Articles · Buyer decision · 2026-09-13
Screw pump filling machines: the low-shear answer for honey, jam and cosmetics
Some products lose quality the moment they are sheared. Screw pump fillers protect them — but only inside the right product window.
Why shear matters in filling
Shear breaks down structure. A honey that recrystallises differently, a jam that loses its fruit body, a cosmetic cream that turns watery — these are classic shear damage symptoms from an aggressive dosing pump. A screw pump filler (progressing cavity) moves product with a rotating screw inside a stator, creating a continuous, gentle, low-pulsation flow with very little mechanical agitation. That is why it is the traditional answer for delicate, sticky, high-viscosity products.
Where screw pump filling shines
- Honey and syrups: thick, sticky, shear-sensitive — screw dosing preserves natural texture.
- Fruit jam and marmalade: fruit pieces travel gently without being crushed into pulp.
- Cosmetic creams and lotions: emulsions stay stable when sheared softly.
- Pharmaceutical ointments: consistent dose without altering formulation structure.
- Food pastes with soft solids: where particles must arrive intact.
The limits to know before you buy
A screw pump is not automatically the best choice for every thick product. Consider these four checks:
| Check | Why it matters |
|---|---|
| Fibrous or hard particles | Long fibres can wrap the screw; very hard solids can shorten stator life. Hard, abrasive particles favour a rotor pump with open passage. |
| Fill accuracy at high speed | Screw metering is gentle but can drift at very high cycle rates; servo control is essential for tight tolerance. |
| Cleaning and changeover | Stator and rotor need proper CIP or disassembly; changeover time is longer than a simple seatless rotor chamber. |
| Stator wear | The elastomer stator is a wear part with product-dependent life. Budget for replacement as normal maintenance. |
Screw pump vs rotor pump: how we decide
Both handle high-viscosity product, so the distinction is about the product's nature, not its thickness. We recommend a screw pump filler when the priority is gentleness on a shear-sensitive product with limited particle size. We recommend a rotor pump filler when the product contains larger or abrasive particles, when very high dosing accuracy (±0.5%, error ≤1 g) must be held over a wide fill range (5 ml to 300,000 ml), or when CIP-capable seatless construction is the deciding factor.