Recommended DRAFT angles

hi guys,

I was wondering if you guys know some information for minimal draft angles for plastic parts? I would like to know the minimal draft angles for certain length (depth) of parts. EX: the height of the rib/ boss/ wall is 10 mm, what's the minimal recommended draft angle, etc..

if anyone can provide a table would be very nice..

thanks in advanced.

alvin164,

when considering how much draft to employ you should consider what to draft first. A simple list:
1) Material used- makes a difference what draft is appropriate, especially when using materials like PC, some nylons can handle no draft
2) Texture- the texture type requires a minimum draft which is suggested on the texture sample plates given by certain companies like moldtech
3) Mold construction- some features can be made with little or no draft or even an undercut if the conditions are right including materials and mold design. Helps to show the tool maker the part design so they can advise you
4) feature shape-some features can be so long that they will not easily release and could be stretched or damaged. A feature such as this might need a special mold construction

you might consider this:
smooth surface: 0-2deg
textured surface: 1-(whatever is called out)

more draft rarely hurts as long as the part maintains an even thickness...look into the signs of insufficient draft such as stretching or grooves cut parallel with the mold release...do some research from the material brands you want to use, they often have suggested guidelines, for their respective material, for part design

cheers...

M

thanks for the suggestion M....

Hi Friends,
You can refer to document below :
http://rapidshare.com/files/23982643/Plastic_Part_Design.doc
Hope this help.
Regards

Hi Guys


normally, PC, PS, ABS, SAN, PET, and like material required 1~2 degree/side. Specially on ribs etc. other materials like PP, PE, PA required 0~1 degree/side draft angle. But remember, not only this formula, but u must consider, the design, ejection resistence etc etc to determine what draft u need to put. There is a lot of books and plasitc design handbooks available in the market.

Hy Khuu Hien


can u email me that file?? its not available now on rapidshare.

these links may be useful:

https://plastics.bayer.com/plastics/emea/en/technology/1013/ article.jsp?docId=1593&cid=1013

http://www.mold-tech.com/texturing/wall.shtml#draft

http://www.plastics1.com/CIM/DesignGuide.php

http://www.paralleldesign.com/moldability_101/index.htm

Bayer has a complete set of resources for plastic design.


[url]http://www.bayermaterialsciencenafta.com/resources/index.cfm ?f=10247629-D94D-FDDD-B63BB6BDC92B451A [/url]