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Product Description
Compounding is not a volume game — it is a margin game. A compounding plant does not win by running one formulation at maximum throughput year-round. It wins by running ten formulations profitably, switching between them on a Tuesday afternoon without destroying the schedule, the budget, or the pellet quality.
The problem with single-purpose extrusion lines is arithmetic: a compounding plant with five dedicated lines, each processing one formulation, is fully utilized when all five formulas have orders. When only three have orders — as happens every month — two lines sit idle. Their capital cost, their floor space, their maintenance — all still accruing cost while generating zero revenue. The lean compounding plant does not add extruders for each new formula. It makes one extruder do all of them.
This is the design philosophy behind Chenxing's CX-TSE and CX-TSH parallel co-rotating twin screw extruder series: one machine, unlimited formulations, changeover measured in hours not days.
The key is the modular segmented screw. Unlike single-screw extruders — where the screw is a single machined shaft, and changing the mixing intensity means buying a new screw — the twin screw extruder's screw is assembled from interchangeable elements: conveying elements for transport, kneading blocks for dispersive and distributive mixing, and reverse elements for pressure build-up. Slide them off the shaft, rearrange them, slide them back on. The screw reconfigures to the formulation — not the other way around. A line that ran 80% CaCO3-filled PP masterbatch on Monday runs 30% glass fiber reinforced PA6 on Wednesday. Same machine. Different screw configuration. Different throughput. Same pellet quality.
This modularity, combined with a parallel three-axis gearbox delivering high torque density, the TSH high-torque series for formulations demanding 50-80% more throughput from the same screw diameter, ±1°C barrel temperature control for heat-sensitive formulations, and four pelletizing options for any downstream requirement, makes the CX-TSE/TSH series the compounding industry's most adaptable platform.
The twin screw is not a single piece of steel. It is a shaft onto which individual elements — each 20-50mm long, each with a specific function — are slid and locked into position with a keyway and a retaining nut.
There are three fundamental element types, and every screw configuration is a sequence of them:
Conveying Elements — Helical flights that transport material forward. Pitch (the distance between flights) determines conveying speed: wide pitch (1.5D to 2D) for fast transport in the feed zone, narrow pitch (0.5D to 0.75D) for controlled transport in the melt zone. Conveying elements fill the screw partially — they create the space into which kneading blocks will work the material.
Kneading Blocks (KB) — Staggered discs that shear, stretch, and re-orient the melt. Kneading blocks are the heart of the twin screw's mixing capability. Wide disc staggering (90°) provides high dispersive mixing — breaking down agglomerates, distributing filler particles, wetting glass fibers. Narrow disc staggering (30-45°) provides distributive mixing — spreading components evenly throughout the polymer matrix. The number, stagger angle, and disc width of the kneading blocks determine how much shear energy the material receives in each zone.
Reverse Elements / Mixing Elements — Elements with reverse flights or neutral (0° pitch) design that create back-pressure and fill the screw channel upstream to 100%. A filled screw channel is essential for mixing — kneading blocks mixing air are kneading blocks wasting energy. Reverse elements ensure the kneading zone is fully filled with melt, maximizing mixing efficiency while controlling residence time.
The CX-TSE and CX-TSH screws are fully intermeshing and co-rotating — both screws turn in the same direction. As each screw rotates, its flight wipes the adjacent screw's flight and root. This self-cleaning action prevents dead spots — regions where material would stagnate, degrade, and eventually contaminate subsequent batches with black specks. In a co-rotating twin screw, every particle sees the same shear history. Residence time distribution is tight. Color change from black to natural takes minutes, not hours.
A typical screw configuration divides the barrel into functional zones:
Zone 1 — Solids Conveying (Feed Zone): Deep-flight conveying elements rapidly draw pellets, powder, and filler from the feed port. The channel is partially filled. No back-pressure. Material advances freely.
Zone 2 — Melting / Plastication: The first set of kneading blocks. Frictional heat from the kneading discs, combined with barrel heating, melts the polymer. Kneading blocks compress and shear the melt, breaking down pellet size and initiating filler wetting.
