Radio frequency dryer

in-linefiberglassdehumidifying

Overview Stalam offers a wide range of Radio Frequency (RF) equipment specifically designed for the drying of glass fibres in various forms — mainly direct rovings, assembled rovings, yarns and chopped strands. RF drying significantly reduces processing time while preserving finishing chemicals and surface appearance compared with conventional hot-air ovens.

Direct rovings Precision-wound direct rovings weighing up to 35–40 kg each (approx. 18–22 kg industrial standard), placed vertically or horizontally on the RF dryer conveyor over suitable wooden or composite holders designed for automated handling and transport systems, can be dried to a residual moisture content below 0.1% in approximately 2–4 hours (depending on winding density and fibre count) instead of the 20–30 hours usually required by conventional hot-air circulation ovens. Longitudinal/transverse expansion during the process does not exceed 2–3 mm and there is no migration of finishing chemicals to the roving’s outer layers nor the surface yellowing typical of conventional drying.

Assembled rovings The residual moisture content of assembled rovings can be controlled accurately by a suitably adjusted RF field, while obtaining ribbonisation (formation of a coherent ribbon) of the fibres when required.

Chopped strands and other products Chopped strands can be dried quickly and efficiently without air movement, greatly reducing dust formation on the shop floor. Other glass-fibre products such as bobbins and packages after wet treatments can be dried to the desired final moisture content consistently and without adverse effects on finishing chemicals.

Benefits

• High production capacity: from 2 tons/day up to 40 tons/day per dryer; installations with multiple inline modules (e.g. up to 6 modules, overall lengths > 30 m) are possible.
• Reduced labour costs: continuous in-line operation; full loading/unloading automation can be fitted.
• Time- and energy-efficient: 70–90% shorter drying times compared with conventional systems while using less energy.
• Consistent product quality: uniform drying with no wet spots, no overheating, no yellowing and no migration of finishing chemicals.

Technical characteristics

• Drying technology: Radio Frequency (RF).
• Applicable product forms: direct rovings, assembled rovings, yarns, chopped strands, bobbins and packages.
• Production capacity (per dryer): from 2 tons/day to 40 tons/day.
• Typical installed configuration: up to 6 drying modules inline; overall lengths reported > 30 m.
• Precision-wound direct rovings weight: up to 35–40 kg each (approx. 18–22 kg industrial standard).
• Drying time for precision-wound direct rovings: approx. 2–4 hours (vs. 20–30 hours in conventional ovens).
• Achievable residual moisture: below 0.1%.
• Longitudinal/transverse expansion during process: ≤ 2–3 mm.
• Chopped strands drying: rapid drying without air movement, drastically reduced dust generation.
• Quality outcomes: no migration of finishing chemicals, no surface yellowing, no overheating, no wet spots.
• Automation capability: continuous in-line operation with options for full loading/unloading automation.
• Energy/time savings: 70–90% reduction in drying time while using less energy.