Halogen-Free Flame Retardant Compound Production

HFFR (Halogen Free Flame Retardant) compounds are highly mineral-filled polymer blends developed to meet critical performance requirements such as fire safety, low smoke density, and the prevention of corrosive gas formation. VOLDE HFFR Compound Production Facilities offer integrated raw material preparation and feeding solutions covering the entire process — from the precise dosing of the polymer base, metal-hydroxide-based flame retardants, and performance additives, through their correct feeding into mixing and extrusion equipment, to the storage of the final granular product. The systems are engineered to account for the flow and dosing challenges created by high filler ratios

| Gravimetric Dosing for Very High Mineral Filler Content

In HFFR formulations, the ratio of flame-retardant fillers such as aluminum hydroxide (ATH) or magnesium hydroxide (MDH) can rise to 60–70% or higher in most applications. Filler loading at this level makes feeding accuracy and mixture continuity the most critical element of the process. VOLDE systems ensure the precise application of the formula by gravimetrically dosing each of the polymer granule, mineral powder, and additive components separately, and deliver the material to the compounding equipment in a controlled manner.

• Controlled feeding systems for the polymer base material
• Enclosed dosing for fine mineral powders such as ATH/MDH
• Loss-in-weight feeders
• Multi-component recipe management
• High-accuracy continuous dosing

| Feeding Infrastructure Suited to Compounding Equipment

For the mixing and extrusion equipment used in HFFR compound production to operate efficiently, raw materials must be fed from the correct point, in the correct order, and at the correct flow rate. Due to the high filler ratio, the material's flow behavior can weaken, and incorrect feeding can directly affect product quality. VOLDE contributes to the stable operation of the compounding line by designing raw material preparation and transfer systems suited to the main feeding and side feeding points.

• Separate dosing systems for main feeding and side feeding points
• Controlled material transfer and flow rate management
• Pneumatic or mechanical transfer options
• Design compatible with vacuum and gas vent lines
• Infrastructure suitable for high-capacity production lines

| ATEX-Compliant Dust Management, Pneumatic Conveying, and Intermediate Silos

Fine-particle mineral fillers such as ATH and MDH can carry a risk of forming an explosive dust atmosphere due to their low flowability, high dust-generation tendency, and fine fractions that can remain suspended. For this reason, all storage, transfer, and dosing equipment must be designed not only according to process needs but also in compliance with ATEX directives. VOLDE systems offer an enclosed, controlled infrastructure that ensures mineral fillers are safely conveyed from the main storage silos to intermediate silos and dosing units. Pneumatic conveying lines and intermediate storage points both facilitate production planning and enable orderly feeding of the compounding line.

• Main storage silos and intermediate silos (day bins)
• Equipment selection compliant with ATEX zone classification
• Pneumatic conveying systems (pressure or vacuum)
• Safe silo discharge and feeding solutions
• Explosion vent panels and isolation equipment
• Closed-loop transfer and a design that minimizes dust dispersion