EP0705206A1 - Filtre a the pour machines a cafe automatiques - Google Patents

Filtre a the pour machines a cafe automatiques

Info

Publication number
EP0705206A1
EP0705206A1 EP94921189A EP94921189A EP0705206A1 EP 0705206 A1 EP0705206 A1 EP 0705206A1 EP 94921189 A EP94921189 A EP 94921189A EP 94921189 A EP94921189 A EP 94921189A EP 0705206 A1 EP0705206 A1 EP 0705206A1
Authority
EP
European Patent Office
Prior art keywords
brew chamber
tea
filter pack
filter
water
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.)
Withdrawn
Application number
EP94921189A
Other languages
German (de)
English (en)
Inventor
Dana Paul Gruenbacher
Michael Joseph Kupneski
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.)
Procter and Gamble Co
Original Assignee
Procter and Gamble Co
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 Procter and Gamble Co filed Critical Procter and Gamble Co
Publication of EP0705206A1 publication Critical patent/EP0705206A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J31/00—Apparatus for making beverages
    • A47J31/06—Filters or strainers for coffee or tea makers ; Holders therefor
    • A47J31/0615—Filters or strainers for coffee or tea makers ; Holders therefor with special arrangements for making tea or the like, e.g. where the infusion liquid is kept a certain time in the filter before flowing out
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D85/00—Containers, packaging elements or packages, specially adapted for particular articles or materials
    • B65D85/70—Containers, packaging elements or packages, specially adapted for particular articles or materials for materials not otherwise provided for
    • B65D85/804—Disposable containers or packages with contents which are mixed, infused or dissolved in situ, i.e. without having been previously removed from the package
    • B65D85/8043—Packages adapted to allow liquid to pass through the contents
    • B65D85/8061—Filters