Zone 3 — Mixing / Dispersion: Tightly staggered kneading blocks with a reverse element downstream to ensure 100% fill. Maximum dispersive mixing — agglomerates are broken, fillers are distributed, glass fibers are wetted and reduced in length. This is where the formulation is made.
Zone 4 — Venting / Degassing: An open vent port (atmospheric or vacuum) with conveying elements underneath. Volatiles — moisture, residual monomers, reaction byproducts — escape from the decompressed melt surface. Vacuum venting (typically -0.06 to -0.08 MPa) pulls out dissolved gases and low-molecular-weight fractions, critical for moisture-sensitive materials (PET, PA, PC) and food-contact applications.
Zone 5 — Pressure Build-Up / Discharge: Narrow-pitch conveying elements and a reverse element build melt pressure to push through the die plate. The degree of pressure build-up depends on the die resistance and pelletizing system.
The CX-TSE/TSH barrel is the Euro-style rectangular design — flat, precision-machined surfaces with internal cooling channels arranged for optimized reflux refrigeration. Unlike cylindrical barrels with external heating/cooling bands, the rectangular barrel provides more surface area for cooling contact, resulting in smaller temperature gradients across each zone and faster temperature response to control input. For heat-sensitive formulations — PVC compounds, halogenated flame-retardant masterbatches, biodegradable starch blends — this means processing at the formulation's optimal temperature without hot spots causing degradation.
One motor drives one input shaft. The gearbox splits this single input into two output shafts — one for each screw — with exactly equal torque, exactly synchronized rotation, and zero phase drift between the two screws. This is the parallel three-axis design: input axis, and two parallel output axes, integrated in a single compact housing.
The gearbox achieves this through three engineering decisions:
Import-grade bearings on all critical shafts — the thrust bearings that absorb the axial load from screw pressure build-up (tens of tons at the die for large machines) and the radial bearings that maintain gear mesh alignment. Bearing life — not gear life — determines gearbox overhaul intervals.
Super-intensity alloy carburizing steel for all transmission components — gears, shafts, couplings. Carburizing diffuses carbon into the surface layer, creating a hard (58-62 HRC), wear-resistant case over a tough, ductile core. Post-carburizing gear grinding achieves AGMA Class 10-12 accuracy — tooth-to-tooth spacing within microns — which is what enables the low noise and vibration that operators notice immediately.
Integrated soakage and forced lubrication — the gearbox sump provides constant oil immersion of the lower gears, while a pump circulates filtered, cooled oil to the upper bearings and gear mesh points. An over-pressure sensor shuts down the line if lubrication pressure drops. Oil temperature, not gear wear, is the limiting factor on gearbox continuous-duty rating — the external cooling circuit keeps oil below 60°C, doubling oil life and protecting bearing grease.
Seventeen models span from lab-scale R&D (0.5 kg/h) to high-volume production (2,250 kg/h), with the TSH high-torque series delivering 50-80% more throughput than equivalent-diameter TSE standard-torque models.
