Food products run the gamut of viscosities and particulate content, both of which profoundly determine the best type of filling machine for this industry. Sauces and dressings can be as chunky as crude salsa or as thin as vinegarette. Syrups and edible oils have their own peculiarities in filling based on bulk density and viscosity changes with temperature. Some commodity food products are only filled in bulk. This means that almost every filler we manufacture has some application in the food industry depending on the product. This wide range of product characteristics also suggests that filling machines with great flexibility and versatility are the most valuable.

About Food Grade Construction

Obviously, when you are talking about food, you are talking about clean. A food grade filling machine MUST be easy to completely clean and must have a fluid path constructed of sanitary materials such as 316 stainless steel and food grade polymers. Threaded fluid connections area generally disallowed even for low level sanitation requirements. Instead tri-clamp sanitary fittings are used thoughout the fluid path. These food grade filling machines may be required to fill at high temperatures or at least, be cleaned at high temperature to maintain sterility between operational shifts. High temperature will also affect the choice of materials and components in a food grade filler. Depending on the regulatory agencies involved with your products, the filling machines may have additional sanitary construction and finish requirements. The “3A” sanitation approval or even higher standards such as USDA approval, is often needed for machines even on the periphery of the meat and dairy industries. Because almost all food grade machinery must be washed down regularly with detergents and caustic chemicals, the electrical and sensor systems design must be suitably watertight and provide resistance to corrosion.

Because some food grade requirements are less stringent than others, the construction strategies and therefore, the variability of costs between food grade machines can be great. This means that the buyer should expect a thoughtful and complete level of customization of their filling machine based on the actual operating requirements needed. Our experienced and expert sales engineers can help you avoid the mistakes of buying too much or too little machine for your food grade applications. Please note that our experience in this area culminates from 17 years of food grade installations in the most demanding of companies and environments.

Generally speaking, if a food product is fairly thin and flowable with no particulates or particulates not exceeding 1/16″ diameter in it, an Overflow Filling Machine would be the best economic choice. Examples of these types of products would be hot filled syrups, barbeque sauce, salad dressings, etc. Please note that many products such as barbeque sauce and ketchup become fairly thin liquids when heated to their proper fill temperatures. Since many of these products are sometimes filled in glass, the Overflow Filling Machine is the only practical filling machine that can be used. The reason for this is that the Overflow Filling Machine is a “fill to level” filling machine which means that the product will always appear to have the same fill height in the container regardless of the manufacturing (and volumetric) variations that occur in glass. The reason that particulates must be kept low in this type of filling machine is that they will have a tendency to clog up the overflow nozzle if the solid content is too high. An example of this might also include juices with an extremely high pulp content or flowable salad dressing but with ¼” onion or garlic pieces in it. Essentially, once particulates enter the picture, a more expensive piston or pump filling machine will be specified instead.

Food products that are thick like heavy sauces and pastes or that have a high particulate content including large pieces of meat or vegetables like chunky salsas, require a filling machine with the necessary force and large enough fluid path to pass these products. A thick paste simply will not pass through an overflow filling machine and 1″ pieces of tomato and onions will clog up overflow and gravity filling machine nozzles immediately. Therefore, the piston filler with rotary three way valves is used widely to handle these types of products. In fact, in the food filling business, it is probably the most common filling machine with an excellent cost to performance profile. Piston fillers are more costly than overflow fillers with similar bottle per minute outputs. Piston fillers with less expensive check valves can pass fluids with viscosities greater than an overflow filler such as low temperature syrups but generally, piston fillers are constructed with 3 way valves for maximum versatility.

Piston fillers are relatively fast producers with typical outputs of 10 to 15 containers per minute per nozzle. These types of filling machines are also very accurate providing a volumetric fill size that is precise. Accuracies of +/- 1% of volume or better is typically achieved on this filler. These machines can also be configured with jacketed product hoppers to maintain hot fill temperatures as well as rotary agitators to keep heavy particulates in proper suspension. It should be noted that while these machines are ideally suited to thick or chunky food products, they are not optimal for thin flowable products as described in the Overflow Filling Machine description above. Although it is possible to fill water thin products in a typical food piston filler, the large fluid path, piston seal design and nozzle design are optimized for thick and chunky products. This means that the machine may be prone to drips or leaks on thin products. Inline Filling Systems has component designs that can overcome these tradeoffs on filling thin products on a piston filler but generally, the piston filler is not the machine of choice when the product viscosity is in the low range.

Some expensive food products or commodity products with low margins that are filled in bulk are filled by weight either because of economics or because that is the way the product is normally sold. A fine commodity example of this is edible oil that when filled in bulk, it is important for the producer to not give away any extra product. In the case of edible oil, the containers are usually imprecise vessels and moreover, the product volume varies with ambient temperature. These factors make volumetric filling of edible oil impractical in bulk; the solution is a Net Weigh Filling Machine. Another example is high value extracts and flavorings that are normally sold by weight for obvious reasons. The Net Weigh Filling Machine is very accurate but are typically slower speed and often reserved for the realm of bulk filling. The delivery method of the products are also either by gravity or by pump which means that these products typically are free flowing in nature with few if any particulates. The Net Weigh Filling Machine is well understood and valuable in circumstances described above but they are not as prevalent the bottle filling marketplace (other than bulk filling) owing to their higher capital cost and fairly low output.

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The Servo Pump Filling Machine is an extremely flexible, easy to use and easy to clean filling machine in a class of its own and able to fill almost any food grade product you can imagine. A computer controlled pump dedicated to each filling nozzle allows for total programmatic control of all filling parameters with unlimited fill sizes, high volumetric accuracy and the ability to deliver almost any thick, thin, particulated or non particulated sanitary product into almost any container. Because it can handle an extremely wide range of viscosities and can pass particulates up to 3/4″ diameter without chopping, it can be used to fill Juices, salsas, jellys and jams, salad dressings , syrups, sauces, mayonnaise and some pastes.

In food grade operations, this filling machine is extremely attractive because of its ease of cleaning and nearly instantaneous changeovers. These filling machines have been successfully installed in USDA plants because of their cleanability and because the machine’s operating system is easy to validate. For contract packagers that have many different flavors or products to produce in one day, the fast changeover greatly enhances profitability.

All of this flexibility does come at a high capital cost. Each servo controlled pump/nozzle combination typically costs over $10,000 per nozzle. However, as the marketing of consumer products becomes more fragmented and while the number of SKU’s increase and the individual volumes of each SKU declines, this machine pays for itself by offering a level of efficiency not matched by other types of filling machines.