Note: Descriptions are shown in the official language in which they were submitted.
CA 022~6~0 1998-11-30
FIL~. r~ ~5.'.S Ar''P' '.~ -
T~' i''i.'.9.,~ AI'~O~I
DESCRIPTION
A NON-WOVEN FABRIC COMPRISING STAPLE FIBERS AND AN
ABSORBENT ARTICLE USING THE SAME
TECHNICAL FIELD
The invention relates to a non-woven fabric comprising staple
fibers. More specifically, it relates to a non-woven fabric comprising
staple fibers, which is suitable for sanitary materials such as
disposable diapers, sanitary napkins, incontinence pads, nursing pads
or the like, or wipers, and to absorbent articles using the non-woven
fabric comprising staple fibers.
BACKGROUND ART
Hitherto, as this kind of non-woven fabric comprising staple
fibers, Japanese Patent Publication No. Sho 52-12830 discloses a non-
woven fabric produced by a process wherein thermal adhesive
conjugated fibers are aligned by the use of a carding machine and then
piled up and entangled to be adjusted to the predetermined basis
weight, followed by conducting a thermal adhesion between fibers by a
thermal treatment.
However, the above mentioned conventional non-woven fabrics
lose the bulkiness of the non-woven fabric contributed by fibers,
because the fibers of the non-woven fabric are arranged in the machine
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direction by combing fibers with a card clothing having needles of the
carding machine. Therefore, the bulky non-woven fabrics in which the
sufficient contribution by fibers is exhibited have not been produced,
and the conventional non-woven fabrics are not always satisfactory.
The object of the present invention is to provide a bulky non-
woven fabric in which the sufficient contribution to bulkiness by fibers
of the non-woven fabric is exhibited.
DISCLOSURE OF INVENTION
The non-woven fabric comprising staple fibers of the present
invention and the absorbent article using the non-woven fabric of the
present invention are as follows.
(1) A non-woven fabric formed of staple fibers, which comprises
at least one kind of staple fiber having a fiber length of 3 to 25 mm and
a single fiber fineness of 1 to 100 denier, and is produced by the fibers
being dropped and dispersed to be accumulated and adhered at the
intersection point of each staple fiber; the non-woven fabric has a
specific volume of 40 to 200 cm3/g, the number of fiber lumps having a
volume of not less than 1 mm3 is not more than 5 lumps per 20 g of the
non-woven fabric.
(2) The non-woven fabric comprising staple fibers according to
the above item (1), wherein the fiber length of the staple fiber is in the
range of 5 to 10 mm.
(3) The non-woven fabric comprising staple fibers according to
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the above item (1), wherein at least one kind of staple fiber is a staple
fibers having 3 to 20 spiral type crimps per inch (2.54 cm).
(4) The non-woven fabric comprising staple fibers according to
the above item (1), wherein at least one kind of staple fiber is a
thermoplastic fiber.
(~) The non-woven fabric comprising staple fibers according to
the above item (1), wherein at least one kind of staple fiber is olefin
thermoplastic fiber or polyester thermoplastic fiber.
(6) The non-woven fabric comprising staple fibers according to
the above item (1), wherein at least one kind of staple fiber is a
thermoplastic conjugated staple fiber having a component which is
capable of thermal adhesion as one component.
(7) The non-woven fabric comprising staple fibers according to
the above item (1), wherein at least one staple fiber is a staple fiber
having an eccentric core and sheath type structure comprising high
crystalline polypropylene as a core component and high density
polyethylene as a sheath component.
(8) An absorbent article using the non-woven fabric comprising
staple fibers according to any one of the above items (1) to (7).
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a side elevational view of an apparatus for producing the
non-woven fabric of the present invention.
Fig. 2 is a partial cutaway view of an air laid apparatus 1 of the
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CA 022~6~0 1998-11-30
apparatus shown in Fig. 1.
Fig. 3 is a cross sectional view taken on line E-E' of the
apparatus according to Fig. 2.
BEST MODE FOR CARRYING OUT THE INVENTION
As the fibers used for the non-woven fabric comprising staple
fibers of the present invention, the following examples can be
mentioned: natural fibers such as pulp, cotton and the like; regenerated
fibers such as rayon; semi synthetic fibers such as acetate; and
synthetic fibers such as nylon, vinylon, polyester, acrylic, polyethylene,
polypropylene, polystyrene and the like. The fibers used for the non-
woven fabric of the present invention are not particularly limited as
long as they are adhered in a case where binders are used and they do
not give an adverse effect on the uniformity of the non-woven fabric.
However, thermal adhesive thermoplastic fibers being capable of
thermal adhesion between fibers at the intersection points in a short
time, without using powder-like binders that fall in the form of small
particles or water soluble binders that need to be dried, are preferable.
The fiber length of the staple fiber constituting the non-woven
fabric comprising staple fibers of the present invention needs to be in
the range of 3 to 25 mm. Preferably, it is in the range of 3 to 15 mm,
more preferably, in the range of 5 to 10 mm. In particular, in the case
of the spiral type crimps, the number of crimps is approximately 5
crimps per inch (2.54 cm). Therefore, the appropriate fiber length is 5
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mm which corresponds to the length of once winding of crimp and 10
mm which corresponds to the length of twice winding of crimps. If the
fiber length is less than 3 mm, the strength of the non-woven fabric
lowers. Moreover, if the fiber length is more than 25 mm, it is difficult
to produce a uniform web, because fibers are entangled with each
other before passing through a sieve or a screen.
The fiber thickness is in the range of 1 to 100 denier, preferably
in the range of 1.5 to 35 denier. More preferably, it is in the range of
1.5 to 20 denier. If the fiber thickness is less than 1 denier, the
density of the fiber in the cylindrical screen increases, so that a
uniform web cannot be produced. On the other hand, if the fiber
thickness is more than 100 denier, the ability of fibers to entangle each
other becomes strong, so that it is difficult to produce a uniform web.
The specific volume of the non-woven fabric comprising staple
fibers of the present invention is in the range of 40 to 200 cm3/g.
Preferably, it is in the range of 70 to 150 cm3/g. It is not preferable for
the specific volume of the non-woven fabric to be less than 40 cm3/g,
since the non-woven fabric becomes hard. Also, it is not preferable for
the specific volume of the non-woven fabric to be more than 200 cm3/g,
since the strength of the non-woven fabric is lowered.
