Liquid Filling Machinery
Liquid filling machines are used for a broad range of products. These include liquids for human consumption such as water, milk, carbonated drinks, edible oils, medicinal syrups, e-liquids and alcoholic beverages.
For domestic and industrial uses, liquid filling machines are key to the packaging of a wide range of lubricants, fuels, cleaning fluids, dyes, refrigerants, chemicals and many more products.
See a full list of PPMA member companies who are experts in Liquid Filling Machines.
How does a liquid filling machine work?
Bottling machines are in use in many liquid filling production lines for bottles made of glass, plastic and other materials such as aluminium and steel. Other containers used for liquid filling include cans, cartons, kegs, pouches, tubs and tubes.
The main issues for bottling machines are accuracy of fill, speed and product integrity. Accuracy is integral to the ability of a bottling line to fill to a level within a very small range of tolerances. Too little or too much affects profitability and the accuracy of labelling and can lead to spoilage. As in most packaging processes, speed is an essential productivity consideration. Liquid products need to be bottled hygienically if they are for human consumption, and must not be compromised if produced for other uses.
Bottling involves a series of processes and considerations which are specific to different products. For example, a wine bottling line will feature pumping, filtration, filling and corking or capping. For potentially dangerous products such as bleach, safety is a key issue for bottling lines, with the speed of capping a key consideration to minimise the release of toxic fumes and deterioration of the product. For viscous liquids, pumping is a critical consideration for ensuring a fully regulated flow of product.
The bottled water market in the UK alone is worth in the region of £1.5billion (Statista). It is the world’s most consumed drink, with demand outstripping the biggest-selling soft drinks such as Coca-Cola.
The majority of water is filled in PET bottles, although the process for glass bottles and cans follows the same steps. Bottling lines feed hygienically clean PET bottles of various sizes into the filling area where they are nozzle-filled with the correct volume of liquid. For carbonated water, CO2 is injected directly from a saturation unit into the bottle. Bottles are then conveyed to a capping line. Once labelled and packed in boxes or shrink-wrapped trays, the bottles are ready for onward transport.
Filling rates can be as high as 90,000 bottles per hour for high speed mass-market water, but for many smaller producers of crafted waters, much slower rates of 1,000 bottles per hour or less are more appropriate.
Can filling machines operate in a similar way to bottling machines? The optimum material for canning is lightweight, malleable aluminium. Rinsed, sanitised cans are fed into the filling station where multiple nozzles fill the cans with liquid. Lids are then placed on the open cans and seamed to create an airtight seal. The cans are then rinsed to clean off spills, dried, labelled, packed and palletised.
Pouches are increasingly being used as a lightweight packaging solution with the advantages of lower transport costs, recyclability and good printability which enhances graphics and text without the need for labelling.On a pouch filling line, preformed pouches are fed in a lane where they are printed or embossed before being opened by suction pads or vacuum. The pouches are filled by nozzles with a set dose of the product. Deflators expel excess air from the pouches before they are sealed by heat or ultrasonically. A second seal can be used to reinforce the closure. Cooling bars flatten the seal and add perforations if required. The pouches then go on to be packed in cartons.
What are the types of liquid filling machines?
In a packaging workflow, filling machines are specified according to the type of liquid (e.g. viscosity, carbonation) and the type of packaging (e.g. rigid, flexible). The technologies available through PPMA Member companies cover a full spectrum of liquid filling requirements, including semi-automatic and fully-automatic solutions.
- There are three categories of liquid filling machines:
- level filling machines, including gravity, pressure and vacuum fillers
- weight filling machines
- volumetric filling machines.
Level Filling Machines
These fill containers to a pre-determined level in the container by vacuum, pressure or gravity. The level is accurately measured by inspection equipment.
Level filling mechanisms are used to fill a product, usually liquid, to a predetermined level in a container, with the product flowing under gravity. This is the classic method of filling non-carbonated drinks into glass bottles. Fillers of this type are suitable for accurate filling of products at low, medium and high speeds.
Pressure Filling Machines
Level filling equipment fills carbonated liquid products under gravity to a predetermined level in a rigid container, with the product under pressure. Fillers of this type are suitable for the accurate filling of products at both medium and high speeds.
Vacuum Filling Machines
Vacuum filling machines fill a liquid to a pre-determined level in a rigid container. The flow is initiated by applying a vacuum to the container. This technique is used for filling liquids like wine and free-flowing powders like milk powder. Vacuum fillers are suitable for accurate filling of products at both low and medium speeds.
Weight Filling Machines
Also known as weigh fillers, these machines fill containers with a set weight of liquid (or powder, gas or solids) directly into the package which is resting on a weighing instrument that controls the filling operation. This method of weighing is used for products as diverse as jars of instant coffee, litre bottles of oil and 200 litre drums of chemicals. Gross weighing machines are suitable for the accurate filling of products at both low and medium speeds.
