Fiber Recoaters Information

Fiber recoaters are benchtop injection molding machines that inject a UV-cured acrylate or polyimide recoating material around a fiber optic splice to restore the primary coating and provide a smooth and flexible outer coating. Each recoater accepts standard or custom molds that are changeable to accommodate different cable sizes and lengths of splices. Fiber recoaters support the cable within the mold and allow the recoat material to flow and encapsulate the splice. Extended length recoaters are available for lengths up to 110 mm where original optic cable coating was stripped away. Once the recoat material has flown around the splice the resin is cured using a UV light source.

fiber recoaterMost recoaters come with a proof-test mechanism to ensure the splice is strong enough to survive handling, packaging, and extended use. Unlike standard heat shrink protection sleeves, a recoated fiber can be handled and coiled normally, without risking the fusion-spliced section of fiber.


There are two key types of recoaters: automatic and manual. These are distinguished by the type of mold assembly used in the device and the amount of hands-on interaction. Both allow for the direct injection of material into the mold cavity.

Manual recoaters use a hinged top that can be opened and closed by hand. They inject the material into the mold cavity through a cross channel in the mold top plate. Manual recoaters are preferred for low-volume applications or if the mold size or process must be changed frequently.

Automatic recoaters recoaters use an automated pneumatic mold assembly. They involve a pneumatic gripper assembly to open and close the mold plates in a front-to-back direction. This allows direct injection of the recoat material into the mold cavity without any excess material to clean after each recoat. Once the fiber is positioned the entire recoat process is performed automatically. Fully automatic operation makes this system ideal for high-volume fiber processing.

Proof Testers

Proof testers—which apply tensile testing for production and laboratory environmentsare also supplied with many fiber recoaters. The two types of proof testers are linear proof testers and rotary proof testers.

Linear proof testers apply a set load at a controlled rate to an optical fiber or fusion splice to assess the long-term reliability of the fiber. Linear proof testers take the fiber optic cable up to a predetermined load and then release it. The testing process is fully programmable and allows the user to select parameters such as the load, the rate at which the load is applied, and the hold time.

Linear proof testers are designed for production proof testing with forces up to 22 N. Motorized clamps with rubber inserts ensure that the fiber coating is not damaged during the testing process.

Rotary proof testers apply a destructive test by taking the load on the fiber to its breaking strength. The fiber is supported by a special clamping mechanism and is wrapped around two mandrels. Rotary proof testers take the fiber up to its breaking point and record the results in units of tension or stress. These testing processes are typically fully programmable.


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  • Fiber lasers
  • Sensing
  • Medical
  • Aerospace and defense

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