The optical fiber outer jacket, strength member, inner jacket and fiber coating components are prepared for the bonding process by stripping and cleaning.
Cut the required length of cable off the spool. In order for the finished length to be correct, an additional 6 inches should be added to the required length to accommodate a bend that must be put in the end of the cable to hold the optical fiber in place during the first termination process.
Removal of Outer Jacket:
- Using a felt tip pin, make a mark on the outer jacket in accordance with the strip dimensions for the termination being performed.
- Using an outer jacket stripper, position the cable between the tools jaws until the tool’s blade is on the measured mark.
- Allow the tool to close gently (DO NOT FORCE) around the outer jacket.
- Rotate the tool 360 degrees around the cable. DO NOT ROTATE THE CABLE.
- Open the tool and remove the cable without stripping away the outer jacket.
- Pinch the outer jacket with your fingertips, on opposite sides of the scored area, using both hands, as close as possible to the score.
- Bend the cable slightly at the scored area to break the outer jacket free.
- Remove the cut portion of the outer jacket.
- Using ceramic scissors, trim the strength members’ flush to the outer jacket. This will insure a uniform length necessary for achieving a proper fit on the connector.
- Using a felt tip pin, make a mark on the outer jacket in accordance with the length of the strength members for the termination being performed.
- Using the outer jacket stripper, position the cable between the tools jaw until the tool’s blade is on the measured mark.
- Repeat steps 2 through 7.
- Straighten and comb out the braid of the exposed strength member by hand.
- Slide a pre-cut scrap piece of 1/8” diameter heat shrink tubing, down over the inner jacket so that all of the strength member filaments are on the outside of the tubing. Continue sliding the tube down, folding back the strength member filaments against the outer jacket to approximately 1/10-inch past cut edge. This keeps the strength member filaments pulled tightly back out of the way for the next operation.
Removal of Inner Jacket:
- Open the stripping tool and insert the cable’s inner jacket between the triangular portion of the tool’s jaws until the first triangular piece contacts the cable’s folded strength member.
- To cut the inner jacket, apply a slow light steady pressure to the tool handle until the tool stop is felt and a slight click is detected. This click is produced by the tool itself. Do not over-squeeze the handle as damage to the tool and cable can result.
- Do not rotate the tool or cable.
- Open the inner jacket stripper tool without stripping away the inner jacket.
- Using both hands, pinch the inner jacket with your fingertips as close to the cut as possible.
- A quick pull in opposite directions will separate the inner jacket at the scored area. If the inner jacket does not separate at the scored or cut area and tends to stretch, the stripper tool blades may be dull or damaged.
- Inspect the fiber coating for any nicks or cuts. Because of the extremely small dimensions between the inner jacket and the fiber coating, the inner jacket stripper tool compresses the fiber coating slightly during the stripping operation. This slight compression should not be confused with a fiber coating nick. The compression in the fiber coating relaxes back to the original fiber coating diameter after a short period of time.
- Determine the length of stripped fiber required for the type of termination being performed. Place a mark on the fiber coating with a felt tip pen.
- The chemical strip must be shaken thoroughly before each and every use to ensure proper chemical action and stripping times. Shake the chemical strip in a securely capped container for about 1 minute prior to use.
- Insert the fiber into the chemical stripper (a small beaker of methylene chloride) up to the mark. Make sure not to insert past the mark or insert the strength member filaments into the chemical stripper.
- Hold the fiber in the stripper for a minimum of two minutes.
- Remove the fiber after the appropriate time has elapsed and proceed immediately to the next step so that the softened fiber coating does not dry out which will make it difficult to remove.
- Hold the fiber coating firmly with one hand and with the other holding a shop wipe moistened with cleaning solvent, grasp the softened end and pull gently in opposite directions.
- If the fiber coating does not come completely off easily, place back in stripper for an additional one-minute.
- Note: The strength of the chemical strip will vary over time, particularly after it has been used for many stripping operations and after it has been exposed frequently to air. If the coating is not easily and completely removed after two immersions in the chemical strip, the chemical strip is weak and must be discarded.
- Using Shop wipes and IPA solvent, remove all residue stripper from the fiber.
- Inspect with a microscope at 50x minimum to insure all fiber coating has been removed and that there are no nicks on the outside of the fiber and no wicking of the stripping solution has occurred.
- Slide a pre-cut piece of heat shrinkable tubing over the cable’s stripped strength members.
- Rinse the cable’s fiber coating using a beaker of cleaning solvent. Immerse approximately 0.25 inch of the fiber coating into the cleaning solvent for 1 minute.
- Be careful not to let the inner jacket touch the solvent as solvent may wick up the cable and not dry out in time for the bonding operation.
- Remove the coating from the solvent and wipe with a dry shop wipe.
- This step flushes the fiber coating of chemical strip residue which may be present at the very end of the cable’s fiber coating after stripping.
- Remove the scrap piece of heat shrinkable tubing from the stripped cable end.
- Using a temperature controlled oven, bake out the fiber coating for 15 minutes at 85 º C. Insert at least 1 inch of the cable’s fiber coating into a middle oven cell.
- This step ensures that any chemical strip residue in the very end of the fiber coating is baked out thus preventing mixing of the chemical strip and the epoxy.
- Be careful not to break off the glass fiber by contacting the sides or bottom of the oven.
Inspect the stripped cable end for defects.