JPS6011148B2 - nonwoven material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to nonwoven fabrics, and more particularly to nonwoven fabrics comprised primarily of synthetic thermoplastic fibers having desirable woven-like properties.

A first object of the present invention is to provide a nonwoven material consisting primarily of synthetic thermoplastic fibers that can be advantageously economically produced and has desirable woven-like properties. In particular, one object of the present invention is to provide a nonwoven material that is strong yet has woven-like drape and is uniformly opaque, thus exhibiting a cloth-like appearance.

Another object of the present invention is to provide a nonwoven material of the above characteristics that is non-tacky, has a substantial texture, and has a pleasant moist feel rather than clammy feel.

Yet another object of the present invention is to provide a nonwoven material that is sufficiently breathable for use in garment-related applications, yet has the desired water-repellent properties, and also has the above-mentioned properties. It is.

Another object of the invention, closely related to this object, is to provide such materials which can be independently processed by simple and conventional means to impart water-absorbing properties. Yet another object of the invention is to provide such materials with desirable surface wear properties.

Yet another object of the present invention is to provide a nonwoven material that is simple and inexpensive to manufacture and is useful in a wide variety of applications such as clothing, linens, medical applications, and the like. Other objects and advantages of the invention will become apparent from the following description of the accompanying drawings.

Preferred embodiments of the present invention will be described below, but it goes without saying that the present invention is not limited to these embodiments.

On the contrary, such modifications and equivalents as may be included within the spirit of the invention as defined in the claims are intended to be included within the scope of the invention. FIG. 1 shows a nonwoven material 10 in the form of a laminate, which generally has as an overlying layer an aggregated mat 12 of discontinuous thermoplastic microfibers 14, and which has randomly deposited and molecular It has as an underlayer a web 16 of substantially continuous filaments 18 of thermoplastic polymer oriented in the same direction.

As shown, there is interlayer adhesion between the mat and web with intermittent discrete bonding areas 20 arranged in a generally regular pattern over the surface of the nonwoven material to provide a unitary structure. As explained later,
The two individual bonding regions are preferably formed by applying heat and pressure in the intermittent regions shown;
Other methods of interlayer attachment can also be used, such as separate adhesive applications or mechanical intertwining of the fibers, such as needle stitching techniques. Thermoplastic polymer microfiber integrated mats are manufactured by "Industrial and Engineering Chemistry"
The title ``Super Fine thermoplastic fiber (SupeMin
It can be manufactured by a known method such as that described in the paper entitled "eThermoplastic Fi[rs]".

Report 1 of the Naval Technical Research Institute dated April 15, 195
See also US Pat. No. 3,676,242 to Prentice, dated July 11, 1972.

The process for making mats basically involves extruding a molten polymeric material into a fine stream and then passing a high velocity heated gas (usually air) in the opposite direction to break the polymer stream into small diameter discrete fibers. It consists of becoming thinner. The fibers are then collected onto a porous screen belt or drum or the like to obtain a microfiber mat. This mat has some degree of thermal bonding or self-bonding between the fibers, and each fiber in the mat is intertwined, so it has integrity.
This integrity is particularly strong when the accumulation is carried out only a short distance after extrusion. Generally, the microfibers contained in such mats have an average fiber diameter of no more than about 10 microns, with very few, if any, fibers exceeding 10 microns in diameter.
The average diameter of the fibers in such mats is usually about 2 to 6 microns. The fibers in the mat are primarily discontinuous, but their lengths are generally longer than the length of the staple fibers. In the case of a substantially continuous filament web 16, methods for making this web are also known and described in the following patents: US Pat.

