Title of Invention

METHOD AND APPARATUS FOR PRODUCING POLYMER FIBERS AND FABRICS INCLUDING MULTIPLE POLYMER COMPONENTS IN A CLOSED SYSTEM

Abstract A closed fiber spinning system includes a spin beam assembly including a plurality of polymer distribution manifolds to independently deliver different polymer component fluid streams to a spin pack and independently maintain those fluid streams at different temperatures. The spin beam assembly in combination with the closed spinning system facilitates the production of a wide variety of multiple polymer component fiber and fabric products having a desired denier and degree of uniformity.
Full Text Description:
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to methods and apparatus for producing
fibers and fabrics in a closed fiber spinning system, where the fibers and fabrics
include a plurality of different polymer components.
Description of the Related Art
A number of closed fiber spinning systems are known in the art for
manufacturing spunbond fabrics having certain desirable characteristics. For
example, U.S. Patent Nos. 5,460,500, 5,503,784, 5,571,537, 5,766,646,
5,800,840, 5,814,349 and 5,820,888 all describe closed systems for producing
spunbond webs of fibers. The disclosures of these patents are incorporated
herein by reference in their entireties. In a typical closed system, filaments are
spun, quenched and drawn in a common enclosed chamber or environment,
such that the air or gas stream that is utilized to quench the fibers emerging
from a spinneret is also utilized to draw and attenuate the fibers downstream
from the quenching stage.
In direct contrast to open fiber spinning systems (i.e., systems in which
extruded filaments are not spun, quenched and drawn in a common chamber or
environment and are typically exposed to the ambient environment during some
or all of the fiber forming steps), closed systems eliminate any interference from
uncontrolled and potentially detrimental air currents during fiber formation. In
fact, a typical closed fiber spinning system limits exposure of extruded filaments
to only desirable air or gas currents having selected temperatures during fiber
formation, thus facilitating the production of very delicate and uniform fibers
having desirable deniers that are difficult to obtain from a typical open fiber
spinning system.
One important component in any fiber spinning system is the polymer
delivery system, typically referred to as the spin beam, which provides molten
polymer streams at a selected metering or flow rate to the fiber spinning system
for extrusion into filaments by a spinneret. One type of spin beam typically
utilized and highly advantageous for spinning fibers in a closed system is
commonly referred to as a "coat hanger" spin beam. This type of spin beam is
typically formed by two sections, constructed of metal or other suitable material,
joined together in a fluid tight relationship at facing or mating surfaces, where
each mating surface has grooves etched into the surface that correspond with
and mirror grooves etched in the mating surface of the other section. The
grooves etched on each mating surface form a profile that resembles a
triangular "coat hanger" configuration.
An exploded view of a conventional "coat hanger" spin beam is illustrated
in Fig. 1. Spin beam 2 includes two generally rectangular halves or sections 3
having a number of electric heaters 12 disposed within each section to heat
polymer fluid flowing within the spin beam toward the spinneret. In operation, a
molten polymer stream is directed (e.g., via a pump) into an inlet portion 4 of the
"coat hanger" channel profile of spin beam 2 and travels into an upper portion of
the triangular channel portion 6 of the "coat hanger" profile that is disposed
below and in fluid communication with inlet portion 4. The "coat hanger"
channel defined by the inlet portion and the triangular portion is formed by
corresponding grooves disposed on the mating surfaces of the two spin beam
sections 3. Upon entering channel 6, the molten polymer stream splits into the
two diverging channel sections 7 of the triangular channel portion, where the
split streams continue to travel and then converge within a horizontal channel
section 8 disposed at a lower end of the "coat hanger" channel between the
lower ends of the diverging channel sections. The horizontal channel section
also extends longitudinally along a lower end of spin beam 2. Affixed at the
lower end of the spin beam are a screen filter and plate 9 and a spinneret 10
having a plurality of orifices disposed along its longitudinal dimension. The
screen filter, plate and spinneret also extend longitudinally along the lower end
of spin beam 2 and are aligned and in fluid communication with horizontal
channel section 8. Thus, the molten polymer stream traveling into horizontal
channel section 8 of the "coat hanger" channel proceeds to flow through screen
filter and support plate 9 to spinneret 10, where the polymer stream is then
extruded through the spinneret orifices to form a plurality of polymer filaments.
The "coat hanger" channel configuration is particularly advantageous because it
is simple in design and creates a substantially uniform pressure differential
within the channels, resulting in a uniform delivery of the polymer stream into
the horizontal channel portion of the "coat hanger" channel" and uniform
extrusion of molten polymer through the spinneret orifices.
While a closed fiber spinning system combined with a "coat hanger" spin
beam is useful for manufacturing certain polymer fibers having desirable
uniformities and deniers, the "coat hanger" spin beam encounters problems
when two or more different polymer components are utilized to produce more
complex fibers and spunbond webs of fibers. In particular, it is very difficult in a
"coat hanger" closed system to process two or more different polymer
components having different melting temperatures when manufacturing
multicomponent fibers or fabrics containing multiple polymer components. For
example, a bicomponent fiber consisting of two polymer components with
significantly different melting points would be extremely difficult to produce
utilizing a closed spinning system with a "coat hanger" spin beam (e.g., by
utilizing a double "coat hanger" spin beam with "coat hanger" channels being
