JP3408615B2 - Nonwoven fabric for surface protection of sheet metal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-woven fabric for protecting the surface of a thin metal plate, which is used in the manufacturing process of a thin steel plate.

[0002]

2. Description of the Related Art In a rolling process of a thin metal plate such as stainless steel, copper, and aluminum, a thin metal plate wound in a coil on one reel is unrolled from a reel and then rolled again on the other reel. Wrap it in a shape. When one rolling pass is completed, the sheet metal is then rolled back in the opposite direction and rewound onto the first reel. When such a reciprocating rolling process is repeated, the thin metal plate gradually becomes thinner, and when the target thinness is reached, the rolling process is completed.

In the rolling process of a thin metal plate, it is important to finish the surface of the thin plate smoothly without causing scratches. However, when it is wound into a coil as described above, looseness and tightening occur due to slippage due to the smooth surface of the coil, causing layer misalignment within the coil and causing the surface of the thin plate to slip. Scratches occur.

In order to eliminate this drawback, the actual fair 2-3
Japanese Patent No. 5365 discloses a technique in which a non-woven fabric made of polyester long fibers having a smooth surface is wound between layers of thin steel plates wound in a coil shape so that the steel plates do not come into direct contact with each other. There is.

The polyester filament non-woven fabric disclosed in Japanese Utility Model Publication No. 2-35365 prevents the generation of fluff by smoothing the surface as described above, and the fluff causes a scratch on the surface of the steel sheet. To prevent that.

Further, the strength in the warp direction is set to 5 kg / 3 cm width or more, and the warp / weft strength ratio is set to 1.2 to 3.0, so that the nonwoven fabric can be obtained even when the winding speed of the steel material is 500 m / min or more. This non-woven fabric is designed to be used repeatedly so that it does not tear.

Furthermore, the stress at 10% elongation in the warp direction is 3 k
g / 3cm width or more, steel material winding speed is 500m
Even when it is set to / min or more, the non-woven fabric retains dimensional stability in the width direction, so that wrinkles are prevented from occurring and good winding is performed.

[0008]

By the way, in the case of forming a non-woven fabric from a simple substance of polyester as disclosed in Japanese Utility Model Publication No. 2-35365, a thermal calender having a smooth surface when the surface of the non-woven fabric is smoothed. It is common to use rolls to surface the entire surface of the web. By doing so, the heat of the roll uniformly fuses and bonds the fibers over the entire surface of the web, and the surface becomes smooth.

However, when the fibers of the web are fused and bonded by using the heat calender roll as described above, the polyester is actually embrittled by heat, and the strength of the nonwoven fabric, particularly the tear strength, is lowered. There is a point. When the treatment temperature by the heat calender roll is lowered for the purpose of preventing the reduction of strength due to this thermal embrittlement, the fusion between the fibers becomes insufficient this time, and fuzz occurs on the contrary and the heat treatment is insufficient. There is a problem in that the strength is reduced due to.

Therefore, the present invention solves such a problem, can prevent the occurrence of thermal embrittlement due to the conventional thermal calendering treatment, has no fluff, and has sufficient strength. An object of the present invention is to obtain a non-woven fabric which does not cause scratches on the surface of a thin metal plate when wound between layers of a metal thin plate wound in a coil shape.

[0011]

In order to achieve this object, the present invention comprises polyester filaments having a single yarn fineness of 1 denier or more and is partially embossed by thermocompression bonding. The area ratio of the part that is partially thermocompression-bonded in the unit area is 10 to 40%, and the distribution density of the part that is partially thermocompression-bonded in the unit area is 20 points / cm ^2. The area of one point that is partially thermocompression-bonded is 0.1 mm ² or more, and the depth from the nonwoven fabric surface to the bottom of the part subjected to thermocompression-bonding is 25 μm or more. Provided is a nonwoven fabric for surface protection of a thin metal plate.

