Patent Application
20090101294
This disclosure relates to processes for making bamboo fiberfill, and to articles comprising the bamboo fiberfill.
A number of household textile articles are generally characterized as nonwoven fiberfill household textile articles. Broadly speaking, a fiberfill household textile article is comprised of a ticking or other type of casing filled with manufactured fibers, most commonly, polyester fibers, specially engineered for use as filling material. Common fiberfill household textile articles include beddings such as pillows, comforters, quilts, bedspreads, pads and other fiber products used or intended to be used on or about a bed or other place or other place for reclining or sleeping. For such articles, it is often desirable to have fibers with not only good resiliency and loft, but also anti-bacterial and deodorization properties as well.
Synthetic fibers are commonly used as nonwoven fiberfill for household textile articles. Examples of synthetic fibers include polyester, polypropylene, acrylics, nylon, rayon, and the like. Such synthetic fibers are chemically produced and can be thermally extruded and spun to form fibers. Synthetic fibers typically have high loft, low density, and good resiliency. Synthetic fibers typically do not have anti-bacterial or deodorization properties, and therefore, are often sprayed or coated after manufacturing with compounds to artificially give the fibers such properties. Moreover, synthetic fibers are produced from the hydrocarbons of fossil fuels, and they do not readily decompose after their disposal.
Natural fibers are also commonly used as nonwoven fiberfill. Examples of natural fibers include cotton, wool, hemp, silk, and the like. Natural fibers are formed from natural resources and typically readily decompose eliminating the waste and environmental concerns associated with synthetic fibers. Many of these natural fibers, however, also do not possess the anti-bacterial and deodorizing properties desirable in household bedding articles, and therefore, are also coated with artificial compounds.
Accordingly, it is desirable to produce a natural fiber that inherently possesses anti-bacterial and deodorizing properties, without the environmental concerns associated with synthetic fibers.
Disclosed herein is a process for producing bamboo fiberfill. In one embodiment, a process for producing bamboo fiberfill from raw bamboo fiber includes obtaining a bale of the raw bamboo fiber, picking up and separating the raw bamboo bale fiber into tufts of bamboo fiber with a bale opener, feeding the bamboo fiber tufts into a blending hopper configured to blend the bamboo fiber tufts, feeding the blended bamboo fiber tufts into a beater configured to open the bamboo fiber tufts, and feeding the opened bamboo fiber tufts into a fine opener configured to reduce the size of the opened bamboo fiber tufts and refine the opened bamboo fiber tufts into the bamboo fiberfill, wherein the bamboo fiberfill has a fiber length of about 30 millimeters to about 60 millimeters and a linear density of about 0.5 denier to about 5.0 denier.
The inventors hereof have found that bamboo fiber can be processed and formed into a nonwoven web or air blown and used as fiberfill in articles such as bedding, quilting, pillows, comforters, blankets, home furnishing, and the like. The bamboo fiber is derived from the pulp of the bamboo plant. The bamboo plant is naturally anti-bacterial and possesses deodorizing abilities as well. The bamboo fiber retains these characteristics, and therefore, the fibers require no additional manufacturing processes or treatments to exhibit such qualities. As an added benefit, the bamboo plant can be grown without the need for environmentally harmful pesticides or fertilizers. The bamboo pulp can be processed into a fiber through a “green” process, having minimal environmental impact. All of these attributes make bamboo fiberfill a unique choice for household articles in an increasingly environmentally conscious consumer market.
Disclosed herein is an exemplary process for producing nonwoven fiberfill (i.e., filling) from bamboo fibers. In one embodiment, the process includes air blowing the fiber to explode the bamboo fibers and produce a highly resilient, high loft fiber for use in a pillow. In another embodiment, the bamboo fiber can be needlepunched to produce a dense, low loft nonwoven fiberfill for use in quilts and the like. In yet another embodiment, the bamboo fiber can be bonded to produce a high loft, resilient, and insulating nonwoven fiberfill for use in comforters and the like.
Raw bamboo fibers can be readily purchased in bulk form. The raw staple fibers can be shipped from the manufacturer in the form of bales. The process as disclosed herein begins with preparation of the raw staple bamboo fibers. In general, the bamboo fiber preparation includes mechanical and pneumatic processes from handling the fiber bale to the point where the bamboo fiber is introduced into a web-forming machine. This part of the process can sometimes be referred to as an opening line. The opening line is configured to reduce the size of the raw bamboo fiber tufts from the bale to a chute feed, which can supply a web forming machine. The opening line can comprise, among other things, a bale opener in operative communication with a blending hopper and feeder. For processes where the raw bamboo fiber is purchased in bale form, the bales can be first unstrapped and placed in line with the milling head of a bale opener.
