Bonded Fiber Wick
A hydrophilic fiber wick is provided, the wick made up of a self-sustaining fluid transmissive body having a plurality of bicomponent fibers bonded to each other at spaced apart contact points. The bicomponent fibers have at least one biodegradable material and collectively define tortuous fluid flow paths through the fluid transmissive body.
This application is a continuation of U.S. application Ser. No. 12/795,403, filed Jun. 7, 2010, which is a continuation of U.S. application Ser. No. 11/765,538, filed on Jun. 20, 2007, now U.S. Pat. No. 7,731,102, which claims priority to U.S. Provisional Patent Application No. 60/815,822, filed on Jun. 22, 2006, each of which is incorporated herein by reference in its entirety. This application is also related to U.S. application Ser. No. 11/333,499 filed on Jan. 17, 2006, titled “Porous Composite Materials Comprising a Plurality of Bonded Fiber Component Structures,” which is also incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTIONThe present invention is generally directed to wicks. In particular, it is directed at wicks where the capillary is formed by fibrous materials. More particularly, the present invention is directed to composite bonded fiber wick structures that displace a specific amount of fluid relative to an amount that is initially absorbed.
It is known in the art to manufacture isotropic wicks for a variety of applications. Such isotropic wicks are generally three-dimensional, porous, bonded fiber elements that may serve to wick a fluid from a first location to a second location. These wicks may be used in diverse applications, such as in air freshener devices, lighters, writing instruments, and for a variety of biological fluids, such as urine and/or blood. Such wicks are disclosed in U.S. patent application Ser. No. 11/333,499, which is herein incorporated by reference in its entirety.
When such bonded fiber wicks are used in air freshener devices, the wick is often immersed in a fluid (typically containing a fragrance), and by capillary force the fluid is drawn into the bulk of the wick. Generally, the end of the wick opposite of the end immersed in the fluid is exposed to air, and the fluid may evaporate from the surface of the wick broadcasting the fragrance into the space around the air freshener device.
However, isotropic wicks used in such air freshener devices and similar applications have several drawbacks. One of the more significant drawbacks is that when an isotropic wick is used to dispense volatile air freshener solutions, the wick generally absorbs an amount of air freshener solution when it is placed in the container. When the wick has a large volume relative to the volume of the container, this may cause the level of liquid in the container to drop as it is absorbed into the wick. In transparent devices sold into the consumer market, such as an air freshener container made of glass or clear plastic, this often creates the negative perception that the consumer is buying a less than full a container of air freshener.
Although a smaller diameter wick may at least partially resolve this problem, the surface area of the wick is reduced due to the smaller diameter, and the dissemination of fragrance may be impaired as a result of less surface area of the wick for evaporation.
Accordingly, there is a need for a wick that initially provides a desired amount of fluid displacement while providing sufficient wick surface area for fragrance dissemination. There is also a need for a wick that displaces an amount of fluid approximately equal to the amount of fluid it initially wicks, resulting in a neutral displacement.
SUMMARY OF THE INVENTIONAspects of the invention include a hydrophilic porous wick comprising thermally bonded synthetic bicomponent fibers having pores between the thermally bonded synthetic bicomponent fibers. Another aspect of the invention includes a method of releasing a vaporizable material into the atmosphere comprising: placing a hydrophilic porous wick comprising thermally bonded synthetic bicomponent fibers having pores between the thermally bonded synthetic bicomponent fibers into a fluid containing a vaporizable material; permitting the fluid containing the vaporizable material to wick through the hydrophilic porous wick and release into the atmosphere. Yet another aspect of the invention includes a hydrophillic fiber wick comprising: a fluid transmissive body comprising a plurality of bicomponent fibers bonded to each other at spaced apart contact points and collectively defining tortuous fluid flow paths through the fluid transmissive body.
It is to be understood that both the foregoing and the following description are exemplary and explanatory only, and are not restrictive of the invention. The accompanying drawings, which are incorporated herein by reference, and which constitute a part of the specification, illustrate certain embodiments of the invention and, together with the detailed description, serve to explain the principles of the invention.
In order to assist in the understanding of the invention, reference will now be made to the appended drawings, in which like reference characters refer to like elements. The drawings are exemplary only, and should not be construed as limiting the invention.
