Viscous Liquid Filling Machine

Viscosity is a liquid's resistance to flow, measured in centipoise (cP). Water is 1 cP. Milk is ~2 cP. Honey is 2,000–10,000 cP depending on temperature. Peanut butter can be 250,000 cP. Petroleum jelly reaches 1,000,000 cP. Standard thin-liquid fillers (gravity, flow meter) cannot handle products above ~500 cP because the liquid does not flow fast enough through small nozzles. Viscous filling machines use gear pumps, lobe pumps or large-bore piston cylinders to push the product at controlled pressure. Heated hoppers reduce viscosity before filling, allowing faster speeds and better accuracy. The choice of pump type depends on product shear sensitivity, particulate size and required accuracy.

Gear pump filling: Two intermeshing gears rotate to move a fixed volume per rotation. Suitable for smooth, non-particulate viscous liquids (oil, syrup, adhesive, lotion). Not suitable for shear-sensitive products (some gels, live cultures). Highly accurate at consistent temperatures. Lobe pump filling: Two rotating lobes with large clearances move product gently. Suitable for chunky or shear-sensitive products (jam with fruit pieces, cream with beads, pharmaceutical gel). More accurate than gear pump for particulate products. Piston filling: A large-bore piston draws product from a hopper and dispenses it. The most versatile: handles any viscosity from 500 cP to 1,000,000+ cP, tolerates particles up to 10mm. Less accurate than pump types at low fill volumes but very accurate at large fill volumes (500ml–20L).

Many viscous products (honey, chocolate, wax, petroleum jelly, certain adhesives) are semi-solid or extremely thick at room temperature but flow freely when warmed. A heated hopper jacket heats the product reservoir to a set temperature (typically 40°C–90°C), reducing viscosity by formulation-dependent. This enables higher fill speeds (2–5× faster than cold filling), better nozzle flow (reduces drip and stringing), and improved fill accuracy (viscosity variation is the main source of error in volumetric filling). The hopper can be heated by electric resistance, hot water jacket or steam jacket. Temperature is controlled by PLC and monitored by PT100 sensors. The nozzles are also heated or insulated to maintain product temperature during filling.

Use a heated piston filler when the product flows well only inside a controlled temperature window or begins to solidify in the hopper, hose, cylinder or nozzle. Common examples include palm oil, coconut oil, wax blends, chocolate, petroleum jelly, cosmetic balms and some adhesives. Confirm fill temperature, ambient factory temperature, viscosity at fill temperature, cleaning method and whether the hopper, hose, piston body and nozzle all need heating.

Accuracy for viscous filling depends primarily on viscosity consistency. At constant temperature (heated hopper): gear pump by RFQ, lobe pump by RFQ, piston by RFQ (volume-dependent). Without heated hopper (room-temperature viscous filling): accuracy degrades to by RFQ because viscosity varies with ambient temperature. For products sold by declared weight (honey, cosmetic cream, pharmaceutical ointment), net-weight filling with load cells under the container is recommended, giving by RFQ–tolerance by RFQ independent of viscosity variation. HEMUfill recommends heated hopper systems for any viscous product above 5,000 cP.

HEMUfill viscous liquid filling machines handle: honey (2,000–10,000 cP); syrups and molasses (5,000–50,000 cP); tomato sauce and ketchup (3,000–70,000 cP); body cream and lotion (5,000–100,000 cP); petroleum jelly and salves (50,000–500,000 cP); adhesives and sealants (10,000–300,000 cP); mayonnaise and dressings (5,000–80,000 cP); gel and hair styling products (10,000–200,000 cP); pharmaceutical cream and ointment (15,000–100,000 cP); chocolate and confectionery cream (1,000–100,000 cP, temperature-dependent). Contact us with your product viscosity at fill temperature and we will recommend the right pump type.

Compare the filling principle and heated scope before comparing price. Check whether the quote includes only a filler or also the hopper, agitator, heated hose, heated piston body, heated nozzles, capping, labeling, cleaning parts, spare seals, commissioning and FAT/SAT support. Send product viscosity at fill temperature, container size, fill volume, particulate size and target output for a comparable quotation.