There are several things to keep in mind when selecting liquid fillers to ensure the right fit for your application:
1. Understand how the machine affects the product.
You need to think about the impact of the filler on the product you’re packaging. The state or viscosity of the liquid can be inadvertently changed, based solely on the construction of the equipment. For example, running a liquid through extra elbows, pipes, and pumps can change the viscosity, resulting in a liquid that is much too thin. High speeds can also impact some products negatively. Are you filling a food or drink product with particles (fruit pieces, fibers, or seeds)? Are you filling a cleaning product with special fragrance additives or enzymes that require special handling? Will shearing the product cause undesirable viscosity changes? You need to keep the product characteristics front-of-mind when selecting equipment.
2. Understand how the product dictates the type of filler.
The type of machine utilized for a project is often dependent on beverage/product characteristics and the type and shape of the containers. Free-flowing liquids like beverages work well with a timed-flow or overflow machine, whereas a more viscous product might be better suited for a piston or positive displacement (PD) filler. The type of container, the fill volume, and the diameter of the opening thru which you are filling might also determine the type of machine. Timed-flow and overflow machines are both good for free-flowing liquids but differ in how they deliver product to a container. Timed-flow fillers are a volumetric fill machine, meaning each fill cycle they deliver exactly the same volume of product. These machines are designed for very precise fills regardless of the container shape. However if the container varies in volume, the fill levels may have an inconsistent look. Glass bottles are a good example of containers that often have varying inner shapes and volumes.
3. Know the filling challenges of handling beverages with pulp or fruit pieces.
Pulp or fruit pieces, otherwise known as particulates, require specialized pumps and valves based on the size and density of the individual particulates. Challenges with filling particulates arise whenever there is a significant variance in the size of the pieces. Pickles are a good example of a product that has particulates with a large size variance. Small or soft particulates are usually easier to accommodate.
4. Look at ease of cleaning. Pay attention to the cleanability of equipment.
As with any product destined for consumption, the machine must be made of FDA-approved sanitary materials. Most customers, including beverage providers, want equipment that is easy to clean and maintain. When filling bottles, keeping the nozzle clean is of primary importance to good manufacturing practices. Simpler design is better: Make sure the equipment doesn’t have nooks and crannies that can harbor microorganisms. Machine builders are more aware of hygienic design principles. They focus on eliminating dead legs, sloping horizontal surfaces to make them self-draining, adding spray balls in the product bowl, using wash-down electrical components in the product area, etc. Also look for filling machines that have clean-in-place systems as a standard feature.
5. Lighten up.
Plastic bottle lightweighting continues to be a major trend, and with cost and sustainability advantages, this trend isn’t going away anytime soon. So be sure to look for unscrambling and filling technologies that will accommodate progressively thinner bottles. “Feather bottles,” down to just seven grams of plastic for a half-liter bottle, with a short-skirted cap, call for kinder, gentler unscrambling and filling.
6. Don’t give away product.
Don’t accept a vendor giving you a general average in weight variation. You need to know what that percentage is at the actual container sizes you intend to run today and in the future. Giveaway can actually vary slightly at different container sizes.
7. Avoid complexity.
Complex fillers equal complex maintenance needs. The simpler the machine, the less maintenance, the less training, and the fewer parts that need to be kept on hand. Watch for parts or components that may have the potential to break off. If you don’t have a screen prior to the fill head or nozzle, pieces of metal or plastic can get into your product. Even good inspection systems may not be 100% effective in detecting a piece of metal or plastic in a metal can.
8. Talk about changeovers.
If you know you’re filling different products, or that you may be someday, you need to know about changeover times. Changeover time reductions are a key factor in boosting efficiency. The goal is quick, repeatable changeovers, so you can get your line up and running again as soon as possible. Ask about design simplifications where a change part can be used for multiple packages. Discuss the cost and process for future change parts. Are you limited to the OEM or are there options (sometimes faster and cheaper) to use a vendor who specializes in change parts.
9. Ask for a fill test.
The best way for the vendor to understand your product is with a fill test. Provide them several product samples, bottles, and the key information (fill temperature, viscosity) so they can perform an adequate test. This will help them determine fill time, accuracy, and any potential issues.
10. Know what you need today, but have flexibility for tomorrow.
When selecting a machine, keep an eye on future output. See into Year Two, and think about future new products and their filling needs. Look vertically across your products, as well as upstream in the supply chain. What happens if a key ingredient in the formula of your product changes? Does this mean your nozzles may become ineffective? Think about future filling challenges.