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Recycled plastic pellets leaving the die face of a SUHUI pelletizing line
Knowledge base

Plastic Recycling & Extrusion Technology

Plastic recycling technology explained at the level an engineer specifying a line actually needs — screw geometry and twin-screw compounding, friction washing and float-sink separation, melt filtration, pelletizing methods and downstream vacuum calibration. Each article goes into the process decisions that change output quality, pellet consistency and running cost, rather than describing what a machine looks like. Understanding the plastic recycling technology behind a route is what makes a quotation comparable; if you are still choosing between routes, start from the plastic recycling machine guide or the plastic extrusion machine guide.

Recycling machine guide Extrusion machine guide
16 Guides & explainers PET / HDPE / PP / PVC Materials covered 20+ Years of line-building experience
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20 Aug
Technology | SUHUI Machinery

How Granulator Blades and Screen Size Decide Output

Granulator blades cut plastic by shearing it between rotating rotor knives and stationary bed knives, and the screen underneath decides how small a piece must be before it can leave the chamber. This guide covers the three rotor blade arrangements and what each does to the cutting load, why cutting clearance matters more than sharpness, how screen aperture moves particle size, throughput, heat and fines all at once, how to match blade grade to an abrasive or impact-prone feed, when to sharpen rather than replace, and how to read a handful of regrind to diagnose the chamber.

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19 Aug
Technology | SUHUI Machinery

Underwater Pelletizing vs Strand Water Ring and Die Face

Underwater pelletizing cuts molten polymer at the die face inside a flooded chamber and produces the roundest and most uniform pellets of the four industrial methods, but it is not simply the premium option on a ladder. This guide compares underwater, strand, water ring and die face hot cutting on where the cut happens, what carries the heat away, what pellet shape results, which drying equipment each one drags in behind it, the signature defect each produces when it is put on the wrong material, and how much a changeover costs, using four published SUHUI line configurations as worked examples.

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19 Aug
Technology | SUHUI Machinery

What Is a Pelletizer and the Four Ways It Cuts

A pelletizer is the cutting unit at the end of a plastic recycling line, not the whole machine and not the part that melts the material. This guide separates it from the crusher, the extruder and the line it sits in, walks the four elements every pelletizer contains, names the four ways it can cut, explains why granule shape follows the cut method, and shows which arrangement SUHUI puts on each of its four pelletizing lines.

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18 Aug
Technology | SUHUI Machinery

What Extruded Plastic Profiles Are and How They Are Made

Extruded plastic profiles are continuous lengths of thermoplastic with a fixed non-round cross-section — window frames, cable trunking, channels, trims, seals and lamp diffusers. The process is identical to pipe extrusion and the engineering is not. This article covers why an asymmetric die has to be flow balanced by design, why the die opening is never the shape of the finished profile, why calibration is a series of plates rather than a single sleeve, what co-extrusion adds, and which section geometries are difficult to extrude.

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18 Aug
Technology | SUHUI Machinery

What Makes PVC Extrusion Different From PE and PP

PVC extrusion is treated as its own discipline because PVC degrades rather than simply softening when it is held hot. Its usable processing window is narrow, it needs stabilisers to survive the barrel, it arrives as a dry blend rather than as pellets, and it must be purged before shutdown. This guide works through what each of those facts does to the extruder, the flow path, the materials of construction and the shift routine, and what changes again when the feed is recycled PVC.

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18 Aug
Technology | SUHUI Machinery

How Pipe Extrusion Lines Are Configured Around the Diameter

A pipe extrusion line is configured around one number — the diameter range it has to cover. Diameter sets the melt volume the extruder must deliver, the cooling length the pipe needs before it can be gripped, and the traction the haul-off must apply without deforming a soft wall. This guide walks the eight stations in order, explains which station owns which pipe property, shows why two extruder series overlap in diameter, and covers when running several strands beats buying a bigger machine.

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17 Aug
Technology | SUHUI Machinery

How Screen Changers and Melt Filters Clean Recycled Melt

A screen changer holds the filter screens between the extruder barrel and the die and lets them be replaced without stopping the line. This guide separates the breaker plate from the screen pack, compares manual, slide plate, dual piston and continuous designs, explains how mesh is chosen against real contamination, why screens are changed on melt pressure rather than on a timer, and why melt filtration cannot rescue a feedstock the washing line did not clean.

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Find a Guide by Material

Jump straight to the articles that cover the polymer you actually run.

PET Bottles, flakes and fibre-grade scrap
What Is PET Plastic? Uses, Recycling, rPET and PET Bottle Processing PET Bottle Recycling Machine: Process, Equipment & Buyer Tips
HDPE Milk bottles, jerry cans, rigid scrap and pipe
HDPE Recycling Machine: Process, Equipment & Buyer Tips Plastic Pipe Recycling Process for HDPE, PVC and PP Scrap
PP / PE film Agricultural film, packaging film and woven bags
Plastic Film Recycling Line: 10-Step Process & Equipment How to Choose a Plastic Film Washing Line: Capacity, Stages & Cost
PVC Pipe, profile and compounding scrap
PVCO Pipe Guide: PVC-O Benefits, Uses and Manufacturing Process Plastic Profile Extrusion: Process, Materials and Line Configuration How a Twin Screw Extruder Works in PVC and Recycling Lines
Mixed & general Whole-line process, shredding and pelletizing
What Plastics Can Be Recycled? Plastic Numbers, Materials and Recycling Methods Plastic Recycling Lines Explained: Washing, Shredding, Pelletizing and Turnkey Systems Industrial Plastic Shredder: 4 Types & How to Choose How Plastic Pellets Are Made from Flakes, Regrind and Film Scrap

Browse by Topic

Done reading? Jump from theory to the equipment itself.

Equipment guide Plastic Recycling Machines Shredding, washing and pelletizing lines matched to your material. Equipment guide Plastic Extrusion Machines Pipe, profile and drinking-straw lines built around your product. Proof Case Studies Delivered lines by country, material and output. Catalogue All Machines Every SUHUI machine by production role.

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