CA1221060A - Infusion package - Google Patents
Infusion packageInfo
- Publication number
- CA1221060A CA1221060A CA000468970A CA468970A CA1221060A CA 1221060 A CA1221060 A CA 1221060A CA 000468970 A CA000468970 A CA 000468970A CA 468970 A CA468970 A CA 468970A CA 1221060 A CA1221060 A CA 1221060A
- Authority
- CA
- Canada
- Prior art keywords
- package
- flattened end
- film
- infusion
- product containing
- 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.)
- Expired
Links
Classifications
-
- 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
- B65D85/808—Disposable containers or packages with contents which are mixed, infused or dissolved in situ, i.e. without having been previously removed from the package for immersion in the liquid to release part or all of their contents, e.g. tea bags
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Packages (AREA)
Abstract
INFUSION PACKAGE
Abstract of the Disclosure An infusion bag for particulated food products such as tea, coffee and the like, constructed of a tube of perforated thermoplastic film or other porous material having a central product containing portion and flattened end portions on each end thereof, the perforated thermoplastic film or other porous material having a multiplicity of minute holes or openings which are sufficiently small in size to prevent the migration of the particulated product therethrough and which are sufficiently large in size and number to permit adequate fluid flow there-through. Joining together of the flattened end portions forms a flow-through or dual container type infusion bag and a handle for extending over the side of a cup or pot. The film is also substantially odorless and tasteless.
Abstract of the Disclosure An infusion bag for particulated food products such as tea, coffee and the like, constructed of a tube of perforated thermoplastic film or other porous material having a central product containing portion and flattened end portions on each end thereof, the perforated thermoplastic film or other porous material having a multiplicity of minute holes or openings which are sufficiently small in size to prevent the migration of the particulated product therethrough and which are sufficiently large in size and number to permit adequate fluid flow there-through. Joining together of the flattened end portions forms a flow-through or dual container type infusion bag and a handle for extending over the side of a cup or pot. The film is also substantially odorless and tasteless.
Description
~2~i~)6(~
Case V-5223 IN~USION PACKAGh The pre~ent invention is directed to infusion packages, especially tea packages and the like, and more particularly to an infusion packag~ constructed of a non-woven, fiber-free, perfora~ed thermoplast~c film or other porous material.
The invention is particularly concerned with an lnfusion package constructed of a coextruded multilayer perforated thermo-plastic film having a plurality of uniform minute holes or openings therein, which has a relatively flat configuration for 0 packing and which can be readily converted to a dual chamber or flow-through type bag.
At the present time, most tea bags or packages commer-cially marketed are either the ~pillow~ pack type or the dual bag or Flo-thru type. The bags are made of paper and the latter have strings and tabs attached thereto by staples or glue. Al-though a considerable degree of success has been achieved with these two types of bags, they have poor wet strength. The single compartment or Cpillowr tea bag is a flat bag of liquid pervious material which contains sufficient tea for an individual serving or for multiple servings in the case of the larger packages used by food service industries. The tea spreads the sides of the bag to accommodate the contents. When the tea is wet, it forms a swollen compacted mass that may fill the bag. The swelling tea presses outwardly against the inside walls of the bag.
~i,$
~Z2~ ;0 Squeezing or other ex~ernal pressure on the bag may cause it to break open or split or otherwise undesirably dispel its contents.
To overcome thl~ swelling, ~ome bags have been constructed with pleat~ therein~ Although effective to some degree, they have a lack of wet strength and present other problems.
The art is replete with lnfusion packages containing two or more fill containing segments. The connected segments permit liquld flow between the segments and expose a greater bag surface area to liquid ior extraction therethrough. Although such bags may improve brewing, they have the same lack of wet strength of the pillow~ type bags, and present other problems, such as assembly and packaging.
Infusion-type tea packages are usually rectangular packets or sachets made from single or mult$ple pieces of paper crimped or otherwise sealed along the edges. In another type, a single strip of paper is folded twice longitudinally to form an inner centrally disposed double fold joining the two meeting edges. In a type of flow-through tea bag, a triple transverse fold intermediate the length of the folded strip forms two pockets which are partially filled with tea before the open ends thereof are folded over and stapled to a strand of string usually having a tag on the end thereof.
Over the years, a wide variety o infusion packages or bags, usually for containing tea for subsequent brewing, have been developed. The packages are usually constructed of filter paper or some other type of porous material.
~z~06~
An infusion package which has a natural, expanded or unflattened condition and which is folded to a flattened confi-guration for packlng is disclosed in U.S. 4,290,521. A pull strip with a tab on one end is adhesively attached to the upper part of the package for causing the package to be expanded from its flattened configuration when the strip is pulled.
A type of dosage pack or infusion package having two permeable bags joined to each other along a common seam and arranged in a face-to-face relationship by folding the bags onto 0 one another along a fold line extending in the common seam is described in U.S. 4,055,668. A holder string is positioned between the two bags with one end attached to one of the bags and the other end attached to a tag positioned externally of the two bags.
U.S. 3,899,599 discloses a single chamber or dual chamr ber tea package which has a flexible strip attached to an exte-rior chamber side which can be partially removed to provide a hanger for holdlng the package in place in a container.
An infusion packet having two oppositely disposed, rigidly separated pockets of tea joined together by two tapering end port$ons which form a nar!ow, triangular shaped porous cup is shown in U.SO 3,597,222.
U.S. 3,653,913 discloses an infusion bag made from a rectangular strip of porous fibrous material, the longitudinal margins of which are folded together so as to form a longitudinal 12;~ 60 ~oint consisting of three layers which are knurled together.
The tube i8 divided by a transverse bend so a~ to form a pair of chambers for holding an infusible substance, and the opposite ends of the tube are connected to each other so as to close the package.
An early type of tea bag or tea ball wheeein the bag is a triangularly-shaped pocket formed from a rectangular strip of perforated aluminum foil is described in U.S. 1,581,578.
