EVA FOOTWEAR

[formandfunction]

Hi All

I am a product designer working in Australia and I have recently received a job to design an orthopedic flip-flop which we call 'thongs' in Australia.

My knowledge is limited with material science with plastics and rubber but the idea is to injection mold the flip-flop from EVA but certain areas of the product need to be softer e.g. the arch support and the heel area for comfort. My question is could I create a 1 piece injection molded flip-flop base with a dual density property around certain location? How is the tooling made for this type of mold?

I was also considering using a TPE to do an soft-feature between the large toe for more comfort. Could someone suggest to me or direct me to the right place to find if I could create an 'extra soft' material that can be bonded to the area in between the large toe (example, very soft EVA, or rubber or silicon that is then bonded to the strap which could either be PVC or Rubber)

Any help would be much appreciated

thanks all

 

[Demon3]

You can add oil to adjust the softness of these materials but you'd have to test to make sure it doesn't bleed out over time.

In your shoes (please excuse the pun) I'd talk to Pat Primmer about this as he's the best there is and in Australia too.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[btrueblood]

...and if you wait a few more hours for him to wake up, he'll be replying shortly. After a couple of cups of coffee, he'll be a little less short...

 

[patprimmer]

I have to stay out of this one due to conflicting interests and ND agreements.

Regards
Pat
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for site rules

 

[formandfunction]

Hi All

I don't want to create any conflict of interest here, I guess I just need direction as to whether or not this is possible. I have attached an image that should give some clarity as to what I am trying to achieve. If the outsole of the flip-flop cannot be create with a dual density in the areas highlighted (in orange) then I could create a multi-part design and have them bonded with adhesives but it would be a better approach if I could do a 1 part dual density mold.

It would be great to get some direction or help from the experts here.

Thank you all

 

[patprimmer]

One thing I can say is that gas injection to form bigbubbles in the marked areas could work. Big bubbles in soles have been a marketing tool in joggers for yeard

Regards
Pat
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[patprimmer]

Opps

Last word is years not yeard

Regards
Pat
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