| Model | Screw Dia. (mm) | L/D | Speed (rpm) | Motor (kW) | Capacity (kg/h) |
|---|---|---|---|---|---|
| CX-TSE20 | 22 | 32–44 | 600 | 5.5 | 0.5–10 |
| CX-TSE30A | 31 | 32–48 | 500 | 11 | 5–30 |
| CX-TSE30B | 31 | 32–48 | 600 | 15 | 5–40 |
| CX-TSE35A/B | 35.6 | 32–52 | 600–800 | 15–22 | 30–70 |
| CX-TSE40A | 41 | 32–64 | 400 | 22 | 100–120 |
| CX-TSE40B | 41 | 32–52 | 600 | 30 | 100–160 |
| CX-TSE50A/B | 50.5 | 32–52 | 500 | 45–55 | 180–270 |
| CX-TSE65B | 62.4 | 32–64 | 600 | 90 | 250–350 |
| CX-TSE65C | 62.4 | 32–64 | 600 | 110 | 300–400 |
| CX-TSE75B | 71 | 32–64 | 600 | 132 | 350–550 |
| CX-TSE75C | 71 | 32–64 | 600 | 160 | 400–600 |
| CX-TSE95A | 93 | 32–64 | 500 | 250 | 600–1,000 |
| CX-TSE95B | 93 | 32–64 | 600 | 315 | 800–1,200 |
| CX-TSE135A | 133 | 32–64 | 500 | 550 | 1,500–2,250 |
| Model | Screw Dia. (mm) | L/D | Speed (rpm) | Motor (kW) | Capacity (kg/h) |
|---|---|---|---|---|---|
| CX-TSH35B | 35.6 | 32–52 | 600–800 | 15–22 | 30–70 |
| CX-TSH40B | 41 | 32–52 | 600 | 45–55 | 150–220 |
| CX-TSH52B | 51.5 | 32–60 | 600 | 90–132 | 300–500 |
| CX-TSH65B | 62.4 | 32–64 | 600–800 | 110–160 | 350–500 |
| CX-TSH75B | 71 | 32–64 | 600–800 | 200–250 | 600–800 |
| CX-TSH95B | 93 | 32–64 | 600–800 | 400–450 | 1,200–1,600 |
| Criterion | CX-TSE (Standard Torque) | CX-TSH (High Torque) |
|---|---|---|
| Torque per Screw | Baseline (typically 6-8 Nm/cm3) | 1.5-2x TSE (typically 11-13 Nm/cm3) |
| Throughput (same screw dia.) | Baseline | +50-80% |
| Best For | General compounding, color masterbatch, moderate filler loading (<50%) | High filler loading (>50%), glass fiber >30%, high-viscosity formulations, engineering plastics |
| Gearbox | Standard parallel three-axis | High-torque reinforced three-axis with upgraded bearings and shaft diameters |
| Screw Core Shaft | Standard alloy | Reinforced higher-torque core shaft |
| Capital Cost (same dia.) | Lower | Higher (approx. +30-50% depending on size) |
| Energy Efficiency (kWh/kg) | Baseline | 5-15% better (higher throughput at similar total energy input) |
| Payback | — | 12-18 months via throughput gain for qualifying formulations |
Recommendation: Choose TSH when your formulation's viscosity or filler loading limits throughput on the equivalent-diameter TSE model, and you need the productivity of a larger machine without the floor space and higher base energy consumption. For standard color masterbatch, CaCO3-filled PP, and moderate glass fiber (<20%), TSE is the cost-effective choice.
Feature: Screw assembled from interchangeable conveying elements, kneading blocks (30°/45°/60°/90° stagger), and reverse elements, all keyed onto a splined core shaft. Element materials: W6Mo5Cr4V2 high-speed tool steel or 38CrMoAlA nitride steel, precision-ground and heat-treated. Elements slide on/off the shaft for reconfiguration.
Advantage: A dedicated single-screw extrusion line is locked to one formulation — changing the mixing intensity means changing the screw, which means hours of disassembly, cleaning, and reassembly, often with a spare screw on standby. The modular twin screw reconfigures by sliding elements off the shaft (release the retaining nut, slide, replace) and rearranging them. A compounding plant with a CX-TSE65B can run CaCO3 masterbatch at 250 kg/h on Monday, glass-fiber-reinforced PP at 280 kg/h on Tuesday, and flame-retardant ABS masterbatch at 200 kg/h on Wednesday — each with the optimal screw configuration for that formulation, each producing on-spec pellets. The screw is not a constraint — it is a variable you control.
Benefit: Equipment utilization rises from 50-70% (dedicated single-formulation lines) to 85-95%. One machine replaces 2-4 dedicated lines for a typical job-shop compounder. Formula changeover time drops from 4-8 hours (screw change + purge on single-screw) to 1-2 hours (element reconfiguration + purge on twin screw). For a plant running 3-5 formulas per week, this saves 8-30 hours of downtime per week — effectively adding a day of production capacity without adding capital.
Feature: Single input shaft splits into two parallel output shafts via precision-ground helical gears in a compact integrated housing. All transmission components are super-intensity alloy carburizing steel (carburized, quenched, gear-ground to AGMA Class 10-12). Key bearings are import-grade. Integrated soakage bath and forced oil circulation with external cooling and over-pressure alarm.
