Patent Publication Number: US-6655271-B1

Title: Method, system and apparatus for creating a colorant pattern in porous material

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention generally relates to creating colorant patterns in porous materials. More particularly, the present invention relates to creating colorant patterns in porous materials in a vacuum environment. 
     2. Background Information 
     In the past, patterns were created in porous materials, such as fabric for clothing, by hand, and by processes such as imprinting, stenciling, silk screening, dyeing, transfer, ink jet, tie dye, etc. Each has drawbacks and limitations. For example, creating fabric designs by hand (e.g., by ink application), by tie dye or by silk screening is time consuming and relatively low-volume producing. As another example, imprinting, stenciling and other similar methods place the exact same design on all the fabric created, resulting in a lack of uniqueness in the finished product, which may not be desirable for some applications. As still a further example, silk screening allows for no variation, is a relatively expensive pattern-creation technique, only allows the application of one color per screen, and lacks full penetration of colorant through fabric. 
     Thus, a need exists for a relatively fast, low-cost way to produce volumes of at least slightly varying, high-quality, high-penetration colorant patterns in porous material. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention satisfies the need for a relatively fast, low-cost way to produce high-quality, high-penetration colorant patterns in porous material with at least slightly varying design in volume, by using flow guides in a vacuum environment to guide multiple colorants simultaneously across and into a porous material to create a pattern with high saturation of the porous material. The guides allow for variations in pattern when repeated with another porous material. 
     In accordance with the above, it is an object of the present invention to provide a way to create a pattern in porous material with colorant. 
     The present invention provides, in a first aspect, a method of creating a colorant pattern in porous material. The method comprises guiding a colorant in a vacuum environment across and into a porous material to create a colorant pattern therein. 
     The present invention provides, in a second aspect, a system for creating a colorant pattern in porous material. The system comprises a sealable vacuum chamber with at least one outlet for exiting of the atmosphere, and a template with at least one colorant flow guide for guiding a colorant across and into porous material and toward the at least one outlet when in contact with the template to create a colorant pattern in the porous material. 
     The present invention provides, in a third aspect, apparatus for creating a colorant pattern in porous material. The apparatus comprises a template with at least one colorant flow guide for guiding colorant along the flow guide when under vacuum. 
     The present invention provides, in a fourth aspect, a system for creating a colorant pattern in porous material. The system comprises a sealable vacuum chamber with at least one outlet, and at least one barrier gasket for creating at least two zones in the porous material. Each of the outlets is couplable to one of the zones. 
     The present invention provides, in a fifth aspect, a system for creating a colorant pattern in porous material. The system comprises a sealable vacuum chamber with at least one outlet, and at least one reservoir for providing colorant to the sealable vacuum chamber. 
    
    
     These, and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts one example of a system for creating a colorant pattern in porous material, in accordance with the present invention. 
     FIG. 2 depicts another example of a system in accordance with the present invention featuring a hollow template. 
     FIG. 3 depicts a portion of the system of FIG. 1 with an external colorant feed. 
     FIG. 4 depicts another example of a system in accordance with the present invention. 
     FIG. 5 depicts one example of a collapsing bladder useful with the present invention. 
     FIG. 6 depicts another example of a system for creating a colorant pattern in porous material, in accordance with the present invention. 
     FIG. 7 depicts still another example of a system for creating a colorant pattern in porous material, in accordance with the present invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     FIG. 1 depicts one example of a system  100  for creating a colorant pattern in porous material in accordance with the present invention. System  100  comprises a sealable vacuum chamber  102  including, for example, a base  104 , non-conforming sealing membrane  106 , conforming rubber blanket  107 , and gasket (i.e., perimeter seal)  108 . The sealable vacuum chamber can take many forms, such as, for example, a conventional vacuum table. System  100  also comprises a raised layer  110  providing vacuum flow channels (e.g., channel  112 ) for exiting of colorant  114  as described below. The vacuum is created by vacuum pump  118  drawing atmosphere through at least one opening  116 , and when in operation, sealing membrane  106  and gasket  108  create the seal for the vacuum chamber. 