Definitions

  • This invention relates to low cost, high efficiency, disposable tea filter packs to be used with most commercial drip coffee makers.
  • a typical coffee brew machine comprises a base member with a heater element used to support a glass coffee pot and a coffee filter holder attached to the base in the position above the coffee pot.
  • the coffee filter holder is typically frusto-conical in shape with one or more central apertures through the bottom wall and is designed to receive a disposable coffee filter.
  • Many such holders also contain a wire basket or ribbed inner surface within the filter holder to prevent the filter from pressing against the solid outer wall of the filter holder. This prevents the moistened filter from forming a liquid impervious seal with the solid outer wall, and ensures that the entire surface of the filter is available for filtering purposes.
  • the coffee filter is normally fabricated from porous paper and is also frusto-conical in shape so as to be received within the coffee filter holder.
  • the coffee filter will be placed in the coffee filter holder and a measured amount of roast and ground coffee is placed in the bottom portion of the coffee filter.
  • a measured quantity of hot water is then directed into the interior of the coffee filter onto the ground coffee.
  • the coffee expands and floats up in the filter increasing the coffee/water contact area. The water will then percolate through the ground coffee and flow through the bottom and lower side portions of the porous coffee filter and through the coffee filter holder apertures down into the coffee pot.
  • Coffee manufacturers have substantially eliminated the pot-to-pot brew strength inconsistencies arising from poor measurement of coffee by the operator by providing unitized pouches, each containing a predetermined volume of roast and ground coffee suitable for brewing a single pot of coffee of reasonably consistent strength from one pot to the next.
  • unitized pouches add to cost and disposal problems due to the need for additional packaging equipment and material.
  • they do not eliminate the messiness problems normally associated with bulk coffee/paper filter systems, since loose grounds and filters must still be disposed of.
  • Corresponding unitized tea pouches have been developed by tea manufacturers, but these fare no better than the coffee pouches in addressing these drawbacks.
  • coffee filter packs have been designed in an attempt to overcome some disadvantages from this method.
  • Most of these coffee filter packs are made with heat sealable filter paper or from non-woven polyester, polypropylene, polyethylene or a combination thereof. These materials are typically more expensive than conventional filter paper, which is typically comprised almost entirely of wood fiber.
  • these filter packs are usually circular or square in shape and simply cover the bottom wall of the coffee filter holder. These filter packs are often improperly positioned in the coffee filter holder resulting in inconsistent brew strength from pot-to-pot, since their shape and materials of construction allow water to escape around the sides and through the coffee filter pack without sufficient exposure to all of the coffee contacted in the brew chamber of the filter pack. This results in poor coffee extraction.
  • tea manufacturers have developed corresponding filter packs for their products. Unfortunately, these tea filter packs incorporate the same problems which plague the coffee filter packs, and also additional problems which arise due to the differences in brewing characteristics between coffee and tea.
  • tea leaves absorb water and expand to a much greater extent than roast and ground coffee. Because of this degree of expansion, tea filter packs which allow no more room for expansion than typical coffee filter packs may in fact rupture if the expanded volume of the tea leaves is greater than the maximum available volume within the tea filter pack. This results in pieces of tea leaves floating loosely in the brewed tea, and likely passing down through the filter holder and into the finished product, an undesirable occurrence.
  • Ground coffee also generally contains a much greater proportion of fine, dust-like paniculate material than tea leaves which have been crushed or shredded.
  • coffee tends to pack more tightly and presents a much greater obstacle to the passage of water than does a similar quantity of tea leaves.
  • Wet coffee particles also exhibit a much greater tendancy to clog the pores of porous filters than tea leaves. This clogging tendancy is in large part the reason coffee brewing machines incorporate a wire basket or ribbed inner surface inside the filter holder, i.e., to maximize the available filtering area.
  • Tea filter packs thus relying on the flow rate of the coffee maker to control brewing time will not permit the tea to steep in the hot water for a sufficient amount of time for good extraction, as water will tend to pass too rapidly downwardly through the entire lower surface of the tea filter pack and out through the bottom of the filter holder. This results in poor extraction efficiency and poor utilization of the tea leaves.
  • Applicants have learned that in order to minimize brew time, maximize flavor solids extraction and make a good pot of tea, a substantial portion of the hot water directed into the filter pack must contact the tea in the brew chamber after a substantially steady state brewing condition has been established within the brew chamber, i.e., after the brew chamber has been completely flooded with the incoming hot water so that the chamber expands to its maximum volume and allows substantially all of the tea leaves contained therein to loosely float within the chamber.
  • Applicants have further learned that this is preferably done by providing a substantially water impermeable side wall having a height which is sufficient to retain at least enough water to permit complete immersion of the brew chamber when the brew chamber is in its fully expanded condition in combination with inlet and discharge flow rates into and out of the brew chamber that will cause the water to build up and puddle the tea inside the brew chamber.
  • the failure to properly control the inlet and outlet flow rates and the failure to provide a substantially water impermeable side wall having a height which is sufficient to retain at least enough water to completely immerse the brew chamber when the brew chamber is in its fully expanded condition will allow much of the water to flow directly through or around the brew chamber of the prior art filter pack without ever contacting any of the tea leaves therein.
  • the brew chamber must be large enough to allow the tea leaves enough room to expand and float while water is building up in the brew chamber in order to achieve sufficient tea/water contact, i.e., to achieve a steady state brewing condition. This helps to prevent channeling of the water through the filter pack without sufficient tea/water contact. Minimizing channeling is important, since channeling of the hot water directly through the brew chamber without sufficient tea contact results in poor and inconsistent tea flavor solids extraction.
  • the present invention achieves the desired results by providing an improved tea filter pack of a generally frusto-conical shape, made of inexpensive flexible material, but having a substantially vertically extending conformable side wall which is substantially impermeable to water.
