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.