Aplicación
Automotive Bumper-Grade High-Impact PP Compounding Line (PP + POE / Talc)
Automotive exterior PP c…
Solution
Continuous Strand Pelletizing, Inline Classification, and Automated Packaging Line
Integrated continuous strand cooling, precision cutting, classification screening, and automated bagging system for engineering plastic compounding lines.
- Solution scope
- Multi-Function System
- Flow and installation
- Continuous · Inline
- Capacity
- 300–2000 kg/h
This turnkey solution delivers a fully integrated, high-capacity strand pelletizing and automated packaging system engineered specifically for medium-to-large compounding lines running engineering plastics (PA6, PA66, PBT, PC, POM), masterbatch, and high-filler compounds. Centered around an integrated Strand Pelletizer System (incorporating a stainless steel water cooling bath, high-velocity air-knife dewatering, heavy-duty rotary or Gantry Pelletizer cutting, and linear classification screening), it seamlessly couples with a fully automated bulk bag (FIBC) or 25 kg valve-bag weighing and packaging station.
Traditional strand extrusion lines suffer from frequent strand snapping, inconsistent pellet lengths, excessive fines/tails, and bottlenecked manual bagging stations that restrict overall compounding capacity. Operators struggle with manual strand guiding into water baths, leading to erratic strand cooling, water carryover into the cutter chamber, and knife wear. Furthermore, manual bagging creates severe labor bottlenecks, weight inaccuracy, and dust emissions. This engineered solution automates the post-die workflow from strand cooling and dewatering to precision cutting, classification, and load-cell bulk packaging, enabling continuous 24/7 extrusion run rates.
The problem
What the section changes
Eliminates strand snapping, irregular cuts, and bagging bottlenecks, boosting compounding line productivity and packaging accuracy.
Dónde empieza el cliente
Compounding facilities running strand lines face heavy labor overhead and persistent operational bottlenecks. Two to three operators per line are tied down manually grabbing hot strands from the die head, pulling them through water baths, feeding them by hand into pelletizers, and scooping cut pellets into bags on floor platform scales.
Strand slippage on wet rollers causes irregular pellet cutting lengths (ranging from 1.5 mm to 6.0 mm), generating high fines and long “dog-bone” stringers. Manual bagging slows down packaging, creating messy shop-floor pellet spills, inaccurate package weights, and repetitive strain injuries for workers.
Por qué ocurre el problema
Strand pelletizing depends on maintaining precise, consistent strand tension and temperature between the die face and the pelletizer feed rollers. If strands enter the water bath too cold, they become glass-brittle, causing shattering, splinter fines, and chipping of expensive carbide blades.
Conversely, if strands are insufficiently cooled or carry water into the cutter chamber, the soft polymer cores deform under feed roller pressure, producing angled “beveled” cuts and long stringers, while wet pellets cause mold vent clogging downstream. Furthermore, without automated line-speed matching between the extruder and cutter, strand sag or tension spikes cause frequent strand breaks, stopping the line.
Producción o estado objetivo
Flawlessly uniform, dust-free cylindrical pellets with clean cuts and zero moisture, packed automatically into certified bags with minimal manual labor and zero line stoppages.
Process
The steps, in the order the material flows
The equipment named here is maintained on the step it belongs to, so the list and the quotation cannot disagree.
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Temperature-Controlled Strand Water Bath Cooling
RequiredCooling
Rapidly solidifies molten polymer strands under controlled water immersion to achieve optimal cutting hardness.
Función del equipoStainless steel water bath with adjustable submerged guide rollers maintains uniform water contact. Internal water circulation with heat exchanger maintains consistent bath temperature (35°C–55°C), preventing strand shattering or soft deformation.
Equipos Strand Pelletizer System
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High-Velocity Air-Knife Strand Dewatering
RequiredPost-Pellet Treatment
Strips surface water droplets completely from strand surfaces before entry into the pelletizer cutting chamber.
Función del equipoHigh-velocity top and bottom air knives blow high-pressure air counter-current across the moving strands, eliminating water carryover and preventing wet pellets or roller slippage.
Equipos Strand Pelletizer System
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Precision Rotary Strand Cutting (Conventional / Gantry)
RequiredPelletizing
Cuts parallel solidified strands into precision-length cylindrical pellets with sharp, clean cut faces.
Función del equipoPneumatic upper feed rollers grip the dry strands firmly against a motorized lower roller, feeding them precisely against a stellite bed knife and high-speed tungsten carbide helical rotor (supporting heavy-duty Gantry Pelletizer units for high strand counts).
