Polymer Transfer Pump Selection Guide

Why Polymer Transfer Is a Specialist Duty

Polymers are long-chain molecules, and that chemistry dictates the pumping rules. Many polymer liquids are non-Newtonian: apparent viscosity falls as shear rate rises, so a fluid can look thin in a fast impeller yet stay thick in a pipe. High shear also breaks polymer chains and lowers product quality, so the pump must move the liquid with low, controlled shear rather than high rotor speed or violent impeller action.

Temperature matters as much as shear. Resins, hot-melt adhesives and polymer melts are often pumped just above their softening point, where a small temperature drop thickens the liquid sharply. Polymer transfer therefore belongs to the wider problem of moving thick fluids, ranked in our guide to the best pump for high-viscosity liquids.

Define the Polymer and the Duty First

Before any pump is sized, collect the data that decide the technology:

• Viscosity profile: at operating temperature and at the coldest credible start — one number is never enough for a polymer.
• Rheology: shear-thinning or thixotropic behaviour, and how much shear the product tolerates.
• Solids and fillers: pigments, carbon black or mineral fillers make the fluid abrasive and raise rotor and stator wear.
• Chemistry and temperature: monomers, solvents and curing agents attack elastomers and seals; temperature defines the material and heating limits.
• Flow and pressure: average and peak flow, discharge pressure, and continuous or batch transfer.
• Suction conditions: flooded inlet or lift, available NPSH and inlet piping length.

Guidance on the extreme end of the spectrum is covered in the article on how to pump extremely viscous fluids.

Pump Options for Polymer Transfer

G-type single screw (progressive cavity) pump

For finished polymers — viscous resins, adhesives, latex concentrates and filled compounds — the progressive cavity pump is the standard workhorse. A helical stainless rotor turns inside an elastomeric stator, and sealed cavities advance the liquid with low shear and a steady, low-pulsation flow. Qingdao Green Power publishes the G-type at 0.1–150 m³/h and 0.6–2.4 MPa for oils and resins above about 1500 cSt, with stator grades (NBR, EPDM or FKM) matched to the chemistry. One rule overrides everything else: never run the pump dry — the rubber stator is destroyed within seconds without liquid.

Triple screw and centrifugal options

The 3GB triple screw pump (2.4–241.7 m³/h, up to 350°C) suits clean, low-viscosity fluids at high temperature, relevant where a polymer stream is kept hot enough to stay thin; because the pumped liquid lubricates the screws, the medium must stay clean and non-abrasive. At the other end of the scale, dilute solutions, emulsions and latexes below about 150 cSt can still use an IS/ISW centrifugal pump. Both screw-pump families are detailed on the G and 3GB industrial screw pump page; extrusion and melt-metering lines additionally use gear-type melt pumps, which are compact and precise at high pressure but tolerate only clean polymer.

System Checks That Decide Pump Life

• Feed the suction properly: viscous polymers create high inlet friction — keep the suction short, large-bore and flooded, with enough NPSH margin.
• Run at controlled speed: in progressive cavity pumps speed sets both flow and shear, so select size and gear ratio for slow, product-safe running.
• Protect against dry running: fit level control or dry-run protection; the stator of a G-type pump is destroyed within seconds without liquid.
• Add relief protection: a blocked discharge must not overload the drive or burst the line.
• Match elastomers and materials: confirm the stator grade and wetted materials against the monomers, solvents and temperature in the recipe.
• Plan heating and flushing: jacketed lines and pumps keep melts fluid; flushing prevents reactive resin from curing inside the machine between batches.

The same logic transfers to other demanding media — see heavy oil pump selection, high-viscosity oil transfer and bitumen and asphalt transfer.

Frequently Asked Questions