Hot-Fill Bottles

Clear or drop impact resistant containers, boxes, hot filled bottles, dessert pots, horticultural pots, integrated hinge boxes, bottles and other cans up to several litres, caps and closures for beverage and cosmetic applications, medical disposable trays, containers for irrigation, parenteral, haemodialysis solutions. .. 

When a product cools, it contracts. This distorts the normal shape of the PET bottle panel. Hot-fill bottles are made with panels in the body section and patented features in the bottle base that collapse in a consistent way so that the bottle can be handled and distributed when cold. 

The vacuum that creates the bottle panel has to be contained by the closure, and so hot-filled bottles have a specific closure design and applicator that are different from standard carbonated closure designs (see Section 9.5)... 

To minimize shrinkage and moisture absorption in hot-fill bottles, the first step is to heat-set the bottle. This is a process in which the bottle crystallinity, mainly in the sidewalls, is increased to about 30% under stress to maintain the bottle shape. The crystallization that is desired is strain-induced crystallization, which results in smaller crystallites that do not scatter light. The preform weight for hot-fill bottles is higher also, to help stabilize the finish area. Illustrations of the different preform weights commonly used in industry are in Table 12.1. 

If one can afford the added cost, one can use a slightly higher Tg PET for hot-fill bottles (a resin with a higher molecular weight). This higher Tg is particularly useful in minimizing the dimensional changes in the finish. 

Clear 01 PVC alloy with glutarimide acrylic copolymer for hot-fill bottles Georgia Gulf... 

In 1999, Phoenix Technologies LP became the first company to receive FDA approval for use of 100 percent curbside recycled PET in food containers. In 2001, the company gained approval for use of this material in hot-filled bottles. Commercial production of food-grade curbside recycled PET began in December, 2000. The process is in use in Australia to make 25 percent recycled-content bottles for Coca-Cola. ... 

An added benefit of exposing the bottle to temperatures above the glass transition is that molecular relaxation takes place at the same time crystallinity is building up. Both depend on molecular movement freedom for a molecule to either get into the crystalline structure or slip by other molecules out of the oriented state. This facilitates the dissipation of the orientation and the residual stresses associated with it. Residual stresses are ultimately responsible for any deformation of a product on reheating above the glass transition temperature, like shrinkage or warp-age in hot filled bottles. 

Figure 33.25 Hot fill bottle with waist reinforcing rib.

Double blow (Fig. 33.34) is a process that produces bottles with higher heat stability than heat set-hot fill bottles covered by Yoshino patents [27,28]. 

Purac has invested in new lactides that should potentially provide the food, pharma, and cosmetics industries with cheaper and more effective bioplastic packaging. Netherlands-based Purac, a producer of lactic acid for the food sector, has stated that the new lactides wiU contain L-(-h)- and D-(-)-lactic acids. The new lactides will be sold to companies that will use them to make bioplastics that can withstand greater heat than ever before. The new materials will be suitable for applications as diverse as hot-fill bottles, microwaveable trays, temperature-resistant fibers, and electronics, and will withstand temperatures of up to 175 C. 

Recycled Poly (ethylene terephthalate) (PET) Blends for Hot - fill Bottles J.Patuto, F. Daver and E. Kosior ... 

---