Secrets of Liquid Filling

If you don’t ask the right questions, you won’t get the right answer. Here are some of the key questions to ask when buying a new liquid filler.

Buying a filler is not that difficult. Buying one that optimal for your product can be. A lot of groundwork must be done before the actual purchase. These include gathering information as a vital first step. Some of these seem obvious but readers might be amazed to find how many are overlooked.

1. Product

What kind of product is it? Food, pharmaceutical, beverage, household chemical, cosmetic…? Each industry and product will have specific requirements. Some will be determined by regulation, others simply by industry custom and practice.

1. Precision requirements

The more precise the filler, the more complex it will be. Complexity increases purchase, maintenance and operating costs. A $1000 pharmaceutical product requires a precise fill volume. A 50-cent juice drink, not so much. Underfilling cheats the customer by giving them less than they are paying for so some overfill is required. But even small overfills can waste a lot of product and money

1. Viscosity and flowability

How thick or viscous is the product? Generally, the less viscous the product, the more filling options exist.

1. Special properties

You will need to know any special properties the product has or requires. Some of these can include:

• Sterile

• Flammable

• Light sensitive

• Metal sensitive

• Corrosive

• Foamy

• Modified atmosphere requirements

• Vacuum requirements

• …?

1. Temperature

Most products are filled at room temperature. Some need to be filled hot or cold. When this is the case heating or cooling will be required to assure a stable temperature from mixing to filling.

1. Container

What is the container and the fill volume? How full is the container? A typical bottle with a large main diameter and a relatively small neck diameter will fill slowly until the neck. Then the product level will rise quickly. This can cause control problems. If the product is foamy, the foam will need to be controlled. A long neck bottle may require a deep dive of the filling nozzle to prevent blow-back of the product by the venting air.

Open-mouth containers such as jars or cans, where the neck is the same diameter as the body, can have problems with product splashing. Lightweight PET bottles can be difficult to handle empty because of ease of crushing.

1. How is the product brought to the filler?

There are several ways that product can be brought to the filler. It may be produced in another area of the plant and transferred into large portable tanks that are then moved to the filler. Gaylord containers are pallet-sized tanks that are moved by forklift. Product may come in 5- to 10-gallon containers carried to the filler by operators. Product may be piped to the filler directly from the compounding area.