Liquid Nitrogen Dosing

Increasing the strength of bottles with liquid nitrogen.

Manufacturers of non-carbonated beverages (water, juices, teas, etc.) generally rely on PET (polyethylene terephthalate) to make their drinks bottles. Over the past 20 years, plastic bottles have become thinner in line with environmental and cost pressures. However, doing so has reduced the weight of PET polymers in the bottles, resulting in thinner, weaker bottle walls.

After filling, bottles must be stacked so they can be transported to customers. With thinner walls, weak bottles at the bottom of a pallet buckle under the weight of the bottles above, creating unsafe conditions and costly product losses.

This problem can be avoided by pressurising the bottles. Nitrogen is the perfect medium because it is available in liquid form. When liquid nitrogen vaporises, it expands to 682 times its liquid volume. In addition, it is inert – thus protecting the drink against oxidation, which can lead to drink spoilage and lost revenues.

We supply the liquid nitrogen (LIN) needed for the LIN dosing systems commonly used in bottling facilities. These systems add a droplet of liquid nitrogen and trap it by immediately capping the bottle. The trapped droplet expands as it vaporises and increases the internal pressure. The pressure increase ‘rigidifies’ the bottle, making it robust enough to stack.