Bottom line: piston fillers are the go-to for thick, chunky, or high-viscosity liquids; pump fillers — whether peristaltic, gear, or lobe — handle thin-to-medium viscosity products with continuous, gentle flow.
How a Piston Filler Works
A piston filler uses a cylinder-and-piston mechanism to draw in a precise volume of product and then force it out through a nozzle into the container. This positive displacement action is highly accurate and is unaffected by changes in product viscosity — which is why it performs consistently with thick sauces, pastes, and chunky products.
Piston fillers are ideal for:
- Thick sauces: pasta sauce, salsa, curry paste, mole
- Jams and marmalades (including those with fruit pieces)
- Peanut butter, tahini, nut butters
- Cosmetic creams and lotions
- Chunky products with particles up to a configurable size
- Products requiring high fill accuracy regardless of viscosity
How a Pump Filler Works
Pump fillers use a pumping mechanism — peristaltic, gear, or lobe — to move product from a reservoir to the nozzle. Peristaltic pumps push product through a flexible tube using rollers, making them easy to clean and gentle on sensitive products. Gear and lobe pumps move product between rotating elements, making them suited for continuous high-speed filling.
Pump fillers are ideal for:
- Water-thin liquids: water, juice, spirits, vinegar, soy sauce
- Cooking oils, dressings, and thin condiments
- Medium-viscosity products: BBQ sauce, liquid soap, shampoo
- Products where gentle handling matters (e.g., beverages with pulp)
- Continuous high-speed filling lines
Side-by-Side Comparison
| Factor | Piston Filler | Pump Filler |
|---|---|---|
| Viscosity range | Medium to very thick | Thin to medium |
| Particle handling | Excellent — wide-throat valve options | Limited — small particles only |
| Fill accuracy | High — positive displacement | Good — time-based or flow-metered |
| Fill range | Configurable — contact for specifications | Configurable — contact for specifications |
| Output speed | Moderate to high — configurable | High — continuous flow capable |
| Cleanability | Good — cylinder and piston removable | Excellent (peristaltic) — tube replacement only |
| Hot-fill compatible | Yes — specify temperature at inquiry | Depends on pump type and seals |
| Contact materials | SUS304 / SUS316L, food-safe seals | SUS304 / SUS316L, food-safe seals |
How to Decide
Start with a viscosity assessment. If your product flows easily at room temperature (water, juice, thin sauces), a pump filler is the faster, more economical choice. If your product pours slowly or contains visible chunks or fibres, a piston filler with an appropriately sized throat valve is the correct solution.
For borderline viscosities — products like ketchup, barbecue sauce, or thick shampoo — both types can work. Share a sample description with our engineering team and we will confirm which configuration suits you best.
Both types can be integrated with pouch fillers, bottle fillers, and jar fillers. See our liquid filling machines or browse the full machinery range.
SunGene Liquid Filling — Taiwan Factory, Global Standards
SunGene manufactures liquid filling machines with SUS304 and SUS316L stainless steel wetted parts, CE certification, and voltage configurable to 220V, 380V, or 480V at 50Hz or 60Hz. We ship factory-direct from Taiwan with full documentation — including Declaration of Conformity — included as standard.
Custom nozzle configurations, multi-head setups, and hot-fill specifications are available. Contact our engineers before ordering to ensure the right configuration for your product.
Frequently Asked Questions
Which filler type is best for honey?
Honey is a thick, high-viscosity liquid best handled by a piston filler. The positive displacement action accurately meters high-viscosity products and is easy to clean between batches. Warming the product slightly can also improve flow and fill consistency.
Can a pump filler handle ketchup or thick sauces?
Gear pumps and lobe pumps can handle medium-viscosity products like ketchup and barbecue sauce. For very thick or chunky sauces containing vegetable or meat particles, a piston filler with a wide-throat valve is typically the better choice to avoid shearing or blocking.
What is the minimum fill volume for liquid fillers?
Minimum fill volume depends on machine configuration. Both piston and pump systems are available across a wide fill range — from small sachets to large bottles. Contact SunGene with your target fill volume to confirm the appropriate configuration.
Are SunGene liquid fillers compatible with hot-fill applications?
Yes. SunGene liquid filling machines can be configured for hot-fill applications. Appropriate material selection for seals, gaskets, and contact parts is essential — specify your filling temperature at the time of inquiry.
Are the wetted parts food-grade stainless steel?
All product-contact components on SunGene liquid fillers are manufactured from SUS304 or SUS316L food-grade stainless steel. Food-safe seals and gaskets are standard. CE certification covers electrical and mechanical safety for all export machines.