Dust-Free High-Speed PVC Compounding and Central Vacuum Feeding System

This solution establishes a fully enclosed, dust-free dry-blend compounding and multi-point automated feeding system engineered specifically for rigid and flexible PVC pipe, profile, cable compound, and sheet manufacturers. Centered around a high-intensity heating and cooling mixer combination unit (SRL-Z Series), it integrates negative-pressure dust-tight bag tipping stations, loss-in-weight or volumetric micro-additive dosing, and an automated closed-loop pneumatic transfer network delivering finished dry blends directly to multiple extruder feed hoppers.

PVC dry-blend compounding is notorious for severe shop-floor dusting, heavy plasticizer vaporization, and erratic additive dispersion. Manual bag dumping and open-trough mixing release hazardous airborne lead/calcium-zinc stabilizer dust, titanium dioxide, and calcium carbonate fines into the ambient environment, posing severe health hazards and triggering cross-contamination. Furthermore, improper cooling after high-speed hot mixing leads to caking, thermal degradation, and inconsistent plasticizer absorption. This engineered solution encloses the entire process from raw material intake to extruder throats, ensuring worker safety, 100% dust containment, and micro-scale additive homogenization.

The problem

What the section changes

Eliminates shop-floor toxic dust plumes and stabilizes PVC dry blend quality with automated hot/cold mixing and pneumatic feeding.

Dónde empieza el cliente

PVC pipe and profile processors operate open high-speed mixers with manual bag-dumping directly over open vessel lids. Workers dump 25 kg bags of toxic stabilizers, TiO2, and heavy calcium carbonate by hand, creating dense white dust plumes across the plant floor.

After manual mixing, hot blend is dumped into floor tubs or hand-pushed wheeled carts, causing unabsorbed plasticizer to pool, thermal degradation, and erratic manual scooping into extruder feed hoppers. Extruders suffer from frequent surging, screw wear, and off-spec pipe wall thickness due to variable additive dispersion.

Por qué ocurre el problema

PVC resin particles are porous agglomerates that require intense high-shear frictional heating (up to 115°C–125°C) to open their pore structure and thoroughly absorb liquid plasticizers and lubricants. If mixed at low speeds, plasticizers remain on particle surfaces, causing oily segregation, screw slippage, and irregular melt fusion in the extruder barrel.

Furthermore, standard dry powders (CaCO3, TiO2, organic stabilizers) possess diverse particle sizes (0.5 µm to 150 µm) and bulk densities (0.3 to 1.1 kg/L). In open transport systems, fines readily aerate into shop-floor dust clouds while heavier particles stratify, leading to severe recipe drift and unhygienic working environments.

Producción o estado objetivo

A pristine, dust-free compounding facility with zero manual material handling, producing consistently homogenized, highly fluid PVC dry blends that feed directly to multiple extruders on demand.

Process

The steps, in the order the material flows

Dust-Free Bag Dumping & Dosing
Required

Feeding and Material Transfer

Dust-tight charging of PVC resin, calcium carbonate, and micro-additives into the mixing station under continuous negative-pressure aspiration.

Función del equipo
Integrated bag-dump station with reverse-pulse jet cartridge filters captures all fugitive dust at the bag-slitting shelf, returning collected powder directly into the batch.

Equipos Central Feeding System Vacuum Loader
High-Intensity Frictional Hot Mixing
Required

Mixing

Intense high-shear frictional heating to volatilize moisture and drive plasticizers and stabilizers deep into the PVC resin porous matrix.

Función del equipo
Triple-tier rotating impellers running at 25–35 m/s tip speed generate aerodynamic vortex mixing. Frictional heating rapidly raises batch temperature from ambient to 115°C–125°C in 6–9 minutes without external heaters.

Equipos Compounding Mixer
Jacketed Vortex Thermal Quenching
Required

Cooling

Rapid thermal quenching of the hot dry blend to halt thermal history, prevent agglomeration, and restore dry powder flowability.

Función del equipo
The hot batch is discharged pneumatically into the oversized lower horizontal cooling mixer. A continuous spiral cooling jacket and slow paddle rotor cool the batch from 120°C to ≤ 40°C in 4–6 minutes.

