Compounding

In compounding, various materials (polymers, additives, etc.) are mixed and melted—generally in an extruder of some type—then pelletized. Most compounding extruders purchased nowadays are of the twin-screw corotating/intermeshing variety, though counterrotating twins are used for some applications. Compounding extrusion lines are typically equipped with gravimetric feeding systems that dose materials into the extruders at very specific rates. In certain applications, extruders are equipped with vent ports that pull unwanted moisture and other volatiles from the polymer stream.

Compounding

Durable Cutting Blades From Maag Target FRP Pelletizing

Cutting blades from Maag are for strand pelletizing fiberglass-reinforced plastics and other abrasive compounds.

ESSENTIAL READING

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Know-How 26 Nov 2024

How to Configure Your Twin-Screw Barrel Layout

In twin-screw compounding, most engineers recognize the benefits of being able to configure screw elements. Here’s what you need to know about sequencing barrel sections.

Compounding 26 Aug 2024

What to Know About Your Materials When Choosing a Feeder

Feeder performance is crucial to operating extrusion and compounding lines. And consistent, reliable feeding depends in large part on selecting a feeder compatible with the materials and additives you intend to process. Follow these tips to analyze your feeder requirements.

Know-How 19 Apr 2024

How to Configure Your Twin-Screw Extruder for Mixing: Part 5

Understand the differences between distributive and dispersive mixing, and how you can promote one or the other in your screw design.

best practices 28 Jul 2023

How to Configure Your Twin-Screw Extruder: Part 3

The melting mechanism in a twin-screw extruder is quite different from that of a single screw. Design of the melting section affects how the material is melted, as well as melt temperature and quality.

Know-How 16 May 2023

How to Configure Your Twin-Screw Extruder -- Part 2

Follow these tips to configure your twin-screw elements to promote feeding and solids conveying.

polyolefins 11 Feb 2023

Improving Twin-Screw Compounding of Reinforced Polyolefins

Compounders face a number of processing challenges when incorporating a high loading of low-bulk-density mineral filler into polyolefins. Here are some possible solutions.

Imperial Industries welded resin storage silos

Change molds faster with Smartflow FasTie Tie-In

Latest Compounding News And Updates

k show 5 Aug 2025

Coperion Takes Wraps off High-Volume Feeding Solutions

Suite of gravimetric, volumetric feeders to be showcased at K 2025.

k show 5 Aug 2025

Feddem To Introduce Laboratory Twin, Novel Pelletizing Tool

Compact lab twin and new tool to minimize die residue to debut at K 2025.

Multiscrew 4 Aug 2025

Coperion's Latest in High-Performance Compounding Extruders

At K 2025, Coperion will display two representatives of its high-performance compounding extruder offerings: ZSK 58 Mc18 and STS 35 Mc11.

k show 29 Jul 2025

KraussMaffei Debuts New Extruders for Recycling Applications

KraussMaffei Extrusion will debut compounding solutions for both PET and mechanical recycling at K 2025, Oct. 8-15 in Düsseldorf, Germany. For PET recycling, the company will demonstrate a high-performance twin-screw system based on its BluePower series for throughputs up to 12 tons/hr.

Compounding 9 Jul 2025

Star Plastics in Merger With Trivalence Technologies

Acquisition expected to enhance platform capabilities and market reach.

Feeding & Blending 29 May 2025

PFA-Coated Ribbon Blender for Sensitive Applications

Targets applications where stainless steel or carbon steel may not be suitable.

Featured Posts

sustainability 5 Aug 2025

How This Custom Compounder Leverages AI to Drive Innovation, Sustainability

Alterra has stepped up its cutting-edge Industry 4.0 technology with its own AI platform to further increase its efficiencies.

Compounding 9 May 2025

What You Need to Consider Before Adding a Compounding Line to Your Operation

Material volume, extruder size, facility space and power, and vendor expertise drive equipment choice.

Extrusion 19 Feb 2025

Optimizing Melt-Fed Single-Screw Extruders on Compounding Lines

The main problem with melt-fed extruders that are starve-fed is setting the depth of the metering channel. In this scenario, we describe how this problem was solved.

Multiscrew 24 Jan 2025

Understanding 'Boundary Conditions' in Twin-Screw Compounding

In twin-screw compounding, the objective is generally to produce the highest quality product at the maximum strand. But sometimes there are operating parameters that prevent this objective from being realized.

Know-How 26 Nov 2024

How to Configure Your Twin-Screw Barrel Layout

In twin-screw compounding, most engineers recognize the benefits of being able to configure screw elements. Here’s what you need to know about sequencing barrel sections.

Compounding 8 Nov 2024

Research Deems Bioplastics, Wood Pulp a Sustainable, Economic Alternative for Rigid Packaging

Farrel Pomini and FPInnovations produce biodegradable compound for molding, extrusion and thermoforming applications.

Biodegradable CFAs Molding and Extrusion

FAQ: Compounding

How can I optimize my twin-screw compounding process?

We identify problems in compounding as “chronic” if the results are the same every time a particular formulation is run. For these problems, the treatment requires redesigning the screw configuration or modifying the compounding process. This is the only way to cure such problems.

How to update process for biopolymer compounding on a twin-screw extruder?

Many new players have emerged in the biopolymer space with new materials and many new formulations. Co-rotating twin-screw extruders provide excellent material mixing capabilities for all polymers, including biopolymers. You should consider your machinery supplier as a development partner to achieve your goals in the areas of melt and mix quality, production rates, and other parameters, regardless of formulation. Make sure your machinery supplier has the facilities and the know-how to help you test material formulations and improve your processes.

What is the correct pelletizing system?

Pelletizers are essential components in resin manufacture, compounding, masterbatch production, and recycling. A high-volume system that is appropriate for a polymerization plant will be very different from one that suits the needs of a toll compounder. One that can produce micropellets for use in masterbatch may not be the best choice for processing post-consumer regrind. Here are some different types of pelletizers.