Other types of filter paper tea bags or the like with a 10 variety of handles are illustrated in U.S. 2,328,017 U.S.
Case V-5223 IN~USION PACKAGh The pre~ent invention is directed to infusion packages, especially tea packages and the like, and more particularly to an infusion packag~ constructed of a non-woven, fiber-free, perfora~ed thermoplast~c film or other porous material.
The invention is particularly concerned with an lnfusion package constructed of a coextruded multilayer perforated thermo-plastic film having a plurality of uniform minute holes or openings therein, which has a relatively flat configuration for 0 packing and which can be readily converted to a dual chamber or flow-through type bag.
At the present time, most tea bags or packages commer-cially marketed are either the ~pillow~ pack type or the dual bag or Flo-thru type. The bags are made of paper and the latter have strings and tabs attached thereto by staples or glue. Al-though a considerable degree of success has been achieved with these two types of bags, they have poor wet strength. The single compartment or Cpillowr tea bag is a flat bag of liquid pervious material which contains sufficient tea for an individual serving or for multiple servings in the case of the larger packages used by food service industries. The tea spreads the sides of the bag to accommodate the contents. When the tea is wet, it forms a swollen compacted mass that may fill the bag. The swelling tea presses outwardly against the inside walls of the bag.
~i,$
~Z2~ ;0 Squeezing or other ex~ernal pressure on the bag may cause it to break open or split or otherwise undesirably dispel its contents.
To overcome thl~ swelling, ~ome bags have been constructed with pleat~ therein~ Although effective to some degree, they have a lack of wet strength and present other problems.
The art is replete with lnfusion packages containing two or more fill containing segments. The connected segments permit liquld flow between the segments and expose a greater bag surface area to liquid ior extraction therethrough. Although such bags may improve brewing, they have the same lack of wet strength of the pillow~ type bags, and present other problems, such as assembly and packaging.
Infusion-type tea packages are usually rectangular packets or sachets made from single or mult$ple pieces of paper crimped or otherwise sealed along the edges. In another type, a single strip of paper is folded twice longitudinally to form an inner centrally disposed double fold joining the two meeting edges. In a type of flow-through tea bag, a triple transverse fold intermediate the length of the folded strip forms two pockets which are partially filled with tea before the open ends thereof are folded over and stapled to a strand of string usually having a tag on the end thereof.
Over the years, a wide variety o infusion packages or bags, usually for containing tea for subsequent brewing, have been developed. The packages are usually constructed of filter paper or some other type of porous material.
~z~06~
An infusion package which has a natural, expanded or unflattened condition and which is folded to a flattened confi-guration for packlng is disclosed in U.S. 4,290,521. A pull strip with a tab on one end is adhesively attached to the upper part of the package for causing the package to be expanded from its flattened configuration when the strip is pulled.
A type of dosage pack or infusion package having two permeable bags joined to each other along a common seam and arranged in a face-to-face relationship by folding the bags onto 0 one another along a fold line extending in the common seam is described in U.S. 4,055,668. A holder string is positioned between the two bags with one end attached to one of the bags and the other end attached to a tag positioned externally of the two bags.
U.S. 3,899,599 discloses a single chamber or dual chamr ber tea package which has a flexible strip attached to an exte-rior chamber side which can be partially removed to provide a hanger for holdlng the package in place in a container.
An infusion packet having two oppositely disposed, rigidly separated pockets of tea joined together by two tapering end port$ons which form a nar!ow, triangular shaped porous cup is shown in U.SO 3,597,222.
U.S. 3,653,913 discloses an infusion bag made from a rectangular strip of porous fibrous material, the longitudinal margins of which are folded together so as to form a longitudinal 12;~ 60 ~oint consisting of three layers which are knurled together.
The tube i8 divided by a transverse bend so a~ to form a pair of chambers for holding an infusible substance, and the opposite ends of the tube are connected to each other so as to close the package.
An early type of tea bag or tea ball wheeein the bag is a triangularly-shaped pocket formed from a rectangular strip of perforated aluminum foil is described in U.S. 1,581,578.
Other types of filter paper tea bags or the like with a 10 variety of handles are illustrated in U.S. 2,328,017 U.S.
2,359,292, U.S. 3,566,573; U.S. 4,153,153 and Great Britain 2,087,350. Great Britain 2,053,668 discloses a tea bag having an accordion fold.
Infusion bags with positioning means and flotation means 15 are di~closed in U.S. 3,797,642 and U.S. 3,809,215, respectively.
The tea bags themselves may be made of various materials inclu-ding paper, plastics such as nylon, perforated plastic film, e.g., polyester, or woven or non-woven fabric of natural or synthetic origin.
A percolatable porous bag constructed of a blend of individualized textile or cellulosic fiber and a small amount of thermoplastic fiber is disclosed in Canadian patent 802,720.
Various degrees of success have been achieved with the foregoing infusion bags or packages, with paper or fibrous bags presently dominating the market place. One of the problems with lZ2~360 paper bags is iack of wet str~ngth. Paper packages do not have the strength to withstand squeezlng or other pressures commonly applied by consumer or other u~ers.
kn ~rfusion bag for items such as tea, coffee or similar food products for brewing must have a number of qualities. It must have an inab$1ity to impart a taste factor to the liquid product after brewing. In effect, it must be substantially odor-less and tasteless. It must also be sufficiently strong to con-tain the brewing product in boiling water, e.g., in the steeping 0 of tea, coffee, and similar liquid beverages. The bag must also be porous enough to permit liquid diffusion therethrough, but the pores or openings must be of such size that migration of the beverage material therethrough is inhibited, both when the bag is dry and when the bag has been immersed in a liquid. It is also imyortant that infusion begins to take place within a few seconds and be completed within a few minutes. It is further desirable that a package, bag or sachet, such as a tea sachet, retain sufficient stability that it can be compressed after brewing is completed without destruction of the container.