Moreover, in the non-woven fabric comprising staple fibers of the
present invention, the number of fiber lumps having a volume of not
less than 1 mm3 is not more than 5 lumps per 20 g of the non-woven
fabric. It is not preferable for the fiber lumps of such size included in
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the non-woven fabric to be more than the above mentioned range, since
there arise some disadvantages: the non-woven fabric becomes not-
uniform, has a rough touch and becomes non-uniform in the coloring
due to fiber lumps.
In a case where the fibers used for the non-woven fabric of staple
fibers of the present invention are conjugated fibers comprising at
least two components (hereinafter, the component (A) and the
component (B) will be used for an abbreviation), the below mentioned
resins etc. can be used as materials.
As resins of the component (A), the following can be used:
polyolefins such as polypropylene, high density polyethylene, medium
density polyethylene, low density polyethylene, linear low density
polyethylene, binary copolymer or terpolymer of propylene with other
a-olefin and the like; polyamides; polyesters such as polyethylene
terephthalate, polybutylene terephthalate, low melting point polyester
from copolymerizing diol and terephthalic acid / isophthalic acid etc.,
polyester elastomer and the like; fluororesin; the mixture of the above
mentioned resins; other resins that can be spun.
As resins of the component (B), the following can be used:
polyolefins such as polypropylene, high density polyethylene, medium
density polyethylene, low density polyethylene, linear low density
polyethylene, binary copolymer or terpolymer of propylene with other
a-olefin and the like; polyamides; polyesters such as polyethylene
terephthalate, polybutylene terephthalate, low melting point polyester
. ~ . ~, . .... . .... . .
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from copolymerizing diol and terephthalic acid / isophtalic acid etc.,
polyester elastomer and the like; fluororesin; the mixture of the above
mentioned resins; other resins that can be spun.
It is preferable that the difference in the melting point between
the component (A) and the component (B) is not less than 10~C.
Consequently, when the thermal treatment is conducted at the
temperature not less than the melting point of the low melting point
component and less than the melting point of the high melting point
component, the low melting point component of the conjugated fiber
melts and the high melting point component remains as it is. As a
result, the thermal adhesive non-woven fabric having a three
dimensional network structure can be formed. Moreover, in the above,
when the melting point is not clearly determined, the melting point
denotes the softening point. The measurement of the softening point
is conducted under the conditions specified in JIS K 2531.
As the combination examples of the resin component (A) and (B),
the following examples can be mentioned: high density polyethylene /
polypropylene, low density polyethylene / propylene--ethylene--
butene- 1 crystalline terpolymer, high density polyethylene
polyethylene terephthalate, nylon 6 / nylon 66, low melting point
polyester / polyethylene terephthalate, polypropylene / polyethylene
terephthalate, polyvinylidene fluoride / polyethylene terephthalate,
the mixture of linear low density polyethylene and high density
polyethylene / polyethylene terephthalate and the like.
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It is preferable that a thermoplastic conjugated fiber comprises
olefin resin or polyester resin, or the combination thereof. As the
combination examples of such resin components (A) and (B), the
following examples can be mentioned: high density polyethylene /
polypropylene, low density polyethylene / propylene--ethylene--
butene- 1 crystalline terpolymer, high density polyethylene
polyethylene terephthalate, low melting point polyester / polyethylene
terephthalate, polypropylene / polyethylene terephthalate, linear low
density polyethylene / polyethylene terephthalate and the like.
The shapes of the conjugated fiber are not limited and can be a
core and sheath type, an eccentric core and sheath type, a side-by-side
type, a multi-layer type having three layers or more, a hollow multi-
layer type, a modified (non-circular) multi-layer type etc. and other
structures in which the low melting point resin component forms at
least one part of the fiber surface.
The preferable combination of the component constituting the
conjugated fibers and the shape is: the thermoplastic conjugated fiber
having an eccentric core and sheath type structure comprising high
crystalline polypropylene as a core component and high density
polyethylene as a sheath component and having spiral type crimps. A
fiber having spiral type crimps has much space per a single fiber, so
that a web formed by piling up fibers has a very high bulkiness.
The bulkiness of the web depends much on the number of crimps
of the thermoplastic fibers used for a non-woven fabric. In particular,
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CA 022~76~7~70 1998-11-30
it is preferable that the thermoplastic fiber has 3 to 20 spiral type
crimps per an inch (2.54 cm). Herein, "3 to 20 crimps per an inch
(2.54 cm)" denotes that 3 to 20 crimps are included in an inch (2.54 cm)
of fiber length. Preferably, it is a fiber having 5 to 15 spiral type
crimps per an inch (2.54 cm), more preferably it is a fiber having 5 to 10
spiral type crimps per an inch (2.54 cm). Preferably, the non-woven
fabric using fibers having the above mentioned range of number of
crimps has high bulkiness. If the number of the spiral type crimps is
considerably less than 3 crimps per an inch (2.54 cm), the fiber is not
different from the straight type fiber and the bulkiness tends to be
lowered. On the other hand, in a case where the spiral type crimps are
far more than 20 crimps per an inch (2.54 cm), the space per a single
fiber becomes small, and thus the bulkiness of the non-woven fabric
conversely tends to be reduced.
In the above mentioned conjugated fiber, the composition ratio of
the low melting point component to high melting point component is:
the low melting point resin component is in the range of 10 to 90 wt. %
and the high melting point resin component is in the range of 90 to 10
wt.%. More preferably, the low melting point resin component is in the
range of 30 to 70, wt.% and the high melting point resin component is in
the range of 70 to 30 wt.%. If the low melting point component is less
than 10 wt.%, the tensile strength of the thermal adhesive non-woven
fabric comprising conjugated fibers tends to be reduced. On the other
hand, if the low melting point component is more than 90 wt.%, too
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little core component remains without melting, so that the bulkiness of
the thermal adhesive non-woven fabric comprising conjugated fibers
tends to be reduced.
In the case of the straight type staple fibers, the non-woven
fabric has a uniformity, but does not have the high bulkiness, thus
making the non-woven fabric very flat. As a result, the applicability
as commercial products is reduced. However, in a case where the
staple fiber having actual crimps is used, the non-woven fabric having a
high bulkiness can preferably be produced.