A neutral displacement wick (NDW) in accordance with some embodiments of the present invention will now be discussed. The advantage of a NDW wick when used in air freshener devices or similar applications is that when the wick is first introduced into the fluid reservoir, it may absorb a desired amount of liquid into the wick relative to the amount it displaces, resulting in the liquid level in the fluid reservoir remaining at or near the level present before the wick was introduced, or at some other desired level. If the wick is capped off or otherwise enclosed to prevent evaporation, the device may be shipped to the consumer who may then have the perception that he or she is buying a full container. When the cap is removed, the large surface area of the wick sheath may allow dissemination of fragrance.
With reference to
With reference to
In
In
Other example cross sections may be a wicking core and a non-wicking sheath, or any other configurations that would be obvious to one skilled in the art.
Many materials may be used in the wicking portion of the NDW wick. Such materials may be self-sustaining porous bonded fiber elements that are capable of being engineered to wick a variety of liquids and act as air freshener wick materials. Examples of such materials may include bonded bicomponent polyolefin sheath fibers, bonded bicomponent polyester sheath fibers, bonded bicomponent nylon sheath fibers and bonded pneumatic nylon and pneumatic cellulose acetate.
Other examples of materials that may be suitable for use in the wicking portion of the NDW wick may include porous, non-bonded, wicking fiber elements, which may be stiffened by adhesives or otherwise made structurally sound to enable consistent wicking behavior. Woven, knitted or non-woven fabrics may be used, as well as natural fibrous or non-fibrous products (such as cotton or wool). In addition, open cell foams may be used (as long as they are of sufficient surface energy to allow wetting and wicking of the target fluid). Additionally, porous plastics, such as self-sustaining porous sintered plastic elements, may be used. Various other materials that provide adequate wicking and evaporation will be readily apparent to one skilled in the art.
In general, the non-wicking portion may be any material as long as it is so configured so that the target fluid will substantially not penetrate this portion and thus be displaced by the non-wicking portion. The non-wicking portion of the NDW wick may be impervious, and may be a closed cell foam material, such as a rod-shaped chemically resistant polyethylene or polyurethane foam, a solid rod, such as a variety of plastic or elastomeric rods, or even rods of wood or metal. The non-wicking portion may also be bonded or non-bonded fiber structures, or natural product structures, with the surface energy being such that the material would not wet out or wick the target fluid, even under elevated pressure conditions that may be experienced in a container.
The wicking portion may be tight up against the non-wicking displacement portion to prevent voids from forming. Unsealed voids are unwanted because upon filling with the fragrant liquid, the volume of the container may appear to be less. The wicking portion and the non-wicking displacement portion may be arranged so as to prevent unwanted delamination or separation of the two portions. For example, the wicking portion and the non-wicking displacement portion may be combined into a single unit by interference fit, or may be adhered together. Such adherence may be the result of fibers of the wicking portion bonding to the non-wicking displacement portion, or may result from the use of adhesives applied to the components.
In general, the wick may be sized to achieve the following objectives:
-
- 1. The proper surface area (as determined by the circumference of the wick, the amount of wick exposed in the non-immersion section, and the vapor pressure of the target fluid). A proper surface area may allow a vapor release rate appropriate to the application in question.
- 2. Appropriate volume of liquid wicked up into the wick by capillary action (determined by the cross sectional area of the wicking portion, plus the capillary draw and porosity of the porous element).
- 3. The amount of liquid displaced (determined by (2) above plus the displacement of the displacement portion).
- 4. A desired relationship between the immersion section and the non-immersion section. For example, in some circumstances, it may be desirable to maintain a fluid level at the same height once a wick is inserted. In this situation, the initial volume of the immersion section (comprising the volume of both the displacement portion and the fiber volume of the wicking portion) should be approximately equal to the initial volume of fluid wicked by the wicking portion located in the non-immersion section. In other circumstances, it may be desirable to cause the fluid level to rise or drop once a wick is inserted. In such circumstances, the volume of the immersion section may initially be more or less, respectively, than the volume of fluid initially wicked by the wicking portion in the non-immersion section.
The need for proper sizing of the NDW may be apparent from
The ratio of the volume of liquid displaced by the immersion section (including the displacement portion) to the volume of liquid initially wicked into the wicking portion in the non-immersion section must be designed for each particular application, and must take into account the volume of the container, the size of the NDW and the desired liquid height inside the container before and after the insertion of the NDW. Ratios may range from 0.2 to 4.0. When a particular fluid level prior to NDW insertion is desired to be maintained after NDW insertion, ratios may range from 0.95 to 1.05. Design considerations include, but are not limited to, the desired evaporation rate of the liquid, the surface tension of the liquid that is to be wicked, the density of the wicking portion, the overall dimensions of the wicking portion, and the overall dimensions of the container.
