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WO2002000552A2 - Indicateur de duree de vie d'un filtre a eau - Google Patents

Indicateur de duree de vie d'un filtre a eau Download PDF

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Publication number
WO2002000552A2
WO2002000552A2 PCT/US2001/018870 US0118870W WO0200552A2 WO 2002000552 A2 WO2002000552 A2 WO 2002000552A2 US 0118870 W US0118870 W US 0118870W WO 0200552 A2 WO0200552 A2 WO 0200552A2
Authority
WO
WIPO (PCT)
Prior art keywords
water
indicator
color change
porous medium
color
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2001/018870
Other languages
English (en)
Other versions
WO2002000552A3 (fr
Inventor
Michael L. Kagan
Bradley D. Mierau
Henry C. Reid
John E. Nohren, Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PROFILE SOL-GEL Ltd
Profile Sol Gel Ltd
Innova Pure Water Inc
Original Assignee
PROFILE SOL-GEL Ltd
Profile Sol Gel Ltd
Innova Pure Water Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PROFILE SOL-GEL Ltd, Profile Sol Gel Ltd, Innova Pure Water Inc filed Critical PROFILE SOL-GEL Ltd
Priority to AU2001268342A priority Critical patent/AU2001268342A1/en
Publication of WO2002000552A2 publication Critical patent/WO2002000552A2/fr
Publication of WO2002000552A3 publication Critical patent/WO2002000552A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
    • C02F1/003—Processes for the treatment of water whereby the filtration technique is of importance using household-type filters for producing potable water, e.g. pitchers, bottles, faucet mounted devices
    • G—PHYSICS
    • G04—HOROLOGY
    • G04F—TIME-INTERVAL MEASURING
    • G04F1/00—Apparatus which can be set and started to measure-off predetermined or adjustably-fixed time intervals without driving mechanisms, e.g. egg timers
    • G—PHYSICS
    • G04—HOROLOGY
    • G04F—TIME-INTERVAL MEASURING
    • G04F1/00—Apparatus which can be set and started to measure-off predetermined or adjustably-fixed time intervals without driving mechanisms, e.g. egg timers
    • G04F1/04—Apparatus which can be set and started to measure-off predetermined or adjustably-fixed time intervals without driving mechanisms, e.g. egg timers by movement or acceleration due to gravity
    • G04F1/06—Apparatus which can be set and started to measure-off predetermined or adjustably-fixed time intervals without driving mechanisms, e.g. egg timers by movement or acceleration due to gravity by flowing-away of a prefixed quantity of fine-granular or liquid materials, e.g. sand-glass, water-clock
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/44—Time
    • C02F2209/445—Filter life
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2307/00—Location of water treatment or water treatment device
    • C02F2307/04—Location of water treatment or water treatment device as part of a pitcher or jug

