Method and apparatus for forming final-shaped containers using liquid to be contained therein
A method, system, and preform for liquid forming of the preform into a final-shaped container using the liquid to be contained in the final-shaped container. The preform undergoes a stretching step to a size less than the size of a base of the final-shaped container, before being relocated and stretched to the final shape by the liquid. A stretch rod sealably connects with an interior surface of the preform to partially isolate a gate portion of the preform. The isolation is effected by a portion of the inner surface of the preform extending inwardly, or by a deformable member on the stretch rod which can selectively extend outwardly to contact the interior surface of the preform. The stretch rod includes a selectively heatable tip to heat the gate portion of the preform. The gate portion of the preform includes inner, outer, and core layers which comprise a material configured to affect the thermal properties of the gate portion.
1. An apparatus for simultaneously forming and filling a final-shaped container from a preform using a liquid, the liquid being a product to be contained in the final-shaped container, the apparatus comprising:
a mold cavity for forming the final-shaped container from the preform;
a stretch rod for stretching the preform movable between at least a retracted position outside the mold cavity to an advanced position within the mold cavity,
a lower portion of the stretch rod being configured for sealably connecting with an interior surface of the preform to at least partially isolate a gate portion of the preform; and
a nozzle for sealably connecting with an opening of the preform, the nozzle including:
a channel fluidly communicating with an interior of the preform for transmission of the liquid to expand the preform into conformity with the mold cavity and form the container therein,
the channel being further configured to receive the stretch rod therethrough.
2. The apparatus of claim 1 , wherein the channel further fluidly communicates with a pressurized air source for performing a preliminary stretch of the preform by blow molding.
3. The apparatus of claim 1 , wherein:
the stretch rod comprises a deformable member configured to at least partially isolate the gate portion of the preform from the liquid when extended,
the liquid causing the deformable member to extend out from the stretch rod to contact the interior surface of the preform to form a temporary seal to at least partially isolate the gate portion from the liquid when filling an interior of the preform with the liquid through the nozzle.
4. The apparatus of claim 3 , wherein the deformable member is made at least in part from a thermally isolating material.
5. The apparatus of claim 3 , wherein the deformable member is made at least on part from a material having low thermal conductivity.
6. The apparatus of claim 5 , wherein the material having low thermal conductivity is one of a polymer and a rubber.
7. The apparatus of claim 1 , wherein:
the stretch rod comprises a controllably-extendible sealing member for sealably connecting the lower portion of the stretch rod with the interior surface of the preform the controllably-extendible sealing member selectively and at least partially isolating the gate portion of the preform from the liquid when extended; and wherein
the apparatus further comprises an actuator for extending the controllably-extendible sealing member.
8. The apparatus of claim 7 , wherein the controllably-extendible sealing member is made at least in part from a thermally isolating material.
9. An apparatus for simultaneously forming and filling a final-shaped container from a preform using a liquid, the liquid being a product to be contained in the final-shaped container, the apparatus comprising:
a mold cavity for forming the final-shaped container from the preform;
a stretch rod for stretching the preform movable between at least a retracted position outside the mold cavity to an advanced position within the mold cavity, the stretch rod including:
a selectively heatable tip; and
a nozzle for sealably connecting with an opening of the preform, the nozzle including:
a channel fluidly communicating with an interior of the preform for transmission of the liquid to expand the preform into conformity with the mold cavity and form the container therein, the channel being further configured:
to receive the stretch rod therethrough.
10. The apparatus of claim 9 , wherein the selectively heatable tip comprises an internal resistor for causing at least a lower portion of the stretch rod to heat.
11. The apparatus of claim 9 , wherein the stretch rod defines at least one channel fluidly communicating with an interior of the preform and a pressurized air source, the stretch rod being configured for partial blow-molding of the preform prior to transmission of the liquid.