Thermoplastic films such as polyethylene and polypro-pylene are common packaging materials. Multilayer films of various types are also quite common packaging materials. The films are generally non-porous and impervious to water and other inert liquids. At least one of the layers of film has strong adhesive qualities. Examples of such multilayer films may be 1~2~60 seen in U.S. 4,254,169- U.S. 4,239,826; U.S. 4,233,367, U.S. 3,908,070; U.S. 3,423,231; U.S. 2,817,124 and U.S. 2,817,123.
Perforated thermoplastic films have many useful applications, including packaging of food products such as cheese, gardening and farming to prevent growth of weeds while permitting moisture to be transmitted through the film to the soil beneath and for making absorptive structures such as disposable diapers,for example, see U.S. 3,814,101.
Perforation of thermoplastic films is generally achieved by vacuum perforation of thin plastic films which involves the extrusion of molten polymeric materials such as polyethylene through a slot die. The hot melt web of film exiting the die impinges on a form through which a vacuum is drawn causing the film web to be perforated and holes formed therein. Depending upon the form used, films can be produced which have as few as 50 holes per square inch or which have thousands of holes per square inch. One of the earlier methods for vacuum perforation of plastic film is disclosed in U.S. 3,054,148.
The present invention provides an infusion package or sachet which meets the requirements for tea brewing and additionally overcomes the problems of lack of wet strength and packaging associated with the prior art.
More particularly, the present invention provides an infusion package for particulated or finely ground products consisting of a tube of porous material having a central product containing portion and an elongated flattened end portion on each end thereof, the ends being oppositely ~rc~
~Z2~60 located ends, each of the flattened end portions being sealedly separated from the central product containing portion, the flattened end portions being sufficiently elongated that they may beinterwoven or knotted together, whereby when so interwoven or knotted together a flow through type of package with an intearated handle thereon is formed,allowing a majority of the central product con-tai~ina portion to be suspended therebelow, at least one of the flattened end portions having an elongated slot or opening therein which enables one flattened end portion to be inserted through the other flattened end portion and thereby form the flow through type of bag with an integrated handle thereon, and ^the porous material having a multiplicity of fine openings or holes therein each of which is sufficientlv small in si7.e to inhibit migration therethrough of a part-iculated product contained in the central product containing portion and is sufficiently large in size to permit the flow of liquids therethrough.
Fig. 1 is a top plan view of an embodiment of the invention;
Fig. 2 is a side elevational view of the embodiment of Fig. l;
Fig. 3 is an end view of the embodiment of Fig. l;
Fig. 4 is a sectional view taken across line 4-4 of Fig. l;
Fig. 5 is a top view taken across line 5-5 of Fig. l;
Fig. 6 is a view of the e~bodiment of Fig. 1 illustrating one means of joining together the ends of the package; and ,, jrc: ~~
~22~0~(~
Fig. 7 is a view similar to that of Fig. 6 illustrating another means of joining the ends of the tea bag.
Referring now to the drawings, an infusion package or bag of the present invention is illustrated generally at 10.
The bag or packet 10 is constructed of a rectangular strip of a perforated plastic film 11 which is described in more detail~
hereinafter. For simplicity of illustration, perforations in the film are not shown. The strip of film 11 is folded longitud-inally at 12, sealed at intermediate locations 13 and 14 and filled with a particulated product P which can be seen through the film 11 between the sealings. After the product P is inserted in the sachet 10, the edge 15 is sealed, thereby encasing the product P within the package 10.
The intermediate sealings 13 and 14 provide tabs 16 and 17 on either side of the product P. Conveniently, slits or longitudinal slots 18 and 19 are formed in each of the tabs 16 and~17-, respectively.
As best seen in Figs. 1 and 2, the ends of the elongated flattened end portions (or tabs 16 and 17) are located oppositely of the central produc~ containing portion or the portion between the sealings 13 and 14 containing the product P. The flattened end portions are sufficiently elongated that they may be inter-woven or knotted together as shown in Figs. 6 and 7, respectively.
Once the package 10 is interwoven or knotted together, a flow through package 10 is formed with an integrated handle thereon.
In flow through form, a majority of the central product contain-ing portion is suspended below the handle formed by the flattened end portions.
jrc:
~2:~0i~
The infusion package 10 of the present invention is illustrated in its simplest form. Such packages can be readily made on existing filling and packaging machines with minimal modification. The relatively flat shape of the bags permits easy packaging or boxing in a fashion similar to that of boxing cigars.
- Figs. 6 and 7 illustrate two means by which the package 10 is readily converted to a flow through or dual container in-fusion bag. In Fig. 6, tab 16 is inserted through slot 19 of - 8a --~ ~ jrc:
~;~Z10~;0 g tab 17. Tabs 1~ and 17 are of sufficlen~t length to provide a handle which can readily be extended over the side of a cup or brewing pot.
Ir, ~ig. 7, the slots are not used and the tabs are assembled in a half knot or full knot, if desired. The tabs 16 and 17 are sufficiently long to easily provide the desired handles.
The infusion bag or package 10 is preferably constructed of a coextruded multilayer film 11 comprising an outer layer of 1~ a heat resistant thermoplastic such as polyester, polyolefin, or the like, with p~lyester being preferred, and an inner sealant layer of a somewhat less heat resistant thermoplastic such as polyethylene or the like. The film 11 has a multiplicity of fine holes or capillaries which are of a somewhat tapered con-struction, being more or less in the form of a truncated conewhen the holes are round or oval.
For simplicity of illustration, the holes or openings in the film are not shown. It can be appreciated that the openings may be of any desired shape such as round, oval, rectangular, pentagonal, hexagonal or other geometric configuration. It is desired that the holes be uniform and that they be sufficiently large in size and number to provide adequate infusion and be sufficiently small in size to prevent the migration of particles therethrough such as the particulated product P.
