Conical twin screw barrel for free-foam and co-extruded PVC / WPC foam board lines. Machined in our own Henan workshop — to your drawing, or reverse-engineered from your worn parts.
Foam board punishes both ends of the process: too much shear pops the cells, too little leaves dense streaks. Our foam-board screws hold the blowing agent in suspension until the die, with a compression curve tuned for free-foam and Celuka processes.
Built for PVC free-foam board, WPC foam board and crust-foam (Celuka) lines. Tell us board thickness, density target and blowing system and we match the geometry.
Quote within one business day. We reply with a matching proposal, delivery date and price — no generic catalogue PDF.
Standard range shown. Every dimension below can be changed to your machine, resin and output — custom manufacturing is our daily business.
| Models | SJSZ 55/110, 65/132, 80/156 |
|---|---|
| Design | Foam-tuned compression, gentle metering |
| Material | 38CrMoAlA nitrided / bimetallic for WPC board |
| Processes | Free-foam, Celuka, co-extrusion |
| Board | 1–20 mm PVC / WPC foam board |
| Lead time | 30–45 days |
The honest answer depends on your resin, not on price. Here is how we advise customers.
| Gas Nitrided (38CrMoAlA) | Bimetallic Alloy Lining | |
|---|---|---|
| Best for | Unfilled PE, PP, PS, ABS, virgin PVC | Glass-filled, mineral-filled, recycled, corrosive |
| Surface hardness | HV 900–1020, depth 0.45–0.7 mm | Alloy layer 2–5 mm, metallurgically bonded |
| Typical service life | Baseline | 3–5× baseline on abrasive resin |
| Cost | Lower | Higher, recovered through fewer stoppages |
| Certification | MTC with heat number | MTC + hardness records, third-party on request |
Partly: uneven melt temperature across the die causes density gradients. A foam-tuned screw stabilises the melt; we will also review die temperature settings with you.
The geometry differs slightly: Celuka needs a stronger metering seal for the crust process. Tell us your process and we match it.
Yes for wood-loaded compounds; the abrasive filler makes it the economical choice.

Matched screw and barrel for SJSZ 51/105 conical twin extruders.
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Large-format conical twin set for big-diameter PVC pipe lines.
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Send your machine model, drawing or worn sample — we reply with a matching proposal and quotation within one business day.