  • the brew chamber is constructed so that the flow rate of liquid into the brew chamber is greater than the flow rate of liquid out of the brew chamber.
  • the filter pack is preferably constructed so that the flow rate at which the coffee maker delivers the hot brewing water to the filter pack is equal to or less than the rate at which water passes into the brew chamber and greater than the rate at which brewed tea flows out of the brew chamber.
  • the substantially water impermeable vertically extending continuous side wall of improved tea filter packs of the present invention is comprised of flexible material so that it can automatically conform to the porous filter support means in the coffee maker regardless of how much care is exercised by the operator in placing the filter pack in the filter support means.
  • the substantially water impermeable side wall must be high enough after placement of the filter pack in the filter support means to capture enough of the incoming hot brewing water so that a substantially steady state brewing condition is established within the brew chamber relatively early in the brewing cycle, i.e., a flooded condition in which the brew chamber has been expanded to substantially its maximum volume by the incoming hot water.
  • the brew chamber of the filter pack must be large enough to allow the tea leaves to expand and loosely float within the flooded chamber in order to establish a substantially steady state brewing condition within the brew chamber.
  • the substantially water impermeable side wall of the filter pack must extend upwardly a vertical distance which is at least equal to the maximum vertical height which can be assumed the brew chamber in a fully flooded condition. Otherwise flooding of the brew chamber will not take place.
  • the filter pack may in fact rupture during the brewing operation.
  • the vertical height of the substantially water impermeable side wall is greater than the foregoing minimum to prevent overflow of the incoming hot water from the coffee maker (recall that the discharge flow rate of brewed tea from the brew chamber is normally less than the incoming flow rate of hot water to the filter pack to permit flooding of the brew chamber).
  • the maximum height of the substantially water impermeable side wall is, of course, limited by the vertical height of the filter support means used on the coffee makers which are to employ the filter packs in question. If the filter pack extends vertically beyond the uppermost edge of the filter support means, it is likely to cause interference when attaching the filter support means to the coffee maker.
  • a particularly preferred embodiment of the present invention uses two layers of inexpensive porous filter paper secured to one another about their perimeters by a layer of polymeric material such as polyethylene which is melted during the assembly of the filter to bond the two filter paper layers together.
  • the layer of polymeric material can serve two purposes. First, it can act as an adhesive for bonding one layer of filter paper to the other in order to contain the tea leaves within a region, which is referred to herein as a brew chamber. Second, it can direct the brewing water through the mass of tea leaves by making the substantially vertically extending conformable side walls and a portion of the bottom of the brew chamber substantially impermeable to water.
  • the maximum volume of the brew chamber formed between the unsecured portions of the two layers of filter paper is preferably between about 100 percent and about 400 percent greater than the volume of the dry tea leaves contained therein to allow the tea leaves to expand and float within the chamber during steady state brewing conditions.
  • the layer of polymeric material would preferably be cut into a generally annular shape which would extend over the bottom layer of filter medium, except in a portion of the area coinciding with the brew chamber, where the flow of brewed tea is desired. This, in essence, creates a funnel which not only permits flooding of the brew chamber with water, but which also directs the incoming hot brewing water through the brew chamber of the filter pack.
  • a hydrophobic adhesive which allows the use of relatively inexpensive non-heat sealable filter mediums, such as paper, may alternatively be employed to construct other embodiments of the present invention.
  • This hydrophobic adhesive would preferably be applied everywhere on the bottom layer of filter medium, except in a portion of the area coinciding with the brew chamber, where the flow of brewed tea is desired. This likewise creates a funnel which not only permits flooding of the brew chamber with water, but which also directs the incoming hot brewing water through the brew chamber of the filter pack.
  • the porosity and size of the porous area of the bottom filter medium, where the polymeric material or adhesive is not applied, controls the discharge flow rate of the brewed tea out of the brew chamber of the filter pack.
  • the porosity and size of that centrally located portion of the top filter medium which is not bonded to the bottom filter medium controls the flow rate of incoming hot water into the brew chamber until such time as the brew chamber becomes flooded.
  • the rate at which water can thereafter enter the flooded brew chamber is controlled by the discharge flow rate of brewed tea from the brew chamber.
  • the individual coffee maker being used determines the total volume of concentrated tea product brewed in each batch and the flow rate of water delivered to the filter pack during the brewing cycle.
  • a portion of the hot water which ends up in the finished batch is deliberately routed so as to completely bypass the filter pack.
  • concentrated brewing of the tea is carried out only by that portion of the hot water which is directed through the filter pack.
  • the concentration of the brewed tea exiting the filter pack is then diluted to the level desired by the consumer by the hot water which bypassed the filter pack when the tea exiting the brew chamber is collected in the pot located beneath the filter support means.
  • Systems of the aforementioned type are typically employed to reduce the overall cycle time required to brew a pot of tea.
  • the consumer dilutes the concentrated tea produced by the coffeemaker with the requisite amount of water to the desired concentration.
  • cool or cold water is used for dilution so that the melting time of the ice added is greatly extended in comparison with a scenario in which ice is added directly to freshly brewed, hot tea.
  • Figure 1 is a simplified perspective view of an improved tea filter pack of the present invention.
  • Figure 2 is a simplified, cross-sectional view taken along section line 2-2 of Figure 1.
  • Figure 2A is a simplified, cross-sectional view similar to that of Figure 2, but showing the filter pack in the filter support means of a coffee maker with the brew chamber of the filter pack in a fully expanded, steady state brewing condition.
  • Figure 3 is a flattened planar view of bottom layer 10 of the filter pack shown in Figure 1.
  • Figure 4A is a simplified perspective view of male die 60, female die 70, and a flat tea filter pack of the type shown in Figure 1 prior to closure of the dies upon one another.
  • Figure 4B is a simplified perspective view of the male and female dies of Figure 4A in their closed position with the tea filter pack shown in Figure 4A between them.
  • Figure 4C shows the formed tea filter pack of Figure 1 as it is emerging from the female die shown in Figures 4 A and 4B.
