KR101226225B1 - Aramid nonwoven fabric and preparation method thereof - Google Patents

Abstract

The present invention relates to an aramid nonwoven fabric and a method for producing the same, which are preferably used in a drying apparatus or an ironing apparatus of a laundry, while exhibiting excellent heat transfer efficiency while having excellent shape stability and durability at high temperatures.

The aramid nonwoven fabric is composed of meta-aramid fibers having a fineness of 3 to 10 denier, and has a density of 0.10 to 0.25 g / cm ³ .

Aramid Nonwoven, Fineness, Density, Breathability, Form Stability, Laundry, Drying Equipment

Description

Aramid nonwoven fabric and its manufacturing method {ARAMID NONWOVEN FABRIC AND PREPARATION METHOD THEREOF}

The present invention relates to aramid nonwovens and methods for their preparation. More specifically, the present invention relates to an aramid nonwoven fabric and a method for producing the same, which can be preferably used in a drying apparatus or an ironing apparatus of a laundry as it exhibits excellent heat transfer efficiency while having excellent shape stability and durability at high temperatures.

In the modern world, the laundry industry has been developed so that means can be designed to efficiently and cheaply handle large-scale daily laundry in multi-use facilities such as hotels, youth hostels, condominiums and hospitals. That is, apparatuses capable of simultaneously processing laundry by centrally collecting laundry have been devised and used. These laundering units are made up of individual installations in a huge, consistent process to handle laundry more effectively. Among the laundry machines, machines have been developed that are consistent with the drying and ironing processes, which shorten the process and make the laundry system faster and more efficient.

Figure 1 shows a simplified view of an example of such a drying apparatus or an ironing apparatus.

Such a drying apparatus or an ironing apparatus has a structure in which at least two large cylinders having a diameter of 1M or more and a width of 2M or more are horizontally paralleled. At the bottom of the cylinder, a semi-circular smooth stainless steel plate is fixedly arranged. The gap between the cylinder and the iron plate is spaced into a space that is not large enough for the laundry to pass through, and the laundry is dried or ironed as the laundry moves along this space with the rotation of the cylinder. At this time, a steam of 150 ° C or higher is sprayed into the iron plate to dry or iron the laundry. At the same time, inside the cylinder, the suction device is operated to allow the high temperature of the iron plate surface to move through the laundry and into the cylinder, further accelerating the drying or ironing efficiency.

At this time, the hot air passing through the laundry can be easily sucked in and passed through the cylinder while keeping the laundry close to the surface of the hot smooth iron plate so that the ironing can be performed at the same time as the drying starts and the drying efficiency is further improved. The necessity of attaching a material to the surface of the cylinder appears.

Above all, this material should be excellent in stability at high temperature because it is exposed for a long time at a high temperature of more than 150 ℃. In addition, it must exhibit excellent heat transfer efficiency so that hot air and steam can easily pass, and must also have elasticity in the thickness direction because it must serve to adhere the laundry. In addition, during long-term use, the material should not be embrittled at high temperatures or destroyed by friction with laundry to generate secondary contamination, and dimensional stability before and after use should be maintained.

Although various nonwoven fabrics and the like have been considered as such materials, materials that simultaneously exhibit sufficient stability at high temperatures, durability, and excellent heat transfer efficiency have not been developed.

Accordingly, the present invention is to provide an aramid nonwoven fabric which is excellent in form stability and durability at high temperature and excellent heat transfer efficiency, which can be suitably used in a laundry drying apparatus.

The present invention also provides a method for producing the aramid nonwoven fabric.

The present invention provides an aramid nonwoven fabric composed of meta-aramid fibers having a fineness of 3 to 10 denier and having a density of 0.10 to 0.25 g / cm ³ .

The aramid nonwoven fabric may be of a single layer structure, but is made of meta-aramid fibers having a fineness of 3 to 6 deniers, and has a density of 0.15 to 0.25 g / cm ³ ; And it consists of meta-aramid fibers having a fineness of 5 to 10 denier, and may be composed of two or more layers including a second nonwoven layer having a density of 0.10 to 0.20 g / cm ³ .