arranged in a side-by-side manner), because the "coat hanger" spin beam
would tend to be maintained at substantially the same temperature by the
electrical heaters disposed in the spin beam sections. The difficulty is further
exacerbated when utilizing polymer components that must be maintained at or
very near their melting temperatures to avoid gelling or cross-linking of the
polymers. Moreover, while the "coat hanger" systems deliver a uniform molten
polymer stream to the spinneret, it is difficult to modify the metering of the
molten polymer stream through the "coat hanger" spin beam to the spin pack,
which is an important feature in manufacturing more complex types of fibers
such as multicomponent fibers having varying geometries and/or polymer
component cross-sections. Thus, the flexibility of "coat hanger" spin beams is
very limited in enabling the manufacture of a wide variety of different fibers and
fabrics within a closed fiber spinning system.
Accordingly, there exists a need for producing a wide variety of fibers
and fabrics including two or more polymer components in a closed fiber
spinning system and with a spin beam capable of delivering molten polymer
streams of two or more different polymer components for fiber production within
the closed system.
SUMMARY OF THE INVENTION
Therefore, in light of the above, and for other reasons that become apparent
when the invention is fully described, an object of the present invention is to
provide a closed fiber spinning system capable of producing a wide variety of
single and multicomponent fibers and fabrics including different polymer
components and having a desired denier and degree of uniformity.
Another object of the present invention is to provide a spin beam
assembly for the closed system that is capable of delivering molten polymer
streams to the spinneret of the closed system, where the molten polymer
streams include at least two different polymer components having different
melting temperatures.
A further object of the present invention is to uniformly maintain the two
different polymer components at their substantially different melting
temperatures within the spin beam assembly during delivery of the molten
polymer streams to the spinneret.
Yet another object of the present invention is to provide a plurality of
metering pumps to individually control the flow rate of different molten polymer
fluid streams for extrusion at the spinneret.
The aforesaid objects are achieved individually and in combination, and it
is not intended that the present invention be construed as requiring two or more
of the objects to be combined unless expressly required by the claims attached
hereto.
In accordance with the present invention, the aforementioned difficulties
associated with forming fibers and fabrics having multiple polymer components
in a closed system is overcome by employing a closed fiber spinning system
including a spin beam assembly that is capable of supplying a plurality of
molten polymer streams to a spinneret, where at least two of the polymer
streams contain different polymer components, to form multicomponent fibers or
fabrics including multiple polymer components that have a suitable uniformity
and denier. The spin beam includes a plurality of metering pumps to
independently control the flow rates of one or more polymer streams, as well as
at least two thermal control units that independently and uniformly heat the
different polymer components to their appropriate melting temperatures while
maintaining thermal segregation between the different polymer components.
The above and still further objects, features and advantages of the
present invention will become apparent upon consideration of the following
definitions, descriptions and descriptive figures of specific embodiments thereof
wherein like reference numerals in the various figures are utilized to designate
like components. While these descriptions go into specific details of the
invention, it should be understood that variations may and do exist and would
be apparent to those skilled in the art based on the descriptions herein.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 is an exploded view in perspective of a conventional "coat hanger"
spin beam for delivering molten polymer fluid to a spin pack in a closed system.
Fig. 2 is an elevational side view in partial section of an embodiment of
the closed fiber spinning system of the present invention.
Fig. 3 is a perspective view in partial section of an embodiment of the
spin beam assembly for the closed system of Fig. 1.
Figs. 4-8 are transverse cross-sectional views illustrating embodiments
of different groups of fibers that may be produced by a closed system of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The closed fiber spinning system of the present invention is described
below with reference to Figs. 2 and 3. The terms "closed system" and "closed
fiber spinning system", as used herein, refer to a fiber spinning system including
an extrusion stage, a quenching stage and a drawing stage, where an air or
other gas stream that is utilized to quench the fibers in the quenching stage is
also utilized to draw and attenuate the fibers in the drawing stage, and the
extrusion, quenching and drawing stages are performed in a common enclosed
environment (e.g., a single chamber or a plurality of chambers communicating
with each other). The term "fiber" as used herein includes both fibers of finite
length, such as conventional staple fibers, as well as substantially continuous
structures, such as filaments, unless otherwise indicated. The terms
"bicomponent fiber" and "multicomponent fiber" refer to a fiber having at least
two portions or segments, where at least one of the segments comprises one
polymer component, and the remaining segments comprise another, different
polymer component. The term "single component fiber" refers to a fiber
consisting of a single polymer component. The term "mixed polymer fiber"
refers to a fiber consisting of two or more different polymer components mixed
together to form a substantially uniform composition of the polymer components
within the formed fiber.
Fibers extruded in the closed system of the present invention can have
virtually any transverse cross-sectional shape, including, but not limited to:
