Crosslinking with Amb. Curing Catalyst MB (KISC) |
Products » Cable Compound >> PE Cable Compounds >> Crosslinking with Amb. Curing Catalyst MB (KISC)
The time of cross-linking of the insulation usually dependent on the following factors:
Catalyst concentration Relative humidity
Temperature
Insulation thickness
Processing Guidelines:
1. It is recommended to dry the Catalyst Master batch and Colour Master batch ( if any) at 60°C in air oven in 4 - 6 cm layers for 8 -12 hours. The Grafted Polymer should never be pre-heated.
2. The Grafted Polymer and Catalyst Master batch should be manually mixed at a ratio of 95: 5 at room temperature without shearing, just before consumption. Mixing in large quantities should be avoided, since such leftover premix can not be stored.
4. Recommended start-up procedure is given below:
a) Ensure that the screw, barrel and tools are thoroughly cleaned.
b) Start at slightly lower temperature profile. Allow the frictional heat to build-up to desired temperature and remain steady thereafter.
c) Flush with virgin LDPE (film grade ). Adjust eccentricity and wall thickness inserting conductor.
d) Replace LDPE with XL-03 / KISC premix. Increase line speed to optimum. Adjust temperature to obtain a smooth surface finish.
e) Avoid thermal shock by sudden cooling. Keep sufficient distance between die-head and water trough to allow air Cooling. Avoid inlet water being too cold.
5. It is important that extruder should not be kept idle for more than 15 minutes when filled with XL-03 / KISC premix.
6. During tubing extrusion, build-up of stress should be avoided, size of the core point should be carefully selected to keep the Draw Down Ratio (DDR) below 2: 1 in case of small sizes. For higher sizes of the core, DDR may be increased slightly. It is also recommended that a land be in place, with its length approximately same as that of the finished diameter of the core.
Storage:
The shelf life of the product exceeds 4 months from the date of production, subject to following condition;
Storage temperature not generally exceeding 25°C
Away from direct sunlight and weathering
Closed and unbroken bags
Use of compound within 3 - 4 hours after bags are open
Packaging:
The product is available in 25 kg moisture-resistant bags.
The information given in this document is believed to be reliable and is given in good faith but without warranty. The user should test the product to ascertain the suitability for the intended use. Product specification or the whole document is subject to change without any prior notice.
Polyethylene absorbs water very slowly, means insulation thickness has a relatively large influence on cross-linking speed.
It is evident from the table, the grafted polymer (KI XL-03) and catalyst master batch (KISC) makes it possible to crosslink with in a practical condition and acceptable time frame even at ambient temperature. In practice, the addition of water to the cable core drum by spraying further reduces curing time.
During extrusion, following temperature profile is suggested:
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