  • Figure 5 is a simplified, cross-sectional view analogous to Figure 2 of an alternative embodiment of an improved tea filter pack according to the present invention.
  • FIG 1 shows an improved tea filter pack 1 of the present invention.
  • the features of the filter pack can best be described by looking at Figure 2, which is a simplified cross- sectional view taken along section line 2-2 of Figure 1.
  • the tea filter pack comprises a bottom layer 10 comprised of a flexible porous material and a top layer 20 also comprised of flexible porous material.
  • the inner face 11 of bottom layer 10 is joined to the inner face 21 of top layer 20 about its perimeter by a hydrophobic adhesive coating 30.
  • the hydrophobic adhesive coating makes the porous layers substantially impervious to water wherever it is applied.
  • bottom layer 10 and hydrophobic adhesive 30 creates a flexible and conformable side wall 25 which is substantially impervious to water. Because the combination of bottom layer 10 and hydrophobic adhesive 30 together form a substantially water impermeable side wall, top layer 20 need not extend all the way to the outer perimeter of bottom layer 10 to render side wall 25 substantially impermeable to water. Alternatively, the bottom layer 10 could be smaller and the top layer 20 could be rendered water impermeable by coating its outer perimeter with a hydrophobic adhesive 30. Hydrophobic adhesive coating 30 is extended along the inner face 11 of bottom layer 10 to form an annular ring 15 which coincides with the interior of brew chamber 40, leaving an uncoated permeable circular area 13 at the center of bottom layer 10.
  • the distance to which annular ring 15 extends into brew chamber 40 controls the permeable area 13 and hence the discharge flow rate at which brewed tea is allowed to pass through the bottom layer 10.
  • the water flow rate into brew chamber 40 is controlled by the area of the unsecured central portion 23 of top layer 20. Assuming layers 10 and 20 are comprised of similar material, controlling the size of the permeable areas on the top and bottom layers for a given porosity controls the relative flow rates of liquids through the layers.
  • Figure 2A is a simplified, cross-sectional view similar to that of Figure 2, but showing the filter pack in the filter support means 75 of a coffee maker with the brew chamber of the filter pack in a fully expanded, steady state brewing condition.
  • a wire basket 99 which is present in the filter holder of many coffee makers. This wire basket is designed to prevent a filter from pressing against the solid outer wall of the filter holder. This in turn prevents the moistened filter from forming a liquid impervious seal with the solid outer wall, and ensures that the entire surface of a coffee filter is available for filtering purposes.
  • Some coffee makers alternatively incorporate a series of ribs or blade-like protrusions around the inside surface and on the bottom surface of the filter holder to accomplish the same purpose.- Since tea does not clog the pores of the filter as does coffee, a tea filter without a flow control mechanism would allow the hot water to pass rapidly down through the brewing chamber via the entire lower surface of the filter and out through the holes in the bottom of the filter holder without allowing sufficient steeping time.
  • the flow rates of liquids through the layers and the height of the substantially vertically extending moisture impervious side wall 25 are sized and configured in filter packs of the present invention so that a steady state brewing condition is established within brew chamber 40 during a substantial portion of the brewing cycle.
  • a steady state brewing condition is established within brew chamber 40 when the brew chamber's maximum volume V is filled with water and tea leaves 50, allowing the tea leaves to expand and loosely float within the chamber. This condition is illustrated in the cross-section of Figure 2 A.
  • the flow rate F of incoming hot water through the permeable region 23 of the top layer 20 should be greater than the maximum flow rate F of brewed tea exiting through the permeable area 13 in bottom layer 10. Furthermore, the water delivery flow rate F of the coffee maker to the filter pack 1 should be less than or equal to the incoming hot water flow rate F into brew chamber 40.
  • substantially water impermeable side wall 25 must be at least tall enough to capture enough of the incoming hot water that the brew chamber 40 will become flooded and fully expanded to achieve a steady state brewing condition.
  • this minimum vertical side wall height corresponds to level "L", which represents the maximum possible vertical expansion of porous area 23 in brew chamber 40.
  • substantially water impermeable side wall 25 extends above this minimum, the greater will be the filter pack's insensitivity to careless placement within the filter support means 75, since lack of perfect concentricity with the filter support means will not result in an inability to retain enough hot water to establish a flooded steady state brewing condition within the brew chamber.
  • the vertical height of the substantially water impermeable side wall 25 is greater than the foregoing minimum to prevent overflow of the incoming hot water from the coffee maker (recall that the discharge flow rate of brewed tea from the brew chamber is normally less than the incoming flow rate of hot water to the filter pack to permit flooding of the brew chamber).
  • the maximum height of the substantially water impermeable side wall 25 is, of course, limited by the vertical height of the filter support means 75 used on the coffee makers which are to employ the filter packs in question. If the filter pack extends vertically beyond the uppermost edge of the filter support means 75, it is likely to cause interference when attaching the filter support means to the coffee maker.
  • improved tea filter packs of the present invention deliver comparable brewing efficiency to bulk tea/filter paper systems, but without the need for unitized pouches of premeasured tea leaves to ensure pot-to-pot brew strength consistency and without the mess associated with bulk tea and paper filters.
  • hydrophobic adhesive coating 30, which is preferably a hot melt, is applied in a ring like fashion around the perimeter of the inner face 11 of bottom layer 10, leaving an uncoated porous discharge outlet orifice 13 at the center of bottom layer 10.
  • a predetermined amount of tea leaves 50 having a dry volume V are placed within the area defined by dotted line 35 either before or at the same time as top layer 20 is superposed on bottom layer 10.
  • Top layer 20 is then brought into contact with bottom layer 10 and heat and pressure are applied to only the outer perimeter of top layer 20, i.e., the area which lies outside dotted line 35 in Figure 3. This adheres the outer perimeter of top layer 20 to the outer perimeter of bottom layer 10.
  • dotted line 35 shows the innermost point where the top layer 20 ceases to be adhered to bottom layer 10 and defines the inlet permeable inlet orifice 23 for entry of the incoming hot water into brew chamber 40. Dotted line 35 also defines the outermost circumference of brew chamber 40.
  • the surface area of the inlet orifice 23 to the brew chamber 40 is larger than the surface area of the discharge outlet orifice 13 out of the brew chamber. For any given porosity of the top and bottom layers this will make the flow rate into the chamber greater than the maximum flow rate out of the chamber during build-up to a steady state brewing condition.
