Tooling design & construction considerations for transparant ABS

[Dugan]

Hello,

New member here looking for some insight or resources for learning about tooling design and construction with transparent ABS. More specifically, tooling that can be used with both standard and transparent ABS to make the same part from either material.

I have searched online and not found much other than the most general comments about how transparent parts are more sensitive to visual defects. I would also imagine that more consideration has to where you put parting lines, gates, etc since less is hidden.

Can anyone give me more information on what special consideration is needed when designing and constructing a mold to be used with standard as well as transparent ABS?

Thank You In Advance,

Dugan

[Suhas]

Hi Dugan,
Yes, I doubt if you will find any info on this online. The one thing I will tell you is that to have a good transparent part, you will need a mirror finish on the mold. That will be expensive and difficult to maintain if the people are not trained on it. Of the two, the transparent is the more difficult because of the cosmetics, so design around that and the other will be easier. Note that shrinkage of the various grades of ABS are different. So getting the same size could be an issue.
Regards,
Suhas

[Mandar]

Hello Dugan & Suhas sir,
I have a doubt regarding runner design.
If trapezoidal runner used , how to decide runner dimensions.it depends on part volume, but is their any thumb rule for selection??

Thanx & Regards,
Mandar

[rickbatey]

If you're running clear parts/resins then stay away from trapezoid runners. Full to half round only as they create less shear heating. Also sizing is based off wall stock and calculated from the gate back towards the sprue bushing. Also critical is style of gate. Because the width and depth change with style, wall stock, and resin. Also keep the gate land short for best results. DuPont has free design papers that take all this into consideration as well as Bob Hatch's book; plus I'm sure Fimmtech and Suhas have the answers you seek.
I'm curious; are you the designer, a tool maker, processor, or originator? It might be smarter and cheaper to hire someone with experience to do this for you.
Rick.

[Mandar]

hi sir,
I'm a moldflow user. Can u please tell me, how to select gate back towards sprue bushing. I'm not getting any data related to tooling perticularly runner & gating design. I'm also not getting Bob hitch's book you mentioned above.
Please do needful.

Thanx