| abstract |
A capsule is made by injection-moulding from one or more of a range of thermoplastic materials, typically a soluble polyvinylalcohol, and is constructed to dissolve at varying rates in an aqueous environment. The capsule may have raised or incuse portions moulded into its external surface, which patterns may define a code or simply be rib-like, to assist in its partial dissolution. The injection-mouldable material can contain one or more particulate solid in order to accelerate the rate of dissolution of the capsule. It can also be made from materials that will not hold a static charge. The capsule is for delivering into an aqueous environment substances such as detergents, pesticides, biocides, deodorants, dyes and pigments, and water-treatment chemicals. |