~Z210~6~
In the packaging of an item such as tea, a preferred hole size is fro~ two to 10 mils (0.00508-0.025~ cm), in diameter or across the opening, with a size of three to four mils ~0.00762-0.01016 cm) being most preferred. The film has a thickness of 0.25 mil to two mils (0.000635-0.00508 cm) and 500 holes per square inch (77.5 holes per square centimeter) or more. From 1800 to 4200 holes per ~quare inch (279 to 651 holes per square centimeter) are preferred, with about 2900 holes per square inch t449.5 holes per square centimeter) being most preferred. The porosity of the film is preferably 50 to 500 cubic feet per minute (CFM)~23,597 to 235,973.7 cubic centimeters per second).
The outer layer of the coaxial or coextruded perforated thermoplastic film of the bag is preferably a heat resistant polyester film having a melting temperature of 425F to 600F
(218.83C to 315.56C) with about 525F (273.89C) being most preferred. The inner sealant layer of the coextruded perforated thermoplastic film of the bag is preferably a somewhat less heat resistant polyethylene film having a melting temperature of 180F to 250F (82.22C to 121.11C) with 220F ~104.44~C) being most preferred. The use of an outer polyester layer enables a sealing/melting temperature differential of about 150F (65.56C) to be obtained. The film has a desired seal strength of 3/4 lb.
per inch (133.9 grams/centimeter) width.
1~2106~
A temperature of about 240F ~115.56C) is required to melt the polyethylene film for sealing. To prevent sticking of the outer layer of thermoplastic film to the steel jaws of the sealing device or heat sealing machine, it is impcrtant that the melting temperature of the polyethylene be kept below about 260P (126.67C). It can be appreciated that particular polyolefin resins or other fLlm forming resins may have h~gher or lower melting temperatures; however, it is essential that a melting temperature differential be obtained between each layer 0 to achieve the desired ~eal without a deleterious effect on the film.
The edges of the bags and the intermediate sealing areas may be readily heat sealed using standard sealing and automatic bag making machines. The edges and intermediate sealiny areas may also be effectively sealed with use of impulse or band type sealers, hot wires, hot air or other suitable apparatuses or techniques.
The longitudLnal edge of the film is heat sealed to complete the package. The melt flow of the outer layer must be sufficiently high to prevent the film from sticking to the sealant jaws. The melting temperature of the inner sealant layer must be less than the melting temperature of the outer layer, but sufficiently high to melt the inner layer and achieve the desired seal.
1Z2~L060 For the packaging of a typical commerc~al tea for brewing, a perforated thermoplastic film suitable for construc-ting the infusion bag is a coextruded polypropylene/polyethylene perforated thermoplastic film formed from a high density poly-ethylene resin and a polypropylene resin. The resins are odor-less and tasteless and approved for food packaging.
The film is preferably clear in color, but may be manu-factured in its natural color or a variety of colors as desired or permitted by governmental regulations, etc.
The film has a dry surface and has no tendency to stick, cling or ~block~.
Perforated thermoplastic films suitable for use in the invention have a male side and a female side. In construction of infusion bags, the male side of the film is on the inside of the bag. This relationship effectively seals the tabs of the package which are positioned on either side of the product con-taining pocket or area.
The invention is illustrated in its simplest form, and as a typical small size infusion bag for the packaging of indivi-dual servings of tea for brewing. Larger size packages, such asthose customarily used in the food services industry, can also be constructed. Such larger bags can be similarly constructed or constructed of two rectangular strips of film and sealed on all four edges. The bags or packages of the invention can be con-structed in other geometrical configurations as desired, but ~ZZ1060 rectangular shaped packages are generally more suitable for boxing or other type of group pa~kag$ng and can usually be more easily fabricated.
The product i8 confined to the center portion of the tube and the ends are heat sealed to form the tabs. Other sealing methods can be used if desired, but heat Bealing i6 pre-ferred. The flat tabs also provide a good surface for logos, advertising, lnstructions or for other printing.
Although the cross-sectional geometry of a filled bag is 0 somewhat circular or oval, it can be of any desired geometrical configuration, for example, a star shape to promote flow and greater surface exposure. In another form of the invention, two narrow strips or ribbons of thermoplastic film are aligned male side to ~ale side. The product, such as tea, is deposited in a thin layer on the top (male) surface of the bottom ribbon. The top ribbon is then laid over the product, sealed along each edge and intermittently spot sealed between the edges in a regular pattern or an irregular pattern. The spot seals hold the two ribbons together in close proximity and prevent the product from bunching~ The male surfaces of the film are effectively utilized to prevent the tea or other product from bunching thereby keeping maximum tea surface exposed for brewing.
In addition to the advantages set forth hereinbefore, the present invention also provides improved product distribu-tion, of~ers the possibility of rapid filling, eliminatesstrings, staples or other extraneous mat.er. A unique means of ` ~Z2~06() squeezing a bag is provided by simultaneously pulllng collapsed ends of the tube or package.
Although a coextruded multilayer perforated plastic film i8 preferred, other types of perforated thermoplastic films may be used. Such films, of course, must provide adequate infusion and sufficient strength for the purposes intended.
Some examples of film forming resins suitable for making the perforated thermoplastic films of which the infusion packages of this invention are constructed are polyethylene (PE), poly-0 propylene (PP), crystalline polyester (CPE), amorphous polyester(APE), polycarbonate (PC) and nylon (N).
Some examples of multilayer films suitable for use in constructing the infusion pa~kages of the invention are, in addition to CPE/PE, as follows:
PP~PE PC/PE N/PP
CPE/PP PC/PP N/PE
CPE/APE PC/APE N/APE
In addition to dual layer thermoplastic films, triple layer films or films having as many layers as desired can be used. Such films, of course, must be of the perforated type and meet desired infusion rates and packaging requirements.
Although the ~nvention is particularly directed to infusion packages or bags constructed of perforated thermoplastic films, it is suitable for use with other types of porous materials including paper, cloth or other similar type materials.
lZ;~L06~
These porous materials must also provide adequate infusion and 8 ufficient strength for the purposes intended.
