SEAL PIN FOR CONTAINER FORMING AND FILLING

A seal pin assembly for a forming and filling head configured to inject a product into a thermoplastic preform for simultaneously forming a container from the thermoplastic preform and filling the container with the product. The seal pin assembly includes a seal pin movable within the forming and filling head towards and away from a nozzle of the forming and filling head. The nozzle is configured to cooperate with the thermoplastic preform. A vortex generating member is mounted to the seal pin and configured to convert a stream of the product into a vortex as the product flows across the vortex generating member and out through the nozzle.

FIELD

The present disclosure relates to a seal pin assembly for a forming and filling head configured to inject a product into a thermoplastic preform for simultaneously forming a container from the thermoplastic preform and filling the container with the product.

BACKGROUND

Polymeric containers are used to store various types of food and beverages. Such containers are typically formed from a preform using various processes. One such process involves simultaneously forming the container from a preform and filling the container with any suitable product. This process is commonly referred to as Liquiform®. To simultaneously form and fill the container, a forming/filling head is placed into cooperation with a finish of the preform.

While current Liquiform® heads are suitable for their intended use, they are subject to improvement. For example, flow through existing heads may become “sided” (i.e., non-conical), depending on how the liquid enters the head and how flow drags around the stretch rod. When forming high-density polyethylene containers, gates have been seen to drift off-center to a repeatable container side (with respect to the mold). Also, with existing Liquiform® heads excessive material bubbling may occur during forming/filling, and shoulder areas of the container may not properly form. The present disclosure advantageously provides for an improved seal pin assembly that address these issues. One skilled in the art will appreciate that the present disclosure provides numerous additional advantages and unexpected results as well.

SUMMARY

The present disclosure includes a seal pin assembly for a forming and filling head configured to inject a product into a thermoplastic preform for simultaneously forming a container from the thermoplastic preform and filling the container with the product. The seal pin assembly includes a seal pin movable within the forming and filling head towards and away from a nozzle of the forming and filling head. The nozzle is configured to cooperate with the thermoplastic preform. A vortex generating member is mounted to the seal pin and configured to convert a stream of the product into a vortex as the product flows across the vortex generating member and out through the nozzle.

The present disclosure further includes a method for simultaneously forming a container from a thermoplastic preform and filling the container with a product dispersed from a nozzle of a forming and filling head including a seal pin assembly. The method includes converting a stream of the product into a vortex by directing the stream of the product across a vortex generating member mounted to a seal pin of the seal pin assembly such that the product exits the nozzle and flows into the preform as a uniform, conical stream having a centrifugal motion.

DETAILED DESCRIPTION

FIGS.1and2illustrate a seal pin assembly10in accordance with the present disclosure for use with any suitable machine head, such as forming and filling head12for simultaneously forming and filling a polymeric container from a container preform210. The preform210and the resulting container can be formed of any suitable polymeric material, such as polyethylene terephthalate (PET), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene, and the like, for example. The forming and filling head12is configured for use with any suitable Liquiform® machine, for example, such as described in the following U.S. Pats., each of which is incorporated herein by reference: 7,914,726; 8,017,064; 8,435,026; and 8,573,964.

A nozzle14is secured to an outlet16of the forming and filling head12in any suitable manner, such as with a coupling member20. With the nozzle14secured to the head12, and a finish212of the preform210sealed to the nozzle14, any suitable product can be injected from the head12into the preform210by way of the nozzle14to simultaneously form a container from the preform210and fill the container with the product. Suitable products include, but are not limited to, water, sports drinks, juice, sauces, any suitable foodstuffs, etc.

The seal pin assembly10generally includes a seal pin30, which is moveable within the forming and filling head12to open and close the nozzle14. In a closed position, a seal32of the seal pin assembly10contacts and seals against a nozzle seal34of the nozzle to prevent product from exiting the nozzle14. In an open position, the seal32is spaced apart from the nozzle seal34to allow fluid to flow through the nozzle14and into the preform210. To facilitate forming of the container, a stretch rod36may be extended through the seal32and the nozzle14, and into the preform210.

With continued reference toFIGS.1and2, and additional reference toFIGS.3A,3B, and3C, the seal pin assembly10further includes a vortex generating member50, which may be coupled to a distal end of the seal pin30. The seal32is coupled to the vortex generating member50. The vortex generating member50generally includes a proximal end52and a distal end54, which is opposite to the proximal end52. At the proximal end52is an upper coupling56, which may include any suitable coupling members configured to couple with the seal pin30. In the example illustrated, the upper coupling56includes threads configured to cooperate with threads at a distal end of the seal pin30. At the distal end54of the vortex generating member50is a lower coupling58, which may be configured in any suitable manner to connect the seal32to the distal end54. In the example illustrated, the lower coupling58includes a plurality of threads configured to cooperate with threads of the seal32. The vortex generating member50defines a bore60extending through the vortex generating member50along an axis A thereof extending from the proximal end52to the distal end54. The bore60is sized and shaped to accommodate the stretch rod36.

The vortex generating member50further includes a body70between the upper coupling56and the lower coupling58. The body70includes a plurality of vanes extending from an outer periphery of the body70away from the axis A. The vanes72define channels74. Specifically, each one of the channels74is defined between vanes72that are directly adjacent to one another. The vanes72extend in a helical manner, and the channels74are helical channels. The vanes72extend outward to an inner surface of the nozzle14such that the vanes72abut, or nearly abut, the inner surface of the nozzle14.

Product flowing through the filling head12and the nozzle14flows through the channels74. Because the channels74are helical, a stream of the product is converted from a generally linearly flow into a vortex. As a result, the product exits the nozzle14as a uniform, conical stream having a centrifugal motion.

The centrifugal motion of the product advantageously generates a density gradient where bubbles of the product move towards a center of the container after the container has been formed from the preform210. The bubbles coalesce, rise to a surface of the product, and disperse. As a result, a container formed and filled with product that has flowed through the channels74of the vortex generating member50will have fewer bubbles as compared to product filled with a filling head that does not include the vortex generating member50. The bubbles quickly rise to the surface and disperse because, in part, there is little or no contact/adherence to a sidewall of the container and no isolation in suspension of the bubbles.

The vortex/centrifugal flow of product within the formed container continues for about 15-20 seconds post-formation of the container, at least with respect to products having a viscosity similar to water. During this time, the bubbles move from the sidewall of the container to the center of the container due to centrifugal forces creating a density gradient. As the vortex flow slows, the bubbles combine and rise to the surface of the product as a single mass. As a result, duration of the bubbles is less as compared to containers that are filled with filling heads that do not include the vortex generating member50.

With respect to filling heads that do not include the vortex generating member50, an aneurism often forms close to a gate, and a shoulder of the container is the last portion to form. In contrast, product that has passed through the helical channels74of the vortex generating member50is directed in the “hoop” direction after the product flows out of the nozzle14and into the preform210. As a result, the aneurism is closer to the shoulder of the container, which results in improved formation of the shoulder as compared to containers that are formed/filled with filling heads that do not include the vortex generating member50.