Patent GB-1080678-A (GB)
Title: Method of and apparatus for coating the inner surface of a capillary system
IPC: C23C16/04
Filed: 1965-11-18
Abstract: 1,080,678. Coated capillary system. SCHLADITZ-WHISKERS A.G. Nov. 18, 1965 [Dec. 1, 1964], No. 49125/65. Headings B2E and B2L. The inner surfaces of a capillary system are coated with the decomposition products of a thermally decomposable compound, by a process wherin a liquid or gaseous heating medium is admitted into and pumped out of the capillary system several times until all points of the capillary system have reached the decomposition temprature of the thermally decomposible compound, whereupon the decomposable compound, in gaseous form, is admitted into and pumped out of the capillary system one or more times. The admission and withdrawal of the heating medium and the thermally decomposable compound may be repeated alternately the necessary number of times to achieve the desired thickness of coating. The capillary system may have non rigid walls and the heating medium and the thermally decomposable compound are pumped through the system by means of alternate compression and release of the system. The capillary system may be foamed plastics material or rubber foam. The system may be placed in a chamber in which a partial vacuum is created each time before the heating medium or decomposable compound is admitted. Metals may be deposited from decomposable metal compounds e.g. iron carbonyl or nickel carbonyl; other decomposable compounds specified are ethylene silicide and hydrocarbon. A appartus for carrying out the process for a non rigid capillary system (Figure 1) includes a sealed vessel 1 in which are provided two substantially parallel, perforated plates 2, 3 which can be contra-reciprocated and between which the non rigid capillary system 4 is disposed, means 7 for admitting heating medium into the vessel, means 9 for withdrawing the used heating medium from the vessel, means 8 for admitting to the vessel the thermally decomposable compound, and means 9 for withdrawing therefrom the unconverted compound and decomposition products thereof. The apparatus may include valve controlled means 10, 11 and 12 for admitting and withdrawing the heating medium and the thermally decomposable compound into the vessel. The side walls 5 and 6 of the vessel may be in the form of a bellows or telescopic walls, to which the plates are attached. The walls of the vessels may be composed of or coated with a deposit-repellent material e.g. polytetrafluoroethylene. A suction pump may be connected to the vessel to create a partial vacuum therein. Apparatus for the uninterrupted coating of a web 4' of a non rigid capillary system (Figure 2) includes means for intermittently advancing the web between the plates 2, 3 which move by means of rods 13, 14 which are in turn moved by bellows 15 and 16. As shown in Figure 3, the apparatus may comprise a plurality of chambers 25, 26, 27, 28 containing contromovable plates 2, 3 arranged in a series, through which the web is intermittently advanced, conduits for admitting and withdrawing the heating medium being connected to some of the chambers, as shown 25 and 27, whilst conduits for admitting the thermally decomposable compound and withdrawing the unconverted gases and the gaseous decomposition products of the compound are connected to the other chambers 26 and 28, a chamber receiving the heating medium being followed by a chamber receiving the compound to be decomposed. As shown in Figure 4, the apparatus may include a sealed vessel 38 within which the rigid or non rigid capillary system 4" is disposed, means 7 for admitting the heating medium into the vessel, means 39 for withdrawing the used heating medium from the vessel, means 8 for admitting the thermally decomposable compound into the vessel, means 39 for withdrawing unconverted compound and decomposition products thereof from the vessel, and means for creating a partial vacuum in the vessel each time before the heating medium or the thermally decomposable compound is admitted.