Polymer & Plastics Extrusion Equipment

Diamond America has over 20 years of experience in custom extruder design for polymers and plastics, including expert 3D modeling and Finite Element Analysis (FEA) software systems to optimize die and extruder performance and quality.

Plastics extrusion equipment is used for continuous, high-volume manufacture of a wide range of final products that have constant cross section, such as plastic pipes, frames, sheeting and films.

polymer and plastics extrusion equipment Manufacturer Diamond America

Critical Factors Design Of Polymer Extrusion Equipment

1

Compression Ratio

The compression ratio is the ratio of the screw depth at the feed zone by the hopper, to its depth at the metering zone by the die. Compression ratio varies greatly according to the polymer that is being processed. For example, where rigid PVC requires a compression ratio of around 2.3:1, polypropylene or a more slippery material requires a ratio of nearer 4:1. The compression ratio is also impacted by the relationship of cross sectional areas at the screw feed and metering points. Finally, barrier designs, mixers, and variable lead screws affect not only the compression ratio, but the final screw output as well. The design of polymer extrusion equipment is indeed a very specialized process.

2

Die Design

Due to the wide variety of products, ranging from plastic pipes to films, polymer extrusion die design is very diverse and complex and includes dies for:

Prevention of die swell must be built into the die design by:

Dies have to be carefully designed to handle the specific behavior of plastic extrusion melts. Polymers consist of long chains of molecules which become aligned and oriented in a single direction when forced through a die. On release, they tend to diverge randomly when no longer constrained, causing a phenomenon known as ‘die swell’.

Examples of Polymer and Plastic Extrusion Applications, Materials and Selection Criteria

Windows PVC Extrusion
Building & Construction

Rainwater Pipes, Gutters

Soffits, Fascias

Windows, Doors

Door Seals

Garden Fencing

Rigid PVC

Compact/foamed PVC

Rigid PVC

Co-extrusion

Polystyrene/polyethylene

Strong, UV resistant, color fast

UV resistant, color fast

Appearance, can be cut and welded

Dual properties in one molded profile

Recycled material, does not require painting

Conduit Extrusion
Electrical

Light Diffusers

Conduit and Cable Protectors

Cable Harnesses

Acrylic

Rigid PVC

PTFE Filled PVC

Optical properties

Tough, good insulator, chemically stable

Flexible, resistant to chaffing

Fride Seal Extrusion
Household Goods

Curtain Tracks

Fridge Seals

Rigid PVC

Rubber, PVC and metal

UV resistant, tough material, can be colored

Can be magnetized

Drip Tube
Medical

Drip Tubes, Catheter Tubes

Plastic composites

High integrity, reinforced, can be sterilized

Spray Tube Extrusion
Packaging

Aerosol and Spray Dip Tubes

Polyethylene

Transparent, stable, chemically resistant

Gas and Water Pipe Extrusion Tube
Utilities

Gas Pipes, Water Pipes

Soil Pipes

Polyethylene

Rigid PVC

Corrosion resistant, good integrity

Strong, can be joined using solvent cements

Diamond America Mission

Diamond America Extrusion Test Facility

Diamond America provides a fully equipped test facility for new product process and formulation testing for all applications. The test laboratory boasts several table top extruders for small batch scaled production, as well as full scale twin feed and bulk extruders. Experienced engineers are on hand to assist with extruder customization, die design, system controls and the selection of associated extrusion equipment.

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96 East Miller Ave.
Akron, OH 44301