     In the present example, colorant  114  is situated above porous material  120 , which can be any porous material lending itself to colorant patterning, for example, fabric. Colorant  114  comprises, for example, any fluid or semi-fluid with dissolved or suspended color particles. As used herein, the term “colorant” comprises one color, a plurality of different colors, multiple shades of the same color, or any combination thereof. Of course, the colorant(s) chosen and the viscosity thereof will depend on the particular application, for example, the type of porous material being patterned and the desired patterning effect. A template  122  comprises a plurality of openings (e.g., openings  124  and  126 ) between which is a flow guide  128  for guiding colorant across and into porous material  120 . Template  122  can comprise any number of materials (e.g., plastic, metal, etc.), so long as it is stiff enough so as not to be conforming under vacuum. The template is easily modified and inexpensive, relative to screens, thereby providing a cost advantage. The flow guide(s) can be arranged in any design, for example, the heart design shown in FIG. 1. A flow guide can take any number of forms, so long as it serves the purpose of guiding colorant across the porous material. The flow guide also helps ensure that most or all of the colorant is absorbed by the porous material, in order to significantly reduce or eliminate puddling of colorant. Preferably, the flow guide also allows for at least slight variations in successive patterns created without altering the flow guide itself. This is due to the use of a vacuum and the inherent randomness associated therewith. Each of the example flow guides below allows for such variations. 
     For example, the flow guide can take the form of a channel within or on (see FIG. 1) the surface of template  122 . Where the channel is within the template, it simply acts as a canal between openings. As another example, the flow guide can take the form of a wire (e.g., wire  160 ) on the template strung between two points, for example, between two openings (in this example, openings  162  and  164 ). As another example, the flow guide can simply be one or more openings in the template (e.g., opening  166 ). In conjunction with vacuum pump  118 , and depending on the location of at least some of the colorant other than directly above the opening(s), the opening(s) serve to pull the colorant across the porous material and toward the opening(s). As still another example, the flow guide can take the form of at least two barriers (e.g., barriers  130  and  132 ) on the template, spaced apart such that a channel  134  is created between them. As yet a further example, the flow guide can take the form of at least one capillary, tube or other conduit on the template with a plurality of openings along a length thereof (see FIG.  3  and the description thereof). Of course, through-openings in the template are not necessary for the operation of system  100 . However, the openings assist in exhausting the colorant to the porous material, helping to significantly reduce or eliminate puddling of the colorant. Where no openings are included in the template (e.g., in a situation where the porous material being patterned is relatively small), the colorant would simply flow, when under vacuum, toward a nearest edge (e.g., edge  129 ) to a channel in raised area  110  and toward opening  116 , for example. Of course, there will be a size limit when no openings in the template are used where edge flow will result in insufficient “drainage” causing, for example, puddling of colorant. 
     FIG. 1 also depicts one example of an excess colorant collector  150  in the form of a trough between conforming rubber blanket  107  and gasket  108  around base  104 . The trough is pitched such that colorant  156  therein will flow toward an outlet  152 , which is generally covered with a cap  154  until draining of the colorant is required. As shown, opening  116  to vacuum pump  118  is placed above the trough to reduce the likelihood of colorant entering the pump. Of course, a trough is merely one example of an excess colorant collector. As another example, described in detail with respect to FIG. 2, the excess colorant collector could take the form of a collection trap couplable to the vacuum outlet(s) (here, opening  116 ). 
     It will be understood that non-conforming sealing membrane  106  is stiff enough so as to prevent conformal covering of that which lies beneath it when a vacuum is applied. In the past, conforming bladders providing even pressure, for example, were purposely used to help force ink through a stencil opening and through the fabric underneath. However, such conforming bladders may actually interfere with the flowing of colorant across the porous material in the present invention, due to the even pressure. 
     FIG. 2 depicts another example of a system  200  for creating a colorant pattern in porous material, in accordance with the present invention. A sealable vacuum chamber  210  comprises a non-confirming sealing membrane  212  and base  214 , similar to that in FIG. 1, except that the seal comprises a compressible seal  216  made of, for example, rubber around a periphery of the chamber. In addition, the base  214  must be non-conforming where both sides of the hollow template are used for pattern creation. As with the system of FIG. 1, a seal is achieved by the application of the vacuum, resulting in a pressure differential. 