Kinney U.S. Patents 3,338,992 and 3341
No. 394: Levy U.S. Pat. No. 3,276,944: Peterson U.S. Pat. No. 3,502,538: Hartman U.S. Pat. Nos. 3,502,763 and 3,509,009:
US Pat. No. 3,542,615 to Dobo et al.; and Canadian Patent No. 8,03714 to Harmon. Although there are a variety of methods for initially producing such continuous filament webs, the available methods generally have at least three common characteristics. First of all, these web manufacturing methods involve continuously extruding thermoplastic polymer (either from the melt or solution) through a paper spinneret to form individual filaments. Next, the polymer filament is stretched (mechanically or pneumatically) so as not to break in order to provide molecular orientation and strong plowability. lastly,
The continuous filaments are deposited on a carrier belt or the like in a substantially at random manner to form a web of molecularly oriented continuous filaments deposited at random. A preferred method for making such webs is described in Dorschner et al., US Pat. No. 3,692,618, issued Sept. 19, 1972. In contrast to the previously described microfiber mats, the continuous filaments 18 in web 16 have an average fiber diameter of about 12 microns or more and about 55 microns or less.

Webs containing continuous filaments having an average diameter of about 15-25 microns are preferred for use in the present invention. Moreover, because of the molecular orientation of the filaments, these filaments are significantly stronger than the microfibers in the mat 12. As can be seen, the manufacture of the components of the nonwoven material shown in FIG. 1 is simple and inexpensive, and involves conventional extrusion, melt blowing, and spinning.

Basically, the only raw material required for the production of the nonwoven materials described above is a thermoplastic polymer. Naturally, it is also possible to produce inexpensive colored nonwoven materials by simply adding pigments to the polymer before extrusion, without the need for difficult and expensive post-dying operations. Many different thermoplastic polymers can be used in the production of the microfiber mats and continuous filament webs described above.

The mat and web may be made of the same type of polymer or may be made of different types of polymers. It is also possible to make either the mat or the web or both using two or more different polymers.
Thus, materials embodying features of the present invention can have different physical properties by appropriate selection of polymers or their combination for each mat and web. Although many thermoplastic polymers are used to make the materials of this invention, the most common are polyolefins such as polypropylene and polyethylene, polyamides, polyesters such as polyethylene terephthalate, and thermoplastic elastomers such as polyurethane. It is thought that it will be widely used. The nonwoven materials of the present invention can be manufactured in a variety of weights using the methods described herein, and the particular weight of a given material is chosen based on the intended end use.

For most applications, the total weight of the material is always around 4 oz/sq yd, and typically about 0.75 to 2.5 oz/sq for woven applications. A weight range of approximately 0.0025 to 0.0084 yd/ear is most useful. If particularly high strength is required in the resulting material, it must contain less microfibers by weight than the continuous filament web. However, useful materials embodying features of the invention generally include about 0
. It can be manufactured with a mat to web weight ratio of 2:1 to 4:1.

Referring now to FIG. 2 of the accompanying drawings, this figure illustrates one continuous method of manufacturing a nonwoven material such as that shown in FIG.

In the figure, elements corresponding to those in FIG. 1 are indicated by the corresponding numbers in FIG. 1 with the suffix a added. As can be seen, the continuous filament web 16a is produced after introducing the polymer into an extruder 22 and extruding the polymer in the form of filaments from a spinneret (not shown). After drawing (drawing in a Takeo apparatus 24), the drawn continuous filaments 18a are deposited in a substantially at random manner onto a porous carrier belt driven on rolls 28 to form a web 16. A suitable suction device 30 may be arranged to assist in the formation of the web on the carrier belt 26. The web 16a is substantially unbonded when formed on the belt 26 and is very thin and weak. , the filaments 18a are deposited almost at random to form the web 16a.
However, as a practical matter, complete randomness is hardly obtained, and as a result, the web 16a is not completely uniform in appearance, and as it is, it is less suitable for woven fabric-like applications. . Still referring to FIG. 2, after producing the continuous filament web 16a, the prefabricated integrated microfiber mat 12a is unwound from roll 32 and the web 12a is unwound from roll 32 in the nip between rolls 34 and 36.
6a to form an unbonded two-layer assembly 38.

The unbonded mass 38 is then passed over an idler roll 40 and into contact with a smooth-surfaced heating roll 42, after which a pattern generally shown in FIG. The mat 1 is heated by passing it through a pressure nip formed between it and a heated roll 44 with a number of raised points.
A layered adhesion occurs between 2a and web 16a. The bonded laminate is then transferred from roll 42 to idler roll 4.
6. He is honored by passing the 6th grade. To produce a nonwoven fabric with the desired strength properties and woven-like drape properties, the method shown in Figure 2 requires a nearly continuous filament web to provide effective load support without adversely affecting drape properties. It is necessary to integrate them so that they become components.

