Polyethylene is the commonly used sheathing compound for optical fiber cables for outdoor installation. Polyethylene comes in different grades and different specific gravities. According to the specific gravity, they are classified as HDPE, MDPE, LDPE and LLDPE. Though generally the outer sheath is color is black, there are situations where the customer demands for different colors for outer sheath.
Polyethylene that is used in fiber optic cable comes usually in natural color or black color. If customer asks for different colors, we can add masterbatch to the natural polyethylene. Addition of masterbatch by mixing in natural base color is the best solution since we can control the shade of color by controlling the percentage of masterbatch.
One important thing to be taken care when adding color masterbatch to the natural polyethylene is the weather resistance and ultraviolet resistance of the extruded sheath. In most cases, we need to inform either the natural polyethylene supplier or the masterbatch supplier to add anti-oxidation agents and ultra violet resistant chemicals. Or else we need to add those chemicals before extrusion.
Here we focus on the specification requirements of polyethylene color master batch to be used for mixing with Natural Polyethylene (HDPE/ MDPE/ LDPE).
– 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)
– All the black master batches shall have carbon black content of at least 40%.
– The heat resistance of the material shall be at least 300°C
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.