Parison whose neck is based on an aromatic polyester, and in particular on pet, the neck including a thread having a profile in longitudinal section that is asymmetrical
AssigneeSchmalbach-Lubeca AG
InventorRoland Hebert
Life of this patent
Estimating the term…
Abstract
The parison (1) is made from one or more thermoplastic resins, and includes a neck (2) based on an aromatic polyester and preferably based on PET, which neck is provided with a thread and is not thermally stabilized. The thread has a profile in longitudinal section that is asymmetrical, making it possible to obtain a thread whose profile in longitudinal section is of improved symmetry after the neck (2) has been thermally stabilized. A receptacle, and in particular a bottle, is obtained by stretching and blowing a parison, and in which at least the neck (2) has been thermally stabilized, and has preferably been completely crystallized.
Claims16
Process of making a parison and comprising the following steps:
- making a parison from one or more thermoplastic resins, said parison including a neck made of an aromatic polyester, said neck being provided with a thread that has not been thermally stabilized and that has an initial profile in longitudinal section that is asymmetrical;
- and
- thermally stabilizing at least the neck of the parison thereby obtaining a thread having a final profile in longitudinal section that is more symmetrical than said initial profile, wherein the initial profile of the thread includes a central portion, a top flank defining a flank angle α1 with a plane (PP) that extends transversely to a central longitudinal axis of the parison, and a bottom flank defining a flank angle α2 with the plane (PP), in that the final profile of the thread includes a central portion, a top flank defining a flank angle α′1 with a plane (PP) that extends transversally to a central longitudinal axis of the parison, and a bottom flank defining a flank angle α′2 with the plane (PP), and in that the difference in value between flank angle α′1 and flank angle α′2 is smaller than the difference in value between flank angle α1 and flank angle α2.
Process of making a receptacle and comprising the following steps:
- making a parison from one or more thermoplastic resins, said parison including a neck made of an aromatic polyester, said neck being provided with a thread that has not been thermally stabilized and that has a profile in longitudinal section that is asymmetrical;
- and
- making a receptacle from said parison, said receptacle having a neck which has been thermally stabilized thereby obtaining a thread with a profile in longitudinal section that is more symmetrical than the profile in longitudinal section of the thread of the parison, wherein the profile of the thread of the parison includes a central portion, a top flank defining a flank angle α1 with a plane (PP) that extends transversely to a central longitudinal axis of the parison, and a bottom flank defining a flank angle α2 with the plane (PP), wherein the profile of the thread of the receptacle includes a central portion, a top flank defining a flank angle α′1 with a plane (PP) that extends transversally to a central longitudinal axis of the parison, and a bottom flank defining a flank angle α′2 with the plane (PP), and in that the difference in value between flank angle α′1 and flank angle α′2 is smaller than the difference in value between flank angle α1 and flank angle α2.
Dependencies are inferred from the claim text.