Although the invention i particularly suitable for the packaging of tea, it can be use~ for packaging of other types of finely ground or particulated food products such as coffee and grits. The bags may be used for packaging of any items in which infusion of liquids is desired.
The infusion bags of the present invention have excel-lent wet strength and will not deteriorate in boiling water.
The bags themselves are odorless and tasteless and do not impart any foreign taste to the item being packaged. They are, in effect, substantially inert.
Infusion bags with positioning means and flotation means 15 are di~closed in U.S. 3,797,642 and U.S. 3,809,215, respectively.
The tea bags themselves may be made of various materials inclu-ding paper, plastics such as nylon, perforated plastic film, e.g., polyester, or woven or non-woven fabric of natural or synthetic origin.
A percolatable porous bag constructed of a blend of individualized textile or cellulosic fiber and a small amount of thermoplastic fiber is disclosed in Canadian patent 802,720.
Various degrees of success have been achieved with the foregoing infusion bags or packages, with paper or fibrous bags presently dominating the market place. One of the problems with lZ2~360 paper bags is iack of wet str~ngth. Paper packages do not have the strength to withstand squeezlng or other pressures commonly applied by consumer or other u~ers.
kn ~rfusion bag for items such as tea, coffee or similar food products for brewing must have a number of qualities. It must have an inab$1ity to impart a taste factor to the liquid product after brewing. In effect, it must be substantially odor-less and tasteless. It must also be sufficiently strong to con-tain the brewing product in boiling water, e.g., in the steeping 0 of tea, coffee, and similar liquid beverages. The bag must also be porous enough to permit liquid diffusion therethrough, but the pores or openings must be of such size that migration of the beverage material therethrough is inhibited, both when the bag is dry and when the bag has been immersed in a liquid. It is also imyortant that infusion begins to take place within a few seconds and be completed within a few minutes. It is further desirable that a package, bag or sachet, such as a tea sachet, retain sufficient stability that it can be compressed after brewing is completed without destruction of the container.
Thermoplastic films such as polyethylene and polypro-pylene are common packaging materials. Multilayer films of various types are also quite common packaging materials. The films are generally non-porous and impervious to water and other inert liquids. At least one of the layers of film has strong adhesive qualities. Examples of such multilayer films may be 1~2~60 seen in U.S. 4,254,169- U.S. 4,239,826; U.S. 4,233,367, U.S. 3,908,070; U.S. 3,423,231; U.S. 2,817,124 and U.S. 2,817,123.
Perforated thermoplastic films have many useful applications, including packaging of food products such as cheese, gardening and farming to prevent growth of weeds while permitting moisture to be transmitted through the film to the soil beneath and for making absorptive structures such as disposable diapers,for example, see U.S. 3,814,101.
Perforation of thermoplastic films is generally achieved by vacuum perforation of thin plastic films which involves the extrusion of molten polymeric materials such as polyethylene through a slot die. The hot melt web of film exiting the die impinges on a form through which a vacuum is drawn causing the film web to be perforated and holes formed therein. Depending upon the form used, films can be produced which have as few as 50 holes per square inch or which have thousands of holes per square inch. One of the earlier methods for vacuum perforation of plastic film is disclosed in U.S. 3,054,148.
The present invention provides an infusion package or sachet which meets the requirements for tea brewing and additionally overcomes the problems of lack of wet strength and packaging associated with the prior art.
More particularly, the present invention provides an infusion package for particulated or finely ground products consisting of a tube of porous material having a central product containing portion and an elongated flattened end portion on each end thereof, the ends being oppositely ~rc~
~Z2~60 located ends, each of the flattened end portions being sealedly separated from the central product containing portion, the flattened end portions being sufficiently elongated that they may beinterwoven or knotted together, whereby when so interwoven or knotted together a flow through type of package with an intearated handle thereon is formed,allowing a majority of the central product con-tai~ina portion to be suspended therebelow, at least one of the flattened end portions having an elongated slot or opening therein which enables one flattened end portion to be inserted through the other flattened end portion and thereby form the flow through type of bag with an integrated handle thereon, and ^the porous material having a multiplicity of fine openings or holes therein each of which is sufficientlv small in si7.e to inhibit migration therethrough of a part-iculated product contained in the central product containing portion and is sufficiently large in size to permit the flow of liquids therethrough.
Fig. 1 is a top plan view of an embodiment of the invention;
Fig. 2 is a side elevational view of the embodiment of Fig. l;
Fig. 3 is an end view of the embodiment of Fig. l;
Fig. 4 is a sectional view taken across line 4-4 of Fig. l;
Fig. 5 is a top view taken across line 5-5 of Fig. l;
Fig. 6 is a view of the e~bodiment of Fig. 1 illustrating one means of joining together the ends of the package; and ,, jrc: ~~
~22~0~(~
Fig. 7 is a view similar to that of Fig. 6 illustrating another means of joining the ends of the tea bag.
Referring now to the drawings, an infusion package or bag of the present invention is illustrated generally at 10.
The bag or packet 10 is constructed of a rectangular strip of a perforated plastic film 11 which is described in more detail~
hereinafter. For simplicity of illustration, perforations in the film are not shown. The strip of film 11 is folded longitud-inally at 12, sealed at intermediate locations 13 and 14 and filled with a particulated product P which can be seen through the film 11 between the sealings. After the product P is inserted in the sachet 10, the edge 15 is sealed, thereby encasing the product P within the package 10.
The intermediate sealings 13 and 14 provide tabs 16 and 17 on either side of the product P. Conveniently, slits or longitudinal slots 18 and 19 are formed in each of the tabs 16 and~17-, respectively.
As best seen in Figs. 1 and 2, the ends of the elongated flattened end portions (or tabs 16 and 17) are located oppositely of the central produc~ containing portion or the portion between the sealings 13 and 14 containing the product P. The flattened end portions are sufficiently elongated that they may be inter-woven or knotted together as shown in Figs. 6 and 7, respectively.
