How does polishing reduce product buildup in polymer equipment?

Product clings to the microscopic peaks and grind marks on an as-fabricated surface. Removing those peaks by electropolishing, mechanical polishing or the C-75 process leaves a smooth surface that product releases from, which reduces buildup, bridging and stringers.

Which process is best for conveyor screws and rotary valves?

Electropolishing is the usual choice for stainless screws, rotors and housings because it reaches every surface, including flight roots, and lowers adhesion the most. Mechanical polishing or C-75 is used where the material or the finish target calls for it.

Can polishing reduce stringers and angel hair in transfer lines?

Yes. Stringers form where pellets shear against rough surfaces at elbows and bends. Electropolishing the line interior reduces that roughness and the friction that creates stringers.

Can you polish equipment on-site during a shutdown?

Yes. Harrison field crews polish and passivate installed hoppers, lines and vessels throughout the Houston area and the Gulf Coast, and we schedule around shutdown windows.

What is the Harrison C-75 process?

C-75 is Harrison's polishing process for product-release surfaces in bulk-solids handling. It is used where reducing adhesion, rather than meeting a corrosion or Ra specification, is the goal.

Surface Finishing for Polymer and Plastics Production Equipment

Mirror-polished stainless steel vessel interior finished to reduce polymer product adhesion at Harrison Electropolishing

The short answer: Product buildup is the hidden cost in a polymer plant. Pellets, powders and melt cling to the microscopic peaks on as-fabricated stainless, transfer rates fall, stringers and angel hair form, and the line shuts down to clean. Harrison polishes the product-contact surfaces — hoppers, conveyor screws, rotary valves, transfer lines, dies and vessel interiors — so product releases instead of building up. Intervals between cleaning shutdowns get longer and the cleaning itself gets shorter.

Equipment we finish

Hoppers, silos and bins. Interior polishing to keep pellets and powders flowing and reduce bridging.

Conveyor screws and rotary valves. Electropolished or mechanically polished flights, housings and rotors; see reducing product adhesion.

Transfer lines, elbows and diverter valves. Interior polishing to reduce stringers and angel hair at bends.

Dies, mixers and vessel interiors. Mechanical polishing, electropolishing or the Harrison C-75 process depending on material and finish target.

Choosing the process

Electropolishing dissolves the microscopic peaks and leaves a featureless, chromium-rich surface with the lowest adhesion and best corrosion resistance; it is the usual choice for stainless product-contact surfaces. Mechanical polishing reaches a specified Ra on surfaces or materials electropolishing cannot, and is the first step before electropolishing when the starting surface is rough. The Harrison C-75 process is our polishing process developed for product-release surfaces in bulk-solids handling. We recommend based on your material, the equipment geometry and the finish specification rather than defaulting to one process.

Capacity and turnaround

The Houston facility has four overhead cranes and 15,000 lb material-handling capacity for large hoppers and screw assemblies, and Harrison field crews polish and passivate installed equipment throughout the Houston area and the Gulf Coast. We have served polymer and petrochemical producers since 1980 and are ISO 9001 and ISO 14001 certified. Expedited service is available for shutdown windows; lead times vary with shop load.

Representative project

A Gulf Coast polymer producer was losing throughput to pellet buildup and stringers in a set of stainless transfer lines and the rotary valves feeding its extruders. Harrison electropolished the line interiors and elbows, polished the rotary-valve rotors and housings, and returned the equipment inside the planned shutdown with certificates of conformance. Buildup in the lines dropped, stringer formation at the elbows fell, and the producer extended the interval between cleaning shutdowns.

Request a polymer equipment quote

Tell us the equipment, the material, the product that is building up, and your shutdown dates. We quote within one business day.

Request a Quote · Call 800-245-5707

More to Know

Frequently Asked Questions

How does polishing reduce product buildup in polymer equipment?

Product clings to the microscopic peaks and grind marks on an as-fabricated surface. Removing those peaks by electropolishing, mechanical polishing or the C-75 process leaves a smooth surface that product releases from, which reduces buildup, bridging and stringers.

Which process is best for conveyor screws and rotary valves?

Electropolishing is the usual choice for stainless screws, rotors and housings because it reaches every surface, including flight roots, and lowers adhesion the most. Mechanical polishing or C-75 is used where the material or the finish target calls for it.

Can polishing reduce stringers and angel hair in transfer lines?

Yes. Stringers form where pellets shear against rough surfaces at elbows and bends. Electropolishing the line interior reduces that roughness and the friction that creates stringers.

Can you polish equipment on-site during a shutdown?

Yes. Harrison field crews polish and passivate installed hoppers, lines and vessels throughout the Houston area and the Gulf Coast, and we schedule around shutdown windows.

What is the Harrison C-75 process?

C-75 is Harrison's polishing process for product-release surfaces in bulk-solids handling. It is used where reducing adhesion, rather than meeting a corrosion or Ra specification, is the goal.

Request a Quote

800-245-5707

Electropolishing

Harrison Electropolishing, the Leading Electropolishing, Passivation, Oxygen Cleaning & Mechanical Polishing Company World Wide.

Electropolishing is an electrochemical process by which surface material is removed by anodic dissolution. Electropolishing removes surface material, beginning with the high points within the microscopic surface texture. By removing these points, the electropolishing process will improve the surface finish of a metal such as stainless steel, nickel, and Hastelloy, leaving a smoother and more reflective surface. Common parts and components electropolished include tanks, piping, fittings, rods, discs, large parts & surfaces, and more.