DEVICE AND PROCEDURE FOR MANUFACTURE OF MOLECULAR BI-ORIENTED PLASTIC PIPES Russian patent published in 2011 - IPC B29C49/16 B29D23/00 

FIELD: machine building.

SUBSTANCE: device for manufacture of molecular bi-oriented plastic pipes consists of: form by means of which there is manufactured oriented pipe (10') out of tube work piece (10) by expanding. Also, the form is made with central case (14), first upper part (1) and second upper part (17) connected on opposite sides of central case (14) Further, the device consists of rigid and perforated guide (5) centred in axial direction inside form (1, 17, 14). Guide (5) passes between upper parts (1, 17) and central case (14), has external diametre a little less, than internal diametre of pipe work piece (10) for its lengthwise connection with guide (5) and has orifices (9) for flow of fluid medium (18) through them for expansion of pipe work piece (10) to internal walls of form (1, 17, 14). The device consists of cooling chamber (13) restricted with branch (4) and external surface of central case (14), and of channels (7), connecting said central case (14) with environment via vacuum connecting collector (6). This guide has orifices (9) for flow of fluid medium (18) through it expanding pipe work piece (10) to internal walls of form (1, 17, 14) without any heat exchange between pipe work piece (10) and form (1, 17, 14). Here is also disclosed procedure for production of molecular bi-oriented plastic pipes be means of the said device. The procedure consists in the following stages: a) introduction of pipe work piece (10) through first upper part (1) in lengthwise direction matching its internal surface with external surface of perforated guide (5). Prior to introduction pipe work piece (10) is heated to the same temperature as temperature of form (1, 17, 14). Perforated guide (5) is heated to the same temperature, as temperature of tubular work piece (10) before introduction of fluid medium for expansion(18). b) Closure of form (1, 17, 14) by means of packing bush (2) on first upper part (1) and actuation of fixture element (3) fixing pipe work piece on both ends. c) Introduction of fluid medium for expansion (18) through central orifice (16) formed in support bush (12) for its circulation via internal surface of perforated guide (5) and its flowing out through orifices (9) for expansion of pipe work piece (10), which reaches internal walls of form (1, 17, 14). At the same time the procedure consists in creation of vacuum in the chamber between form (1, 17, 14) and pipe work piece (10) through orifices (8) of upper parts (1, 17) and through channels (7) of collector (6) in such way, that pipe work piece (10) is shaped to internal geometry of form (1, 17, 14) due to pressure of fluid medium for expansion (18).

EFFECT: simple forming plastic pipes with molecular orientation, process and device efficiency and energy saving due to utilisation of gases at manufacture.

9 cl, 5 dwg