What Measures Help O Rings Avoid Residue Contamination in Robotic Camera Lens Sealing?

Number of hits：462026-01-05 14:23:02　

To avoid contamination of optical lenses in robotic vision systems caused by O‑ring extractables, a comprehensive approach is required. Effective solutions must combine material selection, process control, and system design.

Solutions

Selection of Low‑Extractable, High‑Purity Materials

O‑rings should be manufactured from materials with minimal outgassing and extractables. Fluorocarbon rubber (FKM) and perfluoroelastomer (FFKM) that comply with ISO 10993 or USP Class VI standards are recommended. These materials exhibit very low extractable levels in vacuum, high‑temperature, and cleanroom environments. FFKM, in particular, offers exceptional stability against organic solvents and highly corrosive media. Nitrile rubber (NBR) and silicone rubber (VMQ) should be avoided, as they tend to release plasticizers or silicone oils that can contaminate optical surfaces.

Pre‑Treatment and Cleaning Procedures

Before installation, O‑rings should undergo ultrasonic cleaning followed by rinsing with high‑purity isopropyl alcohol (IPA). Vacuum drying is then required to remove residual mold release agents, machining oils, and particulates. Some manufacturers provide “cleanroom‑pretreated” versions that are suitable for direct use in Class 100 cleanroom environments.

Non‑Contact Seal Design

To minimize direct contact between O‑rings and optical components, inert barriers such as PTFE gaskets can be introduced between the lens housing and the O‑ring. Alternatively, dual‑seal configurations with a negative‑pressure exhaust chamber can be employed, ensuring that any extractables remain isolated from the imaging area.

Environmental and Operational Control

The operating environment should be maintained at low humidity and stable temperature to prevent thermal expansion or contraction that could create microcracks in sealing materials. Periodic vacuum baking at 80–120°C for 2–4 hours can accelerate the release of residual volatiles, reducing long‑term contamination risks.

Recommendations

To safeguard imaging accuracy in robotic vision systems, a combined strategy is essential:

Use FFKM or FKM O‑rings with certified low‑extractable properties.

Apply thorough pre‑cleaning and vacuum drying procedures.

Incorporate barrier or isolation structures in the seal design.

Material replacement alone, without cleaning or structural optimization, may still allow trace contamination to accumulate, ultimately affecting repeatability in robotic positioning and degrading image signal‑to‑noise ratio.