B - Operations – Transporting – 29 – C
Patent
B - Operations, Transporting
29
C
B29C 47/90 (2006.01) B29C 47/92 (2006.01)
Patent
CA 2517626
The invention relates to a method for continuously producing plastic tubes by biaxial drawing consisting in producing a blank (E) by extrusion, heating said blank to a molecular orientation temperature, radially dilating it by the internal pressure of a fluid applied between two axially distant obturator rings (7, 11) and in carrying out a calibration (8) and cooling (9) associated with an axial tension produced on a tube at the output thereof. A pressure opposite to the internal pressure is applied to the blank wall from the outside in at least one area which is exposed to the radial dilatation. Said opposite pressure is selected such that it is lower than the internal pressure, thereby preventing a counteraction to said dilatation and remaining sufficient in order to control the dilatation growth in such a way that it is possible to ensure a substantially constant material thickness on the same circumference.
Procédé de fabrication en continu de tubes en matière plastique avec étirage bi-axial, suivant lequel on réalise une ébauche (E) par extrusion, on amène cette ébauche ô température d'orientation moléculaire, on lui fait subir une dilatation radiale en la soumettant à une pression interne de fluide appliquée entre deux obturateurs (7,11) distants axialement, et on assure un calibrage (8) et un refroidissement (9) tout en exerçant une traction axiale sur le tube en sortie. On applique (13) de l'extérieur contre la paroi de l'ébauche dans au moins une zone soumise à la dilatation radiale une pression antagoniste à la pression interne, cette pression antagoniste étant plus faible que la pression interne pour ne pas faire obstacle à la dilatation, mais étant suffisante pour assurer une croissance maîtrisée de la dilatation, avec une épaisseur de matière sensiblement constante sur une même circonférence.
Alphacan
Robic
LandOfFree
Method for continuously producing plastic tubes by biaxial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for continuously producing plastic tubes by biaxial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for continuously producing plastic tubes by biaxial... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1691948