For this purpose, it is important to suitably choose the bonding conditions (temperature, pressure and, to a lesser extent, residence time in the nip) and bonding pattern. To the bond pattern,
In this case, it is preferable to use an intermittent bonding pattern that repeats in a substantially regular manner over the entire surface of the web. The pattern of raised points on roll 44 is such that after passing through the nip, the bond area in the web accounts for approximately 5-50% of the total surface area of the nonwoven material, with 50-10 separate bond areas.
00/elbow (approximately 7.7 to 155/elbow) density. Preferably, the bond area in the web is between 10 and 3
Density 100-500/i〆 (approximately 15-78/i) at 0%
is good. Regarding the bonding conditions, the bonding is to achieve a layered adhesion between the mat and the web and to integrate the continuous filament webs into a cohesive and strong component to provide the desired strength to the resulting nonwoven material. It must have two effects: it must have characteristics and it must have two effects. The above structure containing a microfiber mat in layered contact relationship with a continuous filament web can be used if the thermoplastic polymer of the mat is a polymer with a softening point slightly lower than that of the web polymer. I believe that it can be used to produce two effects. The softening point of the microfiber mat polymer or portion thereof must be at least about 1000 points lower than the softening point of the web polymer, and not more than about 4000 points lower.
3500 lower is preferred.

If the softening point of the mat polymer is significantly lower than the softening point of the web polymer, it is difficult to achieve adequate bonding without the negative effect of forming a film on the surface of the microfiber mat. Differential thermal analysis (DTA) can be used to determine the softening point. Softening point DT
This is the temperature at which the slope of the A graph changes for the first time. Different types of polymers usually have different softening points, and the same type of polymer,
For example, it is natural that the softening point of polypropylene differs depending on its molecular weight and other factors. When manufactured by the method shown in FIG. 2, the mat 12a is pre-contacted with the heated roll 42 before entering the nib, so that the fibers in the mat are in the web in the areas of the mat that are aligned with the raised points of the roll 44. of the continuous filaments and is softened to an extent that not only results in layered deposition but also helps to integrate the continuous filaments into a coherent web. Free bonds also occur between the web filaments in areas aligned with the raised points. However, since the matte polymer helps to hold the web together, one also gains the benefit of not severely disrupting the physical structure of the continuous filaments by using lower pressures, thus preserving the strength of the filaments. I can do it. The most appropriate bonding conditions for producing a given nonwoven material will depend on the particular components used, but can be determined by simple experimentation using the information provided herein. Approximately 270 for materials using polypropylene as thermoplastic polymer for both mat and web. ~360 (approx. 132
．． o~182.2oo), preferably 290o~3
Roll temperatures on the order of 400 F (143.3 C to 171. RO) (lower temperatures in this temperature range are useful for lightweight materials) to 5000 to 5000 SI (approximately 351.0 C).
5-3515k9') "preferably 6000-15
Combined with a nip pressure (above the ridge) of 00 cape si (approximately 421.8 to 105.45 k9' carp) (higher pressures in this pressure range are most effective at low temperatures and enemy mass material). Can be used together. Approximately 100-3
Web speeds through the nip of 0.00 ft/min (approximately 30.5 to 91.5 ft/min) can be used, but higher speeds are used when using lightweight web materials and high roll temperatures. do. As will be described in more detail in the Examples below, a nonwoven material with significantly improved strength properties by producing highly uniform bonding within the intermittent bonding region such that there is little welding of continuous filaments within this region. can be obtained.