Definitions

  • the present invention relates to an elapsed time indicator for indicating the product lifetime of a drinking-water filter. More particularly the present invention relates to a water-filter cartridge for a portable bottle or jug-type water filter where the filter cartridge has an integral indicator which indicates to the user when to change the filter, primarily in terms of the elapsed time since first use of the filter. Such invention is also useful for a myriad of other purposes when elapsed time is of importance and is either automatically enabled by an event or deliberately manually enabled.
  • the dial is moved one position forward.
  • the aperture mechanism will no longer open until it is reset.
  • the user is expected to then replace the water filter and manually reset the mechanism. In the worst case, the user may at this point choose to simply raise the lid to refill the jug instead of using the aperture mechanism.
  • Patent 5,076,912 which describes the use of a color indicator bonded to an ion exchange resin within the filter cartridge, where said indicator changes color when the ion exchange capacity of the filter becomes exhausted
  • this approach shares the previously noted disadvantage that, if the filter is only used rarely, the time taken before the indicator signals that it should be replaced could be beyond the point where the filters replacement would be warranted from a bacteriological point of view. Additionally, this approach suffers from the disadvantage that the color indicator could potentially be released into the drinking water, thereby posing a potential health hazard.
  • U.S. Patents 4,998,228 and 5,457,665 describe a time-based approach to replacement of the filter, where a mechanical mechanism is used to implement a clock.
  • the mechanism employed is the use of a sphere placed inside a tube filled with a viscous liquid. The tube is attached to the water filter cartridge. When the sphere is released, it gradually rises up inside the tube over a time period that can exceed a month. When the sphere reaches the top of the tube, a suitably placed window can show this as a color change indicating that the filter should be replaced.
  • the main disadvantage of this approach is that it requires an explicit activation step by the user in order to release the sphere on its upward journey and thereby start the timer. If this activation is not performed then the lifetime indicator is not triggered and the objective of signaling a replacement at least within certain time parameters is not achieved; potentially giving a false sense of security with respect to the use of the filter.
  • the other disadvantage of this approach is that, being based on a mechanical principle, it requires plastic parts and assembly and thus is significantly more expensive than the approach used by the current invention. Also known in the art are chemical timers and diffusion clocks; examples of such timers including: U.S.
  • Patent 3,520,124 in which two reagent-bearing porous matrices are brought into contact, resulting in a time dependent color changing reaction;
  • U.S. Patent 4,028,876 in which two reagents slowly mix through a porous medium to produce a color change;
  • U.S. Patent 4,195,058 in which a vapor gradually penetrates a vapor permeable barrier to react with a second reagent and produce a visual color change;
  • U.S. Patent 4,229,813 in which a silicon oil slowly diffuses along a porous strip;
  • U.S. Patent 4,248, 597 in which a substance penetrates through a permeable membrane to cause a pH indicator to undergo a color change;
  • Patent 4,292,916 in which components of a carrier mixture react physically and/or chemically with one or more receptive layers to give either a changing color display or to cause the appearance or disappearance of indicia;
  • U.S. Patent 4,404,922 in which gradual permeation of a fluid into a sachet causes the appearance or disappearance of indicia on said sachet;
  • U.S. Patent 5,053,339 in which an acid diffuses through a barrier to cause a pH indicator to change color;
  • U.S. Patent 5,317,987 in which gradual pitting of a barrier between two reagents causes said reagents to react with each other after a given time thereby causing a color change;
  • Patent 5,446,705 in which an adhesive layer dissolves a dye which then migrates through said adhesive layer to cause a visible change
  • U.S. Patent 5,633,835 in which an adhesive layer first dissolves a barrier and then dissolves a dye which then migrates through said adhesive layer to cause a visible change
  • U.S. Patent 5,667,303 in which a viscoelastic material slowly migrates into a into a diffusely light-reflective porous medium in order to provide a visually observable indication.
  • Timing indicator which in turn provides a visual readout graduated in days, or such other unit of measurement as may be deemed appropriate and designed into the timing indicators.
  • a self-contained water reservoir is an independent component of the indicator. To actuate the indicator a separating membrane is ruptured allowing a small amount of water to contact the indicator mechanism.
  • the present invention utilizes concepts from the field of chemical timers and diffusion clocks in order to implement a water-filter lifetime indicator.
  • timers and clocks can be very inexpensively fabricated, but have never been designed so as to function as filter cartridge lifetime indicators.
  • timing devices Nor have such timing devices been conceived that function when immersed in water for short or prolonged periods, in a warm or cool environment while retaining reasonable performance accuracy.
  • the timing device may be immersed in water over its extended life without leaching substances into the water. 2.
  • the timing device may be used as an external indicator of elapsed time showing the numbers of days since activation.
  • a timing device which may be automatic in its actuation or designed to permit manual, planned activation.
  • a timing device which may be inexpensive, as well as a reliable indicator of elapsed time in days with better than ⁇ 20 percent accuracy.
  • one of the objects of the present invention to provide a substantially lifetime indicator for drinking water filters which ensures that a periodic replacement of the filter cartridge is signaled to the user. Accordingly, one of the objectives of the current invention is to obviate the disadvantages of the forgoing devices by implementing a primarily time-based lifetime indicator for a water-filter.
  • the substantially lifetime indicator will be integral to the filter cartridge, in order to maximize the likelihood that the user will respond by changing the filter cartridge, thereby minimizing any potential bacteriological risk.
