Process and equipment for heat treatment of the body of a preform or of an intermediate-stage container made of a thermoplastic material
AssigneeSidel
InventorsGerard Emmer, Paul La Barre
Life of this patent
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Abstract
The invention relates to the thermal treatment of the body of a preform (1) or of an intermediate container made of a thermoplastic material during a process for manufacture of the container, such as a flask or bottle, in particular by blowing or stretching-blowing, the entirety of the body of the preform being heated to a temperature greater than the softening temperature of the material, at least one longitudinal portion (13) of the body (2) of the preform in rotation on itself being heated to a temperature greater than that of the rest (14) of the body, thereby making it possible to produce a finished container incorporating a body having a complex shape.
Claims27
A process for the thermal treatment of the body of a preform or of an intermediate container made of a thermoplastic material during manufacture of a container by blowing or stretching-blowing, during which thermal treatment the preform rotates on a longitudinal axis thereof and travels through an oven wherein the entirety of the preform body is heated to a temperature greater than the softening temperature of the material, the improvement comprising the steps of;
- a) passing at least one part of the length of the preform body in alternating fashion in front of heating zones and non- or reduced-heating zones disposed on at least one side of a path followed in the oven by the preform, so that at least one longitudinal portion of the preform body, or a plurality of longitudinal portions circumferentially separated from each other, extending over at least said one part of the length of the body is preferentially heated to a temperature greater than that of remaining portions of the body, and
- b) spacing the heating zones based on the number of longitudinal portions of the preform body to be preferentially heated and on a perimeter of the preform body, so that the longitudinal portions of the preform body to be preferentially heated are positioned in front of successive heating zones during the combined travel and rotation of the preform, while interposed longitudinal portions to be heated to a lesser degree are positioned in front of successive non- or reduced-healing zones, whereby one or a plurality of relatively hotter longitudinal portions are produced in the body of the preform or of the intermediate container, these portions alternating with relatively cooler interposed longitudinal portions and being capable of being reshaped more easily than said cooler longitudinal potions during subsequent reshaping of the preform body, thereby making it possible to manufacture containers having a body of complex shape and having at all points an approximately uniform wall thickness.
An oven for the heat treatment of the body of a preform or of an intermediate container made of a thermoplastic material during a process for manufacture of a container by a blowing or stretching-blowing process, wherein said oven is configured to heat the entirety of the preform body to a temperature greater than the material-softening temperature, the improvement comprising:
- on at least one side of a path of travel of the preform through the oven while it rotates on a longitudinal axis thereof, an alternating arrangement of heating zones and non- or reduced-heating zones disposed opposite at least one part of a length of the preform body for preferentially heating at least one longitudinal portion of the preform body or several longitudinal portions thereof separated from each other circumferentially and extending over at least said one part of the length of said body to a temperature greater than that of remaining portions of the preform body, wherein the spacing of the heating zones is based on the number of longitudinal portions of the preform body to be preferentially heated and on a perimeter of the preform body such that the longitudinal portions of the preform body to be preferentially heated are positioned in front of successive heating zones during the travel and rotation of the preform, while interposed longitudinal portions to be heated to a lesser degree are positioned in front of successive non- or reduced-heating zones.
Dependencies are inferred from the claim text.