Validated Cleaning for Fluid Bed Dryer Bags

A joint study by Sefar and Borer Chemie evaluating material compatibility, filter performance, and service life under repeated industrial washing conditions.

FBDB Cleaning Study

Advanced Cleaning Solutions for Reliable Performance of Fluid Bed Dryer Bags (FBDB). Material Compatibility and Lifetime Evaluation under Industrial Tumble Washing Conditions.

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Pharma worker setting up the fluid bed dryer bags in a fluid bed dryer in a life science production area

Cleaning Validation Requires More Than Residue Removal

Proper cleaning of fluid bed dryer bags is essential for GMP compliance and contamination control. However, cleaning procedures must also preserve filter performance and material integrity throughout the service life of the filter bag.

To better understand these effects, Sefar and Borer Chemie conducted a systematic study evaluating the impact of repeated industrial washing cycles on polyester (PET) and polyamide (PA) filter bag materials.

Zoom into fluid bed dryer bag fabric

The Challenge

For reusable fluid bed dryer bags, cleaning validation requires both effective residue removal and preservation of material integrity. Cleaning agents and process parameters can influence seam strength, dimensional stability, and air permeability. Understanding these effects is essential for establishing robust and compliant cleaning procedures.

Systematic Evaluation Under Industrial Washing Conditions

The study evaluated PET and PA filter bag materials through 15 complete washing cycles at 60°C, simulating demanding industrial reuse conditions. 

The assessment included:

  • Material compatibility
  • Welded seam strength
  • Air permeability
  • Dimensional stability
  • Surface condition
  • Rinseability using TOC and conductivity analysis
Microscopic analysis of fluid bed dryer bag media

Key Findings

  • Material compatibility depends on cleaning chemistry
    The study identified distinct compatibility windows for PET and PA filter materials under acidic, alkaline, and pH-neutral cleaning conditions.
     
  • Welded seams are a critical indicator
    Welded seam strength proved to be one of the most sensitive indicators of cleaning-induced material degradation.
     
  • Effective rinseability was confirmed
    Testing demonstrated effective cleaner removal with no evidence of residue accumulation throughout the study.

«Customers often ask how to properly clean fluid bed dryer bags. Together with Borer Chemie, we conducted this study to provide data-driven guidance on material compatibility, filter performance, and cleaning parameters.

Denis Hofmann, Team Lead Product Engineering, Sefar AG

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    pdf, 3.33 MB

    WP-PF-LSC-FBDB-Cleaning-EN-2026-10-06.pdf

    Advanced Cleaning Solutions for Reliable Performance of Fluid Bed Dryer Bags. Material Compatibility and Lifetime Evaluation under Industrial Tumble Washing Conditions.