Advantage: The gearbox is the twin screw extruder's most expensive single component — and its most common failure point. A gearbox that cannot sustain full torque at the extruder's rated speed forces the operator to run below capacity, sacrificing throughput to protect the transmission. The parallel three-axis design addresses this at three levels: the carburizing + grinding process produces gear teeth with high surface hardness (wear resistance) and a tough core (shock resistance) — teeth that maintain their profile accuracy under years of continuous reversing torque load; the import-grade thrust bearings absorb the axial load from screw pressure build-up — up to 40+ tons on the CX-TSE135A — without developing the axial play that misaligns gears and accelerates tooth wear; and the forced cooling lubrication system maintains oil temperature below the degradation threshold, preventing the viscosity breakdown that starves gear mesh points.
Benefit: 5+ years of continuous compounding duty between gearbox overhauls. At 30% higher torque density than conventional designs, the CX three-axis gearbox enables the TSH series to deliver 50-80% more throughput from the same screw diameter — a productivity gain that would otherwise require moving up to the next chassis size, consuming more floor space and base energy. The gearbox is not the bottleneck — it is the enabler for high-torque, high-fill formulations that competing machines at the same price point cannot sustain.
Feature: Reinforced parallel three-axis gearbox with oversized shafts and bearings, strengthened screw core shafts (higher torsional rigidity), and motor power ratings 50-80% above the equivalent-diameter TSE model. Operating speed: 600-800 rpm.
Advantage: High-filler formulations (60-80% CaCO3, talc, BaSO4), high glass fiber content (>30%), and high-viscosity engineering plastics (PC, PBT, PA66) demand more mechanical energy per kilogram of output than standard masterbatch or alloying. On a standard-torque TSE, the extruder reaches its torque limit before reaching its volumetric capacity — the motor is at 100% load, the torque safety coupling is near its slip limit, but the screw could accept more material if it had the torque to process it. The TSH solves this by upgrading every component in the torque path: the motor is larger, the gearbox shafts and bearings are sized for 1.5-2x the torque, and the screw core shaft is of larger diameter to resist torsional failure at high torque. The result is an extruder that processes 50-80% more material through the same 62.4mm screw diameter — a CX-TSH65B at 350-500 kg/h vs. a CX-TSE65B at 250-350 kg/h.
Benefit: The TSH-65B at 500 kg/h achieves what a competing standard-torque 75mm machine achieves — at lower capital cost, smaller footprint, and lower base energy consumption. For a compounder running 6,000 hours annually at 450 kg/h, the TSH-65B produces 2,700 tons vs. the TSE-65B's 1,800 tons — an extra 900 tons of revenue-generating output from the same floor space. The TSH upgrade premium (approx. 30-50% over TSE) pays back within 12-18 months from incremental throughput alone, and within months for formulations where torque is the primary throughput constraint.
Feature: Rectangular-profile barrel segments with internal cooling channels arranged for optimized reflux flow. Each barrel zone (typically 6-14 zones depending on L/D) has independent PID temperature control with heating and cooling authority. Barrel materials: nitrided steel (standard), corrosion-resistant alloy (for acidic formulations), or bimetallic wear-resistant lining (for abrasive fillers).
Advantage: Heat-sensitive formulations — PVC compounds, halogenated flame-retardant masterbatches, biodegradable starch/PLA blends — degrade when barrel hot spots exceed the material's thermal stability limit. A cylindrical barrel with external band heaters has a natural hot spot: the area directly under each heater band runs 5-15°C hotter than the barrel's average. The rectangular barrel's flat surfaces and internal cooling channels distribute heat more uniformly, and the larger cooling contact area enables faster heat removal when the control calls for cooling. The result: barrel temperature control within ±1°C of setpoint, even during the exothermic mixing peak in the kneading zone.
Benefit: No thermal degradation — no black specks from PVC decomposition, no color shift from flame-retardant breakdown, no molecular weight reduction from PLA hydrolysis. Batch-to-batch color consistency that pigment buyers measure with a spectrophotometer and reject when the delta-E exceeds 0.5. For the compounder, this means: fewer rejected batches, higher customer retention, and the ability to process formulations that competitors' lines cannot handle without degradation.