Since the heat-resistant polyester filaments are thermocompression-bonded in an embossed manner as described above, the brittleness of the fibers unlike the conventional thermocompression bonding is not caused, and therefore the strength is large. In addition, the stress at the initial elongation also becomes large, and it becomes possible to wrap between the layers of the metal thin plates that are wound at high speed. Further, since the single yarn fineness is 1 denier or more and the long fibers having a necessary thickness for strength are partially thermocompression bonded, the single yarn has a high strength and no fluffing occurs. When the thin metal sheet is loosened or tightened, a gap occurs between the overlapping thin sheets, and when the shear force acts on the cross section of the nonwoven fabric, if the single yarn fineness is less than 1 denier, the fibers are partially Are cut, and the fiber waste adheres to the surface of the thin metal plate, causing pressure scratches. Furthermore, since the surface is embossed, that is, uneven, the soft and highly elastic protrusion, which is a non-thermocompression bonded portion, comes into contact with the surface of the thin metal plate. Therefore, the occurrence of scratches on the surface of the metal thin plate is prevented, and the occurrence of scratches is prevented even when the metal thin plate is loosened or tightened.

Particularly according to the present invention, the melting point is from 250 ° C to 2 ° C.
By using the polyester filaments having a temperature of 60 ° C., the melting point is high, the heat resistance is high, the durability in strength is excellent, and the economy is excellent. That is, due to the heat generated when rolling a thin metal sheet, the temperature reaches 180 ° C. especially when the steel sheet is rolled at a high speed.
For this reason, if the melting point of the fiber is less than 200 ° C, the amount of plastic deformation increases due to heat and stress during rolling, and both ends of the non-woven fabric enter inside and become narrower in the width direction. Wrinkles occur. When this wrinkle occurs, the non-woven fabrics partially overlap with each other to thicken the part, and the surface of the thin metal plate is pressed and damaged. Therefore, it is necessary to use heat-resistant polyester fiber as described above. Good results can be obtained with any composition of the polyester copolymer alone and the composite thereof (including structures such as mixed fibers, core-sheath, and side-by-side), but the melting point is 200 ° C or higher. is necessary.

As described above, the partial thermocompression bonding based on the present invention is effective, but there is a suitable range for the conditions. The appropriate range is an area ratio of 10 to 40% of a part of the unit area that is partially subjected to thermocompression bonding, and a distribution of a part of the unit area that is partially subjected to a thermocompression bonding process. The density is 20 points / cm ² or more, the area of one point that is partially thermocompression bonded is 0.1 mm ² or more, and the depth from the surface of the nonwoven fabric to the bottom of the part subjected to thermocompression bonding is The range is 25 μm or more.

Here, the area ratio of the part which has been subjected to the thermocompression bonding treatment within the unit area means the total area of the thermocompression bonding portion 1 within one unit area a × bcm ² shown in FIG. The product of the area S of the thermocompression bonding portion and the number of thermocompression bonding portions 1 within the unit area a × bcm ² ) is divided by this unit area a × bcm ² . The distribution density of a portion of the unit area that has been partially subjected to thermocompression bonding means the unit area a × shown in FIG.
The number of thermocompression-bonded portions 1 within bcm ² is defined as the unit area a
It means a value divided by × bcm ² . The area of one point that is partially thermocompression bonded means the area of one thermocompression bonding portion 1 shown in FIG. The depth from the surface of the non-woven fabric to the bottom of the portion subjected to the thermocompression bonding means the depth 3 from the surface of the non-thermocompression bonded portion 2 shown in FIG. 2 to the bottom of the concave thermocompression bonding portion 1.

If the area ratio of the part which is partially subjected to thermocompression bonding within the unit area is less than 10%, the frequency of heat fusion between the fibers becomes small, and fluffing occurs during rolling of the thin metal sheet, and At the same time, longitudinal wrinkles are likely to occur in the nonwoven fabric when it is rolled up between the layers of the thin metal plates.
If this area ratio exceeds 40%, the frequency of fusion between fibers becomes large and the number of fusion portions of fibers increases. Therefore, it becomes plastic and becomes brittle, so that the strength is reduced and the number of times of service is reduced.