In addition, the present invention comprises the steps of carding (carding) meta-aramid fibers having a fineness of 3 to 10 denier to form a web; And it provides a method for producing an aramid nonwoven fabric comprising the step of needle punching the web four or more times.

The present invention also provides a method for forming a first web by carding meta-aramid fibers having a fineness of 3 to 6 deniers; Needle punching the first web three or more times to form a first nonwoven layer; Carding meta-aramid fibers having a fineness of 5-10 denier to form a second web; Needle punching the second web three or more times to form a second nonwoven layer; And it provides a method for producing an aramid nonwoven fabric having a two-layer or more structure comprising the step of laminating the first and second nonwoven layer.

Hereinafter, the aramid nonwoven fabric and the preparation method according to the embodiment of the present invention will be described in detail.

According to one embodiment of the invention, there is provided an aramid nonwoven fabric consisting of meta-aramid fibers having a fineness of 3 to 10 denier and having a density of 0.10 to 0.25 g / cm ³ .

The aramid nonwoven fabric according to the embodiment of the present invention basically consists of a main material of meta aramid fibers, most preferably made of 100% of meta aramid fibers. Such meta-aramid fibers exhibit excellent heat resistance, and especially high temperature stability for a long time, even when compared to other fibers known to exhibit excellent heat resistance, such as polyphenylene sulfide fibers, polyimide fibers, para-aramid fibers or carbon fibers, or the like. It is advantageous in terms of elasticity or economy for durability, adhesion of laundry, and the like. Moreover, since the meta aramid fibers have a decomposition temperature higher than 150 ° C. and show little deterioration in elasticity even at high temperatures, compared with other fibers such as polyphenylene sulfide fibers, the aramid nonwoven fabric made of such meta aramid fibers is While exhibiting high form stability and durability at high temperatures, it can exhibit excellent elasticity suitable for adhesion of laundry and the like.

In addition, the aramid nonwoven fabric according to an embodiment of the present invention consists of meta-aramid fibers having a fineness of 3 ~ 10 denier. The thickness of the fibers making up the nonwoven is directly related to elasticity and rigidity. Usually, the larger the fiber, the greater the elasticity and rigidity, and the thinner the elasticity and rigidity, the smaller the fiber. That is, since the aramid nonwoven fabric is made of relatively coarse fibers of 3 denier or more, the fibers forming it exhibits excellent elasticity and rigidity, the aramid nonwoven fabric itself also exhibits excellent elasticity in the thickness direction and high form stability and durability at high temperatures. Can be. In addition, as the aramid nonwoven fabric is made of a relatively coarse fiber, it can exhibit excellent porosity and thus excellent heat transfer efficiency by showing a porosity. However, when the meta-aramid fibers have a thickness of 10 denier or more, the entanglement between the fibers through the needle punch process is insufficient in the manufacturing process of the aramid nonwoven fabric using the same, not only reduces the elasticity of the aramid nonwoven fabric but also tensile strength and surface At the same time, the friction strength may also drop, causing the nonwoven fabric fibers to fall off due to friction with the laundry. Accordingly, it has been found that the aramid nonwoven fabric is made of meta-aramid fibers having a thickness of 3 to 10 deniers, thereby exhibiting excellent elasticity and heat transfer efficiency with excellent stability and durability at high temperature.

In addition, the aramid nonwoven fabric according to one embodiment of the invention has a density of 0.10 to 0.25 g / cm ³ . If the density of the nonwoven fabric is less than 0.10 gr / cm ^3, too bulky structure will appear, so the shape stability at high temperature It becomes poor, and if the density exceeds 0.25 g / cm ³ , the air permeability and thus the heat transfer efficiency may decrease. Accordingly, as the aramid nonwoven fabric has an appropriate level of density of 0.10 to 0.25 g / cm ³ , it can exhibit excellent air permeability and heat transfer efficiency with excellent durability and form stability at high temperature, laundry drying apparatus or ironing It has been found that the device can be preferably used.

