strength and air permeability test for this was carried out in the same manner as in Example 1, the tensile strength of 40kgf and air permeability of 11 or more. Such physical properties are sufficient to be used as a fabric for banners.

<Example 3>

Six filament beams were made using the PLA high-strength biodegradable fiber yarn prepared as in Example 1, and the sloped beams were manufactured by doubling them, and the weft yarn densities were 85 and 55T using PBAT yarns in waterjet looms. After preparing the fabric for the banner under the same conditions as in Example 1, a banner was installed horizontally using the same. Tensile strength and air permeability test for this was carried out in the same manner as in Example 1, the tensile strength 40 kgf and air permeability of 10 or more.

Such physical properties are sufficient to be used as a fabric for banners.

<Example 4>

Using a general biodegradable yarn commercially available or melt spinning equipment as shown in Figure 1 by beaming a high strength PLA biodegradable fiber yarn of strength 5g / den or more produced by spinning a PLA resin having a molecular weight of 200,000 Six beams were prepared, and one beam was prepared with high-strength PLA monofilament yarns, and then connected to a Raschel knitting machine bar equipped with seven bars.

The protective membrane thus prepared should have an allowable tensile strength. The tensile strength of the protective membrane was measured by the following method. Specimens of the protective membranes were cut and carried out at an instron with a tensile test speed of 20 cm / min (test section: 15-30 m / min). The average value measured was 63 kgf using normal biodegradable yarns and 75 kgf using newly prepared high strength polylactic acid fiber yarns. These measurements have been found to have sufficient tensile strength for use in horizontally installed barrier membranes above the minimum allowable strength (60 kgf and above) specified in safety standards.

In addition, a protective film sample (test network) installed horizontally in a size of 3 m x 3 m was made, and the impact strength (deceleration) was measured by the following method. A hanging rope was used to connect the four corners of the test network and the center of each side to the running tools of the fall test facility. A weight having a weight of 90 kg was dropped from the bottom of the test network at the center of the banner at 2.25 m to measure the deceleration of the weight.

The measured deceleration showed a value of 12 or less and 10 or less, which was significantly lower than the value required by the safety standard (15 or less), demonstrating that the protective film fabric of Example 4 has a safe shock absorbing ability.

<Example 5>

A high-strength PLA biodegradable fiber yarn having a strength of 5 g / den or more as in Example 4 was prepared and beamed to prepare six beams, and one beam using high-strength polypropylene fiber (strength of 7 g / den). Was made and applied to a knitting machine as in Example 4 to prepare a protective film fabric.

 Tensile strength and impact strength thereof were carried out in the same manner as in Example 4, and values of 70 kgf and a deceleration of 11 or less were obtained.

The protective film fabric of Example 5 was also shown to possess a safe shock absorbing ability.

 <Example 6>

A high-strength PLA biodegradable fiber yarn having a strength of 5 g / den or more as in Example 4 was prepared and beamed to prepare 6 beams, and one high-strength PET fiber (strength: 8 g / den or more) was used. A beam was made and applied to a knitting machine as in Example 4 to prepare a protective film fabric.

 Tensile strength and impact strength thereof were carried out in the same manner as in Example 4, and values of 80 kgf tensile strength and a deceleration rate of 10 or less were obtained.

The protective membrane fabric of Example 6 was also shown to possess safe shock absorbing capacity.

Outdoor time-saving banner or construction protective film using PLA yarn, which is an eco-friendly biodegradable material, has excellent tensile strength and breathability, so it is not easily damaged by external shocks, and is resistant to environmental changes such as strong winds. Has

The banner or protective film of the present invention is completely decomposed by the microorganisms within a few months even after use, or most of them are decomposed to solve the environmental pollution problem.

PLA high-strength biodegradable yarn of the present invention will be able to extend its use to eco-friendly shopping carts, eco-friendly nets, marine ropes, fishing nets, as well as banners or protective membranes.

In addition, since the yarn was prepared by applying a flame retardant by directly inputting a flame retardant during the manufacture of the yarn, there is an advantage that it is simpler than the existing flame retardant banner in the post-process like the existing banner, and also has the advantage of securing semi-permanent flame retardancy.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims. .