  • the construction of the substantially lifetime indicator be such that it can be fabricated for minimal cost, so that it will be cost-effective to place it on each and every filter cartridge as opposed to having an indicator built into the jug, the lid, or manually attached to the filter cartridge.
  • the substantially lifetime indicator operate in a fool-proof manner in conjunction with water filter applications by obviating the requirement that the user take an explicit action simply in order to activate the indicator.
  • the substantially lifetime indicator is recessed into the top of a carafe style pour through water-filter cartridge such that the indicator is readily viewable by the user each time the cover of the water filtration vessel is removed to fill said vessel with water.
  • the substantially lifetime indicator is to the side or bottom of an exit style filter cartridge as used in portable personal and sport type water filter bottles such that the indicator is readily viewable by the user each time the top and attached filter is removed to fill the bottle with water.
  • a somewhat different embodiment of the basic design for independent self contained application of the invention occurs with the incorporation of a sealed water reservoir. Activation, in this application, is manually controlled by rupturing a membrane separating the water from indicating mechanism. An indicator of this nature would be useful to adhesively affix to a food storage container. A further enhancement would be to graphically show time (days as an example) along the projected path of the indicator. This would function in the same manner as a thermometer with a degree scale.
  • a method of indicating the expiration of substantially the predetermined useful life of a water filter comprising: Operatively connecting a water filter, a pad containing a zinc salt or dye, and a diffusion strip of sol-gel doped with PAR dipped paper. Drawing water associated with the filter into contact with the pad to produce a solution. Slowly diffusing the solution through the diffusion strip so as to produce a color change. And viewing the color change via a mask containing indicia that relates the progress of the diffusion to substantially the predetermined useful life of the filter.
  • a substantially lifetime indicator device for a drinking-water filter comprising: A fluid migration conduit which facilitates fluid migration therein, having a first end and a second end. The first end having an aperture for receiving fluid, and the second end comprising a transparent section allowing an external viewer to observe a color change therein. And a color-changing mechanism which is activated by water and positioned within the conduit, so that when water comes into contact with the indicator, a portion of the water enters the conduit first end, thereby activating the color-changing mechanism which can be viewed at the second conduit end after a predetermined time interval.
  • the device may further comprise a porous medium in the conduit, so that water that has entered the conduit by the aperture slowly migrates through the medium thereby providing the visual indication which progresses down the length of the porous medium over time.
  • the device may further comprise a first reagent located within the conduit so that the water dissolves the first reagent and the solution containing the first reagent then migrates through the porous medium.
  • the device may further comprise a solid dye located within the conduit, and the water dissolves the solid dye so that a dye solution then migrates through the porous medium.
  • the porous medium may also contain a second reagent which reacts with the first reagent thereby producing a color change, and the porous medium may be impregnated with the second reagent, or the porous medium may be doped with the second reagent.
  • the reaction system therebetween may be selected from the group consisting essentially of chelation of a metal ion by a chelating agent, reaction of an acid/base with a pH indicator, reaction of an electron donor/acceptor with a redox indicator, and an enzymatic reaction between an enzyme and a substrate.
  • the metal ions may be selected from the group consisting essentially of zinc, copper, iron, and calcium ions
  • the chelating agent may be selected from the group consisting of 1 ,10 phenanthroline, zincon, and 2,2'-biquioline (cupron) and PAR
  • the acid/base reagents may be selected from the group consisting essentially of hydrochloric acid, citric acid, ascorbic acid, sodium hydroxide, and sodium hydrogen phosphate
  • the pH indicators may be selected from the group consisting essentially of bromothymol blue, methyl red, and cresol red
  • the electron donor/acceptors may be selected from the group consisting essentially of bleaching powder and vanadium salts
  • the redox indicators may be selected from the group consisting essentially of nphenylanthrancilic acid and bleachable dyes.
  • the porous medium itself may be selected from the group consisting essentially of cellulose-based material, paper, sol-gel, silica gel, polymeric micro- porous materials, and particle-filled polytetrafluroethylene, or a combination of at least two of the above mentioned porous materials.
  • the mechanism for migration down the length of the porous medium may be selected from the group consisting essentially of diffusion and capillary action.
  • the porous medium is initially opaque the migration of the water into the pores may cause the pores medium to become substantially transparent, thereby resulting in a visually observable change.
  • the porous medium may have a colored background located therebelow, so that when the porous medium becomes substantially transparent the background color shows through and can be observed from above as a visible color change.
  • the porous medium may be colored by the migration of the dye solution into its pores, resulting in a visually observable change.
  • the fluid migration conduit may employ capillary action to draw water toward the color changing mechanism.
  • the indicator may further comprise a water reservoir serving to drive the migration of fluid through the color changing mechanism; and wherein the volume of the reservoir determines the extent of migration through the color-changing mechanism.
  • the water reservoir may be sufficiently large to drive the migration after only one contact of the water filter with water, so that one filling of the water filter is sufficient to drive the indicator for the entire lifetime of the water filter cartridge.
  • the reservoir is sufficiently small so as to only drive the migration by a small amount, so as to implement a relationship between the number of fillings of the water filter and the extent of the migration, so that the indicator substantially determines the effective lifetime of the water filter by also taking into consideration the number of times that the water filter is refilled.