round, elliptical, ribbon shaped, dog bone shaped, and multilobal cross-
sectional shapes. The fibers may comprise any one or combination of melt
spinnable resins, including, but not limited to: homopolymer, copolymers,
terpolymers and blends thereof of: polyolefins, polyamides, polyesters,
polyactic acid, nylon, poly(trimethylene terephthalate), and elastomeric
polymers such as thermoplastic grade polyurethane. Suitable polyolefins
include without limitation polymers such as polyethylene (e.g., polyethylene
terephthalate, low density polyethylene, high density polyethylene, linear low
density polyethylene), polypropylene (isotactic polypropylene, syndiotactic
polypropylene, and blends of isotactic polypropylene and atactic polypropylene),
poly-1-butene, poly-1-pentene, poly-1-hexene, poly-1-octene, polybutadiene,
poly-1,7,-octadiene, and poly-1,4,-hexadiene, and the like, as well as
copolymers, terpolymers and mixtures of thereof. In addition, the manufactured
fibers may have any selected ratio of polymer components within the fibers.
Referring to Fig. 2, a closed system 100 is depicted including a spin
beam assembly 102 for delivering molten polymer streams to a spin pack 104,
and an enclosed chamber 106 for forming and delivering extruded filaments 108
to a web-forming belt 116, thus forming an nonwoven web of fibers 118. It is to
be noted that the closed chamber design depicted in Fig. 2 is provided for
exemplary purposes only, and the present invention is in no way limited to such
design. For example, any number of enclosed chamber designs may be utilized
in practicing the present invention, including, without limitation, the enclosed
chamber designs of U.S. Patent Nos. 5,460,500, 5,503,784, 5,571,537,
5,766,646, 5,800,840, 5,814,349 and 5,820,888. The spin beam assembly,
spin pack, enclosed chamber and belt are constructed of metal or any other
suitable material to receive and process molten polymer fluid streams.
The spin beam assembly 102 provides a number of independently
metered molten polymer streams to spin pack 104 for extrusion and fiber
formation within closed system 100. Three separate and independent heating
systems are provided in the spin beam assembly as described below to
independently heat two segregated polymer fluid streams flowing into the spin
beam assembly and the spin beam. Referring to Fig. 3, spin beam assembly
102 includes a generally rectangular and hollow frame 103 enclosing a pair of
substantially cylindrical and hollow distribution manifolds 122, 130 and a
generally rectangular spin beam 140. Each distribution manifold 122, 130
extends longitudinally along a rear wall 150 of the frame, with manifold 130
suspended slightly above and aligned substantially parallel with manifold 122.
An inlet pipe 123 extends transversely from a central location of manifold 122
and through the rear wall 150 of frame 103 to connect with a polymer supply
source (not shown). Similarly, another inlet pipe 131 extends transversely from
a central location of manifold 130 and through an upper rear wall 151 of the
frame to connect with another polymer supply source (not shown). A portion of
each inlet pipe also extends within each manifold to connect with a polymer
distribution pipe disposed within the manifold as described below. Manifold 122
is sealed at one end and connected to a heat medium supply conduit 124 at the
other end, with conduit 124 extending through a side wall 152 of frame 103 and
connecting to a heat medium supply source (not shown). Manifold 130 is also
sealed at an end corresponding to the sealed end of manifold 122 and is
connected at the other end to another heat medium supply conduit 132
extending through the side wall 152 of the frame, where the supply conduit 132
is also connected to a heat medium supply source (not shown). The manifolds
are slightly staggered in alignment with respect to each other, with the end of
manifold 122 that is connected to conduit 124 being closer to the side wall 152
of the frame than the corresponding end of manifold 130.
Disposed and extending longitudinally within each distribution manifold
122, 130 is a polymer distribution pipe that connects with the corresponding
inlet pipe 123, 131 protruding into the manifold interior. Each manifold 122, 130
basically surrounds and jackets the distribution pipe disposed therein, allowing
a fluidic heat transfer medium (e.g., Dowtherm) to be delivered by the
respective supply conduit 124, 132 into the manifold so as to surround and
transfer heat to polymer fluid disposed within the distribution pipe. The
manifolds and piping associated with the manifolds facilitate independent and
segregated heating of two different polymer components to different
temperatures within spin beam assembly 102. Additionally, the manifold design
provides uniform heating of polymer fluid flowing inside each polymer
distribution pipe within each manifold by surrounding each distribution pipe with
a heat medium at a substantially uniform temperature. This heating feature is a
significant improvement over the electric heating design provided in the "coat
hanger" style spin beam, because the electrical heaters in the "coat hanger"
spin beam may yield undesirable thermal gradients within the spin beam
sections.
Each distribution manifold 122, 130 further includes a set of six polymer
transfer pipes 126, 134 extending transversely and at approximately equal
longitudinally spaced locations from the manifold toward a front wall 153 of
frame 103, where transfer pipes 126 (which extend from manifold 122) are
substantially parallel with transfer pipes 134 (which extend from manifold 130).
Each transfer pipe 126, 134 also extends into its respective manifold 122, 130
and connects at an appropriate location with the corresponding distribution pipe
disposed therein. Due to the vertical offset between manifold 122 and manifold
130 within the frame of the spin beam assembly, transfer pipes 134 are
immediately routed vertically downward toward manifold 122 upon emerging
from manifold 130 so as to become substantially vertically aligned with transfer
pipes 126 as they extend toward the front wall 153 of the frame. One skilled in
the art will recognize that each distribution pipe and the transfer pipes
connecting to each distribution pipe within each manifold can be independently