As described above, the aramid nonwoven fabric according to one embodiment of the invention is made of meta-aramid fibers having a predetermined fineness, and having a certain level of density, excellent heat resistance, in particular, excellent durability and form stability at high temperatures In addition, it has been found that it exhibits excellent elasticity in the thickness direction, thereby effectively adhering the laundry in the drying apparatus, and exhibiting excellent air permeability and heat transfer efficiency.

Therefore, it has been found that such aramid nonwoven fabric can be preferably used as a material for improving the drying efficiency of laundry by closely attaching the laundry and efficiently transferring heat into the cylinder of the drying apparatus.

On the other hand, in the aramid nonwoven fabric, the meta aramid fibers may have a length of 30mm or more, preferably 30 ~ 80mm. As a result, the aramid nonwoven fabric can exhibit a tensile strength suitable for being applied to a laundry drying apparatus or an ironing apparatus, and can take an appropriate nonwoven form.

In addition, the aramid non-woven fabric may exhibit a breathability of 100 / l / dm ² / min, preferably 100 ~ 500 | / dm ² / min. More preferably, the aramid nonwoven fabric exhibits a breathability of at least 150 | / dm ² / min and most preferably at least 200 | / dm ² / min. As such, the aramid nonwoven fabric can exhibit excellent heat transfer efficiency, and can smoothly remove moisture generated in the form of hot mist when the laundry is dried to suppress contamination of the inside of the workplace and the laundry. In addition, the heat exchange during the drying process can be facilitated to improve the overall drying and ironing process of the laundry. However, if the air permeability of the aramid nonwoven fabric is too high, the structure of the nonwoven fabric is not dense, the morphological stability in the thickness direction may be lowered, thereby suitably for a laundry drying apparatus or an ironing apparatus for a long time maintained at a high temperature of 150 ℃ or more Not applicable

In addition, the aramid nonwoven fabric can exhibit excellent form stability and durability at high temperatures so that it can be suitably applied to a drying apparatus or an ironing apparatus of a laundry that is maintained for a long time at a high temperature of 150 ℃ or more. For example, the aramid nonwoven fabric has a weight loss rate of 10% or less and a post-reduction rate of 20% or less after exposure at 150 ° C. for 2000 hours, thereby exhibiting excellent form stability and durability at high temperatures (heat resistance), Accordingly, the laundry may be suitably applied to a drying apparatus or an ironing apparatus. If the shape stability or durability at high temperature of the aramid nonwoven fabric is less than this, in the process of applying the aramid nonwoven fabric to drying or ironing of the laundry, under the high temperature environment, the contact with the laundry under high temperature may greatly reduce the thickness. Accordingly, the ability to move while holding the laundry or the performance of pressing the laundry in close contact with the hot plate may be greatly reduced. For this reason, it may not be used suitably for the said laundry drying apparatus or ironing apparatus.

The aramid nonwoven fabric described above exhibits excellent thickness direction elasticity and heat transfer efficiency, together with excellent form stability and durability (heat resistance) at high temperatures, and thus, for example, in a laundry or ironing apparatus for laundry as shown in FIG. It can be preferably applied.

That is, such aramid non-woven fabric exhibits excellent elasticity in the thickness direction, it is possible to achieve effective drying and ironing while close to the laundry between the cylinder and the iron plate of the drying apparatus or ironing apparatus. In addition, the aramid non-woven fabric can be made to dry and iron the laundry more effectively while transferring the heat generated in the iron plate to the laundry to the cylinder, for example, the high temperature of 150 ℃ or more is maintained for a long time It can be used for a long time while maintaining good form stability and durability in the drying or ironing apparatus.

On the other hand, the aramid nonwoven fabric described above, for example, carding the meta-aramid fibers having a fineness of 3 to 10 denier (carding) to form a web; And needle punching the web four or more times. That is, while using a meta aramid fiber having an appropriate fineness of 3 to 10 denier, while needle punching at least four times in the needle punching step, made of a meta aramid fiber having a suitable fineness of the 3 to 10 denier, It has been found that aramid nonwovens having a preferred density of 0.10 to 0.25 g / cm ³ can be produced.

