In mold degators

Hi Gendy;

Sorry not to include the email address in the mail, here it is:

rechiu@qq.com

Hello Gendy;

I happened to visit this site and note the discussion regarding degating Insert built inside a mould today, and are very interested in knowing more about this technique.

Facing the hugh manual degating workload, I am looking for solutions to ease the burden of multi cavities ejection and seperation problem, I am glad to see that you are so generous and wise to tell us what you know and how you do the job.

If it will not cause you too much trouble, appreciated if you could forward the captioned draft to me at your conveniency.

Awaiting for you feed back and thank in advance for the assistance you will extend.

All the best wishes.

rechiu

In regards to degating an edge gate...I have used the following method with good success in the past.

1. Put one or two larger ej. pins on the part surface next to the edge gate.
2. Place an ejector pin right at the end of the runner/start of gate land. This pin will have the same design as a sprue puller pin. Delay this pin by about 3/8"-1/2" (This is accomplished by putting a c'bore under the head, adding another short ejector pin upside down (head of the short pin against the head of the puller pin). The other end of the short pin will rest against the bottom clamp plate.)
3. The short pin keeps your puller pin in place under injection pressure and the clearance under the head keeps the runner and gate in place for the first 3/8" to 1/2" of ejection. The gate breaks right at the edge of the part! Then the ejector plate catches the puller pin and moves it up...ejecting the runner and gate.

Note: with short runners/stiff materials...you need to delay all the runner pins.
This will leave some vestige. Works best with a tapered edge gate and if you can design the gate to be slightly below flush. This method is NOT advised for cosmetic parts due to the slight vestige.
Nice thing about this is it is cheap, low to maintain, and if it gives you any problems..just put a plug in the clearance and you've taken out the delay. Good luck!

Regards,
Jeremy
molddesign@hotmail.com

Hi,

you will find submarin or cashew gates from i-mold at
www.i-mold.com.
They have a lot of sizes for different applications.

I will send it to you tomorrow morning once I come back to the office.

Hi Gendy,

I read the message about degating edge gates in mold, could you send me your draft, I have an application were it my work for me.Thanks

jjefferies@itwimpro.com

>Hi Costel,
>
>We are a toolmaker in China.
>
>If I read your means correctly,
>
>you are looking for the self
>de-gating insert.
>It is a wonderful conception,it breaks
>the edge gate with applying
>one insert and one EJ
>blade during the ejection.
>
>I just have a draft about
>this kind insert.
>If you need it, just make
>a sound.
>
>Gendy
>
>Email: gendy_wong@hotmail.com

HI WONG,

CAN U PLZ SEND IT ME TOO. IT WILL BE USEFULFOR MY FUTURE USE.

THANKS & REGARDS

RENGA
genictec@starhub.net.sg

Not Mattel.
www.perlos.com
Gyorgy

Hi Gyorgy,

We are one of the toolmakers in Dongguan, Guang Dong province.
It seems that you have been to China, right?
I know Mattel has plants in Guang Dong.
Are you working for them?

Thanks gendy !
I got it. Where are you located. We have some plants out there and bought a moldmaking company as well.
György

Hi Gyorgy,

A copy about the self degating insert was sent to you.
Please let me know if it failed to reach you.

And thanks for your praise.

Regards,
Gendy

Hi Gendy !
It's nice to see that there are people from China reading the forum, willing to chat and help, not only to sell and advertise. You are the first one, if I remember well.
We should give you a reward.
Anyway, could you send that draft to me as well.
gszekely@freemail.hu
Thanks
Gyorgy

Hi Costel,

We are a toolmaker in China.
If I read your means correctly,
you are looking for the self de-gating insert.
It is a wonderful conception,it breaks the edge gate with applying one insert and one EJ blade during the ejection.

I just have a draft about this kind insert.
If you need it, just make a sound.

Gendy

Email: gendy_wong@hotmail.com

I had someone at Sumitomo explain their Press Alpha in mold degating. You first of all have to have the mold built with a separate ejector box. When you want to cut the gates the machine will move the first ejector box forward in a vibration type mode. The blades or pins in the mold will then cut the gates. After you open the mold the machine ejector will then move the second ejector box forward to eject the parts.

Thank you all for your replies.

Murphy,
Polyshot edge gating is not what I am looking for. That system is most suited for smaller multi-cavity identical parts.

Bill,
Most of our tools have SVG’s (which we are slowly trying to depart from). Hence we have the setup to control pin/plunger actuation independently.

You are right, there is nothing fancy about it. I just need a good tool shop to work with me on this.

György,
That is a concern. However we do a lot of manual degating so we are battling vestige at the gate for a living.

Regardless of down side, an in-mold system will eliminate (or drastically reduce) the manual labor and the scrap.

I am a realistic person. It will not achieve perfection but for me would be a huge leap forward.

That is, if it works.

Regards,

Costel

As Bill wrote. We have in some of our tools. If it is not set corectly, you will end wit cutted runner but a small sprue at gate, dificult to remove it later, and the part may not fit in assy process,
György

Costel

In mold degating using the same technology a valve gate uses except you're driving a pin (insert) usually up against the part wall or something to close off a tab gate.

Nothing magic other than more stuff in your mold - hydraulic cylinders timed to go forward slightly after injection is done, then retract at mold open.

GO FOR IT>

Thanks all!

Murphy,

I will give Doug a call.

Regards,
Costel

Costel,

I think what you are looking for is in-mold degating.

It is a process where plastic is injected into a cavity and before it completely solidifies an actuator like a valve pin moves for and seperates the part from the gate. When the mold opens, the part and gate are ejected already seperated.

In-mold degating is the process used to make CDs and DVDs.

I have heard that polyshot makes a good system.

www.polyshot.com
1.800.polyshot

Speak with Doug Hepler. Polyshot has been feature in IMM.

Hope this helps.

Shear gates work pretty good with many materials. I think you can buy them off the shelf thru DME or Progressive.

[font size="1" color="#FF0000"]LAST EDITED ON 02-21-05 AT 12:56 PM (GMT)[/font][p]There is a company that makes degating inserts for tools. You make small modification to the tool, the degating insert is hard enough for glass filled resins. The blade cuts the runner off from the part as the tool opens. If mounted correctly, the insert can be replaced in the press without a mold tear down. I can't remember the name of them, search the IMM site for a link. Rick.