When viewed under a polarizing microscope, the filaments generally appear cohesive and fixed together at the intersections, with individual filaments visible within the binding region. Within the bonding region, the microfibers are mostly melted and settled, some encapsulating the continuous filament. In nonwoven materials where the pigment concentration in the thermoplastic polymer is not high, discrete bonded areas exhibit a uniformly translucent appearance when viewed under common artificial light sources, and most of the individual areas are also invisible to the naked eye. There is no place that looks transparent. Referring now to FIG. 3, this figure shows a schematic cross-sectional view of the bonding area of the nonwoven material made by the method of FIG. An interesting point to note in this figure is that the indentation of the web caused by passage through the nip occurs primarily on the surface of the microfiber mat in the material, and not on the continuous filament surface in direct contact with the raised points. be. This phenomenon is the opposite of that normally seen when passing materials through nips such as those described above, and is believed to be due, at least in part, to the above-described unique structure of the materials of the present invention. The importance of this feature is that, as is commonly used, the material shown in Figure 1 is used with the microfiber mat surface as the exposed surface. Therefore, having a three-dimensional embossed appearance as shown in FIG. 3 is attractive. However, as previously discussed, it is desirable for the microfibers to be adjacent to a smooth surface roll 42 during bonding to provide sufficient material strength. Thus, it is possible not only to obtain the desired strength properties, but also to obtain a textured microfiber mat surface, consistent with the phenomenon shown in FIG. Next, FIG. 4 shows yet another embodiment of the present invention.

In this figure, nonwoven material 48 consists of microfiber mats 50 and 52 as outer layers and a continuous filament web 54 as an inner layer. Again, as shown in FIG.
achieved by. The nonwoven material as depicted in FIG. 4 is assembled with the microfiber mat 12a and continuous filament web 16a at the nip formed by rolls 34 and 36, as shown in dotted lines in FIG. After combining, this three-layer laminate is rolled into roll 4.
2 and 44 through a bonding nip. Similarly, after forming a microfiber mat on a wire mesh, a continuous filament web can be layered onto one or both sides of the mat to produce nonwoven materials with other structures embodying features of the invention. You will see that you can do it. The following Examples 1-4 illustrate the production of nonwoven materials of the present invention. Measurements of the physical properties of the nonwoven material produced and its individual components are also presented.
These results are the average of the values obtained in the vertical and horizontal directions. The measurements were carried out approximately according to the following method. Energy-Absorption Instron Corporation Manual Method #10-1-lc Water Repellency Add 60% standard saline solution to the main jar.

A sample of the material to be tested is then placed on top of the jar and the split ring is used to securely close the jar. Place the jar upside down on a glass plate a few feet above the mirror. The water repellency of a nonwoven material is measured as the time required for water to first pass through the nonwoven material and wet the glass. The above energy absorption
rption) is Instron.

Corporation Manual No. 10-1-lc (l
nstron CorporationNnenhadaINo
．． 10-1-lc), it was measured by the method described in 10-1-lc). To explain this method, when a load (lbs) is applied to the material and the material is pulled, the material is stretched (inches) as the load gradually increases from 0. In this case, when the amount of load is shown on the vertical axis and the stretched length is shown on the horizontal axis, the relationship between the amount of load and the stretched length is represented by one curve. When the amount of load reaches a certain value, the material reaches a yield point. At this time, the curve from the 0 point of the above curve to the yield point,
The area between the axis and the axis is called energy absorption. Therefore, the energy absorption is calculated by the above area, that is, the load (1
It is expressed by the product of the stretching length (inch) and the stretching length (inch). The bonding was carried out using an apparatus as shown in FIG.

In this case, rolls 42 and 46 are 6 inches (15 inches) in diameter.
2.4 willow) steel roll. The raised points on roll 44 are 4 inches high (approximately 1.016 skins) and the bonded material has regularly spaced bond areas in a diamond pattern with a density of 214/elbow (approximately 33.2/m2). It contained. Each area is approximately 0.03 inches on a side (approximately 0.7
62) squares with their diagonals running vertically.The bonding area is approximately 17% of the surface area of the material.
was occupied. Rolls 40 and 46 are arranged so that the material on the surface of roll 42 is 228.6 side before the bonding nip and 8.6 side after the nip.
It is arranged so that it wraps around an inch (203.2 ribs). Example 1 Material Polypropylene microfiber mat layer (average fiber diameter approximately 6 microns, softening point 137q0) *0.4
5 oz/square yard polypropylene continuous filament web layer (average filament diameter 18 microns, softening point approximately 150 qo) *0.
5 oz/square yard* Same for all examples herein unless otherwise specified.