The NDW may also be made in many different ways, including bonded fiber processes of many types, non-woven wrapping technologies, textile technologies, and a variety of forming technologies. The NDW may be produced by separately manufacturing the porous, wicking portion and the non-wicking portion, and combining the portions into a final unit. As noted above, this combination may utilize an interference fit, may be thermally bonded together as part of the forming process or may utilize additional adhesives.
Alternatively, the wicking portion may be formed integral to the displacement portion. For example, in arrangements such as those depicted in
With reference to
The inner dimensions of the die may form the combined wicking portion 1120 and displacement portion 1110 into a desired cross section. Optionally, a cooling die 1140 may be used to quicken the cooling of the heated fibers. Additionally, the cooling die 1140 may provide additional shaping of the cross section of the final product. Upon exit from the heating die 1130 and optionally the cooling die 1140, the NDW 1170 is formed. The combined NDW 1170 may be pulled through the process by element 1160, and may be cut to desired length by element 1150. Although
As noted above,
It will be apparent to those skilled in the art that various modifications and variations can be made in the method, manufacture, configuration, and/or use of the present invention without departing from the scope or spirit of the invention.
Claims
1. A hydrophilic porous wick comprising thermally bonded synthetic bicomponent fibers having pores between the thermally bonded synthetic bicomponent fibers.
2. The hydrophilic porous wick of claim 1, further comprising natural monocomponent fibers or synthetic monocomponent fibers.
3. The hydrophilic porous wick of claim 1, wherein the synthetic bicomponent fibers are selected from the group consisting of polypropylene/polyethylene terephthalate (PET), polyethylene (PE)/PET, polypropylene/Nylon-6, Nylon-6/PET, copolyester/PET, copolyester/Nylon-6, copolyester/Nylon-6,6, poly-4-methyl-1-pentene/PET, poly-4-methyl-1-pentene/Nylon-6, poly-4-methyl-1-pentene/Nylon-6,6, PET/polyethylene naphthalate (PEN), Nylon-6,6/poly-1,4-cyclohexanedimethyl-1 (PCT), polypropylene/polybutylene terephthalate (PBT), Nylon-6/co-polyamide, polyester/polyester and polyurethane/acetal.
4. The hydrophilic porous wick of claim 2, wherein the synthetic monocomponent fibers are polyvinyl alcohol (PVA) fibers.
5. The hydrophilic porous wick of claim 2, wherein the natural monocomponent fibers are selected from the group consisting of cotton and wool.
6. The hydrophilic porous wick of claim 2, wherein the natural monocomponent fibers are cellulose based fibers selected from the group consisting of vegetable fibers, wood fibers, animal fibers and man-made fibers.
7. The hydrophilic porous wick of claim 2, wherein the thermally bonded synthetic bicomponent fibers comprise about 51 wt % to about 100% wt % of the hydrophilic porous wick.
8. The hydrophilic porous wick of claim 1, wherein the synthetic bicomponent fibers comprise a sheath and a core, and the core has a melting temperature at least more than 10 degrees C. higher than the melting temperature of the sheath.
9. The hydrophilic porous wick of claim 3, wherein the synthetic bicomponent fibers comprise PE/PET bicomponent fibers or polyester/polyester bicomponent fibers.
10. The hydrophilic porous wick of claim 2, wherein the synthetic bicomponent fibers comprise PE/PET bicomponent fibers and the natural monocomponent fibers comprise cotton.
11. The hydrophilic porous wick of claim 2, wherein the synthetic bicomponent fibers comprise PE/PET bicomponent fibers and the synthetic monocomponent fibers comprise PVA or acrylic.
12. The hydrophilic porous wick of claim 1, wherein the synthetic bicomponent fibers are colored.
13. The hydrophilic porous wick of claim 2, wherein the natural monocomponent fibers or the synthetic monocomponent fibers are colored.
14. The hydrophilic porous wick of claim 1, wherein the wick is biodegradable.
15. The hydrophilic porous wick of claim 2, wherein the wick is biodegradable.
16. The hydrophilic wick of claim 15, wherein a component of the wick that is a biodegradable component is at least 40% of the total weight of the wick.