A blending hopper is generally illustrated in
Turning now to
The bamboo fiber, which has been opened by the beater 300 can then be transported (by the blower air) to the feed box 402 of a fine opener 400 (as shown in
To this point the fibers are opened and refined such that they present the qualities, such as resiliency, loft, density, and the like desired in household and bedding fiberfill articles. The process as disclosed herein can be effective to produce bamboo fibers having a fiber length of about 20 millimeters (mm) to about 70 mm, specifically about 30 mm to about 60 mm. The bamboo fibers can also have a linear density of about 0.3 denier to about 7.0 denier, specifically about 0.5 denier to about 5.0 denier. Moreover the process as disclosed herein can be employed to produce article comprising 100 percent by weight bamboo fiber. In other embodiments, the process can be used to refine the bamboo fiber for articles comprising less than 100 percent bamboo fiber. However, in order to impart the desirable qualities of the bamboo fiber onto a finished household article, it is desirable to have greater than or equal to about 50 percent by weight bamboo fiber. The bamboo fiber can be used in combination with one or more additional fibers, synthetic or natural. For example, the bamboo fiberfill can be combined with cotton fiber to form a cotton blend having anti-bacterial and deodorizing properties.
As previously mentioned, for pillow applications, a desired amount of the opened bamboo fibers formed by the process to this point can be separated prior to the web-former. The opened bamboo fibers at this point in the disclosed process are tangled in random fiber orientation. The tangled, exploded bamboo fibers can provide superior filling for high loft applications, such as pillows, furniture cushions, and the like. Blowers and fans can be used to further explode (i.e., fluff) the fibers and blow them into pillow envelopes, cushions, or the like depending upon the desired application. For these applications, the bamboo fibers do not need to be passed through Garnetts or formed into a web. The fibers at this point already have the resiliency required for such applications as pillows. As used herein, the term resiliency when referring to the bamboo fibers is generally intended to refer to the fibers ability to be compressed and to expand back to its original shape, thereby maintaining the comfort of the pillow.
For applications where a layered nonwoven web is more desirable than the tangled exploded bamboo fibers, such as for quilts, comforters, uniform pillows, bedding, and the like, the bamboo fibers can be formed into a web by a number of methods, all of which are intended to be included in the process for producing bamboo fiberfill as disclosed herein. The feed system for the web-forming machine will depend upon the method of web-forming selected and the type of web-former to be used. Chute feeding can be used for feeding bamboo fibers up to about 6 centimeters (cm) in length. When longer bamboo fibers are used, a hopper feed with a shaker-type chute can be used instead. A chute feed is shown in the first example of web-forming—carding.
The bamboo fibers, after being fed by a chute or hopper, can be condensed into the form of a lap or batting. In this embodiment, the fibers exit the chute 510 as a condensed lap and enter a feed roll 512. The bamboo fiber lap can then initially be opened into small tufts by a licker-in 514, which feeds the fibers to the rotating cylinder 502. The needles of the two opposing surfaces of the rotating cylinder and the worker and stripper rolls are disposed at an incline in opposite directions and move at different speeds.
In another embodiment, a garnett can be used to separate the bamboo fibers and form a web. Typically, a garnett can include a group of rolls placed in an order that allows a given wire configuration, along with certain roll speed relationships, to level, transport, comb and interlock the bamboo fibers to a degree that a web is formed. The garnett can deliver a more randomly oriented web than a carding machine. Whether the method of carding or garneting is chosen to separate and orient the bamboo fibers, multiple machines can be used in series or parallel to produce a higher output of nonwoven bamboo fiber webs. Moreover, the webs from multiple garnetts or card machines can be layered, such as by cross-lapping, to build up the desired finished nonwoven weight, as will be described in more detail below.
In another exemplary embodiment of separating and orienting bamboo fibers to form a web, the web created by carding can be improved by capturing the bamboo fibers on a screen from an air-stream. Aerodynamic web formation, or Air-lay as it is sometimes called, can increase the uniformity of the web. A Rando-Webber component is an exemplary embodiment of an aerodynamic web production machine and is illustrated in
Yet another exemplary embodiment of separating and orientating the bamboo fibers to form a web is the centrifugal dynamic random card process. The centrifugal dynamic random card process forms a fiber web by throwing off the bamboo fibers from a cylinder onto a doffer roll with fiber inertia. The fibers are subject to centrifugal force in proportion to the square of the cylinder rotary speed. Through this method, orientation in the web can be three-dimensional and can be either random or isotropic. The random card method can produce about a 12 to about a 50 g/m2 web with fine bamboo fibers of about 1.5 denier, or a web of up to about 100 g/m2 with coarser bamboo fibers. The production of the random card can be generally about 30 to 50% higher than the conventional carding and garnetting processes as described above. The machine direction strength compared to the cross-direction strength (i.e., the direction perpendicular to the process line) can be better than for those bamboo webs produced by carding or garnetting, but typically are not as good as that of the air-laid webs. The number of machines required in the nonwoven bamboo fiberfill production process, however, can be reduced by the use of the random card method.
