Page 47 - Plastics News January 2018

FeAtures

Optimization Approach for Metal to Plastic Substitution

The problem of leakage due to assembly of two parts was addressed in the new optimized design.

• Mold-Trials to freeze the process marks in the thick areas which was affecting the
parameters i.e. flow rate, cooling, quality of the part.
packing profile, mold temp, weight • Longer Injection molding cycles due to higher cooling
of component, etc.
time.
• Process monitoring for achieving • As the length of the part was long, core-deflection
consistency in the quality of the was a major concern
part.
Mr Ashish Desai • High Level rejections of the product in production.
• Part approval from the customer. Director
Jyoti Plastic Works • Optimization of the Process-parameters used for
• Project Sign-off. Pvt Ltd.
Injection molding of the part.
Component Application

Material Selection Criteria

• The component should withstand the pressure of
100psi & it should qualify for the bursting pressure as Typical Product Development Process
per the product requirements given by the customer Conclusion

• The component is used in water application hence the • Product was re-engineered with respect to plastic
plastic material should have lower water absorption. product design guidelines.

• Good Dimensional Stability. • Product Design was optimized by combining two
• The component will be in contact with water, so different parts to form one single part, leading to
the material grade should comply with the FDA & cost saving in Material, Manufacturing cost & Assembly
ROHS regulations (i.e. material grade should be NSF processes without affecting the end application.
approved & it restrict the use of lead, cadmium, • The longer cycle time was addressed by cooling the
mercury, etc).
90% of the part in mould & remaining outside the
• Component should be light in weight mould by putting part in water bath to save on the
cycle time & increase productivity.
Challenges
• By applying various methodology of Six Sigma, FEA,
• Following were the challenges faced during the Moldflow & Scientific Injection Molding we were able
Product Development: -
to solve the chronic issue of porosity & sink marks
• Being a thick walled component, molding the part which was affecting the quality of the part.
defect free with the injection molding process was • Process Capability Study was used to precisely monitor
a challenge. There was a problem of porosity & sink
the consistency in the quality of the part.

47 Januar y 2018 Plastics News