Method for obtaining cardboard tubes with leaktight inner lining, particularly for shuttering (formwork), and devices for implementing it

摘要

According to the method, a tube (2) is produced by spirally winding up strips of cardboard and the inner face of the tube (2) is coated with an impermeable product, then the helical furrow which results from the space remaining between the turns of the first wound-up strip is filled with impermeable product so as to obtain an inner surface which is perfectly uniform and a wall which is entirely protected from the moisture in the concrete. The devices for implementing the method comprise a circular smoothing member (7) and means (7a, 9) permitting the translational displacement of this member (7) in the tube (2). <IMAGE>