Will the jumper expand and deform if immersed in machine tool cutting fluid or transformer oil?
Whether fiber optic patch cords swell and deform when immersed in machine tool cutting fluid or transformer oil primarily depends on the chemical properties of the materials used for their outermost jacket and coating.
I. Physical and Chemical Mechanisms of Swelling and Deformation Induced by Oil Immersion
If the jacket or tight buffer of ordinary fiber optic patch cords uses common polymers (e.g., a conventional PVC jacket):
- Polymer Swelling Reaction: Molecules from machine tool cutting fluids (containing water-in-oil/oil-in-water emulsifiers, rust inhibitors) and transformer oils (such as mineral insulating oil, silicone oil, and other non-polar organic solvents) will penetrate the gaps between the polymer chains of materials like PVC. Upon absorbing these oily solvents, the polymer swells, leading to an increase in jacket volume ( \Delta V / V ), a decrease in hardness, and physical deformation.
- Impact on Optical Signal Transmission: Swelling and deformation of the jacket can cause uneven stress to be exerted on the internal tight buffer and optical fiber, leading to microbending loss. In severe cases, this can cause significant signal attenuation or transmission interruption.
- Oil Migration Resistance: Plasticizers in PVC jackets are easily extracted and dissolved by oils. After prolonged immersion, the jacket will first soften and swell, and then become hard, brittle, and crack as the plasticizers leach out.