SPECIAL CHARACTERISTICS
:
A silane grafted crosslinkable polyethylene black compound,curable by exposure to moisture, for insulation/sheath of power cables and possessing excellent extrudability at high out put rate.
XL-ABC-01 is based on a high molecular weight polymer. It has been specially developed for insulation of core of aerial bunched cable for overhead application.
DESCRIPTION :
This compound utilizes the system for cross-linking of polyethylene developed by DOW coming and known as Sioplas. It is a two component system comprising a silylated ethylene polymer alongwith suitable additives known as XL-ABC-01 the graft copolymer, and a master batch XL-ABC-BLK containing mainly carbon black,u.v.ingredients and a cross-linking catalyst.The two materials should be used in the ratio of 93.7 parts graft to6.3 parts catalyst master batch.
Stored separately,these materials are fairly stable but when mixed and exposed to moisture, cross – linking takes place.
This system allows the compound to be extruded as a normal thermoplastic which will then attain a high level of cross-linking in the processed form.The finished product has all the properties associated with polyethylene cross-linked by other methods.
TECHNICAL DATASHEET :
Property |
Test
Method |
Unit |
Typical
value |
Density |
ASTM-D-1505 |
gm / cm3 |
0.93 |
|
MFI at 190°
C / 2.16 Kg. |
PPIL |
G / 10 |
0.4 |
|
Unaged
mechanical properties: |
|
|
|
Tensile
Strength at Break |
IEC811 |
MPa |
18 |
|
Elongation
at Break |
IEC811 |
% |
450 |
|
Mechanical
Properties after ageing in Air oven, 168 hr. at 135° C : |
|
|
|
|
Variation on
tensile strength |
IEC811 |
% |
+10 |
|
Variation on
elongation at break |
IEC811 |
% |
-15 |
|
Hot set
test, 15 min. at 200° C, 0.2 N / mm2 : |
|
|
|
|
Elongation
under load |
IEC811 |
% |
100 |
|
Permanent
Elongation after Cooling |
IEC811 |
% |
5 |
ESCR;
50° C, 10% lgepal soln. |
IEC811 |
hr |
>96 |
|
Carbon Black
content |
TGA |
% |
2.5 |
|
Carbon Black
Dispersion |
BS 2782;
Part 8 method 823A |
visual
matching |
matching
no2 photo |
|
* Material
is protected against UV radiation.
* All properties are based on moulded/extruded material made from
XL-ABC-01 and XL-ABC-BLK in the ratio of 97.3 : 6.3. |
Electrical
Properties : |
|
|
|
|
Power factor
at 50 Hz at 23° C |
IEC250 |
Nil |
0.0005 |
| Dielectric
constant |
IEC250 |
|
2.3 |
| Volume
Resistivity at 23° C |
IEC93 |
Ohm.cm |
2.4*1016 |
| Dielectric
Strength |
IEC243 |
Kv
/ mm |
22 |
RECOMMENDED EXTRUSION CONDITIONS :
Extruder
Thermoplastic extruders will process PPIL siplas-type compound particularly if the screw is suitable for polyethylene extrusion. An extruder having L/D ratio of atleast 20 and compression of 3:0:1 is recommended.
Extrusion temperature conditions
As a guide the following temperature profile is recommended :-
| Zone 1
|
Zone
2
|
Zone
3
|
Zone
4
|
Head
|
Die
|
| 160°
C |
170°
C |
180°
C |
190°
C |
200°
C |
210°
C |
This profile may vary depending on extruder type design and out put.
Screw water
temperature : 60ºC-70ºC
Screens : 30,100,30 (mesh apertures per linear inch)
HEAD AND TOOL DESIGN :
The head and tools should be so designed to allow streamline flow without the possibility of stagnation of material.
To obtain optimum physical properties in the case of tubing tools, it is generally recommended that a draw down ratio not greater than 2.8:1 should be used both for sector and round shaped conductor. PPIL engineers would be glad to provide comprehensive details of recommended tool design for both round and sector shaped conductor.
CROSSLINKING OR CURE :
Curing can be done in the following ways:
- By immersion in hot water at 70-80ºC
- By exposure to low pressure steam ( about 0.15 bar)
Following factors are important for cure,
- The ratio of conductor to insulation thickness
- Barrel diameter of the cable on which the core is cured
MASTER BATCH :
It is recommended that the catalyst masterbatch be thoroughly dried before usage at 60ºC for 18 hrs. at a depth not greater than 5 cm.
STORAGE :
Store under cold and dry conditions for best results
FORM AND PACKING :
Form : pellets
Packaging : Moisture resistant high density carboy containing 125 kg.
This information is to the best of our knowledge. The values of different parameters and operating conditions listed above are guidance only and should not be used for drawing specifications. The results & operating conditions may vary depending on methods of test and manufacturing / testing equipments.
