Question

For increase the rigidity of injection molded plastic spoons, would changing the design of the mold to allow for thicker produced parts work?

Answer 1

ANSWER - For increase the rigidity of injection molded plastic spoons, would changing the design of the mold to allow for thicker produced parts work?

Yes, It will absolutely work.

Lets see your case in two different ways -

CASE 1) Mould material ( Plastic ) is constant -

If there is a case that you cant change your material from plastic to other, ( Other means some other composition of materials in plastic ) then you should have to change mould die design.

Why change the design?

the answer is , if strength or rigidity of the plastic molded spoon to be increased then there should be change in its shape or size or any extra material to be used. without changing the design as well as material will not change the final part rigidity.

How to change the design?

You can change the design in following ways -

1) Reduce stress concentration - By reducing stress concentration we can easily increase the rigidity of the part. Like by removing sharp corners by round corners etc.

2) Increasing size  

3) Increasing thickness

4) reducing bending moment

CASE 2 ) If the material for spoon can be changed ( From plastic to other similar material which has more rigidity properties )

If material can be changed then no worries , just keep the same design of the mold , and within it rigidity can be increased by using better material than plastic