designed to ensure a suitable residence time of polymer fluid traveling through
the distribution pipe and being heated within the manifold. Further, the lengths
of each of the transfer pipes extending from a particular distribution pipe are
preferably equal to ensure the residence times of the fluid streams traveling
within those transfer pipes is substantially the same.
Spin beam 140 is disposed longitudinally near the front wall 153 within
frame 103. The spin beam houses a set of six generally rectangular pump
blocks 142 longitudinally spaced along the spin beam to correspond with a
single transfer pipe 126, 134 extending from each manifold 122, 130 toward the
pump blocks. Each pump block 142 includes a first metering pump 128 that
connects with a corresponding polymer transfer pipe 126 extending toward that
pump block and a second metering pump 136 that connects with a
corresponding polymer transfer pipe 134 extending toward that pump block.
The transfer pipes 126, 134 extend through a rear wall of spin beam 140 to
connect with their corresponding metering pumps 128, 136. A heat supply
conduit 144 extends from a lower portion of the rear wall of the spin beam and
through the frame side wall 152 to connect with a fluid heat transfer medium
supply source (not shown). The spin beam is heated by heat transfer fluid
medium supplied by conduit 144, which in turn heats and maintains pump
blocks 142 and pumps 128, 136 at a suitable temperature during operation of
the spin assembly. The pump blocks are further constructed of a material
having a low thermal conductivity to control or limit the amount of heat
transferred between the pump blocks, pumps and polymer fluid traveling
through the pumps. For example, in fiber manufacturing processes where two
different polymer components are utilized having different melting temperatures,
the pump blocks are heated to the higher temperature melting point. However,
the polymer component with the lower melting temperature will never achieve
the higher temperature due to the limited heat transfer capacity of the pump
block.
Each metering pump 128, 136 further includes an inlet for receiving
polymer fluid from a corresponding polymer transfer pipe 126, 134 and multiple
outlets for feeding polymer fluid streams at a selected flow rate to inlet channels
in spin pack 104. In a preferred embodiment, each metering pump includes
four outlets, such that the spin beam assembly is capable of providing two sets
of twenty four polymer fluid streams, with the temperature and flow rate of each
set being controlled independent of the other. Such an embodiment could, for
example, provide metered polymer streams from each set about every six
inches along a spin beam having a length of about twelve feet. However, it is
noted that the metering pumps may include any number of suitable outlets
depending upon the number of polymer streams required to be transferred to
the spin pack.
Spin pack 104 includes a plurality of inlet channels for receiving polymer
fluid streams from the spin beam assembly, a polymer filtration system,
distribution systems and a spinneret with an array of spinning orifices for
extruding polymer filaments therethrough. For example, the spinneret orifices
may be arranged in a substantially horizontal, rectangular array, typically from
1000 to 5000 per meter of length of the spinneret. As used herein, the term
"spinneret" refers to the lower most portion of the spin pack that delivers the
molten polymer to and through orifices for extrusion into enclosed chamber 106.
The spinneret can be implemented with holes drilled or etched through a plate
or any other structure capable of issuing the required fiber streams. The spin
pack basically coordinates molten polymer fluid flow from the spin beam to form
a desired type of fiber (e.g., multicomponent fibers, fibers having a particular
cross-sectional geometric configuration, etc.) as well as a desired number of
fibers that are continuously extruded by the system. For example, the spin pack
may include channels that combine two or more different polymer fluid streams
fed from the spin beam prior to extrusion through the spinneret orifices.
Additionally, the spinneret orifices may include a variety of different shapes
(e.g., round, square, oval, keyhole shaped, etc.), resulting in varying types of
resultant fiber cross-sectional geometries. An exemplary spin pack for use with
system 100 is described in U.S. Patent No. 5,162,074 to Hills, the disclosure of
which is incorporated herein by reference in its entirety. However, it is noted
that any conventional or other spin pack for spinning fibers may be utilized with
system 100.
Enclosed chamber 106 includes a quenching station 110 disposed
directly below spin pack 104 and a drawing station 112 disposed directly below
the quenching station. A pair of conduits 114 are also connected at opposing
surfaces of chamber 106 in the vicinity of quenching station 110. Each conduit
114 directs a stream of air (generally indicated by the arrows in Fig. 2) in a
opposing direction from each other and toward extruded filaments 108 exiting
spin pack 104 and traveling through quenching station 110. The extruded
filaments are thus quenched by the converging air streams from conduits 114 at
the quenching station. The air streams are preferably directed in a direction
generally perpendicular to filaments 108 or slightly angled in a direction toward
drawing station 112, which is disposed below the quenching station. However,
it is noted that any number of air currents (e.g., a single air current) may be
directed in any suitable orientation toward the extruded filaments disposed in
the quenching station. It is further noted that any suitable gas other than air
may be utilized to quench the filaments at the quenching station. Further,
depending upon the types of polymer components utilized and the types of
fibers to be formed, one or more controlled vapor or gas treatment streams may
also be employed to chemically treat the extruded filaments within closed
chamber 106 at quenching station 110 or at any other suitable location.
Chamber 106 preferably has a venturi profile at drawing station 112,
where the chamber walls constrict to form a tapered or narrowed chamber