Feature: Interchangeable feeding modules mount at any barrel port along the process length: single-screw volumetric feeder (pellets, granules), twin-screw loss-in-weight feeder (powders, low-bulk-density fillers), hollow-screw feeder with internal cooling (heat-sensitive powders), forced-feeding unit (ultra-low-bulk-density fibers and flakes), side feeder (glass fiber, carbon fiber — introduced downstream to limit fiber breakage), and liquid injection system (plasticizers, oils, reactive monomers).
Advantage: A formulation is only as good as the accuracy with which its components enter the extruder. A 1% error in flame retardant dosing at 20% loading means the pellet's flame rating is compromised — a batch that fails UL 94 testing at the customer's incoming inspection. The CX feeding system addresses this with gravimetric loss-in-weight control on all critical feeders (accuracy ±0.25-0.5% of set rate), side feeding for fragile additives (glass fiber introduced after the polymer is fully melted, so the kneading blocks distribute the fiber rather than break it to an ineffective length), and liquid injection for formulations requiring precise addition of heat-sensitive liquid additives.
Benefit: Pellet composition as specified — every kilogram, every batch, every month. Reduced off-spec: the most expensive compound is the one you must rework or discard. For a compounder producing 3,000 tons annually with a 1.5% off-spec rate, reducing that to 0.5% saves 30 tons of rework annually — approximately $15,000-45,000 in direct cost and immeasurably more in customer confidence.
Feature: The CX-TSE/TSH accepts four pelletizing systems as interchangeable downstream modules: water-cooling strand pelletizing, air-cooling strand pelletizing, water-ring pelletizing, and underwater pelletizing.
Advantage: No single pelletizing method is optimal for every material and end-use. Water-cooled strand pelletizing is the most universal — the melt strand passes through a water bath, solidifies, is air-dried, and cut into cylindrical pellets by a rotating-knife plastic pelletizer. It handles virtually any thermoplastic and allows visual strand inspection before cutting. Air-cooled strand pelletizing eliminates water contact — essential for hygroscopic materials (PA, PC, PET) where water absorption during cooling would require post-pellet drying before packaging. Water-ring pelletizing, used on the water ring pelletizing line, cuts at the die face with water quenching — producing near-spherical pellets with no tailing, ideal for high-volume masterbatch and filler compounds. Underwater pelletizing, the premium option, cuts in a pressurized water chamber — the cleanest cut, highest throughput, and roundest pellets, preferred for engineering plastics and applications where pellet shape affects downstream feeding.
Benefit: The pelletizing system matches the customer's processing requirements, not the extruder supplier's preference. A compounder producing PA6-GF30 for injection molders chooses air-cooled strand — dry pellets, no post-drying needed. A masterbatch producer running 600 kg/h of black PE masterbatch chooses water-ring — high throughput, automated, no operator monitoring strand integrity. The choice is the compounder's. The CX platform accommodates all four.
Feature: Split-clamp (tightened-style) cast aluminum or ceramic heater shells that wrap around the barrel and bolt closed. The heater element is embedded in the clamp shell, making full circumferential contact with the barrel surface.
Advantage: Traditional mica band heaters are wrapped around the barrel and held by a tension strap. Air gaps between the band and barrel reduce heat transfer efficiency, create hot spots on the band (reducing element life), and make heater replacement a two-person job requiring the band to be unwrapped from around the barrel. The clamp-style heater bolts on — full contact, no air gaps, no thermal bridging losses. When a heater fails, the operator unbolts it, replaces it, and re-bolts — 10 minutes, one person, without disturbing adjacent barrel zones.