Once the package 10 is interwoven or knotted together, a flow through package 10 is formed with an integrated handle thereon.
In flow through form, a majority of the central product contain-ing portion is suspended below the handle formed by the flattened end portions.
jrc:
~2:~0i~
The infusion package 10 of the present invention is illustrated in its simplest form. Such packages can be readily made on existing filling and packaging machines with minimal modification. The relatively flat shape of the bags permits easy packaging or boxing in a fashion similar to that of boxing cigars.
- Figs. 6 and 7 illustrate two means by which the package 10 is readily converted to a flow through or dual container in-fusion bag. In Fig. 6, tab 16 is inserted through slot 19 of - 8a --~ ~ jrc:
~;~Z10~;0 g tab 17. Tabs 1~ and 17 are of sufficlen~t length to provide a handle which can readily be extended over the side of a cup or brewing pot.
Ir, ~ig. 7, the slots are not used and the tabs are assembled in a half knot or full knot, if desired. The tabs 16 and 17 are sufficiently long to easily provide the desired handles.
The infusion bag or package 10 is preferably constructed of a coextruded multilayer film 11 comprising an outer layer of 1~ a heat resistant thermoplastic such as polyester, polyolefin, or the like, with p~lyester being preferred, and an inner sealant layer of a somewhat less heat resistant thermoplastic such as polyethylene or the like. The film 11 has a multiplicity of fine holes or capillaries which are of a somewhat tapered con-struction, being more or less in the form of a truncated conewhen the holes are round or oval.
For simplicity of illustration, the holes or openings in the film are not shown. It can be appreciated that the openings may be of any desired shape such as round, oval, rectangular, pentagonal, hexagonal or other geometric configuration. It is desired that the holes be uniform and that they be sufficiently large in size and number to provide adequate infusion and be sufficiently small in size to prevent the migration of particles therethrough such as the particulated product P.
~Z210~6~
In the packaging of an item such as tea, a preferred hole size is fro~ two to 10 mils (0.00508-0.025~ cm), in diameter or across the opening, with a size of three to four mils ~0.00762-0.01016 cm) being most preferred. The film has a thickness of 0.25 mil to two mils (0.000635-0.00508 cm) and 500 holes per square inch (77.5 holes per square centimeter) or more. From 1800 to 4200 holes per ~quare inch (279 to 651 holes per square centimeter) are preferred, with about 2900 holes per square inch t449.5 holes per square centimeter) being most preferred. The porosity of the film is preferably 50 to 500 cubic feet per minute (CFM)~23,597 to 235,973.7 cubic centimeters per second).
The outer layer of the coaxial or coextruded perforated thermoplastic film of the bag is preferably a heat resistant polyester film having a melting temperature of 425F to 600F
(218.83C to 315.56C) with about 525F (273.89C) being most preferred. The inner sealant layer of the coextruded perforated thermoplastic film of the bag is preferably a somewhat less heat resistant polyethylene film having a melting temperature of 180F to 250F (82.22C to 121.11C) with 220F ~104.44~C) being most preferred. The use of an outer polyester layer enables a sealing/melting temperature differential of about 150F (65.56C) to be obtained. The film has a desired seal strength of 3/4 lb.
per inch (133.9 grams/centimeter) width.
1~2106~
A temperature of about 240F ~115.56C) is required to melt the polyethylene film for sealing. To prevent sticking of the outer layer of thermoplastic film to the steel jaws of the sealing device or heat sealing machine, it is impcrtant that the melting temperature of the polyethylene be kept below about 260P (126.67C). It can be appreciated that particular polyolefin resins or other fLlm forming resins may have h~gher or lower melting temperatures; however, it is essential that a melting temperature differential be obtained between each layer 0 to achieve the desired ~eal without a deleterious effect on the film.
The edges of the bags and the intermediate sealing areas may be readily heat sealed using standard sealing and automatic bag making machines. The edges and intermediate sealiny areas may also be effectively sealed with use of impulse or band type sealers, hot wires, hot air or other suitable apparatuses or techniques.
The longitudLnal edge of the film is heat sealed to complete the package. The melt flow of the outer layer must be sufficiently high to prevent the film from sticking to the sealant jaws. The melting temperature of the inner sealant layer must be less than the melting temperature of the outer layer, but sufficiently high to melt the inner layer and achieve the desired seal.
1Z2~L060 For the packaging of a typical commerc~al tea for brewing, a perforated thermoplastic film suitable for construc-ting the infusion bag is a coextruded polypropylene/polyethylene perforated thermoplastic film formed from a high density poly-ethylene resin and a polypropylene resin. The resins are odor-less and tasteless and approved for food packaging.
The film is preferably clear in color, but may be manu-factured in its natural color or a variety of colors as desired or permitted by governmental regulations, etc.
The film has a dry surface and has no tendency to stick, cling or ~block~.
Perforated thermoplastic films suitable for use in the invention have a male side and a female side. In construction of infusion bags, the male side of the film is on the inside of the bag. This relationship effectively seals the tabs of the package which are positioned on either side of the product con-taining pocket or area.
The invention is illustrated in its simplest form, and as a typical small size infusion bag for the packaging of indivi-dual servings of tea for brewing. Larger size packages, such asthose customarily used in the food services industry, can also be constructed. Such larger bags can be similarly constructed or constructed of two rectangular strips of film and sealed on all four edges. The bags or packages of the invention can be con-structed in other geometrical configurations as desired, but ~ZZ1060 rectangular shaped packages are generally more suitable for boxing or other type of group pa~kag$ng and can usually be more easily fabricated.
The product i8 confined to the center portion of the tube and the ends are heat sealed to form the tabs. Other sealing methods can be used if desired, but heat Bealing i6 pre-ferred. The flat tabs also provide a good surface for logos, advertising, lnstructions or for other printing.