The thermocompression bonding process is partially performed within the unit area.
Distribution density of the applied area is 20 points / cm²Less than
And the distance between the thermocompression bonding parts 1 increases,
The distance between heat-fixing parts of polyester fiber
Becomes longer and fluffing is more likely to occur. Thermocompression bonding part 1
That is, the area of one point that is partially thermocompressed is 0.1 mm
²If less than, the frequency of thermocompression bonding of each fiber
It becomes smaller and easier to fluff, and is 3% as described below.
It becomes impossible to set the tensile stress to the required value.

When the depth from the surface of the non-woven fabric to the bottom of the portion subjected to the thermocompression treatment is less than 25 μm, when a compressive force acts in the cross-sectional direction of the non-woven fabric when wound in a reel shape together with a thin metal plate, The hard thermocompression-bonded portion 1 made of plastic may come into contact with the thin metal plate, which easily scratches the thin metal plate, which is not preferable. In addition,
This depth refers to the depth when the nonwoven fabric is unused.

In the nonwoven fabric for protecting the surface of the thin metal plate of the present invention, it is preferable that the thickness thereof is within the range of 30 to 400 μm. If the thickness is less than 30 μm, there is a possibility that the non-woven fabric may not serve as a protective material due to partial thickness unevenness. On the other hand, if it exceeds 400 μm, the reel diameter becomes large, which makes the handling inconvenient, and it becomes impossible to secure the necessary length corresponding to the length of the metal thin plate wound in a coil shape. If you want to make the winding diameter smaller for convenient handling, or if you want to lengthen the length of one winding, heat calendering this non-woven fabric and adjust the thickness to make it thinner. good.

The nonwoven fabric of the present invention has a longitudinal strength of 10 k.
g / 5 cm width or more and lateral strength of 5 kg /
The width is preferably 5 cm or more. This strength is necessary to withstand the impact forces experienced when the rolling process of sheet metal is accelerated. When the strength value is less than the above value, the nonwoven fabric has a usage limit, that is, a service life of about several times, and the replacement frequency increases, resulting in inefficiency. If the rolling speed is about 1000 m / min, the longitudinal strength is 20 kg / 5 cm or more, and the transverse strength is 1
0 kg / 5 cm or more is required. The term “strength” as used herein means that it is obtained based on the tensile test method of JIS-L-1096, and the measurement condition is a width of 5 cm,
The distance between chucks is 10 cm, and the pulling speed is 20 cm / min. The longitudinal direction means the longitudinal direction of the nonwoven fabric producing direction, and the transverse direction means the direction perpendicular to the longitudinal direction.

Further, in the nonwoven fabric of the present invention, it is preferable that the 3% elongation stress in the longitudinal direction and the transverse direction is 3 kg / 5 cm width or more when the nonwoven fabric is measured by the above tensile test. 3 in both vertical and horizontal directions
If the% elongation stress is less than 3 kg / 5 cm, shrinkage occurs in the width direction depending on the number of uses in the initial stage when used in the rolling process, and the non-woven fabric does not exist between the layers at both ends of the metal thin plate, resulting in metal It may not serve the purpose of protecting the thin plate.