  • the device may further comprise a partially transparent mask located above the conduit second end, the mask presenting the underlying color change of the the color-changing mechanism via graphic indicia located on the mask by one or more transparent windows enabling the underlying color change to show through.
  • the color changing mechanism displays a gradual advance of the color change over time.
  • the device may incorporate a scale to display the elapsed time.
  • the invention also relates to a drinking-water filter cartridge incorporating the filtration media and indicator as described above.
  • a substantially lifetime indicator device for a water filter comprising: A small water reservoir for capturing water at the time that a water filter is filled. An element (e.g. thread) drawing the water into contact with a pad containing a zinc salt so that the zinc ions located on the pad are carried into solution. A diffusion strip formed by dipping paper in sol-gel doped with the chelating agent PAR.
  • the reservoir element and strip positioned so that the solution slowly diffuses through the diffusion strip where the zinc ions undergo a chelation reaction with the PAR, yielding a color change from yellow to red, and so that the diffusion front of the color change slowly proceeds along the paper strip and is viewed via a mask containing indicia that relate the progress of the diffusion front to the effective lifetime of the water filter.
  • a substantially lifetime indicator device for a water filter comprising: A small water reservoir for capturing water at the time that a water filter is filled. A thread drawing the water into contact with a paid containing a dye so that the dye is carried into solution. A diffusion strip consisting of a micro-porous material. And wherein the reservoir, thread and diffusion strip are positioned so that the solution slowly diffuses through the diffusion strip so that the diffusion strip undergoes a color change due to the absorption of the dye, and so that the diffusion front of the color change slowly proceeds along the diffusion strip and is viewed via a mask containing indicia that relate the progress of the diffusion front to the effective lifetime of the water filter.
  • the invention also relates to a substantially lifetime indicator device for a drinking-water filter wherein the indicator comprises a liquid which migrates slowly through a porous media resulting in an observed color change, and wherein the appearance of the color change corresponds to the intended effective lifetime of the water filter.
  • the device may incorporate a self-contained but independent water reservoir which may be manipulated in such a manner as to bring the contained water into contact with the timing mechanism in such a manner as to actuate the timing function.
  • FIGURE 1 shows a filter cartridge with a substantially lifetime indicator recessed into the top of the filter cartridge;
  • FIGURE 2 shows a cross-sectional view of the substantially lifetime indicator;
  • FIGURE 3 shows a laminated package containing a slow liquid-migration mechanism;
  • FIGURE 4 shows a graph of the progress of a diffusion front along a micro- porous strip under different filling regimes
  • FIGURE 5 shows a preferred embodiment for displaying the progress of the substantially lifetime indicator
  • FIGURE 6 shows a filter cartridge with integral substantially lifetime indicator mounted inside a jug-type water filtration vessel
  • FIGURE 7 shows the parts and assembly of a linear substantially lifetime indicator and its preferred attachment to a drinking water filter cartridge used in a bottle;
  • FIGURE 8 shows the parts and assembly of a round substantially lifetime indicator and its preferred attachment to a drinking water filter cartridge used in a bottle
  • FIGURE 9 shows the preferred attachment location of a linear or round substantially lifetime indicator to the side of a drinking water filter cartridge used in a pitcher
  • FIGURE 10 shows a self contained substantially lifetime indicator for assembly to an independent object, such as a food storage container, in which the indicator is actuated by rupturing the membrane separating the water reservoir from the timing mechanism and an elapsed timing scale in weeks is also shown.
  • FIGURE 1 An exemplary water filter cartridge according to the present invention is shown in FIGURE 1.
  • the filter cartridge 10 contains a recessed section 12 in its upper surface 14 suitable for the insertion of the substantially lifetime indicator 13.
  • the perforations 16 which admit water to the substantially lifetime indicator 13 together with indicia showing the status of said indicator.
  • indicia will include a clear end-point 18 and preferentially also graphic symbols or alphanumeric indicia showing the gradual advance to said endpoint 18.
  • at least part of the upper surface of the substantially lifetime indicator 13 is transparent, enabling a color change in the underlying mechanism to be viewed through said transparent sections.
  • the end-point 18 and indicia 19 are transparent and a diffusion strip is mounted underneath them. As a color-changing diffusion front advances along said strip the indicia are then seen to change color over time.
  • the starting color of the indicia is the same as the background color of the lifetime indicator 13, and thus any color change of the indicia 19 and end-point 18 stands out clearly.
  • the final color of the end-point 18 is red; a transition to red being readily understandable as a sign that the filter cartridge should be replaced. Referring now to FIGURE 2, there is seen an exemplary embodiment of the cross-section of the top of the filter cartridge 20 where the lifetime indicator 21 has been inserted into a recess in the upper surface.
  • Said indicator comprises a fluid migration conduit for facilitating fluid migration therein, wherein said conduit has a first end and a second end, wherein said first end has an aperture for receiving fluid, and wherein said second end consists of a transparent section for allowing an external viewer to observe a color change therein; and color-changing means which are activated by water and positioned within said conduit; whereby, when water comes into contact with said indicator, a portion thereof enters said first end, thereby activating said color changing means which can be viewed at said second end after a predetermined time interval.
  • this indicator is initiated and runs thereafter by the simple contact of water with the water filter cartridge, and therefore does not require an explicit action by the user specifically to trigger the activity of said indicator.
  • said indicator preferentially comprises perforations 22 for admitting water to said conduit, a reservoir 24 for said water, and a laminated package 26 containing the said color changing means.
  • the change of color over time is viewed via indicia on an upper surface 28 which is at least partially transparent.