As the shape of the crimps of staple fibers used for the non-
woven fabric comprising staple fibers, the following examples can be
mentioned: spiral (three dimensional crimps) type crimps, zig-zag type
crimps, wave type crimps or the like. The staple fibers having any of
the above mentioned shapes of crimps can be applied to a non-woven
fabric comprising staple fibers of the present invention. The most
preferable crimp is a spiral type crimp.
In a case where the shape of crimps of staple fiber is the spiral
type crimps, fibers are not entangled with each other so much and the
bulkiness of the resultant non-woven fabric becomes very high. This
tendency is remarkably found when a fiber has the above mentioned
preferable range of fiber length and the shape of the spiral is
approximately circular.
In a case where the shape of crimps of staple fiber is the zig-zag
type crimps, the larger the number of the crimps is, the more securely
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and deeply the crimps are set. As a result, the bulkiness of the
resultant non-woven fabric is higher. However, if the number of the
crimps is far more than the above mentioned preferable range, fibers
tend to be easily entangled with each other and an uniform non-woven
fabric is not obtained.
In a case where the shape of crimps of staple fiber is the wave
type crimps, the tendency of the fibers to entangle is more remarkable,
so that large fiber lumps generate and easily cause the blocking of a
sieve or screen. Consequently, the production of the non-woven fabric
becomes difficult.
However, with any type of crimp, unless the number of crimps or
the fiber length is much different from the above mentioned preferable
range, the effect of the present invention is not harmed.
In a case where webs are produced by the use of the conventional
carding machine, fibers are entangled and then the webs are drawn, so
that the bulkiness of the web is reduced. Therefore, as the preferable
embodiment of the present invention, methods in which a web is not
drawn are to be sought. One example of such methods is: the method
in which a web is produced by fibers that are dropped while being
dispersed to be accumulated. In the method in which fibers are
successively dropped with dispersion to be accumulated, fibers are not
drawn with being entangled, and therefore the bulkiness of the fiber
itself is not lost. The non-woven fabric in which the sufficient
contribution to bulkiness by fibers is exhibited can be produced.
11
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In a case where webs are produced by fibers being dropped with
dispersion to be accumulated, if the fibers are long, a uniform
dispersion is difficult and the resultant non-woven fabric has a coarse
density. On the other hand, if fibers are short, a uniform dispersion is
easily obtained, and the non-woven fabric without coarse density can be
produced. Moreover, one of the methods to enhance a uniform
dispersion of fibers is to make fibers pass through a sieve or screen. In
a case where fibers are made to pass through a sieve or screen, even
staple fibers are entangled before passing the screen or sieve and the
fiber lumps of the entangled fibers pass through the screen and are
piled up in the non-woven fabric. As a result, the resultant non-woven
fabric is sometimes not-uniform and includes fiber lumps. The non-
woven fabric contaminated with fiber lumps sometimes has a rough
touch and non-uniform coloring due to the subtle reflecting property of
the fiber lumps.
There are staple fibers that are easily entangled and staple
fibers that are less easily to be entangled. If classified, the staple
fibers having a zig-zag type crimps and having a large number of
crimps and / or having high crimp set force tend relatively to be easily
entangled. Moreover, the staple fibers having the wave type crimps
with fish-hook shaped ends tend to be easily entangled. The staple
fibers having the spiral type crimps are particularly preferable since
their ends of fibers are approximately on the same circumference and
are not easily entangled.
12
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A fiber lump that gives an adverse effect on the uniformity of the
non-woven fabric is divided into two types: one is the entangled fibers
and another is the portion where the fibers are not sufficiently opened.
In the not-opened portions, individual fibers are spaced closely after
the opening step. Therefore, the effective method for preventing the
generation of fiber lumps is to space each fiber less closely.
Specifically, not-opened portions can be reduced by selecting a shape of
crimps. When the shape of crimps is the wave type, fibers are easily
dispersed and few not-opened portions are generated as compared with
the zig-zag type crimps. Furthermore, when the shape of crimps is the
spiral type, fibers are easily be dispersed and few not-opened portions
are generated as compared with the wave type crimps. In other words,
the entanglement of fibers and generation of the not-opening portion
can be inhibited by selecting the shape of crimps.
In other words, the object of the present invention, namely to
provide the bulky non-woven fabric in which sufficient contribution to
bulkiness by fibers is exhibited, can be attained by producing the non-
woven fabric in the following way: a web is produced by making short
fibers pass through a sieve or screen and dropped with uniform
dispersion in three dimensions to be accumulated, and by thermally
adhering the intersection point of each fiber by thermal treatment.
In the non-woven fabric produced by the method of making fibers
pass through a sieve or screen, fibers are dropped with dispersion in
three dimensions to be accumulated. Such non-woven fabric has a
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greater specific volume as compared with the non-woven fabric in which
fibers are aligned in one direction by the carding machine. The non-
woven fabric having a large specific volume has a soft touch and is
particularly suitable for products that directly contact the users' skin,
for example, absorbent articles of disposable diapers, sanitary napkins
or the like. Moreover, since the high specific volume denotes the high
bulkiness and high cushioning property, such non-woven fabric is
preferably used for applications that requires a cushioning property, for
example, bandage or eye bandage, table linen, cooking towel, packing
materials for glass or ceramics, packing materials for fresh products
and flowers, packing materials for instruments and furniture and the
like .
The thermal adhesive conjugated fibers used for the non-woven
fabric comprising staple fibers of the present invention can be produced
by, for example, the following step.
Resins for a core component and a sheath component are melted
and discharged from, for example, the composite spinneret having 100
to 350 holes. At this time, unstretched fibers are cooled by cooling just
below the spinneret. Unstretched fibers of 3 to 400 denier are
produced by taking up at the discharging volume of 100 to 200 g/min
and at the taking up speed of 40 to 1300 m/min. The unstretched
fibers are stretched between the two rollers heated at temperatures of
60 to 120~C, while making the rotating speed of the second roll greater
than that of the first roll. Stretched fibers of 1 to 100 denier are
14
. , ~ .. ,, . ... , ., . , ~ . ......... ...
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produced by stretching with the ratio of the rotating speed of the first
roll to the second roll in the range of 1: 2 to 1: 5. Finishing agents
are applied to the stretched fibers by using a contact roller, followed by
making the stretched fibers pass through a box-type crimp processor to
produce a tow having crimps. It is preferable that the number of
crimps is 0 to 25 crimps per an inch. Since the tow contains
approximately 10 wt.% of water, it is dried by the use of a drier at 60 to
120~C. The dried tow is cut with a push-cutting type cutter into fibers
having the constant length ranging from 3 to 25 mm. Such fiber
length is substantially shorter than fibers used for the non-woven
fabric produced by the conventional carding process.
