PE & PP Compound Systems

Precise Feeding. Stable Formulation. Consistent Compound Quality

VOLDE develops complete raw material handling and extruder feeding systems for PE and PP compounding plants, covering polymer intake, filler and additive handling, intermediate storage, pneumatic conveying and continuous gravimetric dosing. PE, PP, mineral fillers, additives, pigments and reinforcing materials are handled according to their individual flow characteristics and supplied to the compounding line at the required rates. Each system is engineered around the formulation, extruder capacity, ingredient characteristics and feeding points of the process. Central material handling and Loss-in-Weight dosing operate as one coordinated system, providing stable ingredient ratios, automatic feeder replenishment and recipe-based production for a wide range of polyolefin compounds.

| Polymer, Filler & Additive Handling

Polyolefin compounding combines raw materials with very different physical characteristics. PE and PP may be supplied as pellets, granules, powder or regrind, while fillers and additives can range from free-flowing mineral powders to cohesive fine materials and reinforcing fibers.

Depending on plant logistics, materials can be received from big bags, octabins, bags or central silos. Vacuum pneumatic conveying is widely used for polymer pellets and granules, while powders and poor-flowing fillers may require dedicated conveying and discharge arrangements.

• PE, PP and recycled polymer handling
• Big bag, octabin and bag discharge systems
• Intermediate bins and central storage
• Vacuum pneumatic conveying
• Calcium carbonate, talc and additive handling
• Automatic material routing to dosing points

The material handling system is configured so that each ingredient reaches its dosing point with the flow conditions required for reliable continuous feeding.

| Gravimetric Extruder Feeding

In continuous compounding, maintaining the correct relationship between polymer, filler and additives is fundamental to formulation consistency. VOLDE therefore integrates Loss-in-Weight gravimetric feeders at the main and downstream feeding points of the extrusion line.

Each feeder continuously measures material loss from the weighing hopper and automatically adjusts its feeding rate to the recipe setpoint. Feeder type and screw geometry are selected according to the material — from free-flowing pellets to fine, cohesive powders and mineral fillers.

• Loss-in-Weight gravimetric feeding
• Continuous mass-flow control
• Single- and twin-screw feeder options
• Main-feed and downstream-feed applications
• Recipe-based ingredient ratios
• Target / actual flow monitoring

This continuous dosing architecture allows individual ingredients to be metered separately while maintaining the required formulation ratio as production capacity changes.

| Automatic Refill & Extruder Integration

Reliable Loss-in-Weight operation also depends on how the feeder is replenished. VOLDE integrates intermediate bins, vacuum receivers and automatic refill valves above the gravimetric feeders so that material supply can continue without unnecessarily disturbing the weighing cycle.

Refill sequences are coordinated by the PLC according to feeder level, material demand and production status. The feeding system can also exchange operating signals with the extruder so that total feed rate and ingredient ratios follow the production requirement of the compounding line.

• Automatic feeder replenishment
• Intermediate bins and vacuum receivers
• Level-based refill management
• Extruder throughput synchronization
• Main and side feeder interlocks
• PLC/SCADA integration

For plants operating several formulations or production lines, centralized raw material distribution can supply multiple extruders from common storage and material handling systems.

| Flexible Compounding for Fillers, Additives & Reinforcements

PE and PP compounds can contain a broad range of components according to the required mechanical, thermal, electrical or processing properties of the final product. The feeding system must therefore accommodate not only the base polymer but also fillers, pigments, flame retardants, stabilizers and reinforcing materials with very different dosing characteristics.

Depending on the formulation, ingredients can be introduced through the main extruder feed or at downstream side-feeding points. Fine powders may require twin-screw feeding, while pellets, granules and fibers are handled with feeding technologies selected according to their individual behavior.

• PE and PP base polymers
• Calcium carbonate, talc and mineral fillers
• Flame retardants, stabilizers and processing additives
• Pigments and masterbatch
• Glass fiber and other reinforcing materials
• Recycled polymer and rework
• High-filled and functional polyolefin compounds