Patent GB-612504-A (GB)
Title: Manufacture of sheets and coatings of plastics
IPC: D06M10/00
Filed: 1943-07-16
Abstract: <PICT:0612504/III/1> Apparatus for coating fabrics with plastics, e.g. rubber or synthetic rubber, or for making sheets by spreading the plastic in solution or dispersion upon a travelling band and vaporizing the liquid in which the plastic is dissolved or dispersed, comprises a drying chamber through which the travelling band is passed and a source of radiant heat outside the drying chamber in position to irradiate the whole of the coated surface, the wall of the chamber between the coated surface and the radiant source being made of glass or a plastic which is transparent to the principal part of the radiation.  The source of radiant heat is a bank of infra red lamps.  Sheets or coatings of desired thickness are built up by a succession of alternate coating and drying operations and, if desired, the sheet or coating is subjected to further irradiation in order to vulcanize or polymerize the plastic material.  Sheets are prepared on an endless band, whilst coatings on fabrics are obtained by forming the fabric temporarily into an endless band. Alternatively, the fabric to be coated may be unwound from a supply roller and the coated fabric collected on a take-up roller, the full and empty rollers being interchanged to repeat the operation. Alternatively, a sheet may be prepared on an endless band and a fabric subsequently applied to the sheet in order to produce a coated fabric in the manner described in Specification 612,505, [Group VIII].  The endless band may be of polished steel or fabric rendered impervious to the solution or dispersion by a coating of, for example, neoprene.  Dyes or fillers may be added to the plastic material in order to increase its absorbability of the radiation. The bottom of the chamber may have a reflecting or absorbent surface. The apparatus comprises a drying chamber 3 through which is passed an endless band carried by rollers 4 and 5, or a web or fabric 11 to be coated carried by supply and take-up rollers 6 and 7.  The web may travel upon the bottom of the chamber 3 or on a sheet of metal, perforated, if desired, and supported at mid-chamber height, or on rollers, or upon an endless band encircling the rollers 4 and 5.  The chamber is closed with sheets of red glass 12, such as that known by the Registered Trade Mark "Selenalyte," the outer surface being stippled or prismatic if desired.  Irradiation is supplied by banks of infra red lamps 17 supported above the chamber 3.  The lamps may be spaced in staggered rows and may be controlled in sections so as to produce the desired amount of radiation.  Vapours are removed from the chamber 3 by a flue 25.  Plastic material is applied by nozzles (not shown) to the web 11 adjacent the adjustable doctor blade 26. A fan may play on the coated web or film where it leaves the chamber 3 in order to cool it.  If a web of fabric is to be applied to a film, a roller adjacent the spreading device 26 is pressed upon the endless band on which the film has been built up, and the web of fabric is passed beneath it.  Air, preferably preheated, may be admitted to the chamber to assist in carrying off the vapour.  According to the Provisional Specification, if the web is supported above the floor of the chamber 3, the space beneath it may accommodate steampipes or like means of heating.ALSO:<PICT:0612504/IV(a)/1> Apparatus for coating fabrics with plastics, e.g. rubber or synthetic rubber, or for making sheets by spreading the plastic in solution or dispersion upon a travelling band and vaporizing the liquid in which the plastic is dissolved or dispersed, comprises a drying chamber through which the travelling band is passed and source of radiant heat outside the drying chamber in position to irradiate the whole of the coated surface, the wall of the chamber between the coated surface and the radiant source being made of glass or a plastic which is transparent to the principal part of the radiation.  The source of radiant heat is a bank of infra-red lamps.  Sheets or coatings of desired thickness are built up by a succession of alternate coating and drying operations and if desired the sheet or coating is subjected to further irradiation in order to vulcanize or polymerize the plastic material.  Sheets are prepared on an endless band, whilst coatings on fabrics are obtained by forming the fabric temporarily into an endless band. Alternatively, the fabric to be coated may be unwound from a supply roller and the coated fabric collected on a take-up roller, the full and empty rollers being interchanged to repeat the operation.  Alternatively, a sheet may be prepared on an endless band and a fabric subsequently applied to the sheet in order to produce a coated fabric in the manner described in Specification 612,505, [Group VIII].  The endless band may be of polished steel or fabric rendered impervious to the solution or dispersion by a coating of, for example, neoprene.  Dyes or fillers may be added to the plastic material in order to increase its absorbability of the radiation. The bottom of the chamber may have a reflecting or absorbent surface. The apparatus comprises a drying chamber 3 through which is passed an endless band carried by rollers 4 and 5, or a web of fabric 11 to be coated carried by supply and take-up rollers 6 and 7.  The web may travel upon the bottom of the chamber 3 or on a sheet of metal, perforated, if desired, and supported at mid-chamber height, or on rollers, or upon an endless band encircling the rollers 4 and 5.  The chamber is closed with sheets of red glass 12, such as that known by the Registered Trade Mark "Selenalyte," the outer surface being stippled or prismatic if desired.  Irradiation is supplied by banks of infra-red lamps 17 supported above the chamber 3.  The lamps may be spaced in staggered rows and may be controlled in sections so as to produce the desired amount of radiation.  Vapours are removed from the chamber 3 by a flue 25.  Plastic material is applied by nozzles (not shown) to the web 11 adjacent the adjustable doctor blade 26. A fan may play on the coated web or film where it leaves the chamber 3 in order to cool it.  If a web of fabric is to be applied to a film, a roller adjacent the spreading device 26 is pressed upon the endless band on which the film has been built-up, and the web of fabric is passed beneath it.  Air, preferably preheated, may be admitted to the chamber to assist in carrying off the vapour.  According to the Provisional Specification, if the web is supported above the floor of the chamber 3, the space beneath it may accommodate steam pipes or like means of heating.