Patent GB-939420-A (GB)
Title: Apparatus for moulding pulp articles
IPC: D21J3/00
Filed: 1961-12-07
Abstract: 939,420. Moulding pulp articles. HAWLEY INTERNATIONAL Ltd. Dec. 7, 1961 [Dec. 23, 1960], No. 43881/61. Class 87(2). Articles are made from fibrous pulp by forming a preform in a slurry tank 46 on a felting die 55, pressing it between dies 55 and 56, drying between dies 57 and 58, and ejecting it from a discharge station 54. Formation and Pressing. After forming the preform on the die 55, it is moved up to the female transfer die 56 and the preform is first pressed and then transferred to the female die 56 by transferring the vacuum from the die 55 to the die 56 and by using compressed air in the former. During this process the slurry tank 46 is refilled from the reservoir 40 which is linked to the water tank 22 and hopper 35, for the fibrous material, through a mixer 27 and tanks 31 and 32. The male die is cleaned by compressed air and water and returned to the slurry tank where it displaces some of the slurry into the tank 48 below the baffle 69, the latter keeping the upper portion of the tank and the overspill pipe 49 clear of slurry. While another article is being formed in the slurry tank the female die 56 moves down to transfer the article to a male drying die 57 with a similar transference of vacuum and the use of compressed air. Drying the articles. The male die 57 is carried on a base 160 movable, along rails from the transfer position below the die 56 to a drying position below a female drying die 58, by a piston 177, Fig. 3 (not shown). When the drying pressure is applied by the die 58 to the die 57 the springs, which connect the carriage base to the wheels, are compressed until the male die is supported by ribs 163, Figs. 11 and 12 (not shown) on the platen 151. For correct aligning of the die 57 in its two end positions devices 180 and 194, Figs. 8 to 13 resp. (not shown) are provided. Both the drying dies have burner means to provide dry heat and the male die 57 has its outer casing perforated with the holes linked to a vacuum or compressed air source while the female die 58 has holes in its flanges which are connected to three control lines, one a low pressure line for protecting the holes from any fines during the hot pressing, the second a vacuum line for lifting the dried article at the end of the drying cycle and the third a compressed air line for applying a blast of air when ejecting an article from the die 58, Figs. 16, 8 and 9 (not shown). Ejection. After the drying operation the female die 58, with the dried article ascends, and by touching the switch 309 or 310 causes the male die to move to its transfer position below the female transfer die 56 in order to start another drying sequence while the discharge table 59, which moves in concert with the male die 57, moves under the female die 58. The article is ejected from the die 58, first on to the fingers 239 which act as stabilizing devices, and after their withdrawal on to the table 59. As the table moves back to the discharge station 54 it is crammed in to an inclined plane by the ramming member 254 so that the article falls on to a conveyer belt 60. The whole operation is electrically controlled by timers and by switches in the apparatus which are actuated by the moving parts. Figs. 17a and 17b (not shown) give the electric circuit. The number of drying stations which surround the forming station 52 and which in turn dry the preforms, need not be two.