Compressible packages for infusible substances

An infusible package includes a closed bag, containing an infusible substance for infusion in a liquid. The bag is formed from panels of porous material sealed at their peripheral margins; and at least one string. Each string extends through a seal between the panels, enters the interior of the bag at a point on the peripheral margins and extends across the interior of the bag to an anchoring point at or adjacent the peripheral margins. The length of that portion of each string which extends across the interior of the bag between the point on the peripheral margins and the anchoring point is greater than the distance between that point and the anchoring point. With this arrangement, pulling the string initially causes withdrawal from the bag interior of slack string length disposed therein.

We claim:

1. An infusion package comprising a closed bag containing an infusible substance for infusion in a liquid, the bag being formed from panels of porous materials sealed together at their peripheral margins; said bag having an interior chamber formed between said panels and within said peripheral margins, within which said infusible substance is contained; and a pair of drawstrings, each of which extends into the interior of the bag through a seal between the panels at spaced apart entry points on the peripheral margins, and extends across the interior chamber within which said infusible substance is contained to an anchoring point at a generally opposed location from said entry points on or adjacent the peripheral margins without penetrating said panels of the bag; wherein the length of that portion of each string which extends across the interior of the bag between the said one point and the anchoring point is greater than the distance between the said one point and the anchoring point, and provides a length of slack string within the bag; and wherein each drawstring is anchored by sealed together portions of the panels at said anchoring point, the arrangement being such that pulling each string initially causes withdrawal from the bag interior of the slack string length disposed therein without collapsing the bag, and wherein further pulling of the drawstrings in generally opposed directions causes the bag to collapse thereby to express liquid absorbed by the infusible substance during infusion.

2. An infusion package according to claim 1 wherein each drawstring is anchored by being held by two sealed-together portions of the panels.

3. An infusion package according to claim 1 wherein the length of that portion of each string which extends across the interior chamber is greater than one and a half times the distance between the said entry point and the anchoring point.

4. An infusion package according to claim 3 wherein the said length extending across the interior chamber is greater than one and three quarters times the said distance between said entry point and the anchoring point.

5. An infusion package according to claim 1 wherein at least 60% of the total length of each string is disposed within the interior chamber, prior to sue of the infusion package.

6. An infusion package according to claim 1 wherein the length of that portion of each string disposed externally of the infusion package extending from said entry points on the peripheral margin prior to use of the infusion package, is no greater than 30% of the total length of the string.

7. An infusion package according to claim 1 wherein the pair of drawstrings are constituted by two ends of a single continuous length of string.

8. An infusion package according to claim 7 wherein a single tag is employed to link the two ends of said single continuous length of string.

9. An infusion package according to claim 8 wherein the said single tag is provided with a point of weakness to enable the single tag to be divided into two separate tags during use.

10. An infusion package according to claim 1 wherein each string has on an external end thereof a tag.

11. An infusion package according to claim 10 wherein the length of string between the tag and the bag is sufficiently short, prior to use, that the tag lies closely adjacent to the peripheral margins of the infusion package.

12. An infusion package according to claim 1 wherein the pair of drawstrings are anchored at points spaced apart along an opposed location on the peripheral margins of the bag.

13. An infusion package according to claim 1 where the arrangement of the drawstrings is symmetrical about a plane of symmetry passing through the center of the bag.

14. An infusion package according to claim 1 wherein the pair of drawstrings are constituted by two ends of a single continuous length of string, and a loop of the said continuous length of string is held at said anchoring point.

15. An infusion package according to claim 14 wherein the said loop is anchored within the peripheral margin.

16. An infusion package according to claim 14 wherein the said loop is anchored inwardly of the peripheral margin.

17. A method of preparing an infusion package comprising: forming a bag from panels of porous material having peripheral margins and sealing said panels together at said peripheral margins, said bag having an interior chamber formed between said panels and within said peripheral margins, placing an infusible substance in said interior chamber, and wherein prior to said sealing said panels, positioning a pair of drawstrings relative to said bag such that each extends into the interior of the bag through a seal between the panels at spaced apart entry point on the peripheral margins, and extends across the interior chamber within which said infusible substance is contained to an anchoring point at a generally opposed location from said entry points on or adjacent the peripheral margins without penetrating said panels of the bag, said sealing said panels anchoring each drawstring such that each is anchored by sealed together portions of the panels at said anchoring point, and the length of that portion of each string which extends across the interior of the bag between said entry point and the anchoring point is greater than the distance between said entry point and the anchoring point, and provides a length of slack string within the bag, the arrangement being such that pulling each string initially causes withdrawal from the interior chamber of the slack string length disposed therein without collapsing the bag, and further pulling of the drawstrings in generally opposed directions causes the bag to collapse thereby to express liquid absorbed by the infusible substance during infusion.