Flexible tube made from polypropylene and method for production of said tube
OwnerGery Bernard Marie Dambricourtinventor
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Abstract
A flexible tube comprising a skirt and a distribution head, resistant to cracking under stress and forming a barrier to water. The wall of the tube is made from at least one first polymer from the group of polypropylenes, with, at the mid-point from the end of the skirt furthest from the head to the end of the neck forming the distribution hole of the tube, a thickness of between 0.30 mm and 1.00 mm, with a section modulus of between 700 MPa and 80 MPa, the section moduli of the components of the wall being chosen to follow a law of maximum dispersion. The tube finds application in the storage of all products, in particular pasty bodies in cosmetics and pharmaceuticals.
Claims46
1-36. (canceled)
A tube resistant to stress-cracking and forming a water barrier comprising a flexible skirt elongate in an axial direction and a head comprising at least one evacuation orifice and a neck forming a radial extension of the at least one evacuation orifice and being joined to the skirt along the axial direction, at least the skirt and the neck forming a single-piece assembly, a wall of the tube consisting of a mixture of a number “n”, where n is at least equal to 1 of polymers belong to the family of copolymers-olefins prepared from C2 to C10 monomers, the wall at a mid-distance of its length along the axial direction from an end of the skirt distant from the head as far as an end of the neck forming the at least one evacuation orifice and having a wall thickness of between 0.30 and 1.00 mm, at least one polymer of the mixture belongs to the polypropylene family, the constituent mixture of the tube wall having a flexural modulus of between 700 MPa and 80 MPa, according to standard NF EN ISO 178, and each polymer having a flexural modulus defined according to standard NF EN ISO 178 and being conventionally assigned a rank “i” which, in a classification of the “n” polymers of the mixture in decreasing order of their respective flexural modulus values μi, places the polymer between a first polymer (i=1) of maximum rigidity and a last polymer (i=n) of minimum rigidity, and each polymer being contained in the mixture in a weight percentage xi with respect to the total weight of the mixture, the mixture has a dispersion factor (Kd) of the flexural modulus values of no more than 3 or 2.2 according to whether or not it contains a polyethylene, preferably no more than 2 in both these cases, and further preferably no more than 1.5, this dispersion factor (Kd) being defined as:
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A method for fabricating a flexible tube consisting of a skirt and head comprising at least one evacuation orifice and a neck forming a radial extension of the at least one evacuation orifice and being joined to the skirt, at least the skirt and the neck forming a single-piece assembly resistant to stress-cracking and forming a water barrier, the method comprising the steps of:
- using as constituent material of a wall of the tube a mixture of a number “n”, where n is at least equal to 1, of polymers belonging to the family of copolymers-olefins prepared from C2 to C10 monomers, at least one polymer belonging to the polypropylene family, the constituent mixture of the wall having a flexural modulus of between 700 and 80 MPa according to standard NF EN ISO 178;
- and
- fabricating the skirt and head of the tube by injecting the mixture, in a single injection operation, into an injection mould comprising an impression and a core comprising a central part of which one free upper end center bears upon the impression at least during the skirt injection phase.
Dependencies are inferred from the claim text.