  • the filter cartridge comes in contact with water, and some of this water enters the perforations 22 and fills the reservoir 24.
  • the water in this reservoir is in direct contact with the edge of the laminated package 26 and serves to drive the slow liquid-migration mechanism within this package.
  • FIGURE 3 there is seen an exemplary embodiment of a slow liquid-migration mechanism where the migration mechanism used is diffusion through a micro-porous medium.
  • the diffusion medium is a doped sol-gel and the color changing reaction system is a chelation reaction.
  • the mechanism comprises a laminated package 30 containing a zinc-impregnated paper pad 32, a doped sol-gel strip 34 and a thread 36.
  • the thread 36 serves to introduce water via capillary action into the package 30 where it wets the impregnated paper pad 32 thereby dissolving the zinc ions.
  • the capillary action ensures that the dissolved reagent is unable to leach out of the laminated package 30 and potentially enter the drinking water.
  • the resulting zinc solution then proceeds to diffuse slowly through the doped sol-gel strip 34, reacting as it proceeds with the dopant; in this case the chelating agent 4-(2-pyridylazo)resorcinol monosodium salt, hereinafter PAR, is used to yield a color change from yellow to red.
  • the chelating agent 4-(2-pyridylazo)resorcinol monosodium salt hereinafter PAR
  • PAR 4-(2-pyridylazo)resorcinol monosodium salt
  • the support material for the doped sol-gel is standard laser quality paper (80g/m 2 ) paper which is cut into about 1 cm by about 2.5 cm strips and dip coated with the PAR-doped sol-gel.
  • the preparation of the doped sol-gel liquid is performed as follows: About a 5 ml solution of tetraethoxysilane (TEOS) is added to a stirred solution consisting of about 10 ml ethanol, 1 .6 ml triply distilled water, about 4 drops of concentrated (33%) hydrochloric acid (HCI) and about 0.1 g of PAR.
  • TEOS tetraethoxysilane
  • the impregnated paper pad consists of Whatman No.1 filter paper which is dipped into about an 1.5 M methanol or aqueous solution of ZnCl2, dried at about 60°C and then cut into squares of about 0.75 cm by 0.75 cm.
  • This choice of reaction system in the preferred embodiment is especially advantageous as, even if the package were to split open, no pollution of the drinking water would occur as zinc ions are an acceptable constituent of drinking water at levels up to about 5 mg/l and the PAR remains entrapped as a dopant within the sol-gel matrix and therefore can not leach out.
  • the lamination is performed at about 150 degrees C with about a 250 micron laminate. Before lamination a cotton thread (or other thread with like wicking or related properties), like thread 36, is placed across the zinc pad that is positioned on one end of the sol-gel paper strip.
  • FIGURE 8 there is seen an additional preferred embodiment which utilizes the advantage of a capillary wicking mechanism mentioned earlier, in a geometric configuration which is less costly in high speed manufacture.
  • the three components described in reference to FIGURE 3 are still employed, but in this case exhibit radial rather than axial symmetry.
  • the wicking thread becomes a ring of porous material which serves the same function.
  • the zinc impregnated pad becomes a disk of impregnated material which serves the same function.
  • the zinc impregnated pad becomes a disk of impregnated material, and the doped sol-gel strip becomes a disk of doped sol-gel paper.
  • liquid- migration media and a number of alternative reaction mechanisms are feasible.
  • a number of micro-porous media enable a slow-diffusion effect to be implemented; examples include EmporeTM particle-filled Teflon (available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota, USA), silica gel or a micro- porous polymeric material such as TeslinTM (available from PPG Industries Inc., Pittsburgh, Pennsylvania, USA).
  • Other materials suitable for a migration media are cellulose-based materials such as paper where, without wishing to be bound by theory, both capillary action and diffusion would contribute to the migration effect.
  • alternative chelating agents such as 1 , 10 phenanthroline, zincon, or 2,2'-biquioline (cupron) can be incorporated or doped into the porous medium while alternative liquid reagents that would migrate into the porous medium can include solutions of metal ions such as copper ions, iron ions and calcium ions.
  • suitable pH indicators include bromothymol blue, methyl red, cresol red can be incorporated or doped into the porous medium
  • suitable acid/base liquid reagents that would migrate into the porous medium can include the acids: hydrochloric acid, citric acid and ascorbic acid and the bases: sodium hydroxide and sodium hydrogen phosphate.
  • redox indicators such as n- phenylanthrancilic acid or a bleachable dye can be incorporated or doped into the porous medium while alternative liquid reagents that would migrate into the porous medium can include solutions of bleaching powder or of vanadium salts.
  • an enzyme such as a lipase can be incorporated or doped into the porous medium together with a pH indicator while a liquid substrate such as tricaproin would migrate into the porous medium.
  • the reaction product of the enzymatic reaction of a lipase and tricaproin is caproic acid; said acid producing a color shift in the pH indicator.
  • a colorless porous medium with no embedded reagents can be slowly penetrated by a water-soluble dye which is dissolved by the incoming water.
  • a nontransparent porous medium can become transparent upon penetration by water, thereby revealing a color background placed behind the porous medium.
  • a further preferred embodiment based on the same physical layout as that shown in FIGURE 3 uses a non-reactive system to implement the lifetime indicator, where the migration mechanism used is the slow diffusion of a dye through a commercially available micro-porous medium.
  • the diffusion medium is the highly-filled micro-porous polyolefin plastic TeslinTM
  • the dye is red food coloring (available from McCormick & Co., Inc., Hunt Valley, MD, USA).
  • the mechanism comprises a laminated package containing a dye-impregnated paper pad, a TeslinTM strip and a thread. The thread serves to introduce water via capillary action into the package where it wets the impregnated paper pad, thereby dissolving the dye.
  • drawing the liquid into the laminate package could also be performed by other means such as strands of cotton wool, filter paper, blotting paper, or small pin-prick holes made in the lower section of the laminate in the area of the metal ion.
  • said capillary action ensures that the dissolved dye is unable to leach out of the laminated package and potentially enter the drinking water.