section within the drawing station to facilitate an increased flow rate of the
combined air streams passing therethrough. The increased flow rate of the air
streams within the drawing station provides a suitable drawing force to stretch
and attenuate the filaments. Drawing station 112 extends to an exit opening in
chamber 106 that is separated a suitable laydown distance from web-forming
belt 116.
Web-forming belt 116 is preferably a continuous screen belt through
which air can pass, such as a Fourdrinier wire belt. Fibers exiting enclosed
chamber 106 are laid down on the belt to form a nonwoven web. The belt is
driven, e.g., by rollers or any other suitable drive mechanism, to deliver the web
of fibers to one or more additional processing stations. Disposed beneath belt
116 and in line with the exit opening of chamber 106 is a recirculation chamber
120. The recirculation chamber includes a blower (not shown) that develops a
negative pressure or suction within chamber 106 to direct the combined air
streams from quenching station 110 through drawing station 112 and into the
recirculation chamber (generally indicated by the arrows in Fig. 2). The air
streams drawn into chamber 120 are recycled and delivered back to conduits
114 for redelivery into quenching station 110. Preferably, the recycled air
streams are also directed through a heat exchanger and/or combined with fresh
air so as to maintain a suitable temperature for the quenching air before being
recirculated into quenching station 110. In an alternative embodiment, the
closed system may not employ recycled air streams. Rather, a blower may
continuously direct fresh air streams into and through enclosed chamber 106,
with the air dissipating out of the closed system upon emerging from the
drawing station rather than being recycled for further use.
Operation of closed system 100 is described below utilizing an
exemplary bicomponent fiber spinning process, where polymer components A
and B are fed to the spin beam assembly for forming the bicomponent fibers. It
is to be noted, however, that system 100 may produce a wide variety of fibers,
including single component and multicomponent fibers. A molten stream of
polymer A is delivered to spin beam assembly 102 via inlet pipe 123, where it
enters the polymer distribution pipe disposed within distribution manifold 122.
Simultaneously, a molten stream of polymer B is delivered to the spin beam
assembly via inlet pipe 131, where it enters the polymer distribution pipe
disposed within distribution manifold 130. A fluid heat transfer medium,
supplied by conduits 124, 132, is provided within both manifolds to surround the
distribution pipes disposed therein and to uniformly and independently heat
and/or maintain each of polymers A and B at a suitable temperature.
The polymer A stream travels through the distribution pipe in manifold
122 and enters polymer transfer pipes 126, which carry polymer A to the set of
six metering pumps 128 disposed on pump blocks 142 in spin beam 140.
Similarly, the polymer B stream travels through the distribution pipe in manifold
130 and enters polymer transfer pipes 134, which carry polymer B to the set of
six metering pumps 136 disposed on the pump blocks in the spin beam.
Metering pumps 128 establish a suitable flow rate for transferring a plurality of
streams (e.g., twenty four) of polymer A to correspondingly aligned inlet
channels disposed on spin pack 104, while metering pumps 136 establish a
suitable flow rate (which is independent of the flow rate established for the
polymer A streams) for transferring a plurality of streams of polymer B to
correspondingly aligned inlet channels disposed on the spin pack.
The independently metered sets of molten polymer A and B streams are
directed through channels in spin pack 104 and through the spinneret to form
bicomponent polymer fibers consisting of those two polymers. The type of
bicomponent fiber formed (e.g., side-by-side, sheath/core, "islands in the sea",
etc.) is established by the spin pack design, where separated streams of
polymers A and B are combined in a suitable manner upon emerging from the
spinneret. Additionally, a suitable cross-sectional geometry for the extruded
filaments may also be established by, e.g., providing spinneret orifices of one or
more selected geometries.
Filaments 108 consisting of polymers A and B are extruded through the
spinneret and enter quenching station 110 of enclosed chamber 106, where the
filaments are exposed to quenching air streams directed at the filaments from
conduits 114. The blower in recirculation chamber 120 creates a suction within
the enclosed chamber that directs the air streams through quenching station
110 and into drawing station 112, where the velocity of the air streams is
increased due to the constricted profile within a portion of the drawing station.
The extruded filaments are also directed downward with the air streams from
the quenching station into the drawing station, at which point the filaments are
drawn and attenuated in the drawing station. The drawn fibers continue through
enclosed chamber 106 to exit and form a nonwoven web 118 of fibers on belt
116. The web of fibers are carried away by belt 116 for further processing. Air
streams traveling through and exiting enclosed chamber 120 are drawn into
recirculating chamber 120, where the streams are ultimately directed back into
conduits 114 and toward quenching station 110.
The combined features of temperature segregation and independent
delivery of multiple metered streams of molten polymer fluids within the spin
beam in the closed system of the present invention facilitates the production of
a widely diverse range of fibers and fabrics not previously achieved or even
considered in conventional closed systems. For example, providing
independent and substantially uniform temperature control within different
molten polymer streams in the spin beam vastly increases the number of
different polymer combinations and ratios that can be achieved in individual
fibers during fiber formation. An even spinneret temperature profile may be
maintained in the system without forcing temperature changes in the polymer
streams, which is not practical in the electrically heated, "coat hanger" spin
beam. The uniform temperature control provided by the spin beam of the
