PRODUCTS / TWO-STAGE LINES

SHJ Two-Stage Extrusion Lines

A twin-screw first stage combined with a single-screw second stage, decoupling mixing from pressure build-up so heat-sensitive and highly filled compounds can be pelletized gently at low melt temperature.

Overview

In the SHJ configuration, a co-rotating twin-screw extruder performs melting, mixing and devolatilization, then discharges into a single-screw extruder that builds pressure and feeds the pelletizer at low, controlled temperature. Separating these functions keeps shear and heat off sensitive formulations and allows very high filler loadings to be pelletized cleanly.

SHJ75-180 two-stage compounding machine with twin-screw and single-screw extruders mounted at right angles — SHJ75-180 two-stage machine — the twin-screw and single-screw extruders are mounted vertically at right angles, so the melt drops straight from stage one into stage two with no back-pressure return.

Flow diagram of an SHJ tandem line for compounding and air-cooled hot-face pelletizing — Tandem line layout: 1 metering feeder, 2 cramming feeder, 3 twin-screw extruder, 4 single-screw extruder, 5 hot-face cutter with air cooling, 6 cyclone, 7 fluidising bed.

Best suited to

Technical specifications

Each SHJ line pairs a high-speed co-rotating twin-screw first stage with a low-speed single-screw second stage, mounted vertically at right angles. Both machines are listed below: D = screw diameter, L/D = length-to-diameter ratio, N = screw speed, P = main motor power, Q = typical output for the complete line.

Line model	Stage	Machine	D (mm)	L/D	N (r/min)	P (kW)	Q (kg/h)
SHJ50-120	1 — twin-screw	SJSH50	50.5	24–48	500	37–45	150–300
SHJ50-120	2 — single-screw	SJ120	120	7–20	65–85	30–37	150–300
SHJ65-150	1 — twin-screw	SJSH65	62.4	24–48	400–500	55–75	200–500
SHJ65-150	2 — single-screw	SJ150	150	7–20	65–85	37–45	200–500
SHJ75-180	1 — twin-screw	SJSH75	71	24–28	400–500	90–110	300–600
SHJ75-180	2 — single-screw	SJ180	180	7–20	65–85	45–65	300–600
SHJ95-200	1 — twin-screw	SJSH95	93	24–28	300	132–135	500–1000
SHJ95-200	2 — single-screw	SJ200	200	7–20	85	55–75	500–1000

Output by material

Reference throughput for the compounds the two-stage line is most often specified for, in kg/h.

Material group	Representative materials	50/120	65/150	75/180	95/200
Heat-susceptible plastics	PVC cable compound, low-smoke zero-halogen, transparent and medical-grade packaging, shoe sole compound	150–300	250–500	350–800	700–1100
Heat-susceptible plastics	PE peroxide crosslinked cable, silane crosslinked cable, crosslinked piping, PE and EVA shielding compound	120–250	200–450	280–600	800–1400

Catalog reference values — indicative and formulation-dependent. The line is sized against your material, filler loading and required output; screw configuration, venting and pelletizing method are specified per compound.