Join condition roll 42 2730F (133.9qo) roll 44
2800F (137.8qC) Material speed 15 town PM
(45.75 m/min) Pressure on the raised point 3000
Fox si (2109k9/earth) As is clear from the above values, the laminate material produced according to Example 1 exhibits significantly higher strength properties than would be expected from the strength properties of the individual components.

This unexpected increase in strength is due to the mode of construction of the material, particularly where the microfiber mat not only undergoes layered deposition, but also where pouching and weakening of the filaments can occur during application of pressure. This is believed to be due to the fact that it has the effect of gathering and strengthening continuous filaments together. Visual inspection of this material reveals that the bonded area has a nearly uniform translucent appearance. In addition to the favorable strength properties mentioned above, the resulting material has an overall translucent woven appearance, favorable drapability and a substantial feel, with moisture content in equilibrium with the surrounding atmosphere. Gives a pleasant feeling by appearing to do so. Furthermore, the resulting material exhibits surprisingly good abrasion resistance in that the surface does not tend to fuzz during use. As for the continuous filament web side, this excellent abrasion resistance means that the filaments are strongly held together without breaking within each discrete bond area, thus preventing long filaments from exhibiting a tendency to fuzz during use. I believe this is due to the fact that there is no filament span. As for microfiber mats, the integrity of the mat is taken during material formation. It is believed that this together with the additional fiber bonding that occurs during the contact between the rubber 42 and the mat surface improves the abrasion resistance. The nonwoven material thus produced is particularly suitable for applications where decorative or advertising printing is desired.

The microfiber matte surface of this material can be printed with very good color fastness and has a high degree of "bloom" when printed, as well as after exposure to various elements. It was found that it remained clear even after repeated washing. In this regard, it has been found that these benefits are not obtained with continuous filament webs alone. Additionally, the use of this material in textile applications where repeated laundering is anticipated is highly desirable as the material exhibits much less shrinkage upon laundering than when used as a continuous filament web (as is). be. In addition to the above-mentioned favorable properties, the material of Example 1 combines good water repellency with a high degree of air permeability.

The average water repellency of this material was approximately 44 min, and the air permeability was 83 cm/ft2 (approximately 25.315 cm/ft2).・Min/ft2 (20.130〆/min/m2), which is completely different from the microfiber itself and the continuous filament web itself, which has high air permeability but almost no water repellent property. It can be seen that the material has excellent water repellency and air permeability, making it extremely suitable for textile applications where a water repellent and breathable material is desired.Example 2 Material Same material as Example 1 A second polypropylene microfiber mat (0.45 oz/square yard) is applied to the other side of the continuous filament web.

Bonding conditions Same as Example 1 except that the material speed is 16 Cape PM (48.8/min).

As can be seen from the table above, the nonwoven material of Example 2 has the favorable strength properties described in Example 1 as well as the desirable woven-like properties previously described.

Moreover, since the material has a microfiber mat on both sides, it is possible to print on one or both sides of the material with the advantages mentioned above. Example 3 Materials Using the same materials as in Example 1, a second polypropylene continuous filament of 0.5 oz/square yard is applied to the other side of the microfiber mat.

join condition Same conditions as in Example 1.

However, the pressure at the bulge point is 4500 si (3163.
5k9/enemy). The material of Example 3 exhibits a desirable uniform opaque appearance and has pleasant woven-like properties in terms of hand and drape. Moreover, particularly desirable strength properties can be obtained by applying an outer layer of continuous filament web as described above. Example 4 Material polypropylene microphone.

Fiber mat layer 1.6 oz/square yard polypropylene continuous filament web layer 0.5 ounce/square yard bonding condition roll 422.

F (133.900) Roll 44 2800F (137
．． is 0) Material speed: 16-valent PM (48.8 kites/min) Pressure directly above the Long Gai Palace: 39,000 psi (2,741.7 k9
/ ground)* Pressure at uplift point 30,000 psl (2
109&/female) The nonwoven material produced in this example also has many of the favorable properties already identified with respect to Examples 1-3.