At the time of producing the non-woven fabric, a plurality of
forming heads are used and the non-woven fabric having a different
fineness or a different shape of staple fiber is used at each forming head.
Consequently, the non-woven fabric having a density gradient in the
thickness direction can be produced. The non-woven fabric having a
density gradient in the thickness direction, produced by the above
mentioned method, can be used as non-woven fabric materials for
filters, such as a liquid filter, an air filter etc.
When the non-woven fabric comprising staple fibers produced by
the above mentioned method is used for absorbent articles such as
disposable diapers, they can be used for a non-woven fabric as a surface
material, second sheet, or back layer material sheet. In particular,
since the non-woven fabric comprising staple fibers has a high
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bulkiness, it is preferably used for the second sheet that requires the
high bulkiness. Moreover, the non-woven fabric comprising mixture of
pulp, thermal adhesive fibers and high absorptive materials is
preferably used as absorbent articles which do not lose shape when
absorbing urine.
The non-woven fabric comprising staple fibers of the present
invention can be produced as follows with staple fibers having a fiber
length of 3 to 25 mm and by the use of the air laid type apparatus.
As shown in Fig. 1 to Fig. 3, an air laid type apparatus
comprises: a casing 2 having a trapezoidal shaped cross section and
having an opening portion in its bottom face only; fiber feeding
openings 3 and 4 which are provided at both ends of the casing 2; web
forming heads 5 and 6 corresponding to the feeding openings 3 and 4,
comprising cylindrical screens 5a and 6a which are positioned parallel
to the side face of the casing 2 and are capable of rotating; needle rolls
5b and 6b which are provided in a way to contact each inner wall of the
cylindrical screens 5a and 6a, and fiber circulation zones 7 and 8 which
are respectively provided at the both ends of cylindrical screens 5a and
6a and at the both ends of the casing 2. A net conveyor 9a is provided
just below the lower face of the air laid type apparatus. A pair of drive
rolls 17a and 17b and a suction unit 10 are attached to the net conveyor
9a. Moreover, an apparatus for carrying out the next step in the air
laid type apparatus comprises: a suction drier 12 for thermally
adhering the conjugated fibers constituting a web, a net conveyor 9b
16
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which makes the web pass through the suction drier 12, a pair of drive
rolls 17c and 17d for driving the net conveyor 9b thereunder; and a
pressing roll 11 on the drive roll 17c across the net conveyor 9b.
Moreover, a feed roll 18 for feeding the produced thermal adhesive
non-woven fabric 14 and a pair of drive rolls l9a and l9b for driving a
take-up roll 14 are provided.
In the above mentioned apparatus, staple fibers are
mechanically opened by the use of an opening apparatus (not shown)
and then are fed to the fiber feeding circulation duct connected to the
fiber inserting openings 3 and 4. At this time, the fiber bundle is
nearly dissolved. Fibers 15 which are fed into the fiber inserting
openings 3 and 4 are mixed and circulated while moving in the passage
formed by cylindrical screens 5a and 6a and circulating zones 7 and 8 in
the direction of arrows C1, C2, C3, and C4 and in the direction of
arrows D 1, D2, D3, and D4 of Fig.2. The circulated fibers are
discharged through the rotating cylindrical screens 5a and 6a by means
of centrifugal force and shearing effect generated by both the rotations
of the needle rolls 5b and 6b rotating in the direction of arrow AA' and
the cylindrical screens 5a and 6a rotating in the direction of arrow BB'.
The discharged fibers are sucked by the use of the suction unit 10 from
the lower portion of the casing 2 and are collected on the net conveyor
9a. The collected web 16 is pressed between the web pressing roll 11
and the drive roll 17c of the net conveyor 9b. At this time, the
collected fibers are oriented in random directions and form a web.
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The web 16 is pressed by using the pressing roll 11 and provided
to the suction drier 12 and then thermally treated at a temperature not
less than the melting point of the low melting point component and not
more than the melting point of the high melting point component, for
example, in the range of 90 to 170 ~C, for 3 to 10 seconds. By this
thermal treatment, the low melting point component of the conjugated
fiber is melted and the high melting point component of the conjugated
fiber remains as it is. Thus, the thermal adhesive non-woven fabric 13
having a three dimensional network structure is formed and taken up
by the take-up roll 14.
In order to arrange the air carried staple fibers more randomly,
the production method of making the staple fibers pass through a sieve
or net which comprises a wide variety of mesh is conducted.
Specifically, it is preferable that the method of making the staple fibers
pass through a screen with dispersion to be accumulated is conducted.
The shape of holes of the screen of the cylindrical screens 5a and
6a is generally a laterally longer rectangle. It is preferable that the
laterally longer rectangle having the longitudinal length of which is 1
to 3 mm and the lateral length of which is 15 to 30 mm. The shape of
the holes is not limited to a laterally longer rectangle and may be circle,
triangle, quadrangle, polygon and oval besides a laterally longer
rectangle. It is preferable that the rate of the hole area of the screen
is 20 to 50 %. By selecting the above mentioned hole shape and the
rate of hole area, a uniform web can be produced.
18
... . ..
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Among the non-woven fabrics comprising staple fibers of the
present invention, the non-woven fabric comprising thermal adhesive
conjugated fibers is thermally adhered in the intersection point of each
fiber by thermal treatment using the suction drier 12 after the
formation of web. This thermal treatment may be conducted by the
use of heating apparatus such as a thermal calendar roll etc. instead of
the suction drier 12. The basis weight of the resultant non-woven
fabric is not particularly limited. However, it is preferable that the
basis weight is about 10 to 1000 g/m2. In the case of surface materials
for disposable diapers, the basis weight is about 10 to 60 g/m2; in the
case of wipes, about 10 to 600 g/m2; in the case of filters, about 10 to
1000 g/m2. Moreover, the apparent density of the non-woven fabric is
not particularly limited. However, it is preferably about 0.017 to 0.10
g/cm3 when the hand feeling is taken into consideration.
The non-woven fabric having higher density can be produced by
carrying out a thermal pressing process or thermal rolling process or
the like as an after-processing treatment.
