THORLABS vytran PTR308 User Manual page 17

PTR308 Automatic Recoater with Linear Proof Tester
6.2. Recoating
Recommended recoat parameters are preset at time of shipment. Typical values for recoating a 30 mm long stripped
section of standard single mode fiber (e.g. Corning SMF-28) in a 280 micron mold are:
Quantity (μl):
Rate (μl/sec):
The correct inject Quantity depends on the diameter of the mold, the diameter of the fiber, and the length of the
stripped section of fiber (the recoat length). See Table 1 Appendix A: for information on calculating recoat injection
quantities.
To perform a Recoat:

Check that the recoat parameters are set correctly.

Make sure the recoat mold is open.

Load the fiber in the fiber holding blocks, making sure the section of fiber to be recoated is centered left-to-
right in the in mold.

Press the "RECOAT" button on the unit or execute a Recoat command from the Handset controller. The
mold will close and the recoat process will start. When the mold opens the recoat process is complete.

Perform a Proof Test process if desired (see Section 6.3).

Raise the fiber holding block tops and remove the recoated fiber.

Gently wipe the recoat with a dry lens tissue or Kimwipe to remove any uncured recoat material or light
flashing. Do not wipe the recoat with acetone.

Visually inspect the recoat to make sure the recoat reached both coating interfaces and, if an overlap is
required, that it is sufficient length. Also check for voids or bubbles in the recoat, paying particular attention
to the area around the injection port.
If the recoat did not reach the coating interface it may be necessary to increase the Recoat Quantity. It is common
for the first recoat after the system has not been used for some time to come up short. Try a second recoat before
adjusting the Recoat Quantity. If the overlap region is too long or the mold plates are excessively "wet" with recoat
material, reduce the Recoat Quantity. When trying to determine the correct Recoat Quantity, it is recommended
that the Recoat Quantity be initially set to "come up short", and then incrementally increased to achieve the desired
overlap length. Injecting excess material into the mold will necessitate more frequent mold cleaning and, if too
extreme, can cause recoat failures due to the buildup of recoat material beyond the mating surfaces of the mold
plates.
The optimal curing time will vary depending on the diameter of the mold, and the age of the recoat material. The
size of the "nub" at the mold inject port is a good indicator of correct cure time. Make sure to check this before dry
wiping the recoat as this could "wipe away" the nub. A small protrusion of several "tens" of microns is an ideal nub
size. Increasing the Lamp time will increase the nub size. Make sure not to increase the Lamp time too high or the
nub could break off in the inject port and plug the mold. See Chapter 10 for approximate cure times of various
diameter recoat molds.
Note: The mold plates do not need to be cleaned after every recoat. Excessive cleaning can shorten the life of the
mold through damage to the coatings on the mold plates or chipping of the mold channel. It is recommended that
the mold plates be thoroughly cleaned at the start of a shift and then visually checked before each use for obvious
signs of dirt, dust or excessive recoat material. It is typical that after several recoats a slight "misting" of recoat
material will appear between the plates. This is acceptable and does not require cleaning. If the "misting"
approaches the top or bottom edges of the mold plates, or if the mold plates are "wet" with recoat material, cleaning
is required.
Note: It is recommended that while the recoater is in use that the mold plates remain open between subsequent
recoats. If the system will not be used for an extended period (more than several hours), it is recommended that
the mold be "Stored" with lens tissue between the plates (see Section 6.5).
Note: The mating surfaces of the mold plates have an optical coating that blocks UV light. Great care must be taken
not to scratch or abrade this coating. Use only a soft cotton tipped swab to clean the mold surfaces. Do not rub any
hard objects across the surface of the plates as this could scratch the optical coating or chip the edges of the mold
channel and degrade the quality of the recoat.
Rev C, October 19, 2020
1.2
0.2
Chapter 6: Recoat and Proof Test Process
Delay Time (sec):
Lamp Time (sec):
5
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