present invention, which eliminates potential thermal gradients during heating,
is far superior to the electrically heated, "coat hanger" spin beams typically
utilized in closed systems.
The independent control of different polymer component supply
pressures via the separated sets of metering pumps offers greater flexibility of
polymer selection and distribution for any given machine configuration by
providing enhanced control for even delivery of polymer over the entire machine
width. The residence time can be more precisely controlled with the spin beam
assembly and spin pack of the present invention as compared to the "coat
hanger' system, a particularly important feature for heat sensitive polymers
requiring a reduced residence time. In particular, short residence times may be
established in the closed system of the present invention to minimize heat
transfer between polymer streams and the spin beam assembly and spin pack
equipment.
The improved draw uniformity and prevention of external air flow or
temperature disturbances that a closed system provides further enhances the
string-up and production of certain types of sensitive multicomponent fibers.
Additionally, the closed system facilitates the spinning of certain
multicomponent fibers into a controlled vapor or gas atmosphere for chemical
treatment of filaments formed during spinning, while easily containing the
vapors in the closed system. The spin beam assembly and spin pack also
increases the spinneret orifice density and possible orifice configurations in
comparison to the "coat hanger" spin beam (which only produces a linear or
narrow array of extruded filaments from the spinneret) to increase productivity
and multiple polymer component products manufactured in a single closed
system. Further, the multi-stream metering spin beam combined with the
closed system of the present invention facilitates the production of high value
fabrics including, but not limited to, anti-stat fabrics, skin wellness fabrics,
wettability and abrasion resistance fabrics, and fabrics formed by differential
bonding methods (rather than conventionally used heat embossing). Multiple
fabric products may also be continuously produced by a single closed system of
the invention by, e.g., varying the types and grouping of fibers being extruded in
the cross machine direction of the system.
Some examples of polymer fibers that can be produced according to the
present invention are illustrated in Figs. 4-8. Fig. 4 depicts a single, low percent
sheath/core fiber 202 formed among a group of single component or homo-
polymer fibers 204 to introduce a high value, low melt strength, temperature and
residence time sensitive additive into a high quality web formed by the fibers.
Fig. 5 depicts a group of tri-component sheathed side-by-side fibers 302.
These fibers exhibit both of the side-by-side and sheath/core benefits in one
web formed by the fibers with the system of the present invention. In certain
quench sensitive polymer combinations, or in combinations where a viscosity
mismatch exists between polymer components, the spin pack of system may be
configured to deliver formed fibers for optimal orientation relative to the
quenching air to minimize negative effects associated with bending or dog-
legging of extruded filaments from the spinneret and thus increase processing
hole density and overall productivity. Figs. 6a and 6b depict two different
arrangements of side-by-side bicomponent fiber configurations, where the fibers
402, 502 of each configuration are oriented differently with respect to a dual air
quench system (direction of quenching air in Figs. 6a and 6b is depicted by
arrows). Fig. 7 depicts yet another grouping of fibers that may be produced by
the system of the present invention, where dedicated metering techniques are
utilized for producing bicomponent sheath/core fibers 602 mixed with single
component fibers 604. In still another embodiment, the spin beam and spin
pack of the present invention may be designed to deliver exact mixed fiber sizes
through multi-stream dedicated metering so as to produce fabrics with tailored
pore-size gradients. Fig. 8 depicts a grouping of fibers that would produce such
as a fabric, where larger diameter fibers 702 are combined with smaller
diameter fibers 704 during the closed system fiber spinning process.
Other examples of fibers that may be formed utilizing the system of the
present invention are sheath/core fibers where the sheath is a thermoplastic
material with a low melting point and the core material is a thermoplastic
material with high strength characteristics. A spunbond web of these fibers can
be bonded thermally (e.g., using calendar rolls, through-air, etc.) at
temperatures high enough to soften or melt the outer sheath material but low
enough so as not to compromise the strength characteristics of the core
material. Such fibers can also have special properties available in the sheath
such as soft hand, anti-microbial capabilities, and gamma stability. Splittable
fibers can also be formed in which two or more separate polymer components
in extruded filaments are separated after formation of a web thus creating a web
of finer fibers. Additionally, side-by-side fibers can be formed that
spontaneously crimp and bulk when subjected to appropriate treatment. Mixed
polymer fibers may also be formed in the closed system of the present invention
to provide a number of useful properties for final products manufactured utilizing
those fibers.
From the foregoing examples, it can be seen that the closed system of
the present invention is extremely versatile and facilitates the production of a
wide variety of multiple polymer component fiber and fabric combinations in a
single system.
The present invention is not limited to the particular embodiments
described above, and additional or modified processing techniques are
considered to be within the scope of the invention. As previously noted, the
present invention is not limited to the closed chamber configuration of Fig. 2;
rather, the closed system of the present invention may utilize any closed
environment configuration that prevents exposure of the extruded filaments to
uncontrolled temperatures and air currents during fiber formation.
Similarly, the spin beam assembly is not limited to the configuration of