3% elongation stress in longitudinal and transverse directions of 3k
Even if it is g / 5 cm or more, it is not necessary to make the longitudinal 3% elongation stress extremely large, and similarly, it is not necessary to make the lateral 3% elongation stress extremely large. Rather, considering the balance of stress-strain in the vertical and horizontal directions, the ratio of the 3% elongation stress in the longitudinal direction to the 3% elongation stress in the lateral direction is (3% elongation stress in the longitudinal direction) / (3% elongation in the lateral direction). It is preferable that (stress) = 0.5 to 3. More preferably, it is 1 to 1.5. That is, this condition was found from the viewpoint of preventing the nonwoven fabric from being subjected to a tensile load in the longitudinal direction and contracting in the width direction when being wound between the layers of the metal thin plates. If it deviates from this range, wrinkles may occur at the stage of use during rolling. The mechanism of generation of this wrinkle is considered to be as follows. That is, when the non-woven fabric for surface protection is wound between the thin metal plates, a tensile load is applied in the vertical direction,
Due to the load in the longitudinal direction, the nonwoven fabric generates elongation strain in the longitudinal direction, and at the same time, a strain to shrink in the lateral direction, that is, the width direction occurs, and the difference between the longitudinal strain and the lateral strain is within the above range It is considered that wrinkles occur when the size becomes larger than.

As described above, the melting point of the fibers forming the non-woven fabric is 200 ° C. or higher is a necessary condition for preventing the generation of wrinkles. Further, from the viewpoint of preventing the generation of wrinkles, the ratio of the longitudinal 3% elongation stress to the lateral 3% elongation stress is an important factor.

As described above, when the non-woven fabric for surface protection of the present invention is used during rolling of a thin metal plate, wrinkles are generated in the longitudinal direction of the non-woven fabric, and the time limit is reached.
In order to increase the number of times of this use, the bending rigidity per unit length in the transverse direction of the non-woven fabric is 0.15 g · cm ² /
It is preferably at least cm. In addition, by increasing this value as much as possible, it is possible to ensure durability such as withstanding several tens of uses. In order to increase the flexural rigidity, it is sufficient to consider such factors as increasing the basis weight, increasing the binding between the fibers forming the nonwoven fabric, and distributing the fiber arrangement in a large number in the lateral direction.

When measuring the flexural rigidity, the B value of the KES method used for measuring the texture of the woven fabric may be used.
By partially performing thermocompression bonding as in the present invention, this bending rigidity can be increased. That is, if the area ratio of the part that has been subjected to the thermocompression bonding treatment within the unit area is large, the bending rigidity of the non-woven fabric is increased, and the occurrence of wrinkles in the longitudinal direction of the non-woven fabric is suppressed, and its durability is improved. Contribute. Therefore, by setting the area ratio to a value as large as possible within the above range, the flexural rigidity is correspondingly increased, and the number of durable uses of the nonwoven fabric is improved.

[0026]

EFFECTS OF THE INVENTION The present invention is composed of polyester filaments having a single yarn fineness of 1 denier or more, and is partially subjected to thermocompression bonding in an embossed shape, and a portion within a unit area is
Area ratio of the parts that have been subjected to thermocompression bonding is 10-40%
Is, and the thermocompression bonding process is partially applied within the unit area.
Distribution density of 20 points / cm ² or more
The area of one point to be thermocompression bonded is 0.1 mm ² or more.
In addition, the area of
Since it is a non-woven fabric having a depth to the bottom of 25 μm or more, it has a sufficiently large tensile strength, and when applied to a high-speed rolling process of a metal thin plate, stress deformation and thermal deformation are extremely small,
The service life can be greatly increased. Furthermore, using polyester fiber which is a thermoplastic fiber,
Moreover, since it has a partial thermocompression bonding structure, this non-woven fabric is soft and does not damage the surface of the thin steel plate and is used without fluffing. That is, the partial thermocompression bonding structure,
From the surface of the non-woven fabric to the bottom of the part that has been thermocompression bonded
Since the depth is 25 μm or more, it can be used together with a thin metal plate.
Compressive force acts in the cross-sectional direction of the non-woven fabric when it is rolled
When making, the plastic thermo-compression bonding part is
There is no risk of contact with the thin sheet, which will scratch the sheet.
There is an advantage that it is difficult to attach. In addition, since it is chemically neutral, the thin steel sheet is not chemically altered and naturally no rust is generated. That is, the strain that occurs even when subjected to stress and heat during high-speed rolling is small, has morphological stability that prevents the generation of wrinkles, and because it is a soft material, there is a deviation when the thin metal plate is coiled. Even if it occurs, there is an advantage that it is not scratched. Therefore, according to the present invention, it can be prevented that scratches occur on the surface when rolling the sheet metal can finish the sheet to aesthetics, yet able to adapt the speed of recent rolling, the rolling process Efficiency can be measured.