Although the cross-sectional geometry of a filled bag is 0 somewhat circular or oval, it can be of any desired geometrical configuration, for example, a star shape to promote flow and greater surface exposure. In another form of the invention, two narrow strips or ribbons of thermoplastic film are aligned male side to ~ale side. The product, such as tea, is deposited in a thin layer on the top (male) surface of the bottom ribbon. The top ribbon is then laid over the product, sealed along each edge and intermittently spot sealed between the edges in a regular pattern or an irregular pattern. The spot seals hold the two ribbons together in close proximity and prevent the product from bunching~ The male surfaces of the film are effectively utilized to prevent the tea or other product from bunching thereby keeping maximum tea surface exposed for brewing.
In addition to the advantages set forth hereinbefore, the present invention also provides improved product distribu-tion, of~ers the possibility of rapid filling, eliminatesstrings, staples or other extraneous mat.er. A unique means of ` ~Z2~06() squeezing a bag is provided by simultaneously pulllng collapsed ends of the tube or package.
Although a coextruded multilayer perforated plastic film i8 preferred, other types of perforated thermoplastic films may be used. Such films, of course, must provide adequate infusion and sufficient strength for the purposes intended.
Some examples of film forming resins suitable for making the perforated thermoplastic films of which the infusion packages of this invention are constructed are polyethylene (PE), poly-0 propylene (PP), crystalline polyester (CPE), amorphous polyester(APE), polycarbonate (PC) and nylon (N).
Some examples of multilayer films suitable for use in constructing the infusion pa~kages of the invention are, in addition to CPE/PE, as follows:
PP~PE PC/PE N/PP
CPE/PP PC/PP N/PE
CPE/APE PC/APE N/APE
In addition to dual layer thermoplastic films, triple layer films or films having as many layers as desired can be used. Such films, of course, must be of the perforated type and meet desired infusion rates and packaging requirements.
Although the ~nvention is particularly directed to infusion packages or bags constructed of perforated thermoplastic films, it is suitable for use with other types of porous materials including paper, cloth or other similar type materials.
lZ;~L06~
These porous materials must also provide adequate infusion and 8 ufficient strength for the purposes intended.
Although the invention i particularly suitable for the packaging of tea, it can be use~ for packaging of other types of finely ground or particulated food products such as coffee and grits. The bags may be used for packaging of any items in which infusion of liquids is desired.
The infusion bags of the present invention have excel-lent wet strength and will not deteriorate in boiling water.
The bags themselves are odorless and tasteless and do not impart any foreign taste to the item being packaged. They are, in effect, substantially inert.
Claims (18)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An infusion package for particulated or finely ground products consisting essentially of a tube of perforated thermoplastic film having a central product containing portion and an elongated flattened end portion on each end thereof, said ends being oppositely located ends, each of said flattened end portions being sealedly separated from said central product containing portion, said flattened end portions being sufficiently elongated that they may be interwoven or knotted together, whereby when so interwoven or knotted together a flow through type of package with an integrated handle thereon is formed, allowing a majority of said central product containing portion to be suspended there-below, at least one of said flattened end portions having an elongated slot or opening therein which enables one flattened end portion to be inserted through the other flattened end portion and thereby form the flow through type of bag with an integrated handle thereon, and said thermo-plastic film having a multiplicity of minute uniform holes or openings therein each of which is sufficiently small to inhibit migration therethrough of a particulated product contained in the central product containing portion and is sufficiently large to permit the flow of liquids therethrough.
2. The infusion package of claim 1, wherein the per-forated thermoplastic film is a polyester film.
3. The infusion package of claim 1, wherein the film has at least 500 holes per square inch thereof.
4. The infustion package of claim 1, wherein the film has from about 1800 to 4200 holes per square inch thereof.
5. The infusion package of claim 1, wherein the film has about 2900 holes per square inch.
6. The infusion package of claim 1, wherein the holes of said film are round, oval, rectangular, pentagonal, hexagonal or other desired geometrical shape.
7. The infusion package of claim 1, wherein the open-ings or holes of said film are about 2-10 mils across at their widest axis.
8. The infusion package of claim 1, wherein the open-ings or holes of said film are about 3-4 mils across at their widest axis.
9. The infusion package of claim 1, wherein the per-forated thermoplastic film is a polyester film, a polycarbonate film, a polypropylene film, a polyethylene film, a nylon film or a combination of such films.
10. The infusion package of claim 1, wherein said pack-age has sufficient wet strength or stability that it may be compressed after liquid infusion without destruction of the package.
11. The infusion package of claim 1, wherein each of said elongated flattened end portions has an elongated slot or opening therein whereby either elongated flattened end portion may be inserted through the other elongated flattened end portion to form the flow through type of bag with an integrated handle thereon.
12. The infusion package of claim 1, wherein said package is free of any extraneous materials such as staples, strings, tabs, tags or the like.
13. The infusion package of claim 1, wherein said flattened end portions have been interwoven or knotted together and a flow through type of package formed.
14. The infusion package of claim 13, wherein after liquid infusion, the liquid may be squeezed therefrom while withdrawing the package from a cup or container.
15. An infusion package for particulated or finely ground products consisting of a tube of porous material having a central product containing portion and an elongated flattened end portion on each end thereof, said ends being oppositely located ends, each of said flattened end portions being sealedly separated from said central product containing portion, said flattened end portions being sufficiently elongated that they may be interwoven or knotted together, whereby when so interwoven or knotted together a flow through type of package with an integrated handle thereon is formed, allowing a majority of said central product containing portion to be suspended therebelow at least one of said flattened end portions having an elongated slot or opening therein which enables one flattened end portion to be inserted through the other flattened end portion and thereby form the flow through type of bag with an integrated handle thereon, and said porous material having a multiplicity of fine openings or holes therein each of which is sufficiently small in size to inhibit migration therethrough of a particulated product contained in the central product containing portion and is sufficiently large in size to permit the flow of liquids therethrough.