Fig. 3; rather, the spin beam assembly may be designed to receive and
thermally process and meter any number of segregated polymer fluid supply
streams. In other words, the spin beam assembly may include any suitable
number of polymer supply inlets connecting to any suitable number of
distribution pipes within distribution manifolds to independently heat and/or
maintain any number of different polymer streams at a variety of different
temperatures. The spin beam assembly may further include any suitable
number of metering pumps, where each pump has any suitable number of
outlet streams, to independently provide different polymer fluid streams at
varying flow rates to the spin pack. Further, each of the metering pumps may
be configured to deliver one or more polymer fluid streams to the spin pack at a
flow rate independent of the flow rates for streams metered by any of the other
metering pumps.
The spin pack may be designed in any suitable manner to facilitate the
production of fibers and fabrics including any combination of single component
or multicomponent fibers of any suitable cross-sectional geometries. Further,
any number or combination of fiber processing techniques, yarn forming
techniques, and woven and non-woven fabric formation processes can be
applied to the fibers formed in accordance with the present invention.
Having described preferred embodiments of a new and improved closed
system for producing fibers and fabrics having multiple polymer components, it
is believed that other modifications, variations and changes will be suggested to
those skilled in the art in view of the teachings set forth herein. It is therefore to
be understood that all such variations, modifications and changes are believed
to fall within the scope of the present invention as defined by the appended
claims. Although specific terms are employed herein, they are used in a
generic and descriptive sense only and not for purposes of limitation.
WE CLAIM
1. An apparatus for manufacturing a non-woven web of fibers comprising:
a spin beam assembly configured to process and deliver a plurality of polymer
streams for extrusion through spinneret orifices, the spin beam assembly
including a plurality of delivery passages in fluid communication with the
spinneret orifices, wherein at least two of the delivery passages are configured
to deliver separate polymer streams of different polymer components to the
spinneret orifices;
wherein the spin beam assembly includes a plurality of manifolds to segregate
and independently maintain the polymer streams of different polymer
components at different temperatures,
wherein each manifold provides uniform heating of a polymer stream flowing
inside a polymer distribution pipe within each manifold by surrounding each
distribution pipe with a heat transfer medium at a substantially uniform
temperature,
a quenching chamber configured to receive and quench extruded
filaments from the spinneret orifices, the quenching chamber including a gas
supply source to direct a gas stream at the extruded filaments;
a drawing chamber in communication with the quenching chamber and
configured to receive and attenuate the quenched filaments; and
a forming surface configured to receive drawn filaments emerging from
the drawing chamber and form a non-woven fibrous web on the forming
surface;
wherein the system maintains the extruded filaments in an enclosed
environment between the spinneret orifices and the drawing chamber to prevent
uncontrolled gas currents from contacting the filaments.
2. The apparatus as claimed in claim 1, wherein the spin beam
assembly includes a plurality of metering pumps configured to independently
deliver polymer streams of different polymer components at varying flow rates
to the spinneret orifices.
3. The apparatus as claimed in claim 1, wherein the system is
configured to produce arrays of multicomponent fibers.
4. The apparatus as claimed in claim 1, wherein the system is
configured to produce arrays of bicomponent fibers.
5. The apparatus as claimed in claim 1, wherein the system is
configured to produce arrays of single component fibers, wherein at least one
single component fiber consists of a polymer component that is different from a
polymer component of at least one other single component fiber.
6. In an apparatus for manufacturing fibers including a spin beam
assembly, and a quenching chamber in communication with a drawing
chamber, wherein the system maintains an enclosed environment between the
spin beam assembly, the quenching chamber and the drawing chamber to
prevent uncontrolled gas currents from entering the enclosed environment, a
method of forming a non-woven web of fibers comprising:
(a) delivering a plurality of polymer streams from the spin beam
assembly to spinneret orifices, wherein at least two of the polymer streams
include differing polymer components; wherein the spin beam assembly
includes a plurality of manifolds to segregate and independently maintain the
polymer streams of different polymer components at different temperatures
and wherein each manifold provides uniform heating of a polymer stream
flowing inside a polymer distribution pipe within each manifold by surrounding
each distribution pipe with a heat transfer medium at a substantially uniform
temperature.
(b) extruding the plurality of polymer streams through the spinneret
orifices to form a plurality of filaments;
(c) quenching the extruded filaments by contacting the filaments with
a gas stream in the quenching chamber;
(d) drawing the quenched filaments in the drawing chamber; and
(e) depositing the drawn filaments onto a forming surface to form a
non-woven fibrous web on the forming surface.
7. The method as claimed in claim 6, wherein step (a) includes:
(a.1) delivering segregated polymer streams at varying flow rates to the
spinneret orifices.
8. The method as claimed in claim 6, further comprising:
(f) forming an array of multicomponent fibers.
9. The method as claimed in claim 6, further comprising:
(f) forming an array of bicomponent fibers.
10. The method as claimed in claim 6, further comprising:
(f) forming an array of single component fibers, wherein at least one
single component fiber consists of a polymer component that is different from a
polymer component of at least one other single component fiber.