Benefit: Heat-up time reduced by 30% (from ambient to 200°C in 25-35 minutes vs. 40-50 minutes for band heaters), reducing non-productive warm-up at shift start. Energy consumption for heating reduced by 15%+ due to elimination of air-gap losses. Heater replacement time reduced from 30-45 minutes (band) to 10 minutes (clamp) — for a line running 24/6, the cumulative downtime savings over a year are measured in full production shifts.
| Pelletizing Method | Best For | Throughput Range | Pellet Shape | Pros | Cons |
|---|---|---|---|---|---|
| Water-Cooled Strand | Universal — all thermoplastics, standard compounding, masterbatch | 60–2,250 kg/h | Cylindrical | Simple, low cost, visual strand inspection, easy cleaning between batches | Labor for strand threading, water contact (hygroscopic materials need post-drying), tailing possible |
| Air-Cooled Strand | Hygroscopic materials: PA, PC, PET, TPU | 60–1,000 kg/h | Cylindrical | No water contact — pellets stay dry, no post-drying | Longer cooling distance, higher air handling cost, strand breakage risk |
| Water-Ring | High-volume masterbatch, filler compounds, pellet shape-sensitive applications | 200–2,250 kg/h | Near-spherical (lenticular) | Automated, high throughput, round pellets, no tailing | Higher capital cost, cleaning between colors takes longer, not for highly-filled abrasive compounds (die wear) |
| Underwater | Engineering plastics, premium compounds, high-throughput continuous | 300–2,250 kg/h | Spherical | Highest throughput, cleanest cut, roundest pellets, automated | Highest capital cost, complex water system, die plate wear with abrasive fillers, not for water-sensitive materials |
Selecting your system:
Water-cooled strand: The default choice. Start here unless your material or customer requirements dictate otherwise.
Air-cooled strand: Add this when processing PA, PC, PET, or TPU — the avoided post-drying cost justifies the longer cooling section.
Water-ring: Upgrade to this when throughput exceeds 300 kg/h and pellet roundness matters to your customers.
Underwater: The premium choice for engineering plastics at production scale. The capital premium pays back in throughput, automation, and pellet quality for customers who pay for round pellets.
For downstream handling after pelletizing, Chenxing offers complete vibrating screen classification, STG-U hopper drier post-drying, and high-speed mixer blending to ensure your pellets meet the packaging specification.
A masterbatch compounder running 15-20 colors per week — PE, PP, ABS, PA, PET carriers, organic and inorganic pigments, loadings from 1% (let-down ratio 100:1) to 40% — needs a machine that switches colors in 30 minutes, not 4 hours. The modular screw enables a "universal" masterbatch configuration (medium-shear kneading blocks + distributive mixing elements) that works across pigments, with side-feeder addition for pigments that require low-temperature introduction. A plastic crusher for scrap reprocessing closes the material loop.
A filler compounder running 70-80% CaCO3 in PP needs torque — lots of it — to wet, distribute, and disperse filler at loadings that approach the theoretical maximum packing fraction. This is TSH territory. The high-torque gearbox and reinforced screw shafts handle the 50-80% higher specific mechanical energy input vs. an unfilled PP extrusion. Side-feeding of filler at barrel zone 4-5 (after the polymer is fully melted) maximizes filler loading without starving the feed zone. The result: 500 kg/h of 80% CaCO3-PP compound from a CX-TSH65B — a throughput that would require a 75mm standard-torque machine.
Fiber length retention is the quality metric that determines the compound's mechanical properties — and its market price. A compound labeled "PA6-GF30" that processes with 50% less fiber length than the competitor's product produces injection-molded parts with lower tensile strength and impact resistance. The customer notices. The solution: introduce glass fiber through a side feeder at barrel zone 5-6 — after the polymer is fully melted — and use low-shear distributive kneading blocks downstream. The side feeder gently introduces the fiber into the melt stream. The kneading blocks distribute it without breaking it. Fiber length retention of 80-90% vs. 50-60% for a configuration that introduces fiber at the main feed port. Pipe extrusion line customers using reinforced compounds are particularly sensitive to fiber length — shorter fibers reduce pipe burst pressure.
Alloying — compatibilizing immiscible polymers (PA/PP, PC/ABS, PET/PBT) through reactive coupling agents — requires precise residence time control, intense mixing to create the interfacial surface area for reaction, and vacuum venting to remove reaction byproducts. The CX twin screw's modular design enables a dedicated alloying screw configuration: tight kneading blocks in the reaction zone, long residence time (controlled by reverse elements), and atmospheric + vacuum venting downstream. For reactive extrusion — grafting maleic anhydride onto PP, chain extension of recycled PET — the liquid injection system meters the reactive monomer precisely into the melt at the optimal process temperature.