In a case where the thermal adhesive non-woven fabric
comprising staple fibers of the present invention is thermally adhered
at the intersection point of each fiber by the use of a thermal calendar
roll, it is preferable to make the rate of the thermo-compression area be
in the range of 10 to 30 %. By selecting the above range of the rate of
thermo-compression area, the non-woven fabric which is excellent in
resistance against falling off of fibers and strength and has a soft hand
19
CA 022~6~0 1998-11-30
feeling and touch can easily be provided.
The non-woven fabrics comprising staple fibers of the present
invention can be used for a wide variety of applications by themselves,
or after being laminated, sewn, or thermally adhered with another
material. For example, when they are used as a member of pants type
disposable diapers, they can be used for the portion where both hand
feeling and strength are required, for example, as front surface
materials, back sheets etc. As a matter of course, when the non-woven
fabric is used for the pants type disposable diapers and the like, they
can be used in combination with other members or thermal adhesive
non-woven fabric such as a stretchable and contractable material for
closely contacting with the trunk or legs portions. Moreover, the
thermal adhesive non-woven fabric can be used as cover materials of
the above mentioned front surface materials or back surface materials
or the like, by laminating other non-woven fabric or tissue papers, webs,
films or the like.
The non-woven fabric comprising staple fibers of the present
invention can be used as wipes for furniture, cars and the like by
applying various kinds of lubricant.
Further, the non-woven fabric comprising staple fibers can be
made into filter materials by subjecting the non-woven fabrics to an
after-processing treatment such as a pleat processing, forming into a
cylindrical shape, winding the thermal adhesive non-woven fabric to
form into a cylindrical shape, and winding while heating to form into a
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thermally adhered cylindrical shape.
Hereinafter, the present invention will be further described by
referring to the Examples but is not limited to them alone.
The definition of values of the physical properties etc. of the
thermal adhesive non-woven fabric in the Examples and the measuring
method for determining the values are as follows.
The specific volume of the non-woven fabric comprising staple
fibers of Table 1 is determined and measured in the below mentioned
method.
(1) Specific Volume
The basis weight and the thickness of the non-woven fabric were
measured and the value calculated by the following equation was
defined as the specific volume.
Specific Volume = (Y x 100 x 100) / X
wherein X denotes the basis weight of the non-woven fabric (g/m2) and
Y denotes the thickness of the non-woven fabric (cm).
Moreover, the size of the non-woven fabric sample used herein
was 25 cm x 25 cm.
The number of the fiber lumps of the non-woven fabric
comprising staple fibers of Table 1 was determined and measured by
the below mentioned method.
(2) Number of Fiber Lumps
The number of fiber lumps having a volume not less than 1 mm3
existing in 20 g of the non-woven fabric was defined as the number of
21
CA 022~6~0 1998-11-30
fiber lumps.
However, ten pieces of 20 g of non-woven fabric were sampled
and the average value of each number of fiber lumps observed in each
sample was defined as the number of fiber lumps.
(3) Hand Feeling and Appearance of Non-Woven Fabric
Five panelists evaluated the hand feeling of the non-woven fabric
in the viewpoints of uniformity, a rough feeling, and non-uniformity in
the color phase, the color phase becoming non-uniformity due to the
fiber lumps. The hand feeling and appearance of the non-woven fabric
were judged based on the following standards. When three or more
panelists evaluated that the non-woven fabric had at least one defect
among the following items: that is, the non-woven fabric had a non-
uniformity; the non-woven fabric had a rough feeling; and the non-
woven fabric is not uniform in color phase, then the hand feeling was
regarded as "bad". In any other cases, the hand feeling of the non-
woven fabric was judged as "good".
~,xample 1
A method for producing a non-woven fabric where rayon staple
fibers and thermal adhesive fibers are mixed and the intersection
points of fibers are adhered by thermal treatment:
40 wt. % of rayon fibers having 12 zig-zag type crimps per inch
(2.54 cm), the fiber fineness of 1.5 d/f and the fiber length of 5 mm
(hereinafter, the expression like "1.5 d/f x 5 mm" will be used for an
22
....
CA 022~6~0 1998-11-30
abbreviation) and 60 wt. % of an eccentric core and sheath type
conjugated fiber comprising polypropylene as a core component and
high density polyethylene as a sheath component, having 7 spiral type
crimps per inch (2.54 cm) and being 3 d/f x 5 mm were fed into and
made to pass through an opening apparatus and thereby fibers were
opened mechanically. Then, the opened fibers were fed into an air laid
type apparatus shown in Fig. 1 to Fig. 3 and treated therein.
Specifically, rayon fibers and thermal adhesive fibers 15, which were
made to pass through the opening apparatus, were inserted into the
fiber insertion openings 3 and 4 by way of the fiber feeding circulation
duct and discharged from the rotating cylindrical screens 5a and 6a.
The discharged fibers were collected on the net conveyor 9a having the
suction apparatus 10 moving at the speed of 90 m/min to form the web
16. After the web 16 was compressed with the web compressing roll 11,
it was thermally treated at 150 ~C for three seconds by the use of the
suction drier 12, and thereby high density polyethylene of the sheath
component was melted and adhered to produce the non-woven fabric 13.
Then the non-woven fabric 13 was taken up into the take-up roll 14.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 3.6 mm, specific volume of
143 cm3/g, and the number of the fiber lumps of 2.1 lumps per 20g.
The results are shown in Table 1.
Example 2
23
.. . ~, . , . , , " .. . . ., _
CA 022~6~0 1998-11-30
A method for producing thermal adhesive staple fibers:
High crystalline polypropylene having MFR (melt flow rate) of
11 g per 10 minutes (the conditions 14 specified in JIS K7210) as a core
component and high density polyethylene having MI (melt index) of
16.5 g per 10 minutes (the conditions 4 specified in JIS K 7210) were
spun out of an eccentric core and sheath type spinneret having 621
holes at the discharging ratio of high crystalline polypropylene to high
density polyethylene of 5: 5 and at the discharging volume of 450 g/min,
and then taken up at the speed of 592 m/min to produce 11 denier
unstretched fibers. When spinning was conducted, fibers were cooled
by air cooling just below the spinneret, and then finishing agent
comprising lauryl phosphate potassium salt as a main component was
applied by using a contact roll.