As already described above, the aramid nonwoven fabric thus produced exhibits excellent thickness direction elasticity and heat transfer efficiency, together with excellent durability and form stability at high temperatures, and thus can be preferably used in a drying apparatus or an ironing apparatus for laundry.

In the method for producing the aramid nonwoven fabric, in the needle punching step, the needle punch may be performed only in either of the upper and lower surfaces of the web, but preferably, the needle punch is alternated from both sides of the web. As such, an aramid nonwoven fabric can be produced in which the fibers are sufficiently entangled with each other on the front and back surfaces of the aramid nonwoven fabric, which exhibits better high temperature morphological stability and heat transfer efficiency.

In the method for producing the aramid nonwoven fabric, the process of carding the meta aramid fibers to form a web and the other conditions of the needle punching the web is in accordance with the conventional manufacturing process of aramid nonwoven fabric, which is obvious to those skilled in the art.

In addition, although the aramid nonwoven fabric mentioned above may consist of a single layer structure as mentioned above, it may have a structure of two or more layers demonstrated below.

According to another embodiment of the present invention, the first non-woven fabric layer made of meta-aramid fibers having a fineness of 3-6 denier, having a density of 0.15-0.25 g / cm ³ ; And a second a nonwoven layer consisting of meta-aramid fibers having a fineness of 5 to 10 denier and having a density of 0.10 to 0.20 g / cm ³ .

In this aramid nonwoven fabric, for example, in the drying apparatus or the ironing apparatus as shown in Fig. 1, the nonwoven fabric layer in the direction of contact with the laundry and the nonwoven layer in the direction of contact with the opposite cylinder were separately formed. That is, the first nonwoven fabric layer in the direction of contact with the laundry is formed of meta-aramid fibers having a lower fineness of 3 to 6 denier, and formed to have a higher density of 0.15 to 0.25 g / cm ³ , and The second nonwoven layer in the contacting direction was formed to have a lower density of 0.10 to 0.20 g / cm ³ while being made of meta-aramid fibers having a higher fineness of 5 to 10 denier.

As such, the first nonwoven layer in contact with the laundry exhibits better smoothness and surface abrasion resistance, so that the drying efficiency and the ironing efficiency of the laundry can be better, and the second nonwoven layer has better form stability at high temperatures. And excellent heat transfer efficiency, and thus, heat can be more effectively transferred to the cylinder while maintaining stability and performance for a long time in contact with a high temperature cylinder, thereby further improving the drying efficiency and the ironing efficiency of the laundry.

In addition, the aramid nonwoven fabric having such a multilayer structure may have a structure of three or more layers, and in this case, a separate nonwoven fabric layer may be added between the first nonwoven fabric layer and the second nonwoven fabric layer.

Such multi-layered aramid nonwoven fabric may include, for example, carding meta-aramid fibers having a fineness of 3 to 6 deniers to form a first web; Needle punching the first web three or more times to form a first nonwoven layer; Carding meta-aramid fibers having a fineness of 5-10 denier to form a second web; Needle punching the second web three or more times to form a second nonwoven layer; And it can be produced by a method comprising the step of laminating the first and second nonwoven layer. In this manufacturing method, the first and second nonwoven fabrics may be needle punched one or more times in the step of laminating the first and second nonwoven fabrics.

That is, in the method for producing the aramid nonwoven fabric of the multi-layer structure, using the meta-aramid fibers having different fineness of each, carding them to form a web and needle punching three or more times, the first and second nonwoven fabric layer To prepare a separate, the first and second non-woven fabric layer by overlapping the needle punch one or more times, finally to produce aramid nonwoven fabric having a structure of two or more layers.

In this manufacturing process, it is preferable to needle punch alternately from both sides of the first or second web, and other conditions of the process of forming the first or second web and the process of needle punching the first or second web. Is in accordance with conventional aramid nonwoven fabric manufacturing processes apparent to those skilled in the art.

As described above, according to the present invention, an aramid nonwoven fabric and a method for producing the same may be provided that exhibit not only excellent form stability and durability (heat resistance) at high temperatures, but also excellent heat transfer efficiency and elasticity in the thickness direction.