[0027]

EXAMPLES Examples of the present invention will be described below. In addition, in Tables 1 to 3, the underlined data indicates data that deviates from the preferable range based on the present invention. [Example 1 and Comparative Example 1] Table 1 shows data on the nonwoven fabric for surface protection of Example 1 of the present invention and the nonwoven fabric of Comparative Example 1. The non-woven fabric of Example 1 is a so-called spun-bonded non-woven fabric in which a melted polymer is extruded from a nozzle, spinning and drawing are continuously performed under an air stream to form a wave, and then the wave is partially thermocompressed. The thermoplastic synthetic filament non-woven fabric obtained as above was applied. The material of the thin metal plate was stainless steel. In Comparative Example 1, a thermal bond type non-woven fabric was used in which a short-fiber low-melting point polyester and a normal polyester were mixed.

[0028]

[Table 1]

In Comparative Example 2, the thermal bond type non-woven fabric prepared by mixing the short melting point low melting point polyester and the normal polyester was fluffed due to its use and was inferior in durability. On the other hand, in the non-woven fabric of Example 1 of the present invention, the number of cycles during rolling was significantly improved. [Example 2-5, Comparative Example 2-7] Table 2 shows data on the nonwoven fabric of Example 2-5 of the present invention, and Table 3 shows data on the nonwoven fabric of Comparative Example 2-7. In each case, the type of surface protective material was a long fiber nonwoven fabric by the spunbond method. All of them had a composition of polyester and a melting point of 260 ° C. The fineness of the fibers constituting the non-woven fabric was 2 denier.

[0030]

[Table 2]

[0031]

[Table 3]

As the non-woven fabric of Examples 2-5, the embossed thermo-compression condition was applied within the range of suitable numerical values according to the present invention. In detail, the value of the thermocompression bonding area ratio was close to the upper limit in Examples 2, 3 and 5, but was close to the lower limit in Example 4. The value of thermocompression bonding density is near the lower limit in Example 3, but in other Examples, a value higher than that was applied. The value of the thermocompression bonding area is in the vicinity of the lower limit in Example 4, but in other Examples, a value higher than that was applied. The depths of the recesses forming the thermocompression bonding portion are close to the lower limit values in Examples 2 and 5, but are limited to Examples 3 and 4.
Then, a value larger than that was applied. Then, in each of the nonwoven fabrics, when the material of the thin metal plate was stainless steel, it was possible to obtain a sufficient durability during rolling.

The thickness of the non-woven fabric is close to the lower limit value in Example 5, but in other examples, the thickness above that is applied. That is, as the non-woven fabric of Example 5,
A non-woven fabric obtained by partially heat-bonding polyester filaments having a fineness of 2 denier into an embossed shape was further subjected to a heat calendering treatment at 200 ° C. to reduce its thickness and applied.

The non-woven fabric of Comparative Example 2 had a thermocompression-bonding area ratio smaller than the preferred range of the present invention, and the non-woven fabric was fluffed, so that the non-woven fabric was used a few times. The non-woven fabric of Comparative Example 3 had a thermocompression bonding area ratio larger than the preferred range of the present invention, and in this case as well, the number of times of durability was small.

The non-woven fabric of Comparative Example 4 is the same as the non-woven fabric of Jpn. Pat. Appln. KOKAI Publication No. 2-35365 described above. It is processed so that the ratio becomes 100%. In this case, fluffing occurred and the durability was poor.