This unstretched fiber was stretched between the first roll and
the second roll to produce a stretched fiber having the fineness of 3
denier and spiral type crimps. At this time, the first roll was 90 ~C
and the second roll was 20 ~C, and the rotating ratio of the first roll to
the second roll was set to be 1: 4.5. This stretched fiber having spiral
type crimps was cut into fibers of 5 mm in length by using the push-
cutting type cutter.
Hereinafter, the method for producing a non-woven fabric
comprising the thermal adhesive fibers will be explained.
The conjugated fibers were fed into and made to pass through an
opening apparatus and opened mechanically, and then treated by
24
CA 022~6~0 1998-11-30
feeding the opened fibers to the air-laid type apparatus shown in Fig. 1
to Fig. 5. Specifically, the opened conjugated fiber 18 was fed into the
fiber inserting openings 3 and 4 by way of the fiber feeding circulation
duct and discharged from the rotating cylindrical screen 5a and 6a.
The discharged fibers were collected on the net conveyor 9a having the
suction apparatus 10 moving at the speed of 90 m/min to form into the
web 16. After the web was compressed with the web compressing roll
11, it was thermally treated at 150 ~C for three seconds by the use of
suction drier 12, and thereby high density polyethylene of a sheath
component was melted and adhered to produce the non-woven fabric 13.
Then the non-woven fabric 13 was taken up by the take-up roll 14.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 4.6 mm, specific volume of
185 cm3/g, and the number of the fiber lumps of 1.2 lumps per 20g.
The results are shown in Table 1.
Exa~ple 3
The non-woven fabric was produced under the same conditions as
Example 2 except that the fiber length of the conjugated fiber was made
to be 10 mm.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 4.4 mm, specific volume of
176 cm3/g, and the number of the fiber lumps of 1.9 lumps per 20g.
The results are shown in Table 1.
Example 4
CA 022~6~0 1998-11-30
The non-woven fabric was produced under the same conditions as
Example 2 except that the fiber length of the conjugated fiber was made
to be 15 mm.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 4.25 mm, specific volume of
170 cm3/g, and the number of the fiber lumps of 3.8 lumps per 20g.
The results are shown in Table 1.
F,xample 5
A method for producing the non-woven fabric using polyester
staple fibers and side-by-side type conjugated fiber:
30 wt. % of polyester fibers having 14 zig-zag type crimps per inch (2.54
cm), and being 2 d/f x 5 mm and 70 wt. % of side-by-side type
conjugated fibers comprising a polypropylene component and a high
density polyethylene component, having 6 spiral type crimps per inch
(2.54 cm) and being 2 d/f x 5 mm were fed into and made to pass
through an opening apparatus, thus opening the fibers mechanically.
Then, the opened fibers were fed into an air laid type apparatus shown
in Fig. 1 to Fig. 3 and treated therein. Specifically, the opened
polyester fibers and side-by-side type conjugated fibers 15 were
inserted into the fiber insertion openings 3 and 4 by way of the fiber
feeding circulation duct and discharged from the rotating cylindrical
screens 5a and 6a. The discharged fibers were collected on the net
conveyor 9a having the suction apparatus 10 moving at the speed of 90
m/min to form into the web 16. After the web was compressed with the
26
. , , , ,, , " . , . ~ . . . .
CA 022~6~0 1998-11-30
web compressing roll 11, it was thermally treated at 150 ~C for three
seconds by the use of the suction drier 12, and thereby high density
polyethylene of the sheath component was melted and adhered to
produce the non-woven fabric 13. Then the non-woven fabric 13 was
taken up by the take-up roll 14.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 3.4 mm, specific volume of
137 cm3/g, and the number of the fiber lumps of 2.2 lumps per 20g.
The results are shown in Table 1.
~xalnple 6
A method for producing thermal adhesive staple fibers:
The non-woven fabric was produced under the same conditions as
Example 2 except that high crystalline polypropylene having MFR of 11
g per 10 minutes (the conditions 14 specified in JIS K7210) and high
density polyethylene having MI of 16.5 g per 10 minutes (the conditions
4 specified in JIS K 7210) were spun out of a side-by-side type
composite spinneret having 621 holes at the discharging ratio of high
crystalline polypropylene to high density polyethylene of 5: 5 and at
the discharging volume of 450 g/min, and then taken up at the speed of
592 m/min to produce 8.1 denier unstretched fibers.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 4.5 mm, specific volume of
181 cm3/g, and the number of the fiber lumps of 1.3 lumps per 20g.
The results are shown in Table 1.
27
CA 022~6~0 1998-11-30
~,~ample 7
Fibers were produced under the same conditions as Example 6
except that the number of holes of the spinneret was 60, the
discharging volume was 200 g/min, the taking-up speed was 417 m/min,
the unstretched fiber was 72 denier, the stretched fiber was 18 denier
and the number of spiral crimps was 6 crimps per inch (2.54 cm).
The conditions for producing non-woven fabrics were made to be
the same as Example 5.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 3.9 mm, specific volume of
156 cm3/g, and the number of the fiber lumps of 0.5 lumps per 20g.
The results are shown in Table 1.
Example 8
A method for producing thermal adhesive staple fibers:
Polypropylene having MFR of 16 g per 10 minutes (the conditions
14 specified in JIS K7210) as a core component and high density
polyethylene having MI of 16.5 g per 10 minutes (the conditions 4
specified in JIS K 7210) were spun out of a core and sheath type
spinneret having 621 holes at the discharging ratio of high crystalline
polypropylene to high density polyethylene of 5: 5 and at the
discharging volume of 450 g/min and taken up at the speed of 919
m/min, to thus produce 7.1 denier of unstretched fibers. When
spinning was conducted, fibers were cooled by air cooling just below the
spinneret.
28
CA 022~6~0 1998-11-30
This unstretched fiber was stretched between the first roll and
the second roll to form 2 denier stretched fiber. At this time, the first
and second rolls were heated at 90 ~C respectively and the rotating
ratio of the first roll to the second roll was set to be 1: 4. A finishing
agent comprising lauryl phosphate potassium salt as a main component
was applied to this stretched fiber by using a contact roll. Then, they
were made to pass through a box type crimp processing apparatus to
produce a tow having 14 zig-zag type crimps per inch.
Since this tow contained a water component, it was dried at the
temperature of 90 ~C by using a drier and then it was cut into fibers of
10 mm in length by using a push-cutting type cutter.
