Discover Electropolishing and Mechanical Polishing Services

Astro Pak offers a comprehensive collection of cleaning and surface polishing services customized to every customer's needs. Electropolishing, mechanical polishing, and electrolytic cleaning can be used as separate approaches, but merging one or more of these services ideally satisfies specific needs.

Customers will experience the utmost in contamination and corrosion protection for prolonged, dependable performance when using Astro Pak’s chemical cleaning and passivation services.

Using tailor-made tooling, Astro Pak ensures ideal contact with complex stainless-steel surfaces and proprietary chemistry for better results. The surface roughness decreases to a level at or below the specified surface finish.

Astro Pak uses microscopic and profilometry testing to confirm complete quality assurance. “Ra,” or surface roughness, is ensured. Its profilometers measure surface roughness, while Ultrasonic testers gauge the thickness of the tank wall. Producing findings that fulfill or outdo industry standards is possible by recording these measurements before and after remediation.

Astro Pak performs all three services onsite to help clients improve and maintain the surface finish conditions of vessel interiors or exteriors with minimal downtime. When used as part of the pre-commissioning of a vessel, Astro Pak's methods improve system dependability by overcoming problems generated by installation and manufacturing.

The exclusively trained restricted space entry crews are proficient in servicing difficult-to-access equipment. These crews can function 24/7 to swiftly return process vessels to service. These services are also offered across a nationwide network of shops.

Customer service is always second to none, from the technicians performing the work in the field to the office staff. Everyone expressed professionalism and great communication skills.

Project Manager, Pharmaceutical Company, Devens, MA

What is Mechanical Polishing?

Mechanical Polishing — a surface finishing process — uses abrasives to polish and smooth a surface. This leads to even surface conditioning to meet or exceed ASME BPE and ASTM B912 standards. Mechanical polishing removes pitting, corrosion, scratches, or etchings that comprise the passive layer of stainless steel and creates a low-chromium area that is more prone to corrosion.

Mechanical activities or chemical responses can cause this damage. Mechanical polishing also smooths welds where valves and ferrules have been added or replaced. For dry product vessels, mechanical polishing alone is usually sufficient. It is typically the first step before electropolishing and passivation for other applications.

Mechanically Polished.

Mechanically Polished. Image Credit: Astro Pak Corporation


Electropolished. Image Credit: Astro Pak Corporation

Mechanical Polishing | Surface Finishing Stainless Steel Tank

Video Credit: Astro Pak Corporation

What is Electropolishing?

Electropolishing — an electrochemical surface finishing process — employs a DC current supplied via an electrolyte solution to dissolve the metal surface to a certain depth. The resulting finish fulfills or outdoes the requirements of a biopharmaceutical surface finish. It can reduce Ra measurements by up to half that from mechanical polishing alone.

Electropolishing also removes inclusions, impurities, and other implanted contaminants, also known as the Bielby layer formed during mechanical polishing. The outcome is a smooth, mirror-like finish where contaminants, residue, and single-cell bacteria do not have a place to lodge. 

Electropolishing is the ultimate process in getting a vessel ready for service. Merging it with passivation results in a smooth, chromium-rich surface with better cleanability and higher corrosion resistance. For high-purity applications, this level of finish is critical.

Benefits of Electropolishing

  • Improved Durability
  • Increased Corrosion Resistance
  • Enhanced Sterility
  • Improved Cleanability

Before MP/EP.

Before MP/EP. Image Credit: Astro Pak Corporation

After MP/EP.

After MP/EP. Image Credit: Astro Pak Corporation

Astro Pak : Microscopic View of Electropolishing - Narrated

Microscopic View of Electropolishing. Video Credit: Astro Pak Corporation 

Electrolytic Cleaning

Electrolytic cleaning is a shorter version of electropolishing with identical chemistries and tooling. With an ELC (electrolytic cleaning) method, rouge and other metallic surface contaminants can be quickly removed from austenitic stainless (300 series). 

Removal of contaminants takes significantly less time as they are not ‘bonded’ to the surface as firmly as the base metal, so rouge is expelled from the surface quickly. The substrate is left in a disinfected state and then prepared for passivation, additional polishing, or a return to production. Since electrolytic cleaning is restricted to the outer surface of the metal and does not need a deep process to remove, it can also eliminate heat tint or weld color.

This information has been sourced, reviewed, and adapted from materials provided by Astro Pak Corporation.

For more information on this source, please visit Astro Pak Corporation.


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