The non-woven fabric of Comparative Example 5 had a thermocompression bonding density lower than the preferred range of the present invention, and a satisfactory durability was not obtained. In the non-woven fabric of Comparative Example 6, one thermocompression bonding area was smaller than the preferred range of the present invention, and fluffing occurred in the non-woven fabric, resulting in a small number of cycles. In the non-woven fabric of Comparative Example 7, the depth of the concave portion forming the thermocompression bonding portion is smaller than the preferred range of the present invention,
Since this thermocompression bonding part rubs against the surface of the stainless steel thin plate,
Occurrence of scratches was recognized on the surface of this thin plate. [Example 6 and Comparative Examples 8-9] Table 4 shows data on the nonwoven fabric of Example 6 of the present invention and the nonwoven fabrics of Comparative Examples 8 and 9. In each case, the type of surface protective material was a long fiber nonwoven fabric by the spunbond method. The fiber fineness was 2 denier in each case.

[0037]

[Table 4]

For the nonwoven fabric of Example 6, not only the embossed thermocompression bonding conditions but also the strength conditions thereof were
Those within the preferable numerical range based on the present invention were applied. The sixth embodiment is similar to the previous embodiments,
Good results were obtained with respect to the number of cycles of rolling.

In the non-woven fabric of Comparative Example 8, the lateral stress at the time of 3% elongation and the longitudinal-lateral stress ratio at the time of 3% elongation are out of the preferred numerical ranges according to the present invention. Compared with non-woven fabric, the number of cycles of rolling was significantly reduced. Since the nonwoven fabric of Comparative Example 9 used polypropylene as the composition of the thermoplastic fiber, it had a low melting point and caused a problem in terms of heat resistance. Further, since the stress at the time of elongation by 3% was out of the preferable range, it could not be practically used in the rolling step.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the surface structure of a nonwoven fabric for protecting the surface of a thin metal plate according to the present invention.

FIG. 2 is a cross-sectional view of the nonwoven fabric shown in FIG.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Oi No. 3 Hikari, Kashima-machi, Kashima-cho, Kashima-gun, Ibaraki Sumitomo Metal Industries, Ltd. (56) Reference JP-A-4-126862 (JP, A) HEI 6-7044 (JP, A) JP-A-2-286241 (JP, A) JP-A-2-234967 (JP, A) Actual public H2-35365 (JP, Y2) (58) Fields investigated (Int .Cl. ⁷ , DB name) D04H 1/00-18/00 B21C 45/00-49/00 B29C 57/00-59/18

Claims (4)

(57) [Claims] 1. A single filament fineness of polyester denier having a fineness of 1 denier or more, which is partially thermocompression-bonded in an embossed shape, and partially thermocompression-bonded within a unit area.
The area ratio of the treated area is 10-40%,
Of the area that has been partially subjected to thermocompression bonding within the area
Distribution density of 20 points / cm ² or more, partial thermocompression bonding
The area of one point is 0.1 mm ² or more, and
The depth from the surface of the woven fabric to the bottom of the part that has been thermocompression bonded
Is 25 μm or more, a nonwoven fabric for protecting the surface of a thin metal plate. 2. The non-woven fabric for protecting the surface of a thin metal plate according to claim 1, which has a thickness of 30 to 400 μm. 3. The longitudinal strength is 10 kg / 5 cm width or more, and the lateral strength is 5 kg / 5 cm width or more,
The longitudinal 3% elongation stress is 3kg / 5cm width or more,
The lateral 3% elongation stress is 3 kg / 5 cm width or more,
The ratio of 3% elongation stress in the longitudinal direction to 3% elongation stress in the lateral direction is (3% elongation stress in the longitudinal direction) / (3% elongation stress in the lateral direction)
= 0.5-3, The claim 1 or 2 characterized by the above-mentioned.
A non-woven fabric for protecting the surface of the thin metal plate described. 4. The flexural rigidity per unit length in the lateral direction is 0.
The non-woven fabric for protecting the surface of a thin metal plate according to claim 3, which has a weight of 15 g · cm ² / cm or more.