- All
- Product Name
- Product Keyword
- Product Model
- Product Summary
- Product Description
- Multi Field Search
English
Views: 0 Author: Site Editor Publish Time: 2026-02-28 Origin: Site
The extrusion die has three main elements, i.e., inlet channel, manifold, and land region. The inlet channel of the die matches the exit of the extruder. The design of the extrusion die should include features that allow for slow, laminar flow across the die channel and maintain a uniform velocity profile. Blow-up ratio = Dx/Dd = final diameter/die diameter. It is important to have a ratio between 2:1 and 5:1 for good film properties.
The length and diameter of the screw and flight depth are important parameters for extrusion. The L/D ratio is typically 40 or higher for better mixing and blending of plastics. The plastic flows through a breaker plate at the end of the extruder with a screen pack. The screen pack is used to trap contaminants and to improve mixing of the plastics. The hot plastic exits the extruder through a die. The extrusion die can be many configurations that mold the plastic into the desired shape. Annular dies are used to make tubing, pipe, and wire coating. Slit dies are used to produce flat film and sheet. Profile dies are used to produce shapes other than annular, circular, or rectangular.
After the plastic is extruded to shape through the die then it must be converted to final shape for
–Pipe or tubing
–Tee shirt bag or trash bag with designs and cutout shapes
–Fiber
Auxiliary equipment can include a puller, rollers for proper thickness, and a windup or cutoff to trim the extruded shape into the final part or pellet dimensions. Fig. 13.10 shows the extrusion die parts for a simple profile.