Heat-sensitive biodegradable formulations — starch-filled PE, PLA/PBAT blends — require the barrel temperature control precision that makes or breaks the product. The starch in a starch-PE masterbatch degrades (browns, burns) at 180°C; the PE carrier needs 190-210°C to melt and wet the starch. With the CX rectangular barrel's ±1°C control, the compounder can process at 175-180°C — just below the starch degradation threshold — while still achieving adequate PE melting through the mechanical energy input from the kneading blocks. The result: white, not brown, biodegradable masterbatch pellets that compounders downstream will actually buy.
The modular segmented screw is the answer. To change formulations, operators release the retaining nut at the screw tip, slide off the existing screw elements, rearrange or replace them according to the new configuration, and slide them back on. A complete reconfiguration from a masterbatch setup to a glass-fiber-reinforced setup takes 1-2 hours, including the purge cycle to clean residual material from the barrel. With a spare screw shaft (purchased with the machine), the reconfiguration can be done offline — one shaft runs while the other is being reconfigured on the bench. Changeover downtime drops to 30-45 minutes. Compared to a single-screw extruder requiring a screw change (4-8 hours), or a non-modular twin screw requiring the same, the productivity gain over a year of multi-formula production is substantial: 8-30 hours of additional uptime per week for a typical job-shop compounder.
Choose TSH when your specific mechanical energy (SME) demand — the energy per kilogram required to process your formulation — exceeds what the equivalent-diameter TSE can deliver. This typically occurs with: filler loadings above 50% (CaCO3, talc, BaSO4), glass fiber content above 30%, high-viscosity engineering plastics (PC, PA66, PBT), or formulations with multiple high-viscosity components. Signs that you need TSH: your current extruder runs at 100% motor load and 60-70% design RPM because increasing speed would trip the torque limit; your throughput has plateaued despite adequate feeding capacity; or your screw elements show accelerated wear (a sign of operating at the torque limit where any process upset overloads the shaft). The TSH-65B at 500 kg/h achieves what a standard-torque 75mm machine achieves — at lower capital cost and in a smaller footprint.
High-filler formulations demand three things from the screw configuration: maximum dispersive mixing to break filler agglomerates, sufficient distributive mixing to spread filler evenly through the melt, and enough downstream conveying capacity to move the high-viscosity, high-density melt without over-torquing the shafts. The recommended configuration starts with deep-flight conveying elements in the feed zone (for fast intake of high-bulk-density filler), transitions to 90°-stagger kneading blocks for maximum dispersive energy in the plastication zone, uses side feeding to introduce filler after the polymer is melted (zone 4-5), follows with 45°-stagger kneading blocks for distributive mixing, and ends with narrow-pitch conveying for pressure build-up. A reverse element between the mixing and venting zones ensures 100% fill in the mixing zone. This is a TSH-series configuration — the torque demand of processing 60-80% filler at high throughput exceeds standard-torque capability.
Yes — and the rectangular barrel with reflux refrigeration is the reason. Heat-sensitive formulations degrade when the barrel temperature exceeds the material's stability limit. A cylindrical barrel with band heaters creates hot spots 5-15°C above the control setpoint directly under each heater. The CX rectangular barrel's flat surfaces, internal cooling channels, and larger cooling contact area maintain temperature within ±1°C of setpoint across the entire barrel circumference. For PVC compounds (degradation onset ~180-200°C), this means processing at 175°C without local hot spots crossing the degradation threshold. For brominated flame-retardant masterbatches (degradation onset ~220-250°C), processing at 210°C with ±1°C control prevents the bromine release and color shift that cause downstream customers to reject the masterbatch. Additionally, the clamp-style heaters' rapid response to PID control input enables the cooling channels to remove exothermic heat from the kneading zone before it accumulates and overshoots.