1 is a schematic view of a melt spinning apparatus for spinning the biodegradable polylactic acid high strength fiber yarn of the present invention,

FIG. 2 is an enlarged view of the heating cooling system of FIG. 1.

<Description of the symbols for the main parts of the drawings>

101: spinning emulsion device 102: spinning yarn

110: heating cooling system 111: heating roller

113: cooling roller 112, 114: high temperature roller

121: heating roller 122: cooling roller

123: winding device

Claims (16)

In the melt melt spinning of polylactic acid (PLA) resin, The temperature in the extruder is 180 to 220 ° C. for the feed part, 200 to 230 ° C. for the melt part, 210 to 240 ° C. for the extruder part, 220 to 250 ° C. for the metering part, and 80 to 200 for the radial tension. Biodegradable polylactic acid, characterized in that the stretching in multiple stages while increasing the total draw ratio to 2.0 to 4.5 at uniform temperature in the filament radial and longitudinal direction by the heating and cooling system 110 to repeat the heating and cooling Manufacturing method of high strength fiber yarn. The method of claim 1, Preparation of the biodegradable polylactic acid high strength fiber yarn, characterized in that the addition of further twist processing, or further added twist yarn or ATY processing at a flammable temperature of 80 to 130 ℃, elongation ratio 1.14 to 2.5, D / Y ratio 1.5 to 2.7 Way. The method according to claim 1 or 2, The heating cooling system has a plurality of heating rollers and the cooling rollers are arranged alternately and is equipped with a high temperature roller set for heat setting at the end, the temperature of the cooling rollers is 15 to 50 ℃, the temperature of the heating rollers The biodegradability is characterized in that the temperature of the high temperature roller is set to 90 to 140 ℃, 80 to 140 ℃ the radiated yarn is heat set through the high temperature roller set after passing through the heating rollers and cooling rollers alternately. Method for producing polylactic acid high strength fiber yarn. The method according to claim 1 or 2, The method of producing the biodegradable polylactic acid high strength fiber yarns, characterized in that the melt spinning method is a multi-stretch stretching spin draw method. The method according to claim 1 or 2, Wherein the PLA resin is the L-type stereoisomer PLLA (Poly Laevo enantiomer Lactic Acid), the method of producing a biodegradable polylactic acid high strength fiber yarn, characterized in that the molecular weight of 10,000 to 200,000. The method according to claim 1 or 2, 3 to 10% by weight of the phosphorus-based flame retardant is added to the PLA resin in a master batch method. delete  50 to 800 denier of polylactic acid biodegradable fiber yarn produced by the method of claim 1 is inclined, and the warp density is 50 to 120 T and weft density using general biodegradable yarn or polylactic acid biodegradable fiber yarn as weft yarn. Weaving to 40 to 120T; Refining or dyeing the woven fabric in a conventional manner; Heat setting at a temperature of 100 to 130 ° C .; And Cutting by melt cutting using heat to an appropriate size; Method for producing a fabric for banners using biodegradable fiber yarns made of. The method of claim 8, wherein the general biodegradable yarn is PLA or PBS yarn. 10. The method according to claim 8 or 9, Method of manufacturing a fabric for a banner using the biodegradable fiber yarn, characterized in that the coating to a thickness of 10 to 100㎛ with a biodegradable resin in order to improve the print quality and form stability after the heat setting step. delete A biodegradable polylactic acid high strength fiber yarn prepared by the method of claim 1 is used to knit a Raschel knitting machine, wherein some of the plurality of beams are made of another high strength yarn, and the length of the mesh is 1 to 8 cm Method for producing knitted fabric for protective membrane using biodegradable fiber yarn. delete The method of claim 12, The other high strength yarns are any one or more selected from the group consisting of polylactic acid monofilament yarn, high strength nylon yarn, high strength PE yarn, high strength PET yarn, and high strength PP yarn. Method for producing a protective film for the protective film. The method of claim 12, There are seven beams, and six of the seven beams are made of the biodegradable polylactic acid high strength fiber yarn, and one of the beams is the other high strength yarn. Manufacturing method. The biodegradable fiber yarn is prepared by the method of claim 12, wherein the biodegradable polylactic acid high strength fiber yarn and the other high strength yarn are mixed and knitted, and the mesh is 1 to 8 cm in length. Method for producing knitted fabric for protective membrane.

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