  • the resulting colored solution then proceeds to diffuse slowly through the TeslinTM strip, changing the color of said strip from white to red. As the diffusion front proceeds along the TeslinTM strip, the sharp color change which results is clearly seen from above via the partially transparent indicia mounted above the strip.
  • a further preferred embodiment involves the use of a significantly smaller reservoir 24 or, advantageously, no reservoir so that extent of the liquid migration performed per filling of the vessel will be limited.
  • the lifetime indicator will function as an integrated time-volume indicator in which the lifetime of the indicator will be determined by some function of both time and filling rate.
  • the zinc-impregnated paper pad 32 serves as a miniature reservoir collecting sufficient water at the time of each filling to drive the migration a limited distance.
  • FIGURE 4 there is seen a graph showing the progress of a diffusion front in terms of the extent to which the zinc-impregnated paper pad 32 is in contact with water.
  • the line on the graph marked 'continuous' represents the case in which the use of a sufficiently large reservoir 24 ensures that the zinc- impregnated paper pad 32 is continuously in contact with water via the thread 36.
  • the line on the graph marked 'twice a day' represents the case in which only the zinc-impregnated paper pad 32 stores water and this pad is wetted twice per day, resulting from two fillings of the water filtration vessel per day.
  • the line on the graph marked 'once a day' represents the case in which only the zinc-impregnated paper pad 32 stores water and this pad is wetted once per day, resulting from one filling of the water filtration vessel per day.
  • the line on the graph marked 'every two days' represents the case in which only the zinc-impregnated paper pad 32 stores water and this pad is wetted once every two days, representing one filling of the water filtration vessel every second day.
  • the upper surface 50 of the lifetime indicator comprises a background color together with one or more transparent sections.
  • this surface is prepared by printing the required background color on a laminate while leaving clear any desired indicia such as: (a) an end-point 52 to show when the lifetime indicator has reached its end, and (b) appropriately designed indicia 51 to show the progress of the indicator towards said end-point 52.
  • the lower surface of the laminated package 54 is shown together with the liquid-migration medium layer. As the migration or diffusion front 57 progresses along said medium, a color change is generated in the area 56 behind the front.
  • this color change is from yellow to red, and thus the area 56 behind the diffusion front 57 is red and the area 58 ahead of said front is yellow.
  • the resulting view 59 shows the progress of the diffusion front as a red area progressively creeping along an arrow-like shape, while the remainder of the arrow and the end-point remain yellow. Later in time, when the end-point has also become red, the need to change the filter cartridge is clearly signaled.
  • this front can serve to turn a non-transparent medium to a transparent one.
  • a second backing color is required beneath said medium in order that this second color will show through as the diffusion front progresses.
  • indicia showing the progress of the diffusion front may also be employed, including but not limited to various arrows, curves, lines and points of different sizes.
  • FIGURE 6 there is seen a jug-type water filtration vessel
  • the filter cartridge 66 On filling of the vessel 60 with water, the filter cartridge 66 becomes temporarily submerged beneath the water and this action causes the lifetime indicator 69 to admit water and thus start its timing function.
  • an exemplary linear indicator is made from parts shown.
  • a thread 1 , pad 2, and strip 3 are sealed between two laminating sheets 4 to make an assembly 5.
  • the pad 2 preferably slightly overlaps the strip 3 and the thread I is the only part that extends to the edge of the assembly 5.
  • the thread 1 permits water to reach the pad 2.
  • a label with an opening or transparent window affixed to the assembly 5 is shown as 6.
  • An exemplary filter cartridge 7 is shown in side and bottom view with labeled filter assembly 6 affixed to the side near the top.
  • an exemplary round indicator is made from parts shown.
  • a pad 8 and strip 9 are sealed between two laminating sheets 10 to form an assembly 11.
  • the central hole in pad 8 is slightly smaller than the strip 9 so there is a slight overlap when they are assembled.
  • a cut 12 into the edge of the assembly 11 permits water to reach the pad 8.
  • a label with an opening or transparent window affixed to the assembly is shown as 13.
  • An exemplary filter cartridge 7 is shown in side and bottom view with labeled filter assembly 13 affixed to the bottom.
  • an exemplary jug-type water filtration vessel 19 is shown side view with an exemplary attachment location 20 for a linear or round indicator.
  • the filtration vessel 19 has a spout 14, handle 17, cap 15, reservoir 16, and cartridge 18.
  • the exemplary attachment location 20 for the round or linear indicator is on the side of the cartridge 18 near the bottom.
  • the indicator is always visible through the side of a transparent filtration vessel.
  • the indicator is submerged when the filtration vessel is filled and may remain submerged until the level of water in the filtration vessel drops below the indicator location 20.
  • FIGURE 10 there is shown side and top views of an alternative method of wetting the pad 7. These views show the components of the invention and also show the invention assembled 11.
  • the components shown are the label 1 , the window in the label 2, the text on the label 3 which may include indicia showing the passage of time, the top laminate 4, with the empty blister 5, and the water filled blister 6.
  • the bottom figure on the side view and the top view is the assembled invention 11.
  • This assembly shows the empty blister 5, the water filled blister 6 the adhesive backing 10, the window in the label 2 through which can be seen part of the strip 8, Also shown in the assembly is the text on the label 3 which may include indicia showing the passage of time.
  • the function of the empty blister 5 and the water filled blister 6 is to enable the user to initiate timing by pressing on the water filled blister 6 until it ruptures and forces water into the empty blister 5 which as assembled is in direct contact with the pad 7.
  • the empty blister 5 is now water filled and in contact with the pad 7 so that said pad 7 is now wetted and will initiate timing. Further, in this deign no undesirable forces are exerted.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Water Treatment By Sorption (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)

