1. A method for producing a hydrocolloid foam comprising the steps of:
combining a hydrocolloid polymeric material in an aqueous solvent to form a solid gel; and
exposing the solid gel to radiant energy under vacuum to boil the solvent from the gel and form a foam.
2. The method of claim 1 wherein the hydrocolloid polymeric material is selected from the group consisting of: cellulose acetate phthalate (CAP), carboxy-methyl-cellulose, pectin, sodium alginate, hydroxyl propyl methyl cellulose (HPMC), methyl cellulose, carrageenan, gum acacia, xanthan gum, locust bean gum, isolated soya protein, chitosan, maltodextrin, collagen, salts of alginic acid, polyglycolic acid, starches, gelatin, and combinations thereof.
3. The method of claim 1 wherein the solvent is distilled water.
4. The method of claim 1 wherein the aqueous solvent additionally comprises an additive selected from the group consisting of coconut oil, corn oil, peanut oil, hydrogenated vegetable oil, olive oil, mineral oil, and combinations thereof.
5. The method of claim 1 wherein a surfactant is added to the aqueous solvent.
6. The method of claim 5 wherein the surfactant is selected from the group consisting of glycerol, propylene glycol, lecithin, Tween-80, Tween-20, wax, and combinations thereof.
7. The method of claim 1 additionally comprising the step of cutting the solid gel to a desired shape.
8. The method of claim 1 additionally comprising the step of freezing the solid gel.
9. The method according to claim 1 wherein the radiant energy under vacuum is provided in a chamber having pressure maintained between 30 and 760 mmHg.
10. The method according to claim 1 wherein the radiant energy under vacuum is provided at a level of from 150 to 5000 Watts per kilogram of initial mass of solid gel.
11. The method according to claim 1 wherein radiant energy is provided using microwave power.
12. The method according to claim 1 wherein the radiant energy is provided using a wavelength ranging from 1 cm to 10 meters.
13. The method according to claim 1 wherein the polymeric material is selected from the group consisting of:
a mixture of pectin and gelatin;
a mixture of pectin, CAP, and methylcellulose;
a mixture of pectin and methylcellulose;
a mixture of locust bean gum, pectin, methylcellulose, and tapioca starch; and
a mixture of sodium alginate, pectin, carrageenan, and methylcellulose.
14. The method according to claim 1 wherein a biologically active ingredient is added in the step of forming of the solid gel.
15. The method according to claim 14 wherein the biologically active ingredient comprises a drug, a microbicide, a fungicide, a vitamin, a mineral, or a spermicide.
16. The method according to claim 1 wherein the polymeric material when combined with the aqueous solvent results in a Young’s modulus value of from 0.16 kPa to 3000 kPa.
17. The method according to claim 1 wherein the radiant energy under vacuum is applied so that the foam has an average pore size ranging from 0.003 to 500 microns.
18. The method according to claim 1 wherein the radiant energy under vacuum is applied so that the foam has a water activity of less than 0.85.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for manufacturing a notepad comprising:
providing a paper supply; sequentially feeding single pages from said paper supply to a printing and cutting station; printing an image on a pad region of each single page; making at least one irregular cut at an edge of the pad region whilst leaving at least one straight edge of the pad region uncut; collating the printed and cut pages in a stack of desired quantity; cutting the collated stack along the at least one uncut straight edge of the pad region; and gluing the collated stack along any resulting cut straight edge.
2. A process according to claim 1, comprising printing a plurality of identical images at spaced apart pad regions of each single page; making at least one irregular cut at an edge of each spaced apart pad region whilst leaving at least one straight edge of each spaced apart pad region uncut and, after collation, cutting the collated stack along the at least one uncut straight edge of each spaced apart pad region.
3. A process according to claim 1, wherein the stacked pages are collated together with backboards which are correspondingly cut to match the cut pages.
4. A process according to claim 3, wherein the backboards are not printed.
5. A process according to claim 1 comprising the additional step of further cutting the glued collated stack along one or more further uncut straight edges.
6. A process according to claim 1 comprising the additional step of tearing away any waste paper from the region of the irregular cut.