In loose tube optical fiber cables, tubes are colored to make the identification process easier. PBT (Polybutylene Teraphthalate) is a widely used as loose tube material in the cable industry. PBT is easy to process and also easy to buy due to availability that leads to lower price. PBT comes in natural color and looks white. PBT used in cable industry has a granular material comes in 25 kg bags. Color shall be added during the tubing process.
Color is given to PBT by adding color master batches during loose tube extrusion. Color master batches for PBT are available in different colors. 12 of the basic colors used commonly in fiber optic cable industry are: Blue, Orange, Green, Brown, Grey, White, Red, Black, Yellow, Violet, Pink, Aqua (Turquoise).
There will be color master batch unit attached to the extruder. Here we will focus on the specification requirements of color Masterbatch for natural PBT.
– The Master batch shall not contain pigments of other ingredients, which may accelerate the aging of the finished product.
– After mixing the master batch with Polyethylene and after extrusion, the material must have a minimum of 30 minutes at 190°C in the Oxidation Induction test.
– The master batch pigments shall be non-toxic and free of heavy metals (Lead, Cadmium, Mercury)
– The heat resistance of the material shall be at least 300°C.
– The master batch colors shall be as per the order.
Test Certificate: Each incoming delivery/ batch shall be accompanied by a test certificate.
Packing: Material shall be supplied in air tight, moisture proof bags. Material shall be supplied in 25 kg bags.