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Frequently Asked Questions About Silicone Processing Aids for Wire & Cable Extrusion

1. How can die build-up and die drool be reduced in LSZH/HFFR cable extrusion?

Die build-up and die drool can result from high filler loading, melt flow instability, and material accumulation at the die exit. SILIKE Silicone Masterbatch SC940 uses functionalized ultra-high-molecular-weight polysiloxane technology to improve processing lubrication and reduce material adhesion and accumulation at the die. Its effectiveness depends on the polymer formulation, filler loading, and extrusion conditions.

2. Can silicone processing aids improve throughput in high-speed wire and cable extrusion?

Yes. Silicone processing aids can help improve extrusion throughput by reducing processing resistance and improving melt flow.  Silicone-based additive SC940 is specifically developed for high-speed extrusion of highly filled LSZH/HFFR cable compounds. It can help reduce extrusion torque and die pressure while supporting more stable production, particularly in small-diameter wire and cable applications.

3. How can cable diameter fluctuations and screw slippage be reduced during extrusion?

Cable diameter fluctuations and screw slippage may be associated with unstable material feeding, melt delivery, extrusion pressure, and processing conditions.  Silicone additive SC940 can help improve melt flow and extrusion stability, reducing the tendency toward diameter fluctuations and screw slippage. Screw design, feeding conditions, extrusion temperature, and line speed should also be considered during process optimization.

4. Can  Silicone-based additive SC940 improve ATH/MDH filler dispersion in highly filled LSZH/HFFR compounds?

The functionalized polysiloxane structure is designed to promote compatibility and interfacial interactions within the polymer matrix. This can help improve the dispersion of aluminum trihydrate (ATH), magnesium hydroxide (MDH), and other fillers, supporting more uniform processing and compound performance. The degree of improvement depends on the formulation and compounding conditions.

5. What is the recommended addition level of  Silicone-based additive and surface modifier SC940 for cable compounds?

For improved processability and melt flow, the recommended addition level is 0.5–2.0 wt%.

For surface modification, including improved slip, smoothness, abrasion resistance, and scratch resistance, the recommended addition level is 1.0–5.0 wt%.

The optimum dosage should be determined through formulation-specific trials, considering the base polymer, filler loading, processing conditions, and target properties.

6. Will silicone processing aids affect the flame-retardant performance or mechanical properties of LSZH/HFFR cables?

The effect of silicone processing aids on flame-retardant and mechanical properties depends on the polymer system, filler package, and addition level. SC940 is designed to improve processing and surface performance in highly filled LSZH/HFFR compounds. However, flame retardancy, tensile properties, elongation, and other applicable cable requirements should be verified through testing of the final formulation.

7. Does high-speed wire extrusion additive SC940 migrate or affect long-term cable surface performance?

Processing aid SC940 incorporates functionalized ultra-high-molecular-weight polysiloxane designed to improve compatibility with the polymer matrix and reduce the tendency toward additive migration and surface exudation. Long-term surface performance, including coefficient of friction (COF), surface appearance, and abrasion resistance, should be evaluated under relevant aging and service conditions.

8. How should modified silicone masterbatch SC940 be incorporated into wire and cable compounds?

Modified silicone masterbatch SC940 can be dry-blended with the base resin and other formulation components before direct extrusion or incorporated during compounding and pelletization. The processing route and addition level should be selected according to the polymer system, filler loading, extrusion equipment, and required performance. Application trials are recommended to establish suitable processing conditions.