After the bamboo fiber has been formed into webs by any of the above described processes, the web formations can further be made into the desired web structure for a given application by layering of the bamboo webs. Layering can be accomplished in several ways to reach the desired weight and web structure.
In one embodiment, a longitudinal layering process can be employed. It can be advantageous to employ this process when one or more carding machines or garnets were used to form the bamboo web. The nonwoven webs from each of the cards or garnets are simply laid above one another on a conveyor belt, where the layered bamboo web can be optionally sent for bonding. When a longitudinal layering method is used, the layered webs tend to have anisotropic properties due to the unidirectional arrangements of fibers during layering. In other words, the layers tend to be organized uniformly over one another, with each layer in either the machine or cross directions.
In another embodiment, a cross-layering process can be used. The cross-layering process can be done by using two different devices, a vertical cross-lapper or a horizontal cross-lapper. A vertical cross-lapper 800 is shown in
In yet another embodiment, a perpendicular layering process can be used. This technique has an advantage over the longitudinal and cross layering processes because of the perpendicular and oriented fibers in the fabric. These perpendicularly layered nonwoven bamboo webs can have high resistance to compression and better recovery after repeated loading due to the orientation of the fibers in the layers.
Again, for pillow applications, a desired amount of the layered nonwoven bamboo web can be separated after layering, prior to reaching the bonding process. Alternatively, the nonwoven bamboo web can be bonded and used for pillow applications. For certain pillow applications, particularly those where a uniform pillow is desired without the lumps that can be associated with blown fiber, the layered nonwoven bamboo web can be cut to size and shape, rolled to a desired thickness, and slid into a pillow envelope.
For those applications were a uniform badding is desirable, such as filling for quilt and comforter articles, the layered nonwoven bamboo web can be bonded to form the bamboo fiberfill. The term bonding is generally intended to mean the process by which the nonwoven bamboo web is tacked together to form solid bamboo fiberfill structure that is not easily pulled apart. Examples of bonding include, without limitation, mechanical, chemical, and thermal bonding.
An exemplary embodiment of mechanical bonding is known as needlepunching. Needlepunching is a process of bonding the nonwoven bamboo web by mechanically interlocking the bamboo fibers throughout the web. Barbed needles, mounted on a board, punch the bamboo fibers into the web and then are withdrawn leaving the fibers entangled. The needles can be spaced in a non-aligned arrangement and are designed to release the bamboo fiber as the needle board is withdrawn.
An exemplary needlepunch process 900 is illustrated in
The shape of the needle is important to the process as it must push the fibers through the web in order to interlock, without damaging the web or removing the fibers as the needle retracts. The proper selection of gauge, barb, point type, blade shape (e.g. pinch blade, star blade, conical), and the like, are all examples of important needle design configurations and will depend on the type of bamboo fiber being used and the desired application for the nonwoven web. The gauge of the needle can be defined as the number of needles that can be fit in a square inch area. Thus the finer the needles, the higher the gauge of the needles. Coarse fibers can use lower gauge needles, while fine and/or delicate fibers will require higher gauge needles.
Continuing with the needlepunch process, as the needleloom beam 908 moves up and down, the blades of the needles penetrate the bamboo fiber batting. Barbs on the blade of the needle pick up the fibers on the downward movement and carry these fibers the depth of the needle penetration. The exit draw roll 912 pulls the bamboo batt through the needle loom 914 as the needles 902 reorient the bamboo fibers from a predominately horizontal to a substantially vertical position. The more the needles penetrate the web the denser and stronger the web generally becomes. However, care must be given as to the desired strength of the nonwoven web, as beyond a certain point, fiber damage can result from excessive needle penetration.
In another embodiment, a method of bonding the nonwoven bamboo fiberfill includes stitch bonding. Stitch bonding is another mechanical method of consolidating the bamboo fiber web with knitting elements to interlock the fibers. This process can include the use of a second material to interlock the bamboo fibers. A yarn-like fiber can be used, or a “scrim” substrate can be used and the bamboo fiber punched onto the scrim material. Examples of second materials will depend on the intended applications and the desired properties of those applications. As an example, Lycra® can be used if stretch in the fiberfill is a desired property. Stitch-bonded fiberfills tend to be used in place of woven goods, such as for bedding because they are faster to produce and, hence, the cost of production can be substantially less.
