Polyethylene pouches carry an enormous share of India’s daily milk. Dairies large and small rely on automatic form-fill-seal machines that convert a roll of film into filled, sealed pouches at high speed. Because milk is perishable and delivered daily, these machines must run reliably at odd hours, produce leak-free pouches and keep hygiene standards high.
How a Liquid Pouch FFS Machine Works
A vertical form-fill-seal machine takes printed film from a roll, passes it over a forming collar to shape it into a tube and seals the vertical edge. A horizontal sealing jaw seals the bottom of the pouch. Milk is dosed into the tube, and the jaws then seal the top of the pouch, which also forms the bottom of the next one. The pouch is cut free and drops onto a conveyor.
Dosing Methods
- Volumetric piston dosing: accurate and widely used for milk and other liquids.
- Electronic flowmeter dosing: accurate and easier to adjust, with fewer mechanical parts.
- Timer-based gravity dosing: simpler but less accurate, more sensitive to level and temperature changes.
Film and Sealing
Milk pouches are made from multilayer polyethylene film designed for strength and good sealing. Seal quality depends on temperature, pressure and dwell time. Leaking pouches are one of the biggest complaints in milk distribution, so sealing must be consistent. Impulse sealing or constant-heat jaws are used depending on the machine.
UV Sterilisation of Film
Many milk pouch machines include UV lamps that sterilise the film surface before forming. This reduces the risk of contamination from the packaging. Lamps must be cleaned and replaced according to schedule to stay effective.
Hygiene and Cleaning
Contact parts should be stainless steel, and the dosing system should be cleaned regularly, often through a cleaning in place cycle. Product tanks need covers, and the filling area should be kept clean and dry.
Single and Double Head Machines
Single-head machines suit smaller dairies. Double-head machines double output in nearly the same footprint and are common in larger plants. Output depends on pouch size, film and dosing method.
Common Problems and Solutions
- Leaking seals: check jaw temperature, pressure, Teflon tape condition and film quality.
- Inaccurate fills: check dosing settings, product level and air in the product line.
- Film tracking issues: check roll alignment and film tension.
- Code faults: check the coder and its synchronisation with the film.
Coding Requirements
Milk pouches must carry date, batch and price information. Coders such as thermal transfer or inkjet printers are integrated into the machine to print on the film before forming.
Planning for Early Morning Runs
Milk packing usually happens in concentrated windows, often at night or very early in the morning, so that pouches reach distributors on time. Machines therefore need to start up quickly and run reliably from the first pouch. Pre-shift checks of film rolls, jaw temperatures, dosing settings and coder messages help avoid delays. Keeping spare Teflon tape, heater elements and sealing jaws at the plant means a minor fault does not hold up deliveries. Many dairies also keep one machine as a standby so that a breakdown does not stop supply to customers who depend on milk every morning.
Choosing a Machine
Consider your daily volume, pouch sizes, product range and available space. Ask about accuracy, seal reliability and spare part support.
Hilden supplies pouch packing solutions for dairy and liquid products and can help dairies select machines suited to their volumes, products and hygiene requirements.