16. An infusion package for particulated or finely ground products consisting essentially of a tube of perforated thermoplastic film having a central product containing portion, a product in said central product containing portion, an elongated flattened end portion on each end, said ends being oppositely located ends, each of said flattened end portions of said central product containing portion being sealedly separated from said central product containing portion, said flattened end portions being sufficiently elongated that they may be interwoven or knotted together, whereby when so interwoven or knotted together a flow through type of package with an integrated handle thereon is formed, allowing a majority of said central product containing portion to be suspended below the handle formed by said flattened end portions, said product containing package having sufficient wet strength or stability that it may be compressed after liquid infusion without destruction of the package, and said product containing package being free of any extraneous materials such as staples, strings, tabs, tags, or the like.
17. The infusion package of claim 16, wherein at least one of said flattened end portions has an elongated slot or opening therein which enalbes one flattened end portion to be inserted through the other flattened end portion and thereby form the flow through type of bag with an integrated handle thereon.
18. The infusion package of claim 17, wherein the package may be lain in a substantially flattened position after filling with a product and a plurality of the packages may be packaged as any group of rectangularly shaped packages.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56182483A | 1983-12-15 | 1983-12-15 | |
| US561,824 | 1983-12-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1221060A true CA1221060A (en) | 1987-04-28 |
Family
ID=24243625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000468970A Expired CA1221060A (en) | 1983-12-15 | 1984-11-29 | Infusion package |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0145500B1 (en) |
| JP (1) | JPS60158061A (en) |
| AT (1) | ATE40330T1 (en) |
| CA (1) | CA1221060A (en) |
| DE (1) | DE3476370D1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4756915A (en) * | 1987-04-09 | 1988-07-12 | Tetley, Inc. | Process for preparing a brewed beverage |
| AUPQ489199A0 (en) * | 1999-12-24 | 2000-02-03 | Rothtech Pty Ltd | Infusion bags |
| GR1009357B (en) * | 2017-03-22 | 2018-09-17 | Γεωργιος Δημητριου Σεμπος | Perforated taste-improving rod for food and infusions in the process of preparation |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE517130A (en) * | 1953-01-23 | 1953-02-14 | ||
| CH399988A (en) * | 1961-12-11 | 1965-09-30 | Hesser Ag Maschf | Process for producing connecting seams on packaging made from fibrous packaging materials |
| US3334803A (en) * | 1965-06-16 | 1967-08-08 | Hyman D Abbey | Beverage infusion bag |
| GB1200090A (en) * | 1967-10-06 | 1970-07-29 | Frederick Percy Andrews | Tea packet and dispensing and forming container therefor |
| US3549381A (en) * | 1967-12-26 | 1970-12-22 | Hercules Inc | Packaging material |
| US3888999A (en) * | 1973-05-30 | 1975-06-10 | Gen Foods Corp | Coffee percolator packages and method |
| CA1002001A (en) * | 1975-10-15 | 1976-12-21 | Robert Rodriques-Ely | Floating infusion filter |
| US4229481A (en) * | 1978-06-16 | 1980-10-21 | Fornari Hector C | Process and means to make aromatic infusions |
| JPS5553367Y2 (en) * | 1978-09-07 | 1980-12-10 | ||
| NL8203234A (en) * | 1982-08-18 | 1984-03-16 | Unilever Nv | FILM FITTED WITH MICROPERFORATIONS. |
-
1984
- 1984-11-29 CA CA000468970A patent/CA1221060A/en not_active Expired
- 1984-12-14 JP JP59264371A patent/JPS60158061A/en active Granted
- 1984-12-14 AT AT84308719T patent/ATE40330T1/en not_active IP Right Cessation
- 1984-12-14 EP EP84308719A patent/EP0145500B1/en not_active Expired
- 1984-12-14 DE DE8484308719T patent/DE3476370D1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0238463B2 (en) | 1990-08-30 |
| DE3476370D1 (en) | 1989-03-02 |
| JPS60158061A (en) | 1985-08-19 |
| EP0145500B1 (en) | 1989-01-25 |
| EP0145500A3 (en) | 1987-01-07 |
| EP0145500A2 (en) | 1985-06-19 |
| ATE40330T1 (en) | 1989-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4605123A (en) | Infusion package | |
| EP0145499B1 (en) | Infusion bag | |
| US2377118A (en) | Package | |
| US5601716A (en) | Filter material | |
| US4815590A (en) | Bag with absorbent insert | |
| US4359357A (en) | Method of making tampon with a non-woven wrap | |
| US2359292A (en) | Infusion package with handle | |
| US20090056277A1 (en) | Floral sleeve with constriction element | |
| US2306400A (en) | Infusion package heat sealing filter-paper manufacture | |
| US5552164A (en) | Infusion package | |
| BG61873B1 (en) | Polymer bag, in particular of polyolefine fabric, and method for its preparation | |
| US2406018A (en) | Method of manufacturing infusion packages | |
| NZ252991A (en) | Sealed flexible sachet; two identical flexible sheets sealed together to provide powdered beverage container, sheet material being oxygen and water vapour impermeable | |
| JPS6099855A (en) | Bag for transport made of thermoplastic resin | |
| US4415597A (en) | Filter-bag for infusion products | |
| NZ249956A (en) | Infusible package; tea/coffee bag with extra length of draw string inside the bag | |
| US4417433A (en) | Method of making infusion package | |
| CA1221060A (en) | Infusion package | |
| US2571138A (en) | Infusion package with expandible bottom and method of manufacture thereof | |
| US20040093794A1 (en) | Floral sleeve having expansion elements | |
| US20070277434A1 (en) | Floral sleeve with constriction element | |
| US6274180B1 (en) | Expandable beverage infusion device | |
| CA1221058A (en) | Infusion bag | |
| CA1221059A (en) | Infusion bag | |
| CA1221061A (en) | Infusion bag |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |