Vytran PTR-200-PRL, Operator'S Manual

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Recoat and Proof Test Process
Vytran LLC: PTR-200-PRL Polyimide Recoater Operator’s Manual Version 1.2 19
4 Recoat and Proof Test Process
4.1 The Polyimide Recoat Process
The PTR-200-PRL utilizes two Fiber Holding Blocks (FHB’s) to securely clamp and position the fiber prior
to recoating. The right-hand FHB has a linear drive mechanism for applying tension to the fiber. A load
cell is incorporated into the linear drive mechanism for monitoring recoat tension. Once the fiber is
positioned and securely clamped in the FHB’s, pressing the recoat button will initiate an automated recoat
process. The right-hand FHB will move to the right until the Recoat Tension is reached. With the fiber
held under tension, the right die is closed and the Undercoat Quantity of material is injected into the die
and the right heater is set to the Precure Temperature. The recoat head will move to the left depositing
material while the right heater will precure the material. Upon reaching the appropriate length, the left die
will close and additional recoat material will be injected into the die. The left heater is set to the Precure
Temperature and the right heater to the Cure Temperature. The recoat head moves to the right
depositing material while the right heater fully cures the previously precured material and the left heater
precures the newly deposited material. Returning to the start position is defined as one loop or pass as
the material initially deposited has been fully imidized.
This process is repeated until the desired recoat thickness has been achieved. A tension test is
performed at the conclusion of the recoat process to verify fiber integrity. The recoated fiber is unloaded
and the unit resets itself in preparation for the next recoat.
4.2 The Fiber Holding Blocks, V-Grooves, and Inserts
The FHBs are designed to accommodate a range of fiber buffer and cladding sizes through the use of
changeable, bottom, FHB inserts. The top insert is spring loaded and does not require any change for 80
or 125 micron fibers. The bottom inserts are V-groove, and incorporate vacuum feed to assist in loading
the fiber. The V-groove provides mechanical alignment to the recoat die. V-groove inserts are labeled
according to clamping diameter in microns. Beyond the V-groove inserts are rubber inserts. The rubber
inserts provide the clamping force and surface area required for tensioning and tension testing.
4.3 Stripped Fiber Requirements
The fiber to be recoated should be free of debris and have a smooth, continuous transition in the jacket
strip region. The jacket interface should not extend beyond the original coating diameter.