Equipos Compounding Mixer
Centralized Vacuum Extruder Feeding
Required

Feeding and Material Transfer

Fully automated, on-demand closed-loop vacuum conveyance of cooled dry blend to individual twin-screw extruder hoppers.

Función del equipo
Central vacuum pump station and rotary diverter valve network deliver sealed, dust-free pneumatic transfer to multiple extruder throats, completely eliminating shop-floor fork trucks and manual hopper filling.

Equipos Central Feeding System Vacuum Loader

Material

What goes in, what comes out

Condición y requisitos de alimentación

Dry suspension PVC resin powder, micronized calcium carbonate (coated/uncoated, 800–2500 mesh), solid one-pack stabilizers (Ca/Zn or Pb), processing aids (CPE, ACR), lubricants (PE wax, stearic acid), and optional liquid plasticizers (DOP, DOTP, DINP). Powder moisture content ≤ 0.3%.

Condición y límites de salida

Fully homogenized, highly fluid, and dust-free PVC dry blend cooled to ≤ 40°C–42°C. Completely absorbed liquid plasticizer, uniform stabilizer dispersion, and zero static caking. Delivered automatically on-demand into extruder hoppers at high conveying rates without manual handling.

500–2500 kg/h

Base de las cifras de capacidad

Based on SRL-Z 500/1000 or SRL-Z 800/2500 high-speed heating/cooling mixer unit running 5 to 6 batches per hour (8–10 minutes total cycle per batch, including charging, frictional heating to 120°C, discharge to cooling mixer, and chilled cooling down to 40°C), delivering nominal throughput from 500 kg/h up to 2,500 kg/h.

Fit

Where this section belongs — and where it does not

Adecuada cuando

Essential for rigid PVC pipe, conduit, window profile, ceiling panel, and siding extrusion plants seeking to eliminate dust violations and boost line output.

Ideal for flexible PVC cable compounding and footwear compounders requiring automated, precise plasticizer dosing and uniform dry blend absorption without oily surface bleed.

No adecuada cuando

Not suitable for coarse virgin polymer pellets (e.g., standard 3 mm PP/PE pellets) without powder components, where high-speed frictional mixers would induce unnecessary thermal softening and blade wear. Vertical batch blenders or ribbon blenders should be used instead.

Not suitable for sticky, abrasive rubber masterbatches or thermosetting phenolic resins with reactive crosslinking kinetics that cure under frictional heat.

Condiciones pendientes de confirmar

Calculations assume standard suspension PVC resin (K-value 57–68, bulk density approx. 0.50–0.58 kg/L) blended with calcium carbonate (CaCO3, 5–50 phr), heat stabilizers, processing aids, lubricants, and pigments. Raw additives must have moisture content ≤ 0.3% prior to batching.

For highly plasticized flexible PVC formulations exceeding 40 phr DOP/DOTP/DINP, an automated liquid injection metering skid with dual atomizing spray nozzles and an oil preheating jacket is required.

Site and connections

What the section assumes around it

Servicios auxiliares

Suministro eléctrico: 380 V / 415 V / 460 V, 50/60 Hz, 3-phase AC.
Agua: Chilled water circulation for cooling mixer: 7°C–12°C inlet, flow rate 10–25 m³/h at 0.3 MPa.
Aire comprimido: 0.6–0.7 MPa clean, dry compressed air for pneumatic cylinders, pulse-jet filter cleaning, and diverter valves (approx. 0.4 m³/min).
Extracción y ventilación: Local exhaust ducting on hot mixer breather to vent volatilized moisture and plasticizer vapors.

Total connected electrical power: 75 kW to 220 kW depending on SRL-Z mixer model size.

Limitaciones de la planta

Superficie ocupada: Approximately 40–70 m² required for mixer platform, intermediate dry-blend buffer hoppers, and blower room.
Altura libre: Vertical clearance of 5.0 m to 6.5 m required to accommodate two-level mixer mezzanine and gravity drop chutes.
Entorno: Dust-controlled indoor compounding workshop; dry ambient conditions; air compressor room nearby.

Mezzanine must be structurally engineered to isolate mixer rotational vibration from building columns.

