GB1385280A - Method and apparatus for producing articles of reinforced plastics or like construction - Google Patents

Abstract

1385280 Coating; coating apparatus E T VOERMANS 15 Dec 1972 [15 Dec 1971] 58106/72 Headings B2E and B2L Articles are produced by adhering plastics or other material to a base of flexible material, the base being rotated or oscillated during said adhering during the application and being held at a plurality of spaced apart locations on the base and being maintained under tension whereby the base is at least partly self supported between said locations. The base may be a fabric of synthetic fibres which may be formed to a. tube. Apparatus for carrying out the method comprises a support, a pair of end members mounted on the support for rotation or oscillation about a common axis and spaced apart from each other, drive means for synchronously rotating or oscillating the end members, holding means mounted upon. the end members to grip or otherwise hold opposite ends of the flexible base placed between the end members and tension means to bias the ends away from each other to place the base in tension while it is so held, and means for adhering coating material to the flexible base. As shown in Figures 1 and 2 the end members comprise discs 32 and 47 with radial slots therein with connector members 37 received in the slots and. positionable radially of the discs. The connector members have hooks for engaging the ends of the base. Disc 32 is supported in a headstock 16 and disc 47 is supported in a tailstock 38 which is slideable lengthwise of the axis of rotation on a bed 39. The tailstock can be selectively positioned relatively to the headstock by means of a hydraulic ram 41. Disc 32 is affixed to a shaft 24 rotatable relative to the headstock and disc 47 is affixed to a shaft 44. rotatable relative to the tailstock. Shaft 44 is constrained against axial movement arid shaft 24 can be variably axially positioned. The base is placed under tension by movement of ram 22 to withdraw disc 32 away from disc 47. A spray nozzle 64 is moveable lengthwise of the apparatus and is also positionable in a horizontal plane and a vertical plane so that the spray head may follow the contours of the base. In operation, base 107, e.g. of stretchable, woven, synthetic material of tubular configuration is secured to disc 32 and 47 so as to extend between them in open configuration. Loops of flexible material are sewn into opposite ends of the tubular base and hooking on to these loops is effected by use of the connector members 37 on each disc. The desired cross-section of the tube having been selected, the connector members 37 are positioned on each disc 32 and 47 in a corresponding array. The base is then placed under tension by movement of ram 22 and discs 37 and 42 are then rotated together with the base and the exterior of the base is coated with plastics material sprayed from nozzle 64. By traversing the base lengthwise as it is rotating horizontal and vertical movement of the nozzles 64 follow the contours of the object being formed. The interior of the base may be coated by means of a nozzle 108 carried at the free end of a tube 109 which is inserted within shaft 24. Intermediate formers such as hoops may be placed within the base section to modify the cross-sectional size, e.g. in the formation of boat hulls, tanks. The cross-sectional size at any point along the length of the base may also be decreased by tyeing the base or by using a suitable former to surround the base. A plurality of necked containers may be simultaneously formed by inserting formers within the tubular section and pinching the section inwardly at intervals along its length to form necks for the containers. A ladder may be formed by securing longitudinal runs of strip between the discs and stapling further lateral strips between the runs, and then coating the strip. The coating material may be liquid plastics, elastomers, bitumen, plastics or metal powder applied electrostatically or by flame-spraying. Simultaneously with application of coating material a reinforcing material such as glass fibre may be applied by electrostatic flocking operations, an electrode replacing the internal spraying nozzle and movement of the internal nozzle being synchronised with an opposed spraying gun on the outer side of the base. Filamentary material or heated extruded plastics material may be wound on to the base as it is rotated. Increased or reduced air pressure may be applied to the interior of the base during the coating. Example relates to the formation of a pair of cylindrical tanks.