Engineering Plastics Modification

Author: Xiangxi Jack Lian

Silicone Masterbatch for Engineering Plastics Modification

Engineering plastic gears and parts modified with silicone masterbatch

PA, PC, PBT and PET compounds demand more from additives: high processing temperatures, glass fiber loading and tight appearance specs. Floating fiber on a GF-PA50 part, high injection pressure on thin-wall connectors, or mold deposit on hot-runner tools — Xiangxi's engineering-plastics lubricants and carrier-free silicone series are built exactly for these high-temperature, high-performance systems.

Key Challenges in Engineering Plastics

Floating fiber (fiber exposure) — glass-filled PA/PC/PBT parts show fibers on the surface, ruining appearance and paintability.
Poor melt flow — thin-wall and long-flow parts need high pressure, raising energy use and stress-related defects.
Mold deposit and wear — abrasive glass fibers and sticky resins shorten tool life and force cleaning stops.
Carrier compatibility — standard masterbatch carriers can react with PA/PC chemistry and reduce performance.
High-temperature stability — additives must survive 280°C+ processing without decomposing.

1. Carrier-Free Silicone Masterbatch & Powder

The non-carrier silicone series is the flagship for PA, PC, PET and TPE systems: with no carrier resin, ultra-high molecular weight siloxane disperses directly into the matrix, wets glass fiber to eliminate floating fiber, improves flow and demolding, and remains stable with no precipitation across the part's life.

2. Engineering Plastics Lubricants

Our engineering-plastics lubricants act as external and internal lubricant in one: lower friction coefficient, higher pulling speed and low dosage — improving surface smoothness of PA/PBT/PET compounds while protecting screws and molds.

3. Interfacial Bonding Alloy (IBA)

For alloy systems (PA/PP, PC/ABS) and filled compounds, the interfacial bonding alloy improves interphase compatibility, raising impact strength and surface quality of modified blends.

Applications & Benefits

System	Benefit
GF-PA6/PA66 (automotive, electrical)	No floating fiber, smoother surface, easier demolding
PC/ABS housings and connectors	Lower inner stress, improved flow, reduced warp and cracks
PBT/PET electrical parts	Stable processing at high temperature, less mold deposit
Polymer alloys and filled compounds	Better interphase bonding, higher impact strength

Silicone masterbatch pellets quality control in laboratory

Why Compounders Choose Xiangxi

With 28+ patents, 40% R&D personnel, ISO9001 production and 20,000+ tons/year capacity, Xiangxi develops high-temperature silicone systems specifically for engineering thermoplastics. Our carrier-free technology avoids carrier compatibility issues, and our lab supports MFI, friction and surface-appearance testing to prove performance on your compound before you scale.

FAQ — Engineering Plastics

Why is a carrier-free silicone better for PA and PC systems?

A carrier can be incompatible with the base resin and dilute performance. Carrier-free siloxane disperses directly, giving stronger lubrication and fiber wetting at lower dosage with no compatibility risk.

What dosage is needed to eliminate floating fiber in GF-PA?

Typically 0.5–2% depending on glass content and tool design. Most GF-PA30 systems see clear surface improvement at around 1%.

Does it withstand high processing temperatures?

Yes. The ultra-high molecular weight siloxane is thermally stable at typical PA/PC/PBT processing temperatures without decomposition or discoloration.

Tell us your resin system and defect — contact Xiangxi and get a grade recommendation with test data.

FAQ