The conditions for producing the non-woven fabrics were made to
be the same as Example 5.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 2.8 mm, specific volume of 79
cm3/g, and the number of the fiber lumps of 4.5 lumps per 20g. The
results are shown in Table 1.
F,xarnple 9
A method for producing the thermal adhesive fibers comprising
staple fibers:
114 denier of unstretched fibers were produced by the use of a
spinneret having 60 holes by taking up at the discharging volume of 200
g/min and at the taken-up speed of 263 m/min, then they were produced
into 32 denier stretched fibers. Thermally adhesive conjugated fibers
29
CA 022~6~0 1998-11-30
were produced under the same conditions as Example 8 except that 10
crimps per inch of zig-zag type crimps were provided and the fiber
length was 10 mm.
The conditions for producing a non-woven fabric were made to
be the same as Example 5.
As to the physical properties, the resultant non-woven fabric
had a basis weight of 25 g/m2, a thickness of 2.6 mm, specific volume
of 45 cm3/g, and the number of the fiber lumps of 3.6 lumps per 20g.
The results are shown in Table 1.
Example 10
Fibers were produced under the same conditions as Example 8
except that 340 denier unstretched fibers were produced by the use of a
spinneret having 100 holes by taking up at the discharging volume of
200 g/min and at the taken-up speed of 53 m/min while cooling the
fibers with water at the time of spinning, then they were produced into
100 denier stretched fibers, and the 10 zig-zag type crimps per inch
were provided and the fiber length was 25 mm.
The conditions for producing a non-woven fabric were made to be
the same as Example 5.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 2.65 mm, specific volume of
58 cm3/g, and the number of the fiber lumps of 2.4 lumps per 20g. The
results are shown in Table 1.
Example 11
CA 022~6~0 1998-11-30
A method for producing thermal adhesive staple fibers:
High crystalline polypropylene having MFR of 11 g per 10
minutes (the conditions 14 specified in JIS K7210) as a core component
and high density polyethylene having MI of 16.5 g per 10 minutes (the
conditions 4 specified in JIS K 7210) as a sheath component were spun
out of a core and sheath type spinneret having 621 holes at the
discharging ratio of high crystalline polypropylene to high density
polyethylene of 5: 5 and at the discharging volume of 350 g/min, and
then taken up at the speed of 996 m/min to produce 5.1 denier of
unstretched fibers. When spinning was conducted, fibers were
cooled by air cooling just below the spinneret.
The unstretched fibers were stretched between the first roll and
the second roll. At this time, the first roll was heated at 90 ~C and
the second roll was heated at 20 ~C and the rotating ratio of the first
roll to the second roll was set to be 1: 4.5. After a finishing agent
comprising lauryl phosphate potassium salt as a main component was
applied to this stretched fiber by using a contact roll, they were made to
pass through a box-type crimps processing apparatus to produce a tow
having 9 wave type crimps per inch. The stretched fibers having wave
type crimps were cut into fibers of 5 mm in length by using a push-
cutting type cutter.
The conditions for producing the non-woven fabric were made to
be the same as Example 6.
As to the physical properties, the resultant non-woven fabric had
31
.
CA 022~6~0 1998-11-30
a basis weight of 23 g/m2, a thickness of 3.75 mm, specific volume of
163 cm3/g, and the number of the fiber lumps of 1.8 lumps per 20g.
The results are shown in Table 1.
F,xample 1~
A method for producing the thermal adhesive staple fibers:
Polypropylene having MFR of 10 g per 10 minutes (the conditions
14 specified in the JIS K7210) and polypropylene having MI of 23 g per
10 minutes (the conditions 14 specified in the JIS K 7210) were spun
out of a side-by-side type spinneret having 350 holes at the discharging
ratio of each polypropylene of 5: 5 and at the discharging volume of 200
g/min, and then taken up at the speed of 635 m/min to produce 8.1
denier unstretched fibers. When spinning was conducted, fibers were
cooled by air cooling just below the spinneret. A finishing agent
containing lauryl phosphate potassium salt as a main component was
applied by using a contact roll.
The unstretched fibers were stretched between the first roll and
the second roll to produce 2 denier stretched fibers having spiral type
crimps. At this time, the first roll was heated at 90 ~C and the second
roll was heated at 20 ~C and the rotating ratio of the first roll to the
second roll was set to be 1: 4.5. The unstreteched fiber having spiral
type crimps was cut into fibers of 10 mm in length by using a push-
cutting type cutter.
The conditions for producing the non-woven fabric were made to
be the same as Example 5.
32
CA 022~6~0 1998-11-30
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 3.25 mm, specific volume of
130 cm3/g, and the number of the fiber lumps of 1.4 lumps per 20g.
The results are shown in Table 1.
~,xample 13
A method for producing the thermal adhesive staple fibers:
High crystalline polyethylene terephthalate having the intrinsic
viscosity of 0.68 dl/g as a core component and high density polyethylene
having MI of 16.5 g per 10 minutes (the conditions 4 specified in JIS K
7210) as a sheath component were spun out of a core and sheath type
spinneret having 621 holes at the discharging ratio of high crystalline
polyethylene terephthalate to high density polyethylene of 5: 5 and at
the discharging volume of 450 g/min and taken up at the speed of 1035
m/min to produce 6.3 denier unstretched fibers. When spinning was
conducted, fibers were cooled by air cooling just below the spinneret.
The unstretched fibers were stretched between the first roll and
the second roll. At this time, the first and second rolls were heated at
90 ~C respectively and the rotating ratio of the first roll to the second
roll was set to be 1: 3.3. A finishing agent comprising lauryl
phosphate potassium salt as a main component was applied to the
stretched fibers by using a contact roll. Then, they were made to pass
through a box-type crimps processing apparatus to produce a tow
having 5 wave type crimps per an inch (2.54 cm). The stretched fiber
having wave type crimps was cut into fibers of 10 mm in length by using
33
CA 022~6~0 1998-11-30
a push-cutting type cutter.
The conditions for producing the non-woven fabrics were made to
be the same as Example 5.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 3.0 mm, specific volume of
101 cm3/g, and the number of the fiber lumps of 2.6 lumps per 20g.
The results are shown in Table 1.
Comparative F,xanlple 1
The non-woven fabric was produced under the same conditions as
Example 2 except that the fiber length was 38 mm and a carding
apparatus was used at the time of production of a web.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 0.9 mm, specific volume of 36
cm3/g, and the number of the fiber lumps of 0.9 lumps per 20g.
