Page 59 - Plastics News November 2025
P. 59
PRODUCT NEWS
prepared, and this may involve the incorpo- applications.
ration of additives in order to enhance the
properties. ♦ Material Utilization: It minimizes the wast-
age, as the material is removed at the point
♦ Casting: The ready resin was added to the where it is required.
mold and allowed to cure.
♦ Surface Finish: Able to achieve finishes on
♦ Demolding and Finishing: Demolding of the the surface, particularly after machining.
solidified component out of the mold and
any finishing tasks which is required. Limitations:
♦ Cost: Additional unit cost of material remov-
Material Selection for Plastics
al, and machining time.
Material properties have a lot of influence on ♦ Complexity: Poor ability to produce very in-
whether to use machined plastics or cast plas- tricate shapes, with no extra tooling.
tics. The comparison of plastics engineering
shows that: B. Cast Semi-Finished Plastics
♦ Machined Plastics: These are commonly Advantages:
used materials with high mechanical prop- ♦ Complex Geometries: It is best suited to
erties, such as acetal, polycarbonate, and manufacture parts of complex forms.
POM.
♦ Cost-Effective for Large Volumes: It is cheap
♦ Cast Plastics: Polyurethane and epoxy are in mass production because of the low tool-
some of the materials used in casting since ing costs.
they could be cast to complex shapes and
could also be used in developing good fin- ♦ Material Properties: Is capable of attaining
ishes on the surface. acceptable material characteristics using ad-
ditives during casting.
The choice of the appropriate material will guar-
antee that the end product will meet the perfor- Limitations:
mance requirements.
♦ Tolerances: Typically casting processes are
Advantages and Limitations unable to tolerances that machining can.
♦ Post-Processing: Finishing further is needed
A. Machined Plastic Components
to achieve the requirements of surface finish
Advantages: and dimension.
♦ Precision and Tolerances: A high degree of Comparing Machined and Cast Plastics
tolerance is obtained with high level of preci-
sion and is, thus, applicable in high-precision In order to have a more vivid comparison, the
following table can be considered:
November 2025 PLASTICS NEWS 59