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Inline Classification & Dedusting
RequiredPost-Pellet Treatment
Screens out rare oversize doublets and fines, delivering 100% qualified pellets to packaging.
Función del equipoLinear vibrating screen with dual screen decks scalps out long stringers and dedusts fines, discharging uniform pellets into the packaging feed hopper.
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Automated Gravimetric Weighing & Bulk Bagging
RequiredStorage and Packing
Automatically meters, weighs, and fills finished pellets into bulk bags (FIBC) or 25 kg bags with high accuracy.
Función del equipoIntegrated load-cell bagging station clamps bags pneumatically, fast-fills and dribble-fills to exact target weight, and releases filled bags onto a takeaway conveyor with zero dust emission.
Material
What goes in, what comes out
Condición y requisitos de alimentación
Continuous parallel polymer melt strands exiting the extruder die plate at temperatures of 180°C to 280°C. Resins: PA6, PA66, PBT, PET, PC, ABS, POM, PP, HDPE, filled compounds, and masterbatches. Strand diameter Ø2.8–4.0 mm entering the water bath.
Condición y límites de salida
Crisply cut, cylindrical pellets (dimensions Ø2.5–3.0 mm x 3.0 mm length) with smooth, flat cut faces. Surface moisture ≤ 0.05%, zero tailing whiskers, and zero agglomerates. Finished pellets automatically weighed and sealed in bulk bags (FIBC) or 25 kg bags with precision load-cell verification.
300–2000 kg/h
Base de las cifras de capacidad
Based on a continuous strand pelletizing line handling from 300 kg/h up to 2,000 kg/h (strand speed 30 to 120 m/min, rotor width 100 mm to 400 mm), matched with an automated bulk bag or dual-spout valve bag packaging system.
Fit
Where this section belongs — and where it does not
The boundaries are part of the solution: they keep a machine from being quoted into a case it cannot serve.
Adecuada cuando
Indispensable for masterbatch and engineering plastics compounders (PA66, PBT, PC, ABS, POM, PET) running twin-screw lines from 300 kg/h to 2,000 kg/h.
Essential for compounding operations seeking to eliminate end-of-line labor bottlenecks, reduce operator headcount, and achieve precise bulk packaging weights.
No adecuada cuando
Not suitable for low-melt-strength polymers or tacky elastomers (e.g., low-hardness TPE/TPU < 85A, high-VA EVA) where molten strands instantly sag, stretch, and fuse inside the water trough. Underwater pelletizing systems must be used instead.
Not suitable for ultra-high throughput single-line applications exceeding 3,500 kg/h where managing over 80 simultaneous strands becomes mechanically unmanageable for operators.
Condiciones pendientes de confirmar
Specifications assume solid, rigid, or semi-rigid thermoplastics extruded as parallel continuous strands (strand count 10 to 60 strands depending on die head width and throughput). Polymer melt strength must be sufficient to support continuous strand drawing without sagging or snapping under water bath tension.
For high-hardness or abrasive glass-fiber/mineral compounds (> 30% filler), the Strand Pelletizer System feed rollers must be equipped with vulcanized wear-resistant polyurethane or specialized diamond-knurled alloy steel, and the rotary cutter rotor must feature solid cemented carbide (tungsten carbide) blades, or employ a heavy-duty Gantry Pelletizer configuration for wide strand arrays.
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
- Process water circulation for cooling bath: flow rate 5–15 m³/h at 20°C–35°C; makeup water < 0.2 m³/h.
- Aire comprimido
- 0.6–0.7 MPa clean, dry compressed air for pelletizer feed roller pneumatic cylinders and bagging clamp spouts (approx. 0.3 m³/min).
- Extracción y ventilación
- Dust aspiration duct connection (DN100) at packaging filling spout to capture displaced air.
Total connected electrical power: 25 kW to 65 kW (including pelletizer motor, dewatering blower, vibrating screener, and bagger).
Limitaciones de la planta
- Superficie ocupada
- Linear straight-line footprint: approximately 12–20 m in length by 2.5–3.5 m in width from extruder die to packaging conveyor.
- Altura libre
- Clear vertical ceiling height of 3.8 m to 5.0 m above the packaging station.
- Entorno
- Standard indoor plastics manufacturing plant; concrete floor with floor drainage trough along the water bath.
