Package for dispensing a fluid treating substance and method and apparatus for heat-sealing the dispensing package

摘要

A package for dispensing a substance that imparts a desirable property to a body of water. The dispensing package comprises a water permeable bag of non-woven fabric enclosing a predetermined quantity of particulated product, such as tea or coffee that releases a flavouring substance in steeping liquid. The non-woven fabric has a thermally activated bonding surface permitting to permanently close the bag by peripherally heat-sealing the bag walls to one another. The heat-sealing operation is performed by driving in the wall portions to be joined a multitude of heated projections that rapidly transfer heat to the thermally activated bonding layers in order to quickly effect the seal. The resulting joint area displays a plurality of perforations formed by the heated projections. The invention also extends to a method and apparatus for heat-sealing the dispensing package.