Abstract

L'invention concerne un indicateur et un procédé servant à indiquer l'expiration de la vie utile prédéterminée d'un filtre à eau, au moyen d'un changement de couleurs simple mais très efficace. L'eau migre dans un mécanisme de changement de couleurs doté d'un milieu poreux et provoque la réaction de premier et second réactifs, ce qui se solde par un changement de couleurs. Le système de réaction entre les réactifs peut être sélectionné parmi le groupe reposant essentiellement sur la chélation d'un ion métallique par un agent chélateur, sur la réaction d'un acide/d'une base avec un indicateur de pH, sur la réaction d'un électrodonneur/d'un électroaccepteur avec un indicateur d'oxydoréduction, et sur une réaction enzymatique entre un enzyme et un substrat. Ledit mécanisme de changement de couleurs affiche une avance graduelle du changement de couleur au cours du temps, et peut comporter une échelle afin d'afficher le temps écoulé. On peut utiliser un masque contenant des indices d'échelle pour rendre compte de la progression de la diffusion en matière de durée de vie utile prédéterminée du filtre.
PCT/US2001/018870 2000-06-23 2001-06-13 Indicateur de duree de vie d'un filtre a eau Ceased WO2002000552A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001268342A AU2001268342A1 (en) 2000-06-23 2001-06-13 Water-filter lifetime indicator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US59956500A 2000-06-23 2000-06-23
US09/599,565 2000-06-23

Publications (2)

Publication Number Publication Date
WO2002000552A2 true WO2002000552A2 (fr) 2002-01-03
WO2002000552A3 WO2002000552A3 (fr) 2002-06-20

Family

ID=24400141

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2001/018870 Ceased WO2002000552A2 (fr) 2000-06-23 2001-06-13 Indicateur de duree de vie d'un filtre a eau

Country Status (2)