Interfaces

Mecánico: Quick-release dairy-grade clamp connections on vacuum conveying lines (DN50–DN76); flanged dust collection ducting (DN150).
Control: Profinet / Modbus-TCP communications bus interfacing with downstream extruder PLCs for automated on-demand hopper level calling.
Aguas arriba y aguas abajo: Upstream: bag tipping station / bulk bag discharger. Downstream: conical vacuum receivers directly mounted on extruder throats.

Targets

What the section is judged on

Shop Floor Airborne Dust Concentration: ≤ 2.0 mg/m³ Airborne laser particle counter testing at 1 m from dump station during active charging
Stabilizer & Additive Dispersion Variance (CV): ≤ 1.0% % XRF / chemical titration across 6 stratified dry-blend batch samples
Discharge Temperature from Cooling Mixer: ≤ 42 °C Direct inline PT100 temperature sensor interlocked to discharge valve

Cómo se evalúa la aceptación

Acceptance testing is conducted across 5 consecutive industrial batches followed by an uninterrupted 4-hour automatic feeding run to all connected extruders. Ambient airborne respirable dust concentration measured at 1.0 m from the bag-dump station and mixer lid during operation must be ≤ 2.0 mg/m³ (meeting OSHA/EU occupational air quality limits).

Additive dispersion is verified by sampling the cooled dry blend across 6 equidistant points: Ca/Zn or Pb stabilizer and TiO2 concentration variation must show CV ≤ 1.0%. The cooling mixer discharge temperature must reliably reach ≤ 42°C before automatic transfer to downstream storage silos.

Scope of supply

What is in the delivery — and what is not

Incluido en el alcance del suministro

High-Speed Heating & Cooling Mixer Unit (SRL-Z Series) Mirror-polished SUS304 hot mixer vessel with 3-tier impeller, oil-jacketed or frictional heating, pneumatic transfer gate, and horizontal cooling mixer with paddle rotor.
Dust-Tight Bag Dump Station with Reverse-Pulse Jet Filter Negative-pressure charging hood with internal high-efficiency PTFE cartridge filters, fan blower, and bag-slitting shelf.
Central Vacuum Conveying & Distribution Network Roots vacuum blower, vacuum receivers with airlock valves for each extruder hopper, centralized pipe manifold, and stainless conveying tubing.
Micro-Additive Loss-in-Weight Batching Module Stainless steel loss-in-weight twin-screw feeders for stabilizers, pigments, and lubricants with high-precision load cells.
Master PLC Control Cabinet with SCADA Interface Siemens PLC with 15-inch industrial color touchscreen, recipe management storage, batch weight logging, and remote diagnostic module.

No incluido en el alcance del suministro

Upstream bulk storage silos and road tanker unloading blowers Outdoor welded storage silos for bulk PVC/CaCO3 delivery unless explicitly quoted in turnkey silo package.
Downstream twin-screw extruders and pipe/profile haul-off lines Extrusion machinery, dies, vacuum sizing calibration tanks, and haul-offs belong to the extrusion contract.
Chilled water generation chiller plant Central plant chiller supplying chilled water to the cooling mixer jacket is customer scope.
Civil foundations and primary floor mezzanines Steel mezzanine structure, floor openings, and civil works are on the customer side.

Before a price

What we confirm before this becomes a quotation

01 PVC formulation sheet (phr breakdown) Resin K-value, exact parts-per-hundred (phr) of filler (CaCO3), liquid plasticizers, stabilizers, and impact modifiers.
02 Extruder line layout and consumption rates Number of downstream extruders, individual extrusion consumption rates (kg/h), distance from mixing room, and plant elevation drawings.
03 Raw material packaging formats Whether PVC resin and calcium carbonate arrive in 25 kg bags, 1,000 kg big bags (FIBC), or bulk road tanker silos.
04 Chilled water supply capacity Available industrial chilled water flow (m³/h) and inlet temperature (7°C–12°C recommended for the cooling mixer jacket).

Request a Quote Send these points with your inquiry; the section can then be quoted against your line, not against an assumption.

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Photos

The section in the workshop

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Placeholder · 1200 × 900 px (4:3)（占位图） Replace with an approved section photos, real workshop or installation views at this size.（按此尺寸替换为正式图片。）

Details

Further details

Problema de producción principal

Dust at loading and transfer
Manual feeding and internal transport
Powder and pellet segregation
Uneven additive distribution