Living Hinge

By serv
Published: June 15th, 2009

I am working on a design that includes a stack of 8 plastic flaps (Material PP, 6" x 2", Thickness= 0.060). These flap need to be hinged along the 2" side and each flap should open at 160 - 180 degree.  I have done some crude experiments with living hinge.

Hinge Operatoin:  Start the whole stack at one side, start hinging to the other side one flap at a time.

Problem:  From the prototype I tried, after two or three flaps, subsequent flaps can't be moved to the other side at the desired angle.

It seems like hinge needs to be almost 1/4" - 1/2" wide for each sheet to open at 180 degree, but this might weaken the hinge.

I'll appreciate any suggestions on how to make it work.  Thanks,

 

 

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Dear Bob and Hank, Thank you

Submitted by serv on June 17, 2009 - 9:39am.

Dear Bob and Hank,

Thank you for your advice.

You must be having experience in the design of living hinges. It will greatly help me if I can discuss this further with you over the phone. Please let me know if you are available. You can email me at

suniti62@gmail.com

I suggest a twin hinge with a

Submitted by Bob Burns on June 16, 2009 - 11:33pm.

I suggest a twin hinge with a rib molded in between to limit the angle and force the second hinge to operate.

You are asking too much to get one hinge to handle 180 degrees. The rib moulded angles will be critical.

Bob Burns

YOU'LL NEVER BE ABLE TO

Submitted by HANK on June 15, 2009 - 11:37am.

YOU'LL NEVER BE ABLE TO RELIABLY PROTOYPE THIS HINGE
WITHOUT ACTUALLY MOLDING IT. THE HINGE THICKNESS IS
ONLY .010-.020 THICK AND FOR PROPER ORIENTATION IT IS RECOMENDED THAT YOU FLEX THE HINGE WHILE WARM AS IT COMES OUT OF THE PRESS (ALTHOUGH I'VE MADE THEM WITHOUT DOING THE FLEXING OPERATION AND THEY WORKED FINE)WILEY PRESS I'M SURE HAS A HINGE DESIGN BOOK AS I'VE SEEN IT ADVERTISED, SPE BOOKSTORE MIGHT ALSO HAVE
SOME MATERIAL