A closed fiber spinning system includes a spin beam assembly including a
plurality of polymer distribution manifolds to independently deliver different
polymer component fluid streams to a spin pack and independently maintain
those fluid streams at different temperatures. The spin beam assembly in
combination with the closed spinning system facilitates the production of a wide
variety of multiple polymer component fiber and fabric products having a
desired denier and degree of uniformity.


Documents:

00267-kol-2008-abstract.pdf

00267-kol-2008-claims.pdf

00267-kol-2008-correspondence others.pdf

00267-kol-2008-description complete.pdf

00267-kol-2008-drawings.pdf

00267-kol-2008-form 1.pdf

00267-kol-2008-form 2.pdf

00267-kol-2008-form 3.pdf

00267-kol-2008-form 5.pdf

00267-kol-2008-gpa.pdf

267-KOL-2008-(29-01-2013)-CORRESPONDENCE.pdf

267-KOL-2008-ABSTRACT 1.1.pdf

267-KOL-2008-AMANDED CLAIMS.pdf

267-KOL-2008-CANCELLED PAGES.pdf

267-KOL-2008-CORRESPONDENCE 1.1.pdf

267-KOL-2008-CORRESPONDENCE 1.2.pdf

267-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

267-KOL-2008-DESCRIPTION (COMPLETE) 1.1.pdf

267-KOL-2008-DRAWINGS 1.1.pdf

267-KOL-2008-EXAMINATION REPORT.pdf

267-KOL-2008-FORM 1.1.1.pdf

267-KOL-2008-FORM 18 1.1.pdf

267-kol-2008-form 18.pdf

267-KOL-2008-FORM 2.1.1.pdf

267-KOL-2008-FORM 26 1.1.pdf

267-KOL-2008-FORM 26.pdf

267-KOL-2008-FORM 3.pdf

267-KOL-2008-FORM 5.pdf

267-KOL-2008-GRANTED-ABSTRACT 1.2.pdf

267-KOL-2008-GRANTED-CLAIMS.pdf

267-KOL-2008-GRANTED-DESCRIPTION (COMPLETE) 1.pdf

267-KOL-2008-GRANTED-DRAWINGS.pdf

267-KOL-2008-GRANTED-FORM 1.pdf

267-KOL-2008-GRANTED-FORM 2.pdf

267-KOL-2008-GRANTED-SPECIFICATION.pdf

267-KOL-2008-OTHERS .pdf

267-KOL-2008-OTHERS 1.1.pdf

267-KOL-2008-PA.pdf

267-KOL-2008-PRIORITY DOCUMENT.pdf

267-KOL-2008-REPLY TO EXAMINATION REPORT 1.1.pdf

267-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

267-KOL-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00267-kol-2008.jpg


Patent Number 251860
Indian Patent Application Number 267/KOL/2008
PG Journal Number 15/2012
Publication Date 13-Apr-2012
Grant Date 12-Apr-2012
Date of Filing 15-Feb-2008
Name of Patentee REIFENHAUSER GMBH & CO. KG
Applicant Address MASCHINENFABRIK, SPICHER STRASSE 46-48, 53839 TROISDORF
Inventors:
# Inventor's Name Inventor's Address
1 HANS-GEORG GEUS BAHNHOFSTRASSE 54A, 53859 NIEDERKASSEL
2 ARNOLD WILKIE EP 7850 SOUTH TROPICAL TRAIL, MERRITT ISLAND, FLORIDA 32954
PCT International Classification Number D01D5/30; D01D5/08; D01F6/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 07003306.3 2007-02-16 EUROPEAN UNION