The two most important container measurements are overflow capacity (OFC) and net fill capacity (NFC). Understanding the difference between the two can assist in picking the correct package for your application and minimizing the amount of filling and label claim errors.
Overflow Capacity (OFC)
This is the maximum volume of liquid that a container can hold if filled to the brim or point of overflowing. OFC is measured in grams (g), milliliters (mL), or ounces (oz), and can be used to estimate the exact amount of product a package can hold based on a specific gravity of 1.0 or water.
Net Fill Capacity (NFC)
This is the commercial volume represented in standard sizes published by the industry. NFC is measured in cubic centimeters (cc), milliliters (mL), or ounces (oz), and refers to the set amount of product that can be put in a fully assembled package or container with a given amount of headspace.
Why This Is Important
Knowing what these two terms mean can help you pick the right package for your product. They can be used as a tool for determining your actual fill and how it compares to your label claim. For example, you want to fill a 100mL bottle with 110cc of liquid – according to the bottle’s NFC, it has a standard capacity of 100cc. However, if the technical specifications of the bottle show that the actual overflow capacity is 135cc, then it can potentially fill this bottle after verification of the fillers fill tolerance.
However, different closures and applications may require different amounts of space at the top of the container, so be sure to make use of test fills to figure out the best solution for the given application.