Such aramid nonwoven fabric can be very preferably applied to a drying apparatus or an ironing apparatus for mass drying and ironing laundry.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to specific examples and comparative examples in order to help understanding of the present invention. However, the following examples are only intended to more clearly understand the present invention, and are not limited to the following examples of the present invention.

[ Example  1-3, Comparative Example 1 -3]

Based on the conditions shown in Table 1, meta-aramid fibers having a thickness of 2 to 13 deniers and a length of 30 to 78 mm are carded to prepare a web, and then passed through four times in a needle punch machine. The aramid nonwoven fabrics of Examples 1 to 3 and Comparative Examples 1 to 3 having a weight of 800 gsm were prepared, respectively.

At this time, the first needle punch machine was for preliminary bonding, and the needle punches 2 to 4 were to adjust the thickness, density and air permeability of the nonwoven fabric by adjusting downward / upward / downward.

The overall physical properties of the aramid nonwoven fabrics of Examples 1 to 3 and Comparative Examples 1 to 3 were measured by the following method.

The measurement standard of the physical property of the aramid nonwoven fabric applied the measurement standard of JISL1096.

First, the tensile strength and elongation of the aramid nonwoven fabric were borrowed from the cut-strip method in the same standard, and the tear strength was the Tongue method.

In addition, the density of the aramid nonwoven fabric was taken by measuring the weight of each 10cm samples taken by the width X length, the thickness of the four sides and the center was calculated and the average value was calculated to calculate the thickness of the sample. The density of the aramid nonwoven fabric was obtained by calculating the volume of the nonwoven fabric and then dividing the measured weight. The density of each aramid nonwoven fabric was computed by measuring 6 or more samples about the nonwoven fabric of width 1M in this way, and calculating an average value.

The air permeability of each aramid nonwoven was measured to DIN 53,887.

The degree of decrease in weight and the rate of weight reduction were measured by directly installing each aramid nonwoven fabric in a drying and ironing apparatus, and then, before and after operating 2,000 hours at 150 ° C. or more. In the measurement of thickness, six samples of 10 cm in width X length were taken from a sample having a width of 1M, the thicknesses of four sides and the center were measured, and the average value was calculated. In addition, the weight was measured by washing three times or more in a drum type washing machine before drying.

The physical properties of the aramid nonwoven fabrics of Examples 1 to 3 and Comparative Examples 1 to 3 measured by the method described above are collectively shown in Table 1 below.

[Table 1]

division unit Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Fineness Denier 5 3 10 2 13 5 Textile mm 52 46 78 34 78 52 Needling Recovery time 4 4 4 4 4 2 The tensile strength
(Radial / up) Kg / 5cm 205/190 220/208 160/110 288/252 130/65 154/103 Shindo
(Radial / up) % 48/62 66/63 26/20 84/60 21/16 29/31 Phosphorus strength
(Radial / up) Kgf 30/20 29/15 42/39 24/10 52/43 36/27 Aeration / Dm ² / min 290 130 440 97 580 325 density gr / cm ³ 0.16 0.25 0.11 0.30 0.08 0.07 Reduction rate % 9.4 5.2 17.6 23 33 25 Weight loss rate % 3.9 2.1 8.5 10.7 14 18 Remarks - - - - Steam generation
Poor drying Poor drying Poor drying

Referring to Table 1, the aramid nonwoven fabric of Examples 1 to 3 made of 3 to 10 denier meta-aramid fibers, and manufactured to have a density of 0.10 to 0.25 g / cm ³ through four or more needle punching process, Compared with the aramid nonwoven fabrics of Comparative Examples 1 to 3, the present invention not only exhibits excellent ventilation and thus heat transfer efficiency, but also exhibits excellent morphological stability and durability (heat resistance) at high temperatures due to its low degree of decrease in weight and weight loss. It became.

In comparison, the aramid nonwoven fabrics of Comparative Examples 1 to 3 not only have a great decrease in morphological stability or durability (heat resistance) at high temperatures (see also post-reduction rate and weight loss rate), and as a result, when the aramid nonwoven fabric is applied to a laundry dryer or the like, It was confirmed that it occurred or that the drying of the laundry was poor.