Start by identifying your material's water sensitivity and your customer's pellet shape requirement. If your material is hygroscopic (PA, PC, PET, TPU), choose air-cooled strand pelletizing — the absence of water contact eliminates the post-drying step. If your material tolerates water and you produce over 300 kg/h, water-ring pelletizing offers automation and round pellet quality at moderate capital cost. If you produce under 300 kg/h or process multiple formulations with frequent changeovers, water-cooled strand pelletizing is the most flexible and lowest-cost option. If you produce engineering plastics at scale (>500 kg/h) and your customers demand the roundest possible pellets for precise gravimetric feeding, underwater pelletizing delivers the highest quality but at the highest capital cost. Chenxing's engineering team recommends the optimal system based on your material portfolio, throughput, and target market.
The gearbox is the twin screw extruder's single most expensive wear component, and gearbox failure — not screw wear, not barrel wear — is the most common reason compounding extruders are taken out of production for major repair. An under-designed gearbox runs hot, wears bearings prematurely, develops gear tooth pitting within 2-3 years, and eventually loses the tooth profile accuracy that ensures equal torque distribution to both screws. The CX parallel three-axis gearbox addresses this through three design decisions: carburized + ground gears (surface hardness 58-62 HRC, tooth accuracy AGMA Class 10-12) that resist pitting and maintain profile for years; import-grade thrust bearings sized to absorb the full axial load from screw pressure build-up without developing axial play; and forced oil cooling that maintains lubricant temperature below 60°C — doubling oil and bearing life. The result: 5+ years between gearbox overhauls in continuous compounding duty. The gearbox's reliability is the line's reliability.
For a compounder producing 2,000 tons annually, selling masterbatch or reinforced compound at 2.4-5M. A CX-TSE65B with feeding, pelletizing, and downstream equipment costs approximately $60,000-150,000 depending on configuration. The payback comes from three sources: throughput (a twin screw processes 2-4x the hourly rate of a comparable single-screw for compounding applications); quality premium (better mixing = better dispersion = fewer customer rejections = consistent market price); and flexibility (one twin screw line replaces 2-3 dedicated single-screw lines, reducing capital cost and floor space). Typical simple payback: 6-18 months for a compounding line operating at >70% utilization. The compounding industry's rule of thumb — "a twin screw pays for itself within the first year of full-capacity operation" — reflects the productivity advantage that modular, co-rotating twin screw technology delivers over single-screw compounding.
Step 1 — Define Your Formula Portfolio: List your current and planned formulations — material, filler type and loading, throughput target, pellet quality specification. This determines whether the standard-torque TSE or high-torque TSH is optimal, and which screw configuration template matches your process.
Step 2 — Select Your Configuration: Our engineering team maps your formula portfolio to the optimal CX-TSE or CX-TSH model — screw diameter, L/D, element configuration, feeding modules, pelletizing system, and downstream handling. We provide a complete line proposal with specifications, screw configuration drawing, floor plan, and pricing within 24 hours.
Step 3 — Contact Nicole for a Quote: Send your formulation details and target throughput to Nicole. For new formulations, we offer lab-scale trials on the CX-TSE20 — validate your process before scaling to production.
Step 4 — Install, Commission, and Start Compounding: Chenxing provides on-site installation supervision, commissioning, screw configuration optimization, operator training, and a spares kit (screw elements, barrel segments, heater clamps, screen packs). After commissioning, your CX-TSE/TSH line runs with 1-2 operators — processing masterbatch, filled compounds, reinforced thermoplastics, or polymer alloys with the flexibility to switch formulas in hours. Our after-sales team provides ongoing support, and spare screw elements ship within 48 hours.
For complementary equipment that completes your compounding plant, explore Chenxing's full range: high-speed mixers for pre-blending, STG-U hopper driers for moisture removal, CJ magnetic frames for metal protection, and vibrating screens for classification. If your process continues to powder grinding after compounding, our SMF disc grinding pulverizer and SMP knife pulverizer series handle PE, PP, PVC, ABS, PET, and nylon. For film and foam recycling, compare our water ring pelletizing line (Cut Compactor for EPS foam and ultra-low-density film) and side force feeder pelletizing line (screw-forced feeding for washed film flakes).
Contact Chenxing Machinery Today:
Contact Person: Nicole
Phone / WhatsApp: +8615951187228
Email: ceo@cxsljx.com
Company: Zhangjiagang Chenxing Machinery Co., Ltd.
Website: www.chenxingmachinery.com