Floor space around the packaging station must accommodate forklift access for pallet removal.
Interfaces
- Mecánico
- Adjustable height water bath inlet chute positioned directly under extruder die face; flanged pellet chute connecting screener to packaging hopper.
- Control
- Profinet / Modbus TCP interface between pelletizer feed roller drive and extruder PLC for automated strand draw synchronization.
- Aguas arriba y aguas abajo
- Upstream: extruder strand die head. Downstream: finished bag conveying or robot palletizing cell.
Targets
What the section is judged on
The numbers are targets agreed per project, not a general promise.
- Pellet Length Uniformity (±0.2 mm of target)
- ≥ 98.0% % Digital vernier caliper measurement on 200 random pellets sampled from screen exit
- Discharged Pellet Surface Moisture
- ≤ 0.05% (500 ppm) % Halogen moisture analyzer testing at 105°C for 10 minutes
- Bagging Weight Accuracy (25 kg bag)
- ± 0.2% (± 50 g) % Certified static checkweigher scale verification across 20 consecutive bags
Cómo se evalúa la aceptación
Acceptance testing requires an 8-hour uninterrupted continuous extrusion run on the target compound (e.g., 30% glass-fiber reinforced PA66 or 60% CaCO3 filled PP) at full line rate. Pellet length distribution must show ≥ 98.0% within ±0.2 mm of target length (typically 3.0 mm), with zero tailing whiskers.
Residual surface moisture of discharged pellets must register ≤ 0.05% (500 ppm). The packaging unit must automatically weigh and seal 25 kg bags with accuracy within ±0.2% (±50 g per bag) or 1,000 kg bulk bags within ±0.1%, with zero manual operator intervention during bag fills.
Scope of supply
What is in the delivery — and what is not
The confirmed scope is stated in the quotation; this is the boundary of the section as designed.
Incluido en el alcance del suministro
- Heavy-Duty Continuous Strand Pelletizer System Turnkey pelletizing package including stainless steel cooling water bath with submerged guides, high-velocity dual air-knife dewatering unit, rotary cutter (or heavy-duty Gantry Pelletizer), and inline linear vibrating classifier screener.
- Stainless Steel Strand Cooling Bath with Submerged Guides Heavy-gauge SUS304 trough, height-adjustable strand guide rollers, water overflow weirs, and plate heat exchanger for bath temperature control.
- High-Velocity Air Knife Strand Dewatering Blower Unit Dual top and bottom adjustable air knives, high-pressure centrifugal air blower, and water catchment tray with drain connection.
- Linear Vibrating Pellet Classifier Screener Two-deck stainless vibrating screener removing oversize agglomerates/twins and dedusting fines before packaging.
- Automated Big-Bag (FIBC) / 25 kg Bagging Station Load-cell weighing platform, pneumatic bag clamping spouts, automated cutoff gate, and dust extraction port.
No incluido en el alcance del suministro
- Upstream twin-screw extruder and melt gear pump Extruder machinery, screw elements, barrel heating, and hydraulic screen changers belong to the extruder contract.
- Finished pallet stretch wrapping and palletizer robot Automatic palletizer robot and stretch hood wrapping line unless explicitly quoted in full packaging package.
- Primary plant chilled water supply for cooling bath Chilled water chiller providing water to the strand bath heat exchanger is customer scope.
- Printed packaging bags and wooden/plastic pallets Supply of empty packaging bags, bulk bags, and shipping pallets is on customer side.
Before a price
What we confirm before this becomes a quotation
- 01 Extruder die head specification and strand count Number of strand die holes, hole diameter (typically Ø3.0–3.5 mm), die face centerline height, and polymer melt temperature.
- 02 Compound rheology and filler data Base polymer type, melt flow index (MFI), filler type and percentage (e.g., CaCO3, talc, glass fiber, carbon black).
- 03 Packaging format requirements Whether final packaging requires 25 kg open-mouth bags, 25 kg valve bags, or 1,000 kg bulk big bags (FIBC).
- 04 Factory floor dimensions and water drainage layout Available straight-line length from extruder die head to packaging area, floor trench locations, and plant compressed air supply.
Request a Quote Send these points with your inquiry; the section can then be quoted against your line, not against an assumption.
Photos
The section in the workshop
Photos go here once the section has been built and the material is cleared to publish.
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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。） -
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
- High surface moisture on the material
- Line output limited by auxiliaries
- Manual feeding and internal transport
- Off-spec pellet size and fines