Satintone® Speciality Aluminium Silicate for PVC Wire & Cable Applications
Blog Archive | 3 minutes | Author: Adam Morgan , Ph.D.
Speciality calcined kaolin from BASF imparts excellent volume resistivity in high and medium voltage wire & cable applications
Satintone® SP-33 is derived from high-purity hydrous kaolin. It is then calcined to impart excellent insulating properties in PVC compounds. Excellent dispersion in polymeric compounds is ensured from the high level of pulverization applied during processing. Water-washed kaolin feed results in low residue, low soluble salts and consistent quality. Satintone® SP-33 calcined kaolin has been specially designed to be an acid scavenger in medium and high voltage PVC wire insulation compounds. It greatly improves volume resistivity under both wet and dry electrical conditions. Due to its high electrical insulating properties, it is also used in combination with calcium carbonate - in lower end PVC wire applications.
Volume resistivity test results of Satintone® SP-33 calcined kaolin
Volume resistivity measurements were based on the PVC wire composition shown in Table 1.
| Component |
Loading (phr) |
| OxyVinyls® 225F PVC resin |
200.0 |
| Palatinol® DPHP plasticizer |
87.6 |
| Dibasic lead phthalate |
12.0 |
| Dibasic lead stearate |
0.4 |
| Satintone-SP33/other fillers tested |
40.0 |
Table 1. PVC wire composition used for subsequent volume resistivity testing.
A comparison of the volume resistivity measurements (Table 2) shows Satintone® SP-33 to be an excellent choice for insulating cables - far outperforming standard and treated calcined kaolins.
| Functional Filler |
Volume Resistivity (ohms-cm) |
| Calcium carbonate |
10 x 1012 |
| Hydrous kaolin |
30 x 1012 |
| Hydrous treated |
50 x 1012 |
| Calcined kaolin |
50 x 1012 |
| Calcined treated |
10 x 1013 |
| Satintone® SP-33 |
33 x 1013 |
Table 2. Volume resistivity of PVC compounds when using different functional fillers.
Cost engineering can be carried out by blending the Satintone® SP-33 with calcium carbonate. Table 3 shows how different blend ratios affect volume resistivity. Excellent results can still be achieved, even at high blend rates of calcium carbonate.
| Functional Filler |
Volume Resistivity (ohms-cm) |
| 100% CaCO3 |
10 x 1012 |
| 60% SP-33/40% CaCO3 |
26 x 1013 |
| 70% SP-33/30% CaCO3 |
29 x 1013 |
| 100% SP-33 |
33 x 1013 |
Table 3. Volume resistivity of PVC compounds when using different blend ratios of Satintone® SP-33 to calcium carbonate.
Conclusion
Satintone® SP-33 calcined kaolin offers the following benefits when used in PVC wire & cable applications:
- High volume resistivity
- Low dielectric constant
- Long service life
- Acts as an acid scavenger
- Low soluble salt
- Low free moisture
Get in touch with our technical sales team to discuss your project (01827 314151) or request a sample on our Satintone® product page.
Author: Adam Morgan , Ph.D.
Adam studied chemistry at the University of Warwick for 8 years, where he obtained a Ph.D. in the field of polymer and inorganic colloid science. He has been with Lawrence Industries since 2014 as a technical sales manager covering all industry areas. He is now responsible for marketing within the company as well.