Country Link
AU (1) AU2001268342A1 (fr)
WO (1) WO2002000552A2 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1671931A1 (fr) * 2004-12-17 2006-06-21 Strix Limited Cuve de traitment d'eau et cartouches associées
WO2008044230A1 (fr) 2006-10-08 2008-04-17 H2Q Water Industries Dispositif de surveillance de filtre pour fluide
WO2012150295A1 (fr) * 2011-05-03 2012-11-08 BSH Bosch und Siemens Hausgeräte GmbH Dispositif filtrant et procédé pour purifier de l'eau
US8454826B2 (en) 2002-08-07 2013-06-04 Strix Limited Water treatment apparatus
US9034192B2 (en) 2009-09-09 2015-05-19 Strauss Water Ltd. Liquid filter device
CN107323808A (zh) * 2017-07-04 2017-11-07 厦门麓山新材料科技有限公司 一种定时装置及使用方法
US10046981B2 (en) 2015-03-23 2018-08-14 Strauss Water Ltd. Water filter and assembly thereof
US10124284B2 (en) 2014-07-25 2018-11-13 Sata Gmbh & Co. Kg Filter system and holder therefor
US12138571B2 (en) 2019-09-25 2024-11-12 Sata Gmbh & Co. Kg Seal arrangement for a filter, in particular a compressed air filter, and filter element for a filter
US12311307B2 (en) 2019-09-25 2025-05-27 Sata Gmbh & Co. Kg Filter element for use in a filter and filter having a filter element

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NL286850A (fr) * 1961-12-18 1900-01-01
US4292916A (en) * 1979-06-18 1981-10-06 Micro-Circuits Company Timer and storage condition indicator
CH642177A5 (de) * 1979-07-13 1984-03-30 Thomas Allmendinger Verfahren zur ueberwachung der temperaturgeschichte eines gutes, indikator zur ausfuehrung des verfahrens und anwendung des verfahrens.
DE3210907C2 (de) * 1982-03-25 1984-07-19 Schwan-Stabilo Schwanhäußer GmbH & Co, 8500 Nürnberg Indikator für die Anzeige einer Zeit/Temperatur-Belastung
WO1989000680A1 (fr) * 1987-07-09 1989-01-26 Thomas Allmendinger Dispositif indicateur de la position d'un fluide qui se repand dans un corps
US5114570A (en) * 1989-08-14 1992-05-19 Teledyne Industries Inc. Water filter cartridge
US5699326A (en) * 1990-01-04 1997-12-16 Temtec, Inc. Time indicator
CA2014409A1 (fr) * 1990-04-11 1991-10-11 Mark Adrian Jozefowicz Indicateurs de temps ecoule liquides et (ou) actives par la temperature, utiles particulierement pour indiquer le degre de cuisson d'aliments
GB9106199D0 (en) * 1991-03-22 1991-05-08 Pilkington Controlled Release Elapsed time indicator
FR2684446B1 (fr) * 1991-12-03 1996-02-02 Cool Sarl Indicateur de conservation pour produits congeles ou refrigeres et procede de mise en óoeuvre de cet indicateur.

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8454826B2 (en) 2002-08-07 2013-06-04 Strix Limited Water treatment apparatus
EP1671931A1 (fr) * 2004-12-17 2006-06-21 Strix Limited Cuve de traitment d'eau et cartouches associées
WO2008044230A1 (fr) 2006-10-08 2008-04-17 H2Q Water Industries Dispositif de surveillance de filtre pour fluide
US8790512B2 (en) 2006-10-08 2014-07-29 Strauss Water Ltd. Fluid filter monitoring device
US9034192B2 (en) 2009-09-09 2015-05-19 Strauss Water Ltd. Liquid filter device
WO2012150295A1 (fr) * 2011-05-03 2012-11-08 BSH Bosch und Siemens Hausgeräte GmbH Dispositif filtrant et procédé pour purifier de l'eau
US10124284B2 (en) 2014-07-25 2018-11-13 Sata Gmbh & Co. Kg Filter system and holder therefor
US10046981B2 (en) 2015-03-23 2018-08-14 Strauss Water Ltd. Water filter and assembly thereof
CN107323808A (zh) * 2017-07-04 2017-11-07 厦门麓山新材料科技有限公司 一种定时装置及使用方法
US12138571B2 (en) 2019-09-25 2024-11-12 Sata Gmbh & Co. Kg Seal arrangement for a filter, in particular a compressed air filter, and filter element for a filter
US12311307B2 (en) 2019-09-25 2025-05-27 Sata Gmbh & Co. Kg Filter element for use in a filter and filter having a filter element

Also Published As

Publication number Publication date
WO2002000552A3 (fr) 2002-06-20
AU2001268342A1 (en) 2002-01-08

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