     A hollow template  218  is shown placed inside a shirt  220 . There are openings on the top  222  and bottom  224  of the template (e.g., openings  226  and  236  on the top, with similar openings on the bottom). Each of the top and bottom of the template serves the same purpose as template  122  from FIG. 1, relative to each of a front side  230  and a back side  232  of shirt  220 , respectively. For example, a flow guide  234  can be placed between openings  226  and  236 . Where there are openings on both the top and bottom of the hollow template, the sides (e.g., side  238 ) are preferably closed off. In such a situation, colorant from a colorant layer  240 , shown partially in FIG. 2 for simplicity, would be pulled down by a vacuum through front  230 , along flow guide  234  and into opening  226  and/or  236 . Similarly, colorant from a bottom colorant layer  237  would be pulled up through the back side  232 , and along flow guides and through openings (not shown) on bottom  224  of the template similar to top  222 . Flow guides on the outer face of both top  222  and bottom  224  allow pattern creation on both front side  230  and back side  232  of shirt  220 . For example, a logo could be printed on the front side and reversed on the back side. The vacuum for system  200  is achieved with, for example, a vacuum pump  246  pulling atmosphere through opening  228  via conduit  244 . Unlike the system of FIG. 1, system  200  does not include a raised layer, due to the hollow nature of the template. Further, it will be understood that hollow template  218  need not lie horizontal in a vacuum chamber; it could also be situated vertically to enhance drainage of excess colorant. 
     One example of an excess colorant collector  250  is also depicted in FIG. 2 in the form of a collection trap coupled to conduit  244 . A combination of colorant  252  and atmosphere  254  enter the collection trap where the colorant falls by gravity to the bottom, while the atmosphere continues back out conduit  244  toward vacuum pump  246 . 
     FIG. 3 depicts one example of a conduit-type flow guide mentioned above with respect to FIG.  1 . Shown in FIG. 3 is porous material  300  atop a template  302  that can be used with sealable vacuum chamber  102  from FIG.  1 . At least one conduit (e.g., conduit  304 ) lies on top of the porous material, and is connected to a colorant feed  306 . Colorant feed  306 , in turn, is connected to a colorant reservoir  308 . Colorant reservoir  308  can be flexible or rigid, open or sealed. Further, the reservoir can be valved to control dispensing. Each conduit comprises a plurality of openings along its length for the colorant  310  to exit, when under vacuum, onto porous material  300  and move thereacross and into toward a nearest opening (e.g., opening  312  shown in phantom) in the template. The vacuum provides the draw for colorant  310 , such that a separate pump is not typically necessary. The capillaries are sized to achieve the desired transport of colorant based on, for example, the viscosity thereof. In the embodiment shown in FIG. 3, the colorant feed and reservoir are external to the sealable vacuum chamber (not show in FIG.3 for simplicity). However, the colorant feed and reservoir could also be internal to the sealable vacuum chamber, for example, if the colorant reservoir took the form of a collapsible bladder. 
     FIG. 5 depicts one example of a collapsible bladder  500 . Bladder  500  can comprise any number of flexible, non-absorbent materials, for example, plastic or vinyl. Colorant  502  is held within bladder  500  until some force, either direct or indirect (here, the vacuum), in effect squeezes bladder  500 . Colorant  502  then flows out of bladder  500  into one or more capillaries or tubes  504  with a plurality of openings therein (e.g., opening  506 ) through which colorant  502  exits onto and into porous material (not shown). 
     FIG. 4 depicts another embodiment of a system  400  in accordance with the present invention. System  400  comprises a cylindrical vacuum manifold  402  with at least one vacuum outlet  404  to a vacuum pump  405  through conduit  407 . A plurality of openings are shown in phantom (e.g., openings  406  and  408 ) leading to vacuum outlet  404  through passages (not shown) internal to cylindrical vacuum manifold  402 . Manifold  402  is made of any number of stiff materials, for example, metal, plastic, etc. As with the other embodiments, colorant flow guides (e.g., flow guide  410 ) are provided between the openings. Thus, the manifold serves the same functions as both base  104  and template  122  in the embodiment of FIG.  1 . Also, it will be understood that no openings need connect the flow guides. Colorant could simply move under vacuum across the guides and toward an opening (e.g., opening  412 ) not covered by porous material  414 . The colorant flow guides can take all the forms mentioned previously with respect to FIG.  1 . Also shown in FIG. 4 is a non-conforming sealing girdle  416  that can seal to vacuum manifold  402  by, for example, a compressible seal  418  similar to that described with respect to FIG.  2 . The non-conforming sealing girdle can be made of any number of stiff materials, for example, metal, plastic, etc. One example of an excess colorant collector  450  is shown in FIG. 4 in the form of a collection trap, similar to that shown and described with respect to FIG.  2 . Excess colorant  452  is trapped in the collection trap, while atmosphere  454  passes through to vacuum pump  405 . 