  • This difference in flow rates in combination with the impermeable side walls of the filter pack 1 causes the incoming hot water to build up and puddle inside the brew chamber 40 in the manner generally shown in Figure 2A. This permits the tea/water exposure and contact time needed to obtain a desired brew strength for a predetermined amount of tea.
  • allowing water to build up causes the tea leaves 50 to loosely float and expand inside the brew chamber 40. This minimizes channeling of the hot water directly through the chamber without sufficient contact with the tea leaves, thereby increasing the efficiency of tea flavor solids extraction and reducing extraction variability from pot-to-pot.
  • Brew chamber 40 should be large enough to encase the desired amount of tea leaves 50 and to allow the tea leaves to expand and loosely float when the chamber is flooded, i.e., during steady state brewing conditions, as generally shown in Figure 2A. Ideally the maximum volume V of brew chamber 40 is between about 100 percent and about 400% larger than
  • the filter pack 1 preferably exhibits a frusto-conical shape, as generally shown in Figure 1, so that even if the operator is careless in installing it in the filter support means or holder 75, the filter pack's shape and the conformability of its side wall 25 will tend to automatically self align the filter pack to produce a situation similar to that shown in Figure 2A, so that the desired funnel effect takes place during the brew cycle.
  • FIGS. 4A, 4B and 4C One method of imparting the frusto-conical shape can be explained by looking at Figures 4A, 4B and 4C.
  • a fully assembled planar filter pack 1 is placed between female die 70 and male die 60 so as to take on the desired shape as shown in Figure 1.
  • the unformed diameter 16 shown in Figure 4 A is larger than the formed diameter 17 shown in Figure 4C.
  • the formed diameter 17 is ideally the same diameter as the bottom of the coffee filter holder 75 of the coffee maker.
  • the foregoing forming process allows the unadhered porous inlet portion 23 of top layer 20 to puff up during brewing and create a large enough brew chamber 40 to achieve good tea extraction, as shown in Figures 2 and 2A.
  • the substantially water impermeable conformable side wall 25 ensures that the hot water needed for flooding of the brew chamber will be available no matter how sloppily the filter pack 1 is placed in the filter holder 75.
  • the present invention is relatively insensitive to operator error.
  • the bottom and top layers used in filter packs of the present invention can be comprised of any paper, synthetic nonwoven, or plastic material that has a porosity and mesh size capable of preventing substantially all of the tea particles from entering into the brewed tea beverage or sifting out while handling the disposable filter pack before or after brewing.
  • both layers are comprised of filter paper comprised substantially entirely of wood fiber. This is the type of filter paper normally used to make conventional coffee filters.
  • the adhesive used to seal and secure the inner and outer layers to one another is preferably comprised of a hydrophobic hot melt material applied as a continuous layer, e.g., a polymeric material, such as polypropylene, applied with a rotogravure, screen, or spray coating system.
  • a hydrophobic hot melt material applied as a continuous layer, e.g., a polymeric material, such as polypropylene, applied with a rotogravure, screen, or spray coating system.
  • the particular hydrophobic adhesive material employed should, of course, be approved for direct contact with food and beverage substances and boiling water.
  • the adhesive ideally has a viscosity of between about 500 and about 15,000 CPS at 350oF for coating application purposes.
  • the adhesive should also have a softening temperature greater than I8O0F in order that the seal between the filter mediums employed in the filter pack 1 does not fail in hot water during brewing.
  • the thickness of the hydrophobic adhesive can be adjusted, as desired, to provide the desired seal strength and degree of water imperviousness.
  • the thickness of the adhesive can also be varied within the different portions of the filter pack to achieve different objectives. For instance, a thickness of 0.5 mils of adhesive may be sufficient to render the conformable side wall
  • a die cut layer of polymeric material such as commercially available polyethylene, would be substituted for layer of hydrophobic adhesive 30.
  • This likewise causes the filter pack to be substantially impermeable to water wherever the polyethylene is present.
  • the three layers of the resultant laminate could, of course, be adhered to one another by applying sufficient heat to soften the polyethylene.
  • the resultant laminate tea filter pack would behave identically to the embodiment shown in Figures 1 and 2.
  • Such a polyethylene layer would preferably have a thickness of between about 1 and about 3 mils.
  • brew chamber 40 could be controlled by making the porous portion 13 of bottom layer 10 less porous than the porous portion 23 of top layer 20. This is usually achieved by making the bottom layer 10 slightly thicker than the top layer 20. In an embodiment of the latter type, the hydrophobic adhesive 30 would not need to extend inwardly beyond dotted line 35 in Figure 3, since the difference in porosity of the layers would produce a difference in flow rates even if their respective areas were identical in size.
  • the layers 10 and 20 could be comprised of a synthetic non-woven material containing hundreds of tiny plastic fibers packed close enough together to prevent tea particles from entering the brewed beverage or escaping from the brew chamber, while still allowing water to pass therethrough.
  • the layers of the filter pack can be comprised of a continuous film of plastic or polymeric material, such as polyethylene, that is initially water impermeable. Water permeable regions can then be made by puncturing the plastic material and making hole sizes which are large enough to let water pass yet small enough to prevent the passage of substantially all of the solid tea particles in the brewing chamber.
  • This puncturing could, if desired, be done by a water jet process of the type generally described in commonly assigned U.S. Patent 4,695,422 issued to Curro et al. on September 22, 1987 and 4,609,518 issued to Curro et al. on September 2, 1986 both disclosures of which are hereby incorporated herein by reference.
  • a mechanical punching process could be employed to perforate the film.
  • Other suitable perforated films are commercially available from Tredegar Industries, Film Products Division, Terre Haute, Indiana.
  • the size and number of holes could be varied to control flow rates through the filter pack.
  • more holes could be provided on the top layer than on the bottom layer so as to make the bottom layer less porous.
  • the holes could be of identical size and density in both layers and the flow areas adjusted in the same manner shown in Figures 1, 2 and 3 so as to control liquid flow rates into and out of the brew chamber in a similar fashion. That is the size of the porous inlet orifice and porous outlet orifices could be varied. No holes would be placed in the side wall portion of the filter pack so as to keep them substantially impermeable to water.
