Laboratory PP Plastic Pelletizing Machine

Updated: 2026-07-18

Overview

A laboratory PP plastic granulator is a downsized version of industrial granulators, designed for research institutions, material labs, and small-scale recyclers. It processes polypropylene (PP) scraps or pellets into uniform granules with consistent size and shape, enabling controlled experiments or prototype production. Unlike industrial models, laboratory units emphasize precision over throughput, offering adjustable parameters like temperature (typically 180-230°C), screw speed (20-100 rpm), and cutting frequency. Their compact footprint (often under 1.5m²) makes them suitable for benchtop use in confined spaces.

Structure and Working Principle

The machine consists of a feeding hopper, electrically heated barrel, rotating screw, die plate, cutting chamber, and control panel. PP material is fed into the barrel, where the screw conveys it forward while shear heat and external heaters melt it uniformly. Molten plastic is forced through a die plate with multiple holes, forming strands that are immediately cut by rotating blades in the cutting chamber. Air or water cooling solidifies the granules, which are collected in a storage bin. Advanced models may include vacuum degassing to remove moisture or volatiles.

Key Features

Precision temperature control (±2°C) via PID systems ensures consistent melt quality, critical for testing modified PP compounds. Variable frequency drives allow screw speed adjustments to optimize residence time and shear rate for different formulations. Modular dies enable quick changes of granule size (commonly 2mm, 3mm, or 5mm diameters). Safety features include emergency stops, overload protection, and thermal fuses. Some units integrate touchscreen HMI for recipe storage and real-time monitoring of torque/pressure.

Application Areas

Primarily used in R&D for developing new PP composites (e.g., glass-fiber reinforced or flame-retardant grades), testing recycled material properties, or small-batch production of specialty masterbatches. Universities employ them for polymer science education, while contract labs use them for client material evaluations. Small recyclers process post-industrial PP waste (e.g., injection molding runners) into reusable feedstock. The granules produced are compatible with injection molding, extrusion, or 3D printing test equipment.

Maintenance and Precautions

Daily cleaning of the barrel and screw with purge compounds prevents carbon buildup. Monthly inspections should check screw wear, belt tension, and heater band connections. Annual servicing includes replacing worn seals and recalibrating temperature sensors. Operators must avoid mixing incompatible materials (e.g., PVC) that may cause corrosion or toxic fumes. Overheating beyond 280°C can degrade PP, reducing granule quality. Always cool the system below 100°C before shutdown to prevent material oxidation.

B2B Procurement Guide

For material research, prioritize granulators with <5kg/h capacity and data export capabilities. Production-focused buyers should consider models with automatic feeding and sieving attachments for higher throughput (10-20kg/h). Verify compliance with lab safety standards (e.g., CE, UL). Request demonstration videos of granule uniformity. Key suppliers include Chinese manufacturers like Nanjing Kairong Machinery and European brands such as Collin Lab. Lead times are typically 4-8 weeks for customized configurations.