Mold Making

[Shawn Wentzel- Wenteq Inc]

We are looking at getting into makeing plastic injection molds and was wondering if anyone had information or books on design characteristic like location of vents or ports, draft angles needed, ect. Any help would be appreciated!

[mold100]

When in doubt farm it out, what my #?

 

Just kidding, is it completely new to you? There are a lot of considerations, as far as type of molds, molded materials, slides ............

[Shawn Wentzel- Wenteq Inc]

Completely new, we do mostly small intricate aluminum parts, but always looking at expanding.

[Dan_AKA_ROY]

There's a mold project example towards the end of Charles Davis Handbook volume 2.

 

Goes over some of the basics with plastic injection molding: like vents, relief vents, gates, runners, etc.

[Code_Breaker]

Aerotech, where are you located?

 

I am working at an injection mold shop, and there is a lot to learn. I came from 15 yrs in extrusion blow molds. May I suggest a book that will be a good basic step in a new direction for you and your shop.

 

"Mold-Making Handbook" 2nd ed., by Stoeckhert/Mennig. Published by Hanser/Gardner Publications, Inc. Cincinnati.

 

It covers:

[*]Injection Molds

[*]Compression and Transfer Molds

[*]Molds for Polyurthane Products

[*]Blow Molds

[*]Molds for Thermoforming

[*]Rotational Molds and Slush Molds

[*]Molds for Products made from Thermoplastics Forms

[*]Molds for Vaccuum Autoclave Technique

[*]Prototype and Short-Run Molds

It also has a section on Mold Material, and a section on Manufacturing and Machining Processes (CNC, EDM, Hobbing, etc). Lastly, it has a section on Standards (Gate Area, Ejection Pins, Mold Heating, etc.)

 

I received it as a gift from my former boss when he retired, so I don't know the price.

 

HTH

 

Code_Breaker

[HevyMetl]

There is so much to consider when building and designing injection molds. Machining is only one part. I have seen many molds fail that were manufactured very well, but the upfront designs were awful. The best bet to get yourself started would be to bring in an individual with alot of MOLD design expierence. They can then work with the customer on part requirements that will drive the mold design. I am not knocking the books, but its kind of like buying a Chiltons manual for a Cheverolet car when you own a Toyota truck. Every part will call for different situations that will then dictate mold characteristics.

[lou]

You may need to hire someone with a strong background in this. There are alot of things that you just cant learn in books. Or, Maybe even a consultent???

 

Just my 2 cents.

 

Have a good day!

[mold100]

quote:

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You may need to hire someone with a strong background in this. There are alot of things that you just cant learn in books. Or, Maybe even a consultent???

 

Just my 2 cents.

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+1

[TREV]

good morning,

like was stated above,if no one at your facility has expeirience designing and building molds you will definitly need to hire people in that capacity.it is such a dog eat dog world out there on bidding and quoting . i have seen jobs go to a competettor for as little as 200 bucks. if you are not set up to build molds ie. people,machines,skills .you will not remain competitive.plan on spending some cash.also things to consider also is the many purchased items needed to build the tool. leader pins, bushings ,wear plates, ejector pins, and so on and so on. you will definitly need to spend some time doing home work.

hth,

best of luck to you,

trevor

[Code_Breaker]

Ya know, I wasn't saying that you can learn this business from reading one book, or hundred books, or even building one mold. Aerotech wanted something, I had something, and I gave something. This book, and other like it, are just for information.

 

I am very thankful for books that have help me greatly. For example, Charles Davis' books on MasterCAM, expecially the 5-Axis Tutorial.

 

Anyway, just had to throw this into the mix.

 

Code_Breaker

[HevyMetl]

Wasn't saying you were. I just cringe when I hear someone ask for a book with information on how to do things. Aerotech stated they were looking to get into the business. My opinion is he needed to look more at expierenced individuals than a book.

Quote:

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We are looking at getting into makeing plastic injection molds and was wondering if anyone had information...

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Everytime and engineer comes into me with his book I end up in trouble.

[Midwest]

+1 to hiring someone who has built a mold before.

[Shawn Wentzel- Wenteq Inc]

Thanks for all the help.

[AARONIS]

O/T....

AeroTech are you familiar with CoD?

[Shawn Wentzel- Wenteq Inc]

What do you mean CoD?

[PBpaul]

I found it interesting that this thread seems to focus on injection molding. Does anyone out there do anything with lost-wax casting, like they do in dental and jewelry?

Paul

[Scott Bond]

I was a wax investment moldmaker for about 20 years, and I still make about 5 molds a year.

[moldmaker10]

I agree, if your shop wishes to get into injection molds you need to hire someone with lots of experience in design and manufacture of these tools. Otherwise you could be lining yourself up for a law suite when the tool does not work. I have on a few instances had to take injection tools made by shop who did not have a clue and try to make them work. Did not get invloved in legalities but heard there were a law suite in progress. Just be careful. If you are dead set on getting into building injection tools you should at least hire the design out to a design house. Good luck.

[Teh Bear without Brains kinda idiot]

+1000 to this

I am moldmaker ,not molddesigner ,yet I build molds too ,but I have people with experience near me .

Now I make molds for 8 years at least and this is

an art too .

You have no right for mistake ,you must work accurate and see from the start what you will get at the end .

Do you know how many mistakes I find before actually making mold on programming stage ?

So you must start from the simple molds and go

deeper into the art slowly .

And have good mold designer with good experience and to read books also is good idea ,but it is not enough .

Teh humble moldmaker

[cadist]

+1000 winnie

I am in this field for last 4and half years.i.e. from the begining of my carreer. But still I can't decide on all points. An injection mold is no just about punch and cavity, there are many points like cooling, injection and ejection which you learn only by experience.

[Bill]

The biggest problem you will encounter with building plastic injection molds is....

 

ENGINEERS!!!! the folks who think if it can be created with cad it MUST be buildable! Uhhh... whatever.

 

Countless times I have encountered an engineer who did NOT want a parting line or a gate for that matter. DOH!!!

 

What Lou Said

[mold100]

quote:

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the folks who think if it can be created with cad it MUST be buildable! Uhhh... whatever.

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priceless advice