  • the top and bottom layers should be secured together and made impermeable around the region corresponding to the side wall 25. This could be accomplished by applying heat and pressure to this region to form an impermeable side wall. Any sealing process could be used that causes the two layers of plastic material to bond together. The sealing should cause the plastic to melt and flow back together, thereby closing substantially all of the holes therein. If the top and bottom layers are made from identical sheets of plastic material having the same size holes and density of holes the flow rates could be adjusted by applying heat and pressure to the bottom layer to close up some of the holes. This reduces the size of the outlet orifice and thereby reduces the flow rate therethrough.
  • a hole size ranging from 4 mils to 10 mils is ideal for retaining dry tea sediment in the brewing chamber. Approximately 40-100 holes, regularly arrayed and spaced, for this size range per square inch of material is ideal for obtaining the good water flow characteristics.
  • surfactants can be applied to the plastic films to aid in water flow. The surfactants can be applied to the surface or incorporated within the material. Suitable surfactants for application on the films surface would include polysorbates, polyglycerol esters and monoglyceride derivatives.
  • FIG. 5 is a simplified cross-sectional view of tea filter pack 101 of the present invention.
  • Tea filter pack 101 comprises bottom layer 110 made from porous filter paper, and top layer 120 made from a continuous film of plastic material, such as those described above.
  • top layer 120 made from a continuous film of plastic material, such as those described above.
  • the plastic material used be a two layer co-extruded plastic film wherein the sealant side of the film, the layer that is to be sealed to another layer, has a lower melting temperature than the outside surface in order to aid in sealing.
  • Figure 5 shows the top layer 120 as being a co-extruded plastic film.
  • Top layer 120 comprises two sub-layers 121 and 122. It is preferred that sub-layer 121 have a lower melting temperature than sub ⁇ layer 122. This difference in temperatures allows for higher sealing temperatures to be used while preventing the non-sealant side of plastic material from sticking to the sealing surface.
  • Typical materials for sub-layer 122 include polyolefins whereas typical materials for sub-layer 121 also include polyolefins but containing EVA's therein.
  • Numerals 23, 25, 40, and 50 refer to structural elements similarly numbered in Figure 2.
  • the water permeable region 13 of the bottom layer in the brewing chamber 40 is generally located in the center of the brew chamber where the tea leaves are placed.
  • a single continuous permeable area 13 is also generally preferred over a multiplicity of discrete porous areas to maximize consistent extraction of flavor solids from the tea leaves 50 contained within the brew chamber 40.
  • a filter pack of the type generally shown in Figures 1, 2 and 3 was constructed using a generally circular shaped piece of James River 20 lb/3000 ft basis weight porous filter paper having a 9.5 inch diameter as the bottom layer.
  • Pierce & Steven's B7209 AE03 water-based hydrophobic adhesive was manually pattern coated on the bottom layer in the pattern generally shown in Figure 3 using a small paint brush and leaving an uncoated circular central area having a 2.25 inch diameter at the center of the bottom layer to act as the discharge flow outlet 13 for brewed tea.
  • a dose of 1 oz. of Tender Leaf Tea having a dry volume of approximately 5 cubic inches was placed in the center of the uncoated portion of the bottom layer.
  • a generally circular shaped piece of James River 20 lb/3000 ft basis weight porous filter paper with a 9.5 inch diameter was employed for the top layer.
  • the top layer was concentrically centered with and heat sealed to the bottom layer to encapsulate the tea.
  • the width of the seal extended radially inwardly from the outer perimeter of the top layer for a distance of 3 inches. This resulted in a porous inlet area 23 to the brew chamber having a diameter of approximately 3.5 inches.
  • the porosity of the filter paper used to make the top and bottom layers was approximately 300 milliliters of water/minute/in . Since the area of the inlet was 9.62 in , the maximum possible flow rate F of hot water into the brew chamber was approximately 2.9 liters/minute. This flow rate is much greater than the flow rate F at which most coffee makers deliver hot water to the filter pack. Therefore the actual flow rate F will, in most instances, be equal to the flow rate F delivered by the coffee maker to the coffee filter pack prior to establishing a steady state brewing condition in the brew chamber. Once a steady state brewing condition has been established within the brew chamber, flow rate F will be substantially equal to the discharge flow rate F of brewed tea exiting the brew chamber.
  • the filter pack was formed, as generally shown in Figures 4A, 4B, and 4C to take on the desired frusto-conical shape and a bottom diameter of approximately 4.5 inches.
  • the forming process used male and female dies, as generally shown in Figures 4A- 4C.
  • the filter pack was first centered over the female die 70.
  • the male die 60 was then forced down into the female die, forming and folding the filter pack in such a way that it was sandwiched between the male and female dies.
  • Hot air at 200oF was blown onto the filter pack side wall 25 to soften the hydrophobic adhesive 30.
  • the filter pack was then cooled for 5 to 10 seconds to allow the adhesive to set to the frusto-conical shape and removed by lifting up the male die 60 and shoving the filter pack through the bottom of the female die as shown in Figure 4C.
  • Seven exemplary tea filter packs of the aforementioned type were brewed using a Bunn OL20 coffee maker having a porous filter support with a bottom diameter of approximately 4.5 inches.
  • the coffee maker delivered approximately 1,870 milliliters of water at 195oF in approximately 2.5 minutes, thereby resulting in an incoming hot water delivery rate F of approximately 748 milliliters/minute.
  • the brew chamber of the filter pack was flooded and a steady state brewing condition established therein within the first 30 seconds of the brewing cycle. This occurred by the time no more than 20 percent of the total predetermined volume V of water delivered to the filter pack had passed through the brew chamber.
  • Samples of the final beverage were taken from all 7 pots of tea brewed. The amount of extractable flavor solids in each sample was measured by weighing the tea flavor solids remaining after evaporating the water in the samples.
  • the extraction efficiency levels averaged 0.267 grams of extracted tea flavor solids/gram of dry tea.
  • the standard deviation for the 7 samples was 0.0031 grams of extracted tea flavor solids/gram of dry tea.
  • the post fabrication forming step could be omitted, and the filter pack could remain substantially flat until insertion into the filter support means of the coffee maker. Because the substantially water impermeable side walls are flexible, insertion of the substantially flat filter support means will cause them to conform to the filter support means and assume an upwardly directed orientation sufficient to produce the desired brewing action. It is intended to cover in the appended claims, all such modifications that are within the scope of this invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Food Science & Technology (AREA)
  • Packages (AREA)
  • Apparatus For Making Beverages (AREA)