The resultant non-woven fabric had a smaller specific volume as
compared with other Examples, because of the non-woven fabric
produced by the carding process. The results are shown in Table 1.
Comparative F.xample 2
The non-woven fabric was produced under the same conditions as
Example 2 except that the fiber length was 30 mm.
As to the physical properties, the resultant non-woven fabric had
a basis weight of 25 g/m2, a thickness of 2.75 mm, specific volume of
110 cm3/g, and the number of the fiber lumps of 8.5 lumps per 20g.
The non-woven fabric was produced by an air laid method.
34
CA 022~6~0 1998-11-30
However, the fiber length was longer than 25 mm, so that fibers are
easily entangled and the resultant non-woven fabric had many fiber
lumps. Therefore, the resultant non-woven fabric was inferior in
uniformity; had a rough touch; and had not uniformed hue, namely,
many white portions were found remarkably in the non-woven fabric
due to fiber lumps. Therefore, this non-woven fabric was evaluated as
bad in hand feeling and appearance. The results are shown in Table 1.
h~,xample 14
In a commercially available disposable diaper having roughly an
"I" shape in a plan view like the side cross sectional shape of a rail of
railway, only the front surface material of the paper diaper was
replaced by the thermal adhesive non-woven fabric substantially
prepared in Example 2.
The commercially available disposable diaper comprised; a front
surface material which was produced from the non-woven fabric
comprising polyethylene / polypropylene thermal adhesive conjugated
staple fibers and the intersection points of the fibers were thermally
adhered; a water absorptive material comprising a pulp and high
absorptive resin as main components; and back surface material
comprising polyethylene film. Only the front surface material was cut
off with a knife and removed, followed by laminating the thermal
adhesive non-woven fabric obtained in the above mentioned Example 3
to the same place where the front surface material had been placed.
Moreover, the thermal adhesive non-woven fabric and the remaining
CA 022~6~0 1998-11-30
non-woven fabric which was located near the leg portions were
thermally adhered. Further, the remaining thermal adhesive non-
woven fabric was cut off with scissors and removed, to thus produce a
disposable diaper in which thermal adhesive non-woven fabric was
laminated as a front surface material. This diaper had a great
strength in the lateral direction (opposite to the longitudinal direction)
of the non-woven fabric, a high bulkiness and soft hand feeling, and
was usable for a preferable disposable diaper.
36
~ ", . . . ... .. .. ..
CA 022~6~0 1998-11-30
Table 1
Denier Fiber Specific Number of Crimps Number of Hand Feeling
LengthVolumeFiber Lumps Crimps Appearance
d/f mm cm3/g Lumps/20g shape crimPs/254cm
Example 1 3 5 143 2.1 spiral 7 good
l .5 5 zig-zag 12
Example 2 3 5 185 1.2 spiral 7 good
Example 3 3 10 176 1.9 spiral 8 good
Example 4 3 15 170 3.8 spiral 7 good
Example 5 2 5 137 2.2 spiral 6 good
2 5 zig-zag 14 good
Example 6 2 5 181 1.3 spiral 7 good
Example 7 18 5 156 0.5 spiral 6 good
Example 8 2 10 79 4.5 zig-zag 14 good
Example 9 32 3 45 3.6 zig-zag 12 good
Example 10 1 00 25 58 2.4 zig-zag 10 good
Example 11 l .5 5 163 1.8 wave 9 good
Example 12 2 10 130 1.4 spiral 8 good
Example 13 2 10 101 2.6 zig-zag 5 good
Comparative 3 38 36 0.9 spiral 7 good
Example l
Comparative 3 30 110 8.5 spiral 7 bad
Example 2
As is apparent from Table 1, by selecting the denier, the fiber
length, the shape of crimps and the number of crimps of the present
invention, the non-woven fabric having a high bulkiness well
CA 022~6~0 1998-11-30
contributed to the fibers and little generation of fiber lumps, and
having good surface properties can be obtained. In addition, the fiber
length of the fiber used for the thermal adhesive non-woven fabric of
the present invention was shorter than that of the non-woven fabrics
produced by the carding method. Consequently, as the number of
fibers constituting fabric increases, uneven dispersion of the fibers was
prevented to thus produce a uniform non-woven fabric. Moreover,
since the non-woven fabric of the present invention is produced by
fibers being fallen with dispersing to accumulate, the non-woven fabric
of the present invention has smaller density and greater ventilation
degree as compared with the non-woven fabric produced by the carding
process in which fibers are combed and oriented in one direction.
The non-woven fabric comprising staple fibers of the present
invention is produced by short fibers being dropped while being
dispersed to be accumulated. As a result, this non-woven fabric
overcomes the defects: the non-woven fabric produced by the carding
process lose the bulkiness because fibers are drawn, to thus provide the
non-woven fabric having a high bulkiness and softness.
In addition, the non-woven fabric comprising staple fibers of the
present invention has shorter fiber length than the non-woven fabric
produced by the carding process, so that fibers are laminated in a
random dispersion state. As a result, the uniform non-woven fabric
having little non-uniformity in the density can be obtained. Moreover,
the non-woven fabrics are produced by fibers which are dropped with
38
... , .. . . . ... ,.. _, . . . .. . .
CA 022~6~0 1998-11-30
dispersion in the three dimensional direction to be accumulated, so that
it has a smaller density, higher ventilation, more excellent soft feeling
and touch as compared with the non-woven fabric produced by the
carding process in which fibers are carded and oriented.
INDUSTRIAL APPLICABILITY
As the effects mentioned above, the non-woven fabric of the
present invention has a soft feeling and is particularly suitable for such
application as directly contacts with users' skin, for example, absorbent
articles for disposable diapers, sanitary napkins, incontinence pads,
nursing pads or the like. Moreover, since the non-woven fabric of the
present invention has a high specific volume, high bulkiness and an
excellent cushioning property, it is preferably used for applications that
require an excellent cushioning property, for example, bandage or eye
bandage, or table linen, cooking towel, packing materials for glass
ceramics, packing materials for fruits and vegetables and flowers,
packing materials for instruments and furniture etc. The non-woven
fabric having a density inclination in the thickness direction produced
by the above mentioned method can be used as non-woven fabric
materials for filters, such as a liquid filter, an air filter etc.
39