17. The hydrophilic porous wick of claim 1, having a density from 0.2 g/ml to 1.0 g/ml.
18. The hydrophilic porous wick of claim 2, having a density from 0.2 g/ml to 1.0 g/ml.
19. The hydrophilic porous wick of claim 1, having a diameter of about 0.04 inches to about 1.0 inches and a length to diameter ratio greater than 50.
20. The hydrophilic porous wick of claim 2, having a diameter of about 0.04 inches to about 1.0 inches and a length to diameter ratio greater than 50.
21. The hydrophilic porous wick of claim 1, wherein the hydrophilic porous wick possesses a wicking rate of deionized water of about 0.5 inches per minute or more in the first 2 inches of length.
22. The hydrophilic porous wick of claim 2, wherein the natural monocomponent fibers are cellulose based fibers.
23. A method of releasing a vaporizable material into the atmosphere comprising:
- placing a hydrophilic porous wick comprising thermally bonded synthetic bicomponent fibers having pores between the thermally bonded synthetic bicomponent fibers into a fluid containing a vaporizable material;
- permitting the fluid containing the vaporizable material to wick through the hydrophilic porous wick and release into the atmosphere.
24. The method of claim 23, wherein the wick further comprises natural monocomponent fibers or synthetic monocomponent fibers.
25. The method of claim 23, wherein the wick releases more than 0.5 gm of vaporizable material in 24 hours.
26. The method of claim 24, wherein the wick releases more than 0.5 gm of vaporizable material in 24 hours.
27. The method of claim 23, wherein the vaporizable material is an aqueous based fragrance or oil based fragrance.
28. The method of claim 23, wherein the wick is biodegradable.
29. A hydrophillic fiber wick comprising:
- a fluid transmissive body comprising a plurality of bicomponent fibers bonded to each other at spaced apart contact points and collectively defining tortuous fluid flow paths through the fluid transmissive body.
30. The hydrophillic fiber wick of claim 29 wherein the self-sustaining fluid transmissive body further comprises a plurality of monocomponent fibers.
31. The hydrophillic fiber wick of claim 30 wherein the monocomponent fibers are bonded only to the bicomponent fibers at spaced contact points.
32. The hydrophillic fiber wick of claim 30 wherein the monocomponent fibers comprise fibers consisting of natural materials.
33. The hydrophilic fiber wick of claim 30, wherein the monocomponent fibers are polyvinyl alcohol (PVA) fibers.
34. The hydrophilic porous wick of claim 30, wherein the monocomponent fibers are selected from the group consisting of cotton and wool.
35. The hydrophilic fiber wick of claim 29 wherein the bicomponent fibers are selected from the group consisting of polypropylene/polyethylene terephthalate (PET), polyethylene (PE)/PET, polypropylene/Nylon-6, Nylon-6/PET, copolyester/PET, copolyester/Nylon-6, copolyester/Nylon-6,6, poly-4-methyl-1-pentene/PET, poly-4-methyl-1-pentene/Nylon-6, poly-4-methyl-1-pentene/Nylon-6,6, PET/polyethylene naphthalate (PEN), Nylon-6,6/poly-1,4-cyclohexanedimethyl-1 (PCT), polypropylene/polybutylene terephthalate (PBT), Nylon-6/co-polyamide, polyester/polyester and polyurethane/acetal bicomponent fibers.
36. The hydrophilic fiber wick of claim 29 wherein the wick is biodegradable.
37. The hydrophilic fiber wick of claim 29 wherein at least a portion of the wick is biodegradable.
38. The hydrophilic wick of claim 37 wherein the biodegradable portion of the wick is at least 40 percent of the total weight of the wick.
39. The hydrophilic fiber wick of claim 29 further comprising:
- a displacement body integrally formed with said fluid transmissive body and configured so that when the fluid transmissive body and the displacement body are at least partially immersed in a fluid pool, the displacement body displaces a volume of fluid approximately equal to a wicked volume of fluid wicked out of the fluid pool by the fluid transmissive body.
Type: Application
Filed: Dec 27, 2010
Publication Date: May 12, 2011
Inventors: Bennett C. Ward (Midlothian, VA), Wolfgang Broosch (Schwarzenbek), Bernhard Kutscha (Reinbek), Richard M. Berger , Nancy B. Berger (Midlothian, VA)
Application Number: 12/978,907
International Classification: A61L 9/04 (20060101);