Abstract

Filtre à thé (1) conformable, à haute capacité d'extraction et à autoalignement, offrant un pouvoir d'extraction de l'arôme identique à celui qu'on obtient à conditions d'infusions égales avec un filtre en papier et la même quantité de feuilles de thé entières, mais qui présente un pouvoir infusionnel sensiblement constant pendant le passage d'un récipient à l'autre avec tous types de machines à café à filtres. La réalisation préconisée est faite de deux couches (10, 20) d'un matériau souple reliées ensemble par leur extrême périphérie, la chambre d'infusion (40) ainsi formée étant remplie d'une quantité prédéterminée de feuilles (50) de thé. La chambre d'infusion (40) offre un volume maximal compris entre environ 100 % et 400 % de celui des feuilles (50) de thé à l'état sec qu'elle contient. Le débit de sortie (F3) de la chambre d'infusion (40) est inférieur à son débit de remplissage pour permettre à l'eau de s'accumuler et d'inonder la chambre d'infusion (40). La paroi souple et conformable entourant la chambre d'infusion (40) s'étend verticalement sur une hauteur suffisante pour recueillir assez d'eau pour submerger totalement la chambre d'infusion (40) lorsque celle-ci est complètement dilatée. Les feuilles de thé (50) peuvent ainsi gonfler et flotter dans la chambre (40) pendant le reste du cycle d'infusion, ce qui assure des conditions d'infusion constantes favorisant un contact maximal entre l'eau et le thé pendant que l'eau traverse la chambre d'infusion (40) pour rejoindre le pot.
EP94921189A 1993-06-29 1994-05-16 Filtre a the pour machines a cafe automatiques Withdrawn EP0705206A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US8405193A 1993-06-29 1993-06-29
US84051 1993-06-29
PCT/US1994/005428 WO1995001293A1 (fr) 1993-06-29 1994-05-16 Filtre a the pour machines a cafe automatiques

Publications (1)

Publication Number Publication Date
EP0705206A1 true EP0705206A1 (fr) 1996-04-10

Family

ID=22182580

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94921189A Withdrawn EP0705206A1 (fr) 1993-06-29 1994-05-16 Filtre a the pour machines a cafe automatiques

Country Status (5)

