Mine-owned nepheline syenite and feldspar since 2007
Crushed potassium feldspar held in the hand
Application Guides

Feldspar & Nepheline for Fiberglass Production

Role of feldspar and nepheline as alumina and flux sources in E-glass and insulation fiberglass.

Fiberglass — both E-glass reinforcement fiber and insulation wool — uses feldspar or nepheline syenite as a source of alumina (Al2O3) and alkali flux in the glass batch.

Application Overview

E-glass, the standard reinforcement fiber for composites (boats, wind turbine blades, automotive parts, circuit boards), requires tight compositional control with specific Al2O3 levels (12-15%) for the required mechanical and electrical properties. Nepheline provides Al2O3 more efficiently than feldspar (20-24% vs 17-19%), meaning less raw material is needed per ton of glass. For insulation fiberglass (building insulation batts and loose fill), nepheline serves primarily as a flux to lower the melting temperature and improve fiberization. Our K100 grade serves most fiberglass applications with reliable quality and competitive pricing.

Technical Details & Formulation

Jumbo bags staged in the warehouse ready for container loading
Jumbo bags staged in the warehouse ready for container loading

Contact us for fiberglass-grade specifications and batch calculation assistance..

Product Recommendation

FAQ

Questions on This Topic

What does Feldspar & Nepheline for Fiberglass Production cover?

Fiberglass — both E-glass reinforcement fiber and insulation wool — uses feldspar or nepheline syenite as a source of alumina (Al2O3) and alkali flux in the glass batch.

Which ports do you ship from?

FOB Tianjin, Qingdao or Lianyungang, all within 6-8 hours by truck from the plant. CIF to your destination port is also quoted on request.

How is the material packed?

1200 kg FIBC jumbo bags as standard, or 50 kg PP woven bags. Bags carry product name, grade, batch number and weight. Custom packaging and private labelling are available.

Take It From Reading to Testing

Send your current specification and the problem you are chasing. Samples follow within a week.