[ Example  4 and 5]

In order to further improve the performance of the aramid nonwoven fabric, nonwoven fabrics having different fiber thicknesses were separately prepared and laminated to produce nonwoven fabrics having the two-layer structure of Examples 4 and 5.

In other words, in the nonwoven fabric having a two-layer structure, the nonwoven fabric is formed into a surface (surface in contact with the laundry) that requires smoother surface wear resistance and a back surface (high temperature air intake surface) requiring high vertical elasticity and form stability. The structure was partitioned. At this time, the nonwoven fabric constituting each layer was treated with three needle punches, and finally, one needle punch was additionally processed when laminating. As a fiber material, all meta-aramid fibers were used, and the fineness and density of the aramid nonwoven fabric were as shown in Table 2 below. The surface and backside nonwoven fabrics were each produced at a weight of 400 gsm and then at a weight of 820 gsm through a laden needling process (a slight weight increase due to shrinkage upon needling lamination).

The physical properties of the aramid nonwoven fabric of Examples 4 to 6 thus prepared were measured in the same manner as in Examples 1 to 3, and are collectively shown in Table 2 below.

[Table 2]

division unit Example 4 Example 5 Surface nonwoven Fineness Denier 3 5 Textile mm 48 52 Backside nonwoven fabric Fineness Denier 8 10 Textile mm 78 78 Laminated nonwoven fabric The tensile strength
(Radial / up) Kg / 5cm 250/210 165/178 Shindo
(Radial / up) % 54/46 44/36 Aeration / Dm ² / min 280 380 density gr / cm ³ 0.17 0.12 Reduction rate % 1.4 0.3 Weight loss rate % 2.3 3.9 Remarks - - -

Referring to Table 2, the aramid nonwoven fabric of the two-layer structure of Examples 4 and 5 is a side surface such as air permeability and the resulting heat transfer efficiency, form stability and durability (heat resistance) at high temperature, such as the rate of decrease or weight loss , It was confirmed that even more excellent physical properties than the aramid nonwoven fabric of Examples 1 to 3 and the like.

Therefore, when more durable and high-quality dry ironing performance is required, it can be expected that good results can be expected by using such a nonwoven fabric having a multilayer structure.

1 is a simplified cross-sectional view showing an example in which a nonwoven fabric is used in a laundry dryer or an ironing machine for laundry.

Claims (11)

A first nonwoven layer composed of meta-aramid fibers having a fineness of 3 to 6 deniers and having a density of 0.15 to 0.25 g / cm ³ ; And A second nonwoven layer composed of meta-aramid fibers having a fineness of 5 to 10 denier and having a density of 0.10 to 0.20 g / cm ³ , Used for drying or ironing laundry The first nonwoven layer is a layer in contact with the laundry for drying or ironing, The second nonwoven layer is an aramid nonwoven fabric which is a layer for transferring heat passing through the laundry and the first nonwoven layer. delete The aramid nonwoven fabric of claim 1, wherein the meta-aramid fibers have a length of 30-80 mm. The aramid nonwoven fabric according to claim 1, which has an air permeability of 100 to 500 l / dm ² / min, and has a weight loss rate of 10% or less and a post reduction rate of 20% or less after exposure at 150 ° C. for 2000 hours. delete delete delete Carding meta-aramid fibers having a fineness of 3-6 deniers to form a first web; Needle punching the first web three or more times to form a first nonwoven layer; Carding meta-aramid fibers having a fineness of 5-10 denier to form a second web; Needle punching the second web three or more times to form a second nonwoven layer; And A method for producing the aramid nonwoven fabric of claim 1, comprising laminating the first and second nonwoven layers. The method of claim 8, wherein the meta-aramid fibers have a length of 30 ~ 80mm. The method of manufacturing an aramid nonwoven fabric according to claim 8, wherein in the lamination step of the first and second nonwoven fabrics, the first and second nonwoven fabrics are needle punched one or more times. The method for producing an aramid nonwoven fabric according to claim 8, wherein in the needle punching step of the web, the first web, or the second web, needle punches are alternately performed from both surfaces thereof.

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