Volumetric filling machines
Liquid fill is measured by volume using a flow meter. If based on an inductive flow-meter these machines are restricted to use with water-based liquids but have the benefit that they are easy to clean and have the tolerance to include solids. Flow-meters can also fill non-aqueous products like oils. Fillers of this type are suitable for the accurate filling of products at both medium and high speeds.
Flexible liquid containers and rigid liquid containers
Rigid containers have been the principal type of container used for liquids for many years. The packaging industry continues to make extensive use of glass bottles and rigid plastics because they are functionally efficient and many bottling and packaging plants are set up to work with them.
Additionally, consumers expect products such as alcoholic beverages and olive oils to be in glass. However, raising awareness of the environmental impact of glass (such as transport of heavy weights) is pushing some businesses to move to lighter weight glass. Industries such as dairy have moved milk from glass bottles to cartons, and it is highly feasible for other sectors to follow the same pattern.
Stand-up pouches offer significant weight advantages over rigid packaging and are now a familiar sight in retail. Their market share is set to grow (the global flexible packaging market is estimated at $350bn).
What are the types of flexible liquid filling machines?
Flexible packaging is developing fast, but its two mainstays are Stand-Up Pouches and Bag-in-a-Box.
- Stand-Up Pouch Filling and Sealing Machine
Packaging machine in which pre-made stand up pouches are taken from a magazine, opened, filled and then sealed in the machine using a variety of methods, but typically heat or adhesive. Stand-up pouch fill and seal machines are used to pack liquids, sauces, soups and foodstuffs such as olives.
- Liquid Bag-in-Box Filling and Sealing Machine
Packaging machine in which a pre-made bag is filled with liquid and sealed. The bag is placed into a carton and the carton is then closed.
What are the types of rigid liquid filling machine?
Packaging machine in which glass ampoules or vials are first filled with liquid then fitted with a closure or fusion sealed with a flame. Typically, the filling methods used are volumetric piston, level, weigh filling or timed flow.
Packaging machine in which bottles are first filled with liquid and then fitted with a cap, cork, crown cork, roll-on pilfer-proof closure (ROPP), or another type of closure. Typically, the filling methods used are volumetric piston, level, weigh filling or timed flow. Machines will usually be rotary with one carousel for filling and a second carousel for capping the bottles.
Packaging machine in which cans are first filled with product, which may be liquid or solids in suspension (e.g. baked beans) and then closed by seaming an end piece or lid onto the can. Typically, the filling methods used are volumetric piston, level, or weigh filling. Machines will usually be rotary with one carousel for filling the cans and a second carousel for seaming the cans.
Packaging machine in which casks or kegs are first filled and then sealed usually with a plug or crimped cap. Typically, the filling method is gross weight filling.
Packaging machine in which pre-made plastic cups or tubs are taken from a magazine or stack, filled and then sealed using a heat sealed aluminium or plastic membrane or with a press on lid, or both. Cups are typically indexed from the filling station to the closing station either using an intermittent motion carousel or an in-line transport mechanism. Cup filling machines are used to pack products like yoghurt, cream or margarine.
Packaging machine that takes a pre-made collapsible tube made from metal or plastic, from a magazine which is filled typically using a volumetric piston filler and then closed by folding, crimping or heat sealing, depending on the material used to make the tube.
Liquid filling machines FAQs
Liquid filling is the process of filling rigid or flexible containers with free-flowing or viscous liquids and pastes for industries including food, beverages, cosmetics, household goods, chemicals and a range of other sectors.
A very basic manually operated machine for single container filling can be found for less than £100 but is suitable only for home-based or very small scale operations. For a commercial business filling 1,000 bottles per hour the costs go up to a range of £5,000 - £20,000, and for a high volume, high speed, complete in-line filling system, the prices get into a similar realm as for any major plant investment. For accurate costs, it is essential to obtain quotations from equipment suppliers based on your requirements.
Liquid filling methods are all based on feeding liquid into a container, with the variations on equipment required for different liquids and different containers. The variety of liquids, from water to oils to paint and pastes, require different types of feed to handle different levels of viscosity, with a range of pumps used to ensure correct movement of the product from tank or hopper to the container. Different types of containers also require different equipment for positioning and handling materials from solid glass to flexible plastic.
Beverage filling machines are used for all kinds of drinks on the market and are generally designed for specific types of products including still, carbonated and viscous liquids. Flexible machines with adjustment settings for a range of liquids are also available. Level filling or volumetric filling is generally used for still liquids, while pressure or vacuum filling is used for carbonated drinks.
By measuring the volume of liquid dispensed, volumetric filling machines accurately deliver the correct amount of liquid into a container. The measurement can be by filling a cylinder of the required size and dispensing the contents by piston into the container. An alternative approach is a timed period of liquid flow which will consistently dispense the right volume of liquid.
Metal capping machines apply metal caps, usually with a plastic-based lining, to bottles and crimp them to ensure an air-tight seal. Plastic capping machines are designed to apply plastic caps of various types including push-fit and screw-fit caps.
Access a list of PPMA member companies who can supply Liquid Filling Machines.