Soluble Unit Dose of Laundry Detergent
A soluble unit dose of laundry detergent which comprises: a) a thin walled hard capsule, having a wall thickness between 0.07 and 0.3 mm and, c) within the thin walled hard capsule a detergent composition comprising at least 1 g of surfactant, which makes up at least 45% wt of the detergent composition. wherein the solubility of the capsule and the detergent composition is such that it will reach a level of 90% of eventually dissolved electrolytes in stirred demineralised water at 25° C. in less than 35 seconds. By choice of a capsule with this wall thickness the solubility is ensured while pressure caking of the contents is resisted to minimise overall dissolution time.
1 . A soluble unit dose of laundry detergent which comprises:
a) a thin walled hard capsule, having a wall thickness between 0.07 and 0.3 mm and,
b) within the thin walled hard capsule a detergent composition comprising at least 1 g of surfactant, which makes up at least 45% wt of the detergent composition.
wherein the solubility of the capsule and the detergent composition is such that it will reach a level of 90% of eventually dissolved electrolytes in stirred demineralised water at 25° C. in less than 350 seconds.
2 . A soluble unit dose according to claim 1 wherein the hard capsule wall thickness is between 0.08 and 0.2 mm.
3 . A soluble unit dose according to claim 1 or claim 2 which floats when added to water.
4 . A soluble unit dose according to any preceding claim wherein the detergent composition has an unconfined compression test value, as defined herein, of greater than 1000 g at 35° C.
5 . A soluble unit dose according to any preceding claim wherein the capsule is formed from hydroxy-propylmethylcellulose.
6 . A soluble unit dose according to any preceding claim wherein the contents of the capsule are of particulate form.
7 . A soluble unit dose according to claim 6 wherein the particles have an average diameter of 0.1 to 2 mm.
8 . A soluble unit dose according to any one of the preceding claims wherein the surfactant is a calcium tolerant surfactant as defined herein.
9 . A soluble unit dose in which the headspace in the capsule is less than 20%, preferably less than 10%.
10 . A soluble unit dose in which the bulk density of the detergent composition is greater than 500, preferably greater than 700 even greater than 900 g/l.
11 . A soluble unit dose in which the weight of the capsule makes up less than 20% of the total weight of the unit dose, preferably less than 15%.
12 . A soluble unit dose according to any preceding claim wherein the capsule is opaque.
13 . A soluble unit dose according to any preceding claim wherein the capsule is coloured.
14 . A soluble unit dose according to claim 12 or claim 13 wherein the outside surface of the capsule is printed.
15 . A soluble unit dose according to any preceding claim wherein the capsule provides a moisture resistant barrier.
16 . A soluble unit dose according to claim 13 wherein the capsule is sealed with a band and provides an effective barrier to the transmission of water vapour.
17 . A soluble unit dose according to any preceding claim wherein a part of the detergent composition is contained in a smaller capsule within the main capsule, the smaller capsule preferably being sealed with a band.
18 . A soluble unit dose according to claim 17 wherein the smaller capsule contains bleach.
19 . A soluble unit dose according to claim 18 wherein the smaller capsule is coated.
20 . A method for laundering garments which comprises the step of introducing into a washing machine at least two thin walled hard capsules which each contain a detergent composition comprising more than 45 wt % surfactant, the weight of surfactant in each capsule being at least 1 g.
21 . The method according to claim 18 in which the filled capsules initially float on water and are introduced to the washing machine via a dispensing drawer from which they are flushed by a flow of water.
22 . A method according to claim 18 or 19 wherein the T90 value for the capsules and their contents is less than 350 s.
23 . A method according to claim 20 wherein the T90 value is less than 250 s.
24 . A method according to claim 20 wherein the T90 value is less than 180 s.