In yet another embodiment, a method of bonding the nonwoven bamboo fiberfill includes thermal bonding. Thermal bonding is a non-mechanical process, which uses heat to bond or stabilize the bamboo web structure. In order for thermal bonding to be useful for bamboo fiberfill, however, a thermoplastic fiber must also exist in the nonwoven web. As will be discussed in more detail below, the above disclosed processes can be useful for nonwoven fiberfill webs completely comprised of bamboo fiber or for nonwoven fiberfill webs wherein only a portion of the fiber is bamboo. For thermal bonding, the thermoplastic fibers are necessary in order to bind the bamboo fibers under heat. The fibers act as thermal binders, thus eliminating the need for latex or resin binders (other non-mechanical binding processes). Polypropylene can be a suitable fiber because it has a low melting point (approximately 165° C.), and therefore the heat will not damage the bamboo fibers. It is also soft to touch, so it does not impact the aesthetic properties of the bamboo. The nonwoven fiber web is passed between heated calender rollers, where the web is bonded. The calender rolls can be embossed or smooth. Embossed rolls can add softness and flexibility to the bamboo fiberfill, while smooth rolls bond the entire surface of the fiberfill, thereby increasing the strength, but reducing drape and softness.
In still another embodiment, the nonwoven bamboo fiberfill can be bonded by means of a chemical binder. The chemical binder can be applied to the web and then allowed to cure. The cured chemical is effective to provide the binding strength to the bamboo fiberfill. One example of a chemical binder is latex. Latex is commonly used because it is inexpensive, easy to apply, and very effective in binding the bamboo fibers. Several methods are used to apply the binder and can include saturation bonding, spray bonding, print bonding, foam bonding, and the like.
The mechanical type bonding, such as needlepunching, is effective in producing a dense, low-loft bamboo fiberfill having a felt-like quality. This material can be advantageously used filling, for example, in quilts used for the craft industry or for top of bed applications in the bedding manufacturing industry. The other types of bonding methods, such as thermal and chemical bonding, are effective in producing a high-loft, resilient, and insulating product. The product can be as much as about 2 inches thick and can be advantageously used in, for example, comforters and channeled comforter applications.
As previously noted, it has been discovered that when bamboo fiber is opened and then processed by way of web forming, layering, and bonding, the end result is a nonwoven fiberfill of bamboo which can be used as a quilt batting, filling for a blanket, filling for a comforter, the wrapping of a foam or polyester core pillow or cushion, garment or apparel creation, and the like. The bamboo fibers advantageously impart the unique attributes of the bamboo plant to the above listed articles. For example, an end product comprising nonwoven bamboo fiberfill will be naturally anti-bacterial, naturally deodorizing, and naturally breathable. Bamboo is also a highly absorbent material and can wick moisture away from the body, thereby offering a cooling effect in warmer climates and an insulating effect in cooler climates. When the bamboo fiber is processed through an opener and just a line of web forming machines (e.g. garnets), a highly lofted web of bamboo material is yielded, which can be used in applications such as bedding materials, including but not limited to quilts and comforters, however, this process offers a thicker, puffier, and more resilient result when finished in a quilt or comforter. When the bamboo fiber is further bonded by one of the methods listed in detail above, a tighter, denser web of bamboo material is formed, which can be used in the manufacture of quilts, blankets, and comforters. Even further, when the bamboo fiber is processed using the openers and the card or garnets in a random fiber orientation, where the fibers are tangled and exploded, the end product is a highly resilient fiber, which can be ideal for the use in the manufacture of pillows for bed pillows, bath pillows, travel pillows, craft pillows, lumbar pillows, decorator pillows, couch cushions, and the like. Moreover, if the bamboo fiber is blown, either with or without pre-opening the fiber, through the use of air and fans and tumbling through a pillow blowing machine, the end-result bamboo fiber can be blown into bed pillows, bath pillows, travel pillows, craft pillows, lumbar pillows, decorator pillows, couch cushions, and the like.
As can be seen, the process as disclosed herein provides methods for making several different options of bamboo fiberfill quality, and all of the bamboo fiberfill produced by the processes disclosed herein have properties that can not be achieved in other synthetic and natural fiberfills without the use of additional process steps and/or chemicals. Moreover, bamboo is a naturally occurring fiber that can be grown and harvested in a sustainably renewable manner and will readily decompose upon discarding, thereby further limiting environmental impact.
The terms “first,” “second,” and the like as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity). Further as used herein “disposed” means that the recited elements are in direct contact with, and fully or partially cover each other. All ranges disclosed within this specification that are directed to the same component or property are inclusive of the stated endpoint, and are independently combinable. All references are incorporated herein by reference in their entirety.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/981,904, filed 23 Oct. 2007, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60981904 | Oct 2007 | US |
