Patent GB-992241-A (GB)
Title: Coating method and apparatus
Inventor: CLARE DENNIS EDWARD
IPC: A23G3/26
Filed: 1960-05-02
Abstract: A method for a batchwise coating of uniform, small confectionery objects comprises the steps of treating the objects with a coating material in a liquid vehicle under uniform conditions in a pan which has an unperforated cylindrical inner surface of uniform cross-section throughout its length rotating around a horizontal axis coincidental with the axis of radial symmetry and has nothing therein to hinder the movement of the tumbling objects, and removing the liquid by drying with air or gas, both the coating material and the drying air or gas being applied evenly to every section of the pan, providing thereby a substantially similar path of travel for each object, and minimizing the statistical distribution of the weight, diameter or thickness of the coated objects.  In examples, peanuts are coated with chocolate, and granules containing equal parts of lactose and glucose are coated with a solution of shellac and powdered magnesium stearate.  Apparatus for carrying out the process comprises a rotatable pan having an unperforated cylindrical inner surface of uniform radial cross-section throughout its length capable of being rotated around a horizontal axis coincidental with the axis of radial symmetry and having nothing therein to hinder the movement of the tumbling objects to be coated and one or more central orifices positioned in one or both walls terminating the cylinder, for introducing the objects to be coated and removing the product, and for introducing supplying means capable of applying coating material in a liquid vehicle and p  drying air or gas directly and evenly to the objects in every section of the pan, providing thereby substantially uniform conditions minimizing the statistical distribution of the weight, diameter or thickness of the coated objects.  The means for applying coating material may comprise a pipe throughout the length of the cylinder with holes spaced along its length.  The drying air may be applied by a similar means.  An exhaust means to remove dust-laden air from the interior of the drum may also be provided.  The liquid coating materials may be poured on or sprayed on.  A sub-coating may be applied as an extra step before the coating process of the invention.  Example 7 describes the granulation of powdered glucose.  Specification 908,282 is referred to.ALSO:A method for a batchwise coating of pharmaceutical tablets, pills or granules or uniform small confectionery objects comprises the steps of treating the articles to be coated with a coating material in a liquid vehicle under uniform conditions in a pan which has an unperforated cylindrical inner surface of uniform cross-section throughout its length rotating around a horizontal axis coincidental with the axis of radial symmetry and has nothing therein to hinder the movement of the tumbling objects, and removing the liquid by drying with air or gas, both the coating material and the drying air or gas being applied evenly to every section of the pan, providing thereby a substantially similar path of travel for each object, minimizing the statistical distribution of the weight, diameter or thickness of coated objects.  In examples tablets are coated with sugar, peanuts are coated with chocolate, pellets of bephenium hydroxynaphthoate are coated with a lacquer soluble in gastric juice, and granules are coated with ethyl cellulose or alternatively with a solution of shellac and powdered magnesium stearate.  Apparatus for carrying out the process comprises a rotatable pan having an unperforated cylindrical inner surface of uniform radial cross-section throughout  its length capable of being rotated around a horizontal axis coincidental with the axis of radial symmetry and having nothing therein to hinder the movement of the tumbling objects to be coated and one or more central orifices positioned in one or both walls terminating the cylinder, for introducing the objects to be coated and removing the product, and for introducing supplying means capable of applying coating material in a liquid vehicle and drying air or gas directly and evenly to the objects in every section of the pan, providing thereby substantially uniform conditions minimizing the statistical distribution of the weight, diameter or thickness of the coated objects.  The means for applying coating material may comprise a pipe throughout the length of the cylinder with holes spaced along its length.  The drying air may be applied by a similar means.  An exhaust means to remove dust-laden air from the interior of the drum may also be provided. The liquid coating materials may be poured on or sprayed on.  A sub-coating may be applied as an extra step before the coating process of the invention.  Specification 908,282 is referred to.