VMT

From a single hollow fiber to a finished, packaged filter – every stage adds risk of defects that can travel through the entire production. That is why quality is checked at every step, from fiber to finished filter.

A single dialyzer contains several thousand hollow fibers whose inspection features lie in the micrometer range – at series volumes and under the documentation and validation requirements of life science manufacturing.

Our machine vision inspects every critical step in this chain non-destructively, at line rate and with traceable results. Defective parts are rejected before further material and process costs are incurred.

One Process. Every Step Covered.

The right technology at every stage.

01

Fiber Production

The hollow fiber membrane is formed from a polymer solution in the spinning process, passes through coagulation and washing baths and is dried. The fibers continue as continuous strands to bundle winding.
Monitoring of continuously running fiber strands, detection without an external trigger signal, stable evaluation under changing reflections on the fiber surface.
Detection of broken fiber strands before they enter the fiber bundle. An undetected fiber break shuts down the spinning line for an extended period and renders the running production unusable.
Technology: VMT Inspection Solutions

02

Bundle Winding and Insertion into the Housing

The fibers are wound into a bundle with a defined fiber count. The bundle is then inserted into the filter housing, positioned and fixed in place.
Inspection of the outer surface across the full circumference of the rotating bundle, separation of surface defects from regular fiber structure, inspection of the bundle once inside the housing.
Defects on the fiber bundle, particles, dents and deviations in fiber orientation are detected. After insertion, fiber loops, kinks, fiber residues and contamination inside the housing are additionally inspected.
Technology: VMT Fiber Bundle Inspection

03

Cutting and Fiber Opening

After potting, the dialyzer is cut to final length. The cut opens the fiber lumens and creates the cut surface for subsequent assembly.
Resolution down to the individual fiber across the entire cut surface, discrimination between open and closed fiber lumens, measurement of the filter end at line rate.
Inline, all fibers on the cut surface are counted and the number of closed fibers as well as the fiber density are determined. In addition, the geometry of the filter end, damage, chip-outs and contamination are recorded.
Technology: VMT Fiber Geometry Inspection and VMT Inspection Solutions

04

Final Assembly of Caps and Sealing Elements

Blood caps and sealing elements are mounted onto the filter ends. Additional components such as tabs are positioned and joined.
Presence inspection on transparent and semi-transparent components, position determination in two axes as input for the assembly step, inspection before joining, as rework is not possible afterwards.
Presence and correct seating of the sealing ring as well as presence and position of further assembly parts are inspected. A missing or incorrectly seated sealing ring results in a leaking dialyzer.
Technology: VMT Inspection Solutions

05

Leak and Integrity Testing

The assembled dialyzer is filled and pressurized. Fiber and seal integrity is assessed via bubble formation in the test medium.
Evaluation of a time sequence rather than a single image, detection of individual rising bubbles in the test vessel, inspection within the stationary window of the cycle.
Leaks are detected by analyzing bubble formation over the test period. The result feeds into batch documentation as a release criterion.
Technology: VMT Inspection Solutions

06

Labeling and Packaging

The dialyzer is labeled, identified and transferred into its sterile final packaging. Sterilization and release complete the manufacturing process.
Reading of plain text, 1D barcode and Data Matrix code on the same label, comparison of the read data against a database or PLC specification, untriggered continuous inspection of the packaging film.
Label position and seating as well as print quality and content of the applied data are inspected. The final packaging film is checked for holes, tears and particles.
Technology: VMT Inspection Solutions

07

Laboratory Quality Assurance

Filters are taken from running production as samples and measured offline in the laboratory. The results support process assessment and release documentation.
Microscopic resolution across a large field of inspection, automated traversing of the cut surface in X and Y, reproducible measurement values for comparison across batches.
Wall thickness, roundness and inner diameter of the hollow fibers are measured. Fiber deformations are detected and assigned to the sampled filter.
Technology: VMT Fiber Geometry Inspection