I need the shrink factor..
I need the shrink factor..
(OP)
We are bidding on a project that calls for :
Polyethylene, ASTM D4976 Group 1 (branched), Class 2 (medium density, grade 5 (flow rate to 0.4) containing
2.50+ .05% carbon by weight, approx. 5.27" OD X 2.79" high,
approx. 6 oz.
Could anyone please tell me the shrink factor of this?
The molded part will resemble a bowl and the wall thickness will be about .187.
Thanks!
Polyethylene, ASTM D4976 Group 1 (branched), Class 2 (medium density, grade 5 (flow rate to 0.4) containing
2.50+ .05% carbon by weight, approx. 5.27" OD X 2.79" high,
approx. 6 oz.
Could anyone please tell me the shrink factor of this?
The molded part will resemble a bowl and the wall thickness will be about .187.
Thanks!






RE: I need the shrink factor..
Shrink is affected by the added carbon. Check with manufacturers or compounders. LNP has a web site.
RE: I need the shrink factor..
I aggree that .187 is a thick wall, however the part dictates this..
Thanks!
RE: I need the shrink factor..
One noticeable point in this regard : if the part geometry is in the form of revolved section the difference in shrinkage along & across flow will cause little deformation on shrinkage but any deviation from revolved geometry will show itself in the form of deformation.
RE: I need the shrink factor..
Regards
Rick Marmei - Tool Designer
http://axis-design.org
RE: I need the shrink factor..
section thickness
orientation
mould tempreature
injection pressure
hold up time
Variations in pigments used for colour will also effect shrinkage.
Regards
pat