     FIG. 6 depicts another example of the present invention. System  600  comprises a top non-conforming sealing membrane  602  and a corresponding bottom non-conforming sealing membrane  604 , together comprising a sealable vacuum chamber. Both membranes are similar to membrane  106  in FIG. 1, with the bottom membrane serving the functions of both base  104  and template  122  in system  100 . The top membrane is sized identical to the bottom membrane. System  600  further comprises a perimeter barrier gasket  606 , similar to weather stripping, that prevents colorant (not shown for convenience) from potentially seeping out. The same type of gasket material is used below porous material  608  to create areas or zones where colorant can be guided separately from other zones. Of course, the gasket material could alternatively be placed on the porous material itself This allows a greater degree of flexibility in design when necessary, as compared to the previous embodiments. The gasket material can be placed passively on the porous material, to be held in place by compression under vacuum, or it can be temporarily adhered to the porous material or template with a non-permanent adhesive, for example. 
     Zone  610  is shown in FIG. 6 as having a star shape, and is coupled, via opening  612  in bottom non-conforming sealing membrane  604  and conduit  614  ultimately to vacuum pump  616 . Zone  610  is created with a barrier gasket  611  like gasket  606 . Similarly, each of the other zones  618 ,  620  and  622  are coupled to the vacuum source by conduits  624 ,  626  and  628 , respectively. Atmosphere through each of the conduits is independently controlled. For example, the atmosphere could be controlled by valves coupled to the conduits (e.g., valve  630 ). The valves could be controlled manually, or even by computer. Alternatively, each zone could have its own vacuum source controlled independently. 
     One example of an excess colorant collector  650  is shown in FIG. 6, taking the form of a common collection trap for excess colorant  652  interposed between the various conduits (e.g., conduit  614 ) mentioned above with respect to the various zones and another conduit  654  coupled to pump  616 . Of course, as another example, the conduits from the various zones could also be commonly coupled to the air pump and each have their own collection trap. 
     Since bottom non-conforming sealing membrane  604  also serves as the template in this embodiment, it will be understood that one or more flow guides as described above with respect to FIG. 1 could be included so as to correspond to one or more zones. This would allow a pattern to be created in a particular zone. Where no flow guides are included for a given zone, the pattern could be allowed to be random, or colorant could saturate the entire zone (e.g., the star zone  610  in FIG.  6 ), or the zone could have a complete absence of colorant. Where an absence of colorant is intended for a given zone, there need be no vacuum established for that zone. 
     FIG. 7 depicts still another example of a system  700  in accordance with the present invention. Like system  600  in FIG. 6, system  700  comprises a top nonconforming sealing membrane  702  and a corresponding bottom non-conforming sealing membrane  704 , together comprising a sealable vacuum chamber  705 . As with system  600 , bottom membrane  704  serves as both a base and template. Bottom membrane  704  includes one or more flow guides as described herein. Although not shown in FIG. 7, it will be understood that the gasket material described with respect to FIG. 6 could also be used to create zones in porous material patterned with system  700 . Another alternative is to have no flow guides or gasket material. Of course, a single reservoir could be used, or less or more reservoirs than shown in FIG.  7 . Each reservoir is coupled to an opening in top membrane  702  via conduits, for example, reservoir  710  is coupled to opening  714  via tubing  716 . In addition, valves (e.g., valve  718 ) are preferably included (here, on the conduits) to regulate the amount of colorant entering the sealable vacuum chamber. 
     In operation, a vacuum pump  720  is coupled to outlets  722  and  724  in bottom membrane  704  via conduits  726  and  728 , respectively. When activated, and when the reservoir valves are opened, the vacuum pump pulls atmosphere through the conduits to cause colorant  730  entering the vacuum chamber to move across and into porous material  732  toward outlets  722  and  724 , in accordance with the flow guides on bottom membrane  704 . Where the gasket material is used, zones would be created in porous material  732 , as described with FIG.  6 . Of course, a separate template could also be used, rather than the combination bottom membrane and template described with respect to FIG.  7 . System  700  further comprises an excess colorant collector  750  in the form of a common collection trap for colorant  752  coupled to vacuum pump  720  via conduit  754 , similar to that of FIG.  6 . 
     The present invention, as described above, provides a relatively low-cost way to produce colorant patterns in porous material with at least slightly varying design in volume. In addition, the penetration of the colorant, at least in fabric, is such that the pattern produced is clear on both the front and back of the fabric with a single application. 
     While several aspects of the present invention have been described and depicted herein, alternative aspects may be effected by those skilled in the art to accomplish the same objectives. Accordingly, it is intended by the appended claims to cover all such alternative aspects as fall within the true spirit and scope of the invention.