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ML or SJ pelletizing line: which one fits your material?

By Meng, Torqplas

The first question in any recycling pelletizing project is how the material will get into the screw. Light, bulky film and dense, free-flowing flakes behave completely differently in a feed throat. That difference decides whether you need an ML or an SJ line.

Film feeds badly, flakes feed easily

Film, raffia and non-woven material have a very low bulk density. Poured into a normal hopper, they bridge and the screw starves. Rigid flakes and regrind are dense and flow on their own, so a standard hopper feed works.

ML series: for clean film scrap and fibrous material

The Jiangsu PURUI ML series is built for clean, dry BOPP, PP, HDPE, LDPE, LLDPE, PS, PLA and PET film scrap, non-woven fabric, woven bags and fibre, fed directly without washing.

Jiangsu PURUI ML film pelletizing line with belt conveyor, cutter-compactor, two-stage extruder with screen changers, pelletizing, dewatering and storage silo — ML film pelletizing line by Jiangsu PURUI: belt conveyor, cutter-compactor, two-stage extrusion with screen changers, pelletizing, dewatering and silo.

Model	Screw diameter	PP (kg/h)	HDPE (kg/h)	LDPE (kg/h)
ML75	75 mm	100	120	150
ML85	85 mm	120	150	180
ML100	100 mm	200	300	400
ML130	130 mm	400	500	600
ML160	160 mm	600	700	1,000
ML180	180 mm	800	1,000	1,200

SJ series: for rigid flakes and regrind

The SJ series is a single-screw recycling extruder for HDPE bottle flakes, crushed rigid PE and PP, PP, PC and ABS regrind, and washed film flakes.

Model	Screw diameter	Output
SJ100	100 mm	250 – 350 kg/h
SJ120	120 mm	300 – 400 kg/h
SJ140	140 mm	500 – 600 kg/h
SJ150	150 mm	600 – 800 kg/h
SJ160	160 mm	800 – 1,000 kg/h
SJ180	180 mm	900 – 1,200 kg/h
SJ200	200 mm	1,000 – 1,500 kg/h

All SJ models run at 10 to 150 r/min with an L/D of 18 to 42.

See a real line: food-grade HDPE milk bottle flakes, SJ110 + TSSK75 two-stage line, with photos and video.

Washed film goes to an SJ two-stage line

After a washing line, film flakes are not pelletized on an ML line. They go to an SJ two-stage line: the first extruder melts and degasses, and the second filters again and pelletizes. For large outputs, a laser filter is added. See the agricultural film recycling guide.

When you need two stages

Heavily printed film, film with residual moisture and material with volatile contamination often need a two-stage line: a first extruder melts and degasses, and a second extruder filters again and pelletizes. Ask for a two-stage configuration if your pellets show bubbles, odor or black specks on a single-stage line.

A quick way to decide

Clean, unwashed film scrap, raffia, non-woven: ML series
Washed film flakes from a washing line: SJ two-stage line, with a laser filter for large outputs
HDPE bottle flakes, crushed rigid PE and PP, PC or ABS regrind: SJ series
Heavily printed or moist film: ask for a two-stage configuration
Mixed film and rigid material: send photos of both; the share of each decides the line

Output always depends on the material, its moisture and the motor configuration. A material trial at the factory is the surest way to confirm it. Full tables are on the recycling machines page.

Tell us your material and target output

Send the material type, output in kg/h and final product. We reply within 24 hours with a configuration and price range.