Moreover, the material of Example 4 exhibits very high water repellency (120 min), but has an air permeability of 6.8 t3·min/f〆(1.
25 min/force), making it suitable for many textile applications. A series of nonwoven materials (Examples 5-8) were then produced in essentially the same manner as Examples 1-4.

however. A woven fabric-wire pattern roll was used in place of the roll 44. This wire pattern resembles a plain weave pattern and has oval elements placed perpendicular to the machine direction and rectangular elements placed parallel to the machine direction. This element has a density of 144/elbow (approximately .3/earth) and is approximately 12%
occupies an area of The height of this element is 0.0 at the highest point
It was 4 inches (approximately 1.016 ribs). The material was bonded at a speed of 130 ft/min (31.11 m/min) and a pressure of 550 min/m in the raised elements.
(calculated from the load of the circle and the area of the element). The temperature of the smooth roll is approximately 2850F (approximately 140
．． 60C), and the pattern roll temperature was about 2900F (about 143.yo). Example 5 Materials Polypropylene Microfiber Mat Layer 0.29 oz/square yard Polypropylene Continuous Filament Web Layer 0.56 ounces/square yard Example 6 Materials Polypropylene Microfiber Mat Layer 0.59 ounces/square yard Polypropylene continuous filament web layer 0.56 oz/square yard Example 7 Materials Polypropylene microfiber mat layer 0.88 ounce/square yard Polypropylene continuous filament web layer 0.56 ounce/square yard From the above physical properties As can be seen, the values of the strength properties of the materials obtained in Examples 5-7 are not much larger than the theoretically estimated values.

Additionally, visual inspection of discrete bond areas in the material shows that many of these individual bond areas do not exhibit a uniform translucency when placed over a visible light source, and many of these bond areas have holes near their centers. Alternatively, the presence of an almost transparent part that was a welded film-like part was observed. This is because the use of a wire pattern in which the height of the raised elements is not approximately the same over the entire surface of the individual elements results in excessively high pressure within the bonding area and concomitant overbonding. It seems that the very high strength performance that could have been achieved was not achieved. However, regarding other aspects such as appearance, drapability, printability, etc., Examples 5 to 7
The material has favorable properties. To further illustrate the present invention, a method similar to that described in Examples 1-4 is used, except that the bonding roll is larger and the lower roll has a density of about 200/200/200/200 (about 31.0/20%). The total land area comprised 24% of the total land area and contained elevated points of uniform height less than 0.03 inches (approximately 0.076 佽). The structure, bonding conditions and physical properties of the obtained material are as follows. Example 8 Materials Polypropylene microfiber mat layer 0.45 oz/square yard Polypropylene continuous filament web layer 1.4 ounce/square yard Bonding conditions Upper roll (OF) 330 (165.ge○) Lower roll (OF) 320 (160qo) Pressure (psi) 1
6500 (1159.95k9' ground) speed (FPM) 1
12 (34.16 m/min) Example 9 Materials Polypropylene microfiber mat layer 0.48 oz/sq yd *Polypropylene continuous filament web layer 1.2 oz/sq yd** *Mat alone, upper roll temperature 3100F (15
4.4 qo), lower roll temperature 30 pi F (148 qo)
, pressure 1490 min si (1047.47 k9') and speed 20 PM (61 m/min).

※※ The web is used separately, and the upper roll temperature is 3300F (1
65.6℃), bottom.

- Temperature: 320°C (160°C), pressure: 1650°C (
1159.95
m/min). Joining conditions (other than above) Upper roll (?) 330? (165.6℃) Lower roll (OF) 32F (16pi0) Pressure (psi) 14
90 snake si (1047.47k9/earth) speed (FPM)
11 PM (34.16/min) Example 14 Materials Polypropylene Microfiber Mat Layer 0.3 oz/sq yd Polypropylene Continuous Filament Web Layer 0.49 oz/sq yd Bonding Conditions Upper Roll (OF) 2870F (141. 7℃) Lower roll (OF) 2900F (143.3℃) Pressure (p
si) 1100 si (773.3k9') speed (
FPM) 30-valent PM (91.5/min) Example 8-1
The material obtained in Example 0 possesses many of the desirable properties already identified for other materials produced according to the present invention, and in particular exhibits unexpectedly high strength properties.

