principle of the process structure process modeling defects design for manufacturing (dfm)
DESCRIPTION
Principle of the process Structure Process modeling Defects Design For Manufacturing (DFM) Process variation. Solid profiles. Shaping Processes For Plastics - Extrusion. Die configurations and extruded products. Extruded product depends on the shape of die. Desired shape. Correction. - PowerPoint PPT PresentationTRANSCRIPT
Module 5c 1
Principle of the process
Structure
Process modeling
Defects / control
Design For Manufacturing (DFM)
Process variation
Module 5c 2
Shaping Processes For Plastics - Extrusion
Die configurations and extruded products
Extruded product depends on the shape of die
Solid profiles
Module 5c 3
Die configurations and extruded products
The main quality problem is related to die swell.
There are several methods to overcome the die swell
a. Increase die opening length
b. A draw operation follows the extrusion
c. For non-round shape, a correction is needed.
Desired shape
Correction
Module 5c 4
Die configurations and extruded products
Defects in Extrusion – melt fracture
Turbulence flow at the entrance of the die
Module 5c 5
Die configurations and extruded products
Defects in Extrusion – sharkskin or bambooing
Friction between die and extrudate
Module 5c 6
Principle of the process
Structure
Process modeling
Defects / control
Design For Manufacturing (DFM)
Process variation
Module 5c 7
Design For Manufacturing – Plastics Extrusion
Shrinkage is a root cause. In the figure below, there are three common types of problems
Module 5c 8
Design For Manufacturing – Plastics Extrusion
Module 5c 9
Design For Manufacturing – Plastics Extrusion
Module 5c 10
Design For Manufacturing – Plastics Extrusion
DFM guideline – wall thickness:
Module 5c 11
Design For Manufacturing – Plastics Extrusion
DFM guideline – wall thickness:
Module 5c 12
Design For Manufacturing – Plastics Extrusion
DFM guideline – wall thickness:
Module 5c 13
Design For Manufacturing – Plastics Extrusion
DFM guideline – sink marks:
Module 5c 14
Design For Manufacturing – Plastics Extrusion
DFM guideline – hole location:
Module 5c 15
Design For Manufacturing – Plastics Extrusion
DFM guideline – hole location: