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Glass Fiber Sizing

Pre-Sizing

In the pre-sizing process, a starch-based sizing solution is applied to individual glass filaments before they are bundled and twisted into fibers. This coating enhances cohesion, adds flexibility, and helps prevent breakage during high-stress processing.

Our Emglass® starches are ideal for pre-sizing, offering:

    • Strong binding power
    • Low ash content
    • Enhanced tack and film flexibility
    • Non-ionic, foam-free formulations
    • Easy dissolving & size prep
    • Excellent compatibility
    • Better open thread characteristics
    • High stability

Starch also brings key sustainability benefits, as it is renewable and biodegradable, has a lower combustion temperature than synthetic alternatives, and helps reduce energy consumption and emissions.

Product Highlights 

Emglass® E 25 S

Emglass® K 150

Warp Sizing

Glass fibers intended for the electronics industry are ultimately woven into fabrics. Before weaving, the fibers are coated in a secondary sizing solution — a process known as warp sizing. This coating enhances the mechanical resistance of the yarns, helping them withstand the high stress of weaving without breaking. After the fabric is formed, the sizing is removed typically through a combination of thermal and air separation techniques. Traditionally, polyvinyl alcohol (PVA) has mainly been used for warp sizing. However, starch offers many advantages over PVA, which is why intensive research is being carried out in this area.

  • Improved biodegradability
  • Energy and cost savings
  • Excellent compatibility with weaving processes