Moreover, these materials were found to exhibit significant duality when saturated with liquid. That is, the liquid becomes concentrated in the microfiber mat layer, leaving the continuous filament web surface relatively dry. Thus, the resulting material is a cloth-like sheet which, when saturated with water and wrung out, effectively acts as a damp cloth on one side and as a semi-dry towel on the other side. Such behavior is believed to be characteristic of materials made according to the present invention in which the continuous filament web is present in an amount of about 60-8% by weight and the microfiber mat is present in an amount of about 20-4% by weight. It is believed that such materials would be particularly useful as rags for applying and removing moisture, polishing agents, solvents, etc., as well as portable hand towels for pre-moistened cleaning. ~7
Several additional nonwoven materials were made using the woven-wire pattern used in Example 1 and using the nylon 6, polypropylene polymer composite to make the microfibers for the mats (Examples 11-12).

The nonwoven fabric material produced in this manner has the following structure. Example 11 Materials Microfiber mat layer (5% by weight of nylon 6
, 5 wt% polypropylene) 0.5 oz/square yard polypropylene continuous filament web layer 1.25 oz/square yard Example 12 Materials Microfiber mat layer (25 wt% nylon 6
, 75 wt% polypropylene) 0.4 oz/squared polypropylene continuous filament web layer 1.3 oz/squared The bonding conditions are as follows.

The physical properties of the obtained material are as follows.

The material obtained here has many of the desired properties identified so far and is a representative material embodying the features of the present invention. Additionally, the nylon component in the microfiber provides a reactive site that chemically bonds with surface finishing agents such as dyes that normally do not react with polypropylene. As described above, the nonwoven fabric material obtained by the present invention fully satisfies the objectives listed at the beginning.

These nonwoven materials have woven-like drape, texture,
and have an appearance. By using the methods presented herein, breathable, liquid-reactive materials can be produced that are highly suitable for garment applications and similar applications. Moreover, the nonwoven material of the present invention with a microfiber mat as the exposed surface can be printed and used advantageously as a decorative woven fabric, and has fluid retention properties making it suitable for use as rags. It has been found that it is also suitable as a receptor which provides absorption properties upon treatment with wetting agents and similar agents. It has also been shown that, by carrying out appropriate bonding, it is possible to produce nonwoven materials according to the invention with particularly outstanding strength properties.

In particular, as shown in Examples 1-4, it is possible to produce nonwoven materials with particularly enhanced energy absorption properties, at least about 25% higher than theoretically estimated energy absorption.
Improvements of more than 100% were obtained in many cases. This high energy absorption is important in that energy absorption is a measure of the ability of a material to deform under strain without undergoing severe failure. A high energy-absorbing capacity means that the material has the ability to carry constant loads when subjected to strain, and this means that it can be used in applications such as the toe area of bed sheets, the elbow and knee areas of clothing, etc. This is particularly important in applications such as clothing and bedsheets, where small areas of the material are constantly strained. Similarly, with respect to other strength properties of the materials of the invention, in particular the grab tensile strength and the trapezoidal tear strength, as already indicated in the text, at least about 30% compared to the theoretically estimated values, Again unexpected strength improvements of at least about 50% are generally obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a section of a nonwoven fabric material according to an embodiment of the present invention, and FIG. 2 is a schematic side view showing one method for manufacturing the material of the present invention. Figure 3 is
FIG. 4 is a cross-sectional view taken along line 3--3 in FIG. 1, and a perspective view of a portion of a nonwoven material according to another embodiment of the present invention. 12: integrated mat, 14: thermoplastic polymer microfiber, 16: web, 18: filament, 20: bonding area of mat and web. "army". 12-tei finished 1 construction; Ku. Tachito 6.

Claims (1)

[Claims] 1 A web of randomly deposited, molecularly oriented, substantially continuous filaments with an average filament diameter of about 12 microns or more and an average fiber diameter of about 10 microns or less and a softening point about 100 µm below the softening point of continuous filaments. a nonwoven material consisting of an integrated mat of generally discontinuous thermoplastic polymer microfibers at a temperature of 10°C to 40°C, the web and the mat being arranged in a layered relationship and subjected to heat and pressure. Non-woven materials characterized in that they are bonded together to form intermittent separated bond areas by adding.