Country Link
EP (1) EP0705206A1 (fr)
CN (1) CN1126462A (fr)
AU (1) AU7200794A (fr)
CA (1) CA2165691C (fr)
WO (1) WO1995001293A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018015423A1 (fr) 2016-07-20 2018-01-25 Technip France Distributeur de gaz pour une installation de conditionnement de poudre et installation associée

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6425317B1 (en) * 2000-09-12 2002-07-30 Objective Design Coffee maker filter basket with steeping feature
DE20105161U1 (de) 2001-03-23 2001-06-28 Melitta Haushaltsprodukte GmbH & Co. KG, 32427 Minden Portionspackung für die Zubereitung eines Aromaauszuges aus Kaffee, Tee o.dgl.
EP1772081A1 (fr) 2005-10-07 2007-04-11 Cense d'Almez S.A. Dispositif pour infuser des boissons
WO2010082727A2 (fr) * 2009-01-16 2010-07-22 주식회사 아로마빌커피 Dispositif d'infusion de café jetable
AU2009347069B2 (en) 2009-06-17 2016-12-15 Koninklijke Douwe Egberts B.V. System and Method for preparing a beverage comprising a soluble substance
WO2010137966A1 (fr) 2009-06-17 2010-12-02 Sara Lee/De N.V. Capsule, système et procédé pour la préparation d'une boisson et procédé de fabrication d'une telle capsule
CN107743368B (zh) * 2015-06-19 2020-09-01 皇家飞利浦有限公司 用于从如存在于咖啡室中的一定量的咖啡颗粒找回香味的方法
CN110113968B (zh) * 2016-11-02 2021-11-12 蓝瓶咖啡股份有限公司 流动优化的倾倒式咖啡冲泡***
DE102018101338A1 (de) * 2018-01-22 2019-07-25 Melitta Single Portions Gmbh & Co. Kg Verfahren zur Herstellung eines Getränks mit einer Portionspackung und Portionspackung
WO2020073142A1 (fr) * 2018-10-11 2020-04-16 FERNANDEZ ROJAS, Maite Alejandra (1%) Ensemble pour préparer des infusions au moyen d'un filtre
CN111493667B (zh) * 2020-06-04 2022-04-01 浙大宁波理工学院 花茶泡茶机

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3446624A (en) * 1967-07-28 1969-05-27 William David Luedtke Disposable coffee drip brewer
US3971305A (en) * 1975-03-27 1976-07-27 Daswick Alexander C Disposable beverage brewer
US4983410A (en) * 1987-10-23 1991-01-08 Southern Tea Company Disposable expandable tea cartridge
DE69205165T2 (de) * 1991-07-05 1996-03-21 Procter & Gamble Kaffeefilterpackung.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9501293A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018015423A1 (fr) 2016-07-20 2018-01-25 Technip France Distributeur de gaz pour une installation de conditionnement de poudre et installation associée

Also Published As

Publication number Publication date
CA2165691C (fr) 2003-09-09
AU7200794A (en) 1995-01-24
CN1126462A (zh) 1996-07-10
WO1995001293A1 (fr) 1995-01-12
CA2165691A1 (fr) 1995-01-12

Similar Documents

Publication Publication Date Title
US5633026A (en) Tea filter pack for automatic brewers
US5298267A (en) Coffee filter pack
US5104666A (en) Single-dose espresso maker for infusions in general to be disposed after use
US8127663B2 (en) Apparatus for brewing and method for making the same
EP0615921A1 (fr) Cartouche rigide pour café ou équivalent
RU2379225C2 (ru) Капсула для приготовления и подачи напитка путем впрыскивания жидкости под давлением в капсулу
JP3150202B2 (ja) たわみカートリッジの形式のパッケージ
US5243164A (en) Beverage maker
AU2009347085B2 (en) System, method and capsule for preparing a beverage
JP5854705B2 (ja) 飲料カートリッジ
EP1808382B1 (fr) Capsule fermée avec une coupelle comportant un système d'ouverture
JP4970251B2 (ja) パッド、及びホルダとそのようなパッドとのアセンブリ
CA2165691C (fr) The conditionne sans filtre pour machines a infusion automatiques
US5010221A (en) Microwaveable coffee makers
US5064980A (en) Coffee maker
EP4251538A1 (fr) Capsule et système de préparation d'une boisson
CA2112400C (fr) Ensemble filtre a cafe
CN1997568A (zh) 用于酿造的设备以及用于制造该设备的方法
WO1991020170A1 (fr) Cafetiere pouvant etre utilisee dans un four a micro-ondes
CA1216163A (fr) Dispositif de preparation de quantites individuelles de boissons
JPH0464686B2 (fr)
MXPA01008153A (en) Sealed cartridge for making a beverage

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19951121

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE GB

17Q First examination report despatched

Effective date: 19960507

RIN1 Information on inventor provided before grant (corrected)

Inventor name: KUPNESKI, MICHAEL, JOSEPH

Inventor name: GRUENBACHER, DANA, PAUL

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19970114