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karelkalip
Posts: 4
Registered: ‎05-04-2009
Accepted Solution

Clamp Force Security Coefficient

601 Views, 5 Replies
10-04-2012 07:29 AM

Hello everyone,

 

Is there any security coefficient for clamp force calculation inside moldflow, or should we muttiply with some number.

I have heard somewhere about multiply with  1.2 but i could not be sure.

 

Best regards.

Levent

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Product Support
Shawn_Gedman
Posts: 27
Registered: ‎06-11-2010

Re: Clamp Force Security Coefficient

10-05-2012 01:44 PM in reply to: karelkalip

Hello Levent,

 

I'd be glad to help with your inquiry, but I'm not familiar with what a "Security Coefficient" would be so could you please explain further?  Are you referring to a Safety Factor that you might want to use when sizing an injection molding machine for your part?

 

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Member
karelkalip
Posts: 4
Registered: ‎05-04-2009

Re: Clamp Force Security Coefficient

10-05-2012 11:11 PM in reply to: Shawn_Gedman

Dear Shawn,

Securty factor is the right term :smileyhappy: I am doubting about clamp force. Moldflow calculated 1470 t, and machine capacity is 1500 t.  Is this secure that using this machine, or should i multiply 1470 with 1.2 (security factor) like 1760 t and use different enj. machine?

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Product Support
Shawn_Gedman
Posts: 27
Registered: ‎06-11-2010

Re: Clamp Force Security Coefficient

10-08-2012 10:58 AM in reply to: karelkalip

Hello,

 

I commonly refer to this as a Safety Factor, but I now understand what you are looking for.  We do not add a Security/Safety Factor in the clamp force calculations.  The solver basically calculates the pressures and surface area in the XY plane and then multiplies the two to derive the clamp force prediction.  It would be up to the engineer to size the machine based off of the clamp force predictions, but a general rule of thumb would be to not exceed 80% of the machines maximum clamp force.  For example, you probably would not want to go higher than 80 ton on a 100 ton press.  Some might push this limit a little further, but then you're not leaving yourself much of a window.

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Active Member
nicola.pavan
Posts: 10
Registered: ‎02-10-2012

Re: Clamp Force Security Coefficient

10-22-2012 04:35 AM in reply to: Shawn_Gedman

Hi Karel Kapil,

nice to meet you again...

 

I agree with Shawn, Safety Factor could span within 80% up to 90% of the force of your machine. It depends just on how much you're confident with your model. Morevoer it depends also on the machine, an old machine probably has a worse control on clamping force respect to a bran new one.

 

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Mentor
madhukeshwart
Posts: 267
Registered: ‎03-18-2009

Re: Clamp Force Security Coefficient

06-24-2013 06:38 PM in reply to: karelkalip

we generally term it as FACTOR OF SAFETY.

 

1. It is best recommended is 20 % more than moldflow calculated.

2.Some times, moldflow over predicts, when there are undercut, side cores & slides, then recommneded  20% to 30 % less moldflow calculated, depends upon overlapping projected ares.

3. when doing moldflow for stack molds, it can 40 % less than moldflow calculated.

4. Even if early switch over is done, it can 10 % more than moldflow calculated.

 

It all depends are case to case basis.

 

Madhukeshwar Talwar
FIAT-CHRYSLER ATC, Chennai
mail: madhukeshwart@gmail.com
09600060862
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