Standard vs. Overflow Capacity: Know the Difference
As fundamental measurements of bottle volume, standard and overflow capacity are two very different values used in bottle manufacturing, packaging, and transportation. They have a profound effect on your choice of the correct bottle to fit your fill application and the accuracy of your fill claim. So, if you do business with a metal, glass, or plastic bottle supplier, you should clearly understand the differences and applications of these two terms.
Standard capacity is, as its name implies, the standard commercial volume measured in cubic centimeters (cc), milliliters (mL), or ounces (oz) of a bottle. This value refers to the amount of space provided inside a container for a specific volume of a product. These measurements are published in standard sizes by the industry.
When filled to their standard capacity, most bottles will have a meniscus around the shoulder and neck area while jars and other containers that don’t feature necks will be filled close to the top with a reasonable amount of headspace.
A bottle’s overflow capacity (OFC) is its actual volume. This measurement is used when you need to estimate the exact amount of liquid the bottle can hold when filled to the brim or point of overflowing.
Why They’re Crucial
Overflow capacity is a beneficial tool when trying to make an accurate estimation of your fill as it’s compared to your label claim. For instance, if your label claim states a standard capacity of 2 fluid ounces (fl. oz.), a 60 cc bottle will effectively hold that much liquid since 2 oz converts precisely to 59.1471 cc. This means that if you fill 2 fl. oz. of liquid in a 60 cc bottle, the bottle will provide enough headspace to account for liquid expansion due to ambient temperature rise as well as other volume-limiting factors while holding the liquid without overflowing.
Of course, different products and closure designs can affect the required headspace, so you should take time to test fill your product and determine the best solution.