Product injection molding?

[SEBASTlAN]

Hey peeps,

I have the 3D drawing of what I want made but now comes the part of finding who to make it for me (obv from China).

Anyone have experience finding a manufacturer that makes custom products?

What pitfalls are there to be wary of?

 

Dislike ads? Remove them and support the forum: Subscribe to Fastlane Insiders.

[SEBASTlAN]

Is your 3D drawing specifically created for injection molding?

Well yeah I specifically asked for an "injection-mold-ready 3D drawing", so here's hoping.

Next, I would recommend finding a local molding company that can prototype your design(s) until you have a final design that you're happy with. This can take several iterations, so having a company you can easily communicate with and who can make changes on the fly is helpful. Also, it's likely you'll want to visit and actually see the process of creating your product so that if you want to make changes in the future, you'll know what's feasible and how tough it would be.

Is that really necessary? I would've wanted to keep correspondence remote and have them send photos of what a prototype would look like based off my drawing.

Either way, thanks for the input. NRE is what again?

 

[Khanh]

Hey peeps,

I have the 3D drawing of what I want made but now comes the part of finding who to make it for me (obv from China).

Anyone have experience finding a manufacturer that makes custom products?

What pitfalls are there to be wary of?

Hi Sebastya,
I believe I am qualified to answer your question. My credentials are that I am a US based manufacturing engineer that works in high pressure aluminum die casting . This is similar to injection molding in the basic sense but more difficult since we operate at 2x the liquid temperatures at faster speeds ~ .75 Mach. I design molds, processes, but mostly manage the engineering aspect of the project from conception (Purchase Order from client) to delivering the first articles. I contract a lot of molds to be constructed in China due to the fact that it cost 4-6 times to build it in the US. The cost of the mold will depend on the complexity, wall thickness, and dimension of your intended design. There are many US based China mold companies here in the US at will build and even run production in China (one stop shop). You asked about pitfalls:
1) Your design needs to be reviewed for DFM (design for manufacturing): Draft, geometry, tolerances, etc.
2) You need to understand the basic cost and components of a mold so you don't get ripped off, i.e. metal type of mold (H13, holder steel, Ulvar Supreme, vacuum, side action, venting, etc). A basic mold( open and close, no slides) for a 2 in x 2in part will run you around 7 grand.
3) You need to understand somewhat of the manufacturing process, ie: what other post processing is needed to get you to the final product like deburring, sand-blasting, machining, powdercoat, etc
4) I suggest arming yourself with as much knowledge as possible or seeking consultant from an manufacturing engineer before you proceed. This will greatly reduce headwind you will face in your process.
5) attend a manufacturing trade show. There will be many vendors there, but be aware that if you don't know some basic knowledge, you will get ripped off.

Good luck!

 

[SEBASTlAN]

Hi Sebastya,
I believe I am qualified to answer your question. My credentials are that I am a US based manufacturing engineer that works in high pressure aluminum die casting . This is similar to injection molding in the basic sense but more difficult since we operate at 2x the liquid temperatures at faster speeds ~ .75 Mach. I design molds, processes, but mostly manage the engineering aspect of the project from conception (Purchase Order from client) to delivering the first articles. I contract a lot of molds to be constructed in China due to the fact that it cost 4-6 times to build it in the US. The cost of the mold will depend on the complexity, wall thickness, and dimension of your intended design. There are many US based China mold companies here in the US at will build and even run production in China (one stop shop). You asked about pitfalls:
1) Your design needs to be reviewed for DFM (design for manufacturing): Draft, geometry, tolerances, etc.
2) You need to understand the basic cost and components of a mold so you don't get ripped off, i.e. metal type of mold (H13, holder steel, Ulvar Supreme, vacuum, side action, venting, etc). A basic mold( open and close, no slides) for a 2 in x 2in part will run you around 7 grand.
3) You need to understand somewhat of the manufacturing process, ie: what other post processing is needed to get you to the final product like deburring, sand-blasting, machining, powdercoat, etc
4) I suggest arming yourself with as much knowledge as possible or seeking consultant from an manufacturing engineer before you proceed. This will greatly reduce headwind you will face in your process.
5) attend a manufacturing trade show. There will be many vendors there, but be aware that if you don't know some basic knowledge, you will get ripped off.

Good luck!

Thanks man.

So, is there a particular person/resource that could help with all of the above? Or would you say it's simply trial and error?

 

Dislike ads? Remove them and support the forum: Subscribe to Fastlane Insiders.

[Khanh]

I see that you are located in LA. There are many China based injection molding companies in the area. I recommend you read up as much about the process as possible. The more you arm yourself with knowledge, the better. Attend a manufacturing show. Before attending, look at what companies are registered there. You will be looking for China injection molding or something along that line. A lot of this shops will have engineering support to help you through the process but will also cost money.

 

[Walter Hay]

There are two people so far with industry knowledge who have provided helpful suggestions.

If you provide the information I requested in reply to your PM I might be able to identify the best process,and maybe the appropriate material and that could help those two be more specific, but I won't reveal anything unless you give the OK.

Walter

 

[#nowhere]

I could give you a rapid prototype maker from china and can also answer your questions on feasability.
Make this things every day on my J.O.B.

The manufacturers need a ".step"-file to make your prototypes, may it be 3D-printing, or molding.

Rapid prototype from china within 5-7 days (shipped to your door). There are two ways they can do it (depending on size):
-gluing milled plastic parts together (bigger overall size)
-3D printing

(Note: A new molding tool for serial production costs 8k-12k (depending on size and complexity))

(I'm a mechanical engineer, Research & development..)


Shoot me a pm, I can deliver the chinese contact. Worked together with them for several protoypes.
Always convenient and sufficient, qualitywise.


all the best

#n

 

Dislike ads? Remove them and support the forum: Subscribe to Fastlane Insiders.

[Ultra Magnus]

Hey OP, if you're up to a bit of reading, check out Bayer's guide to injection molding:

https://pl.scribd.com/doc/175225231/A-Processing-Guide-for-Injection-Molding-Bayer

They have some great info available in a concise and easily digestible format. (They also have an excellent one for reaction injection molding for applications that are more demanding). You can read the injection molding guide in less than 2 hours, it would be a shame not to understand the process.

Generally, engineering knowledge about thermoplastics is easily available, so your design should be OK. But it's your business to know what you're doing, the total costs are significant. So check that guide out to get a grip on what you're intending to do.

Consider a test run using rapid prototyping technologies to see if/how your idea actually works using actual resin. E.g. you can make up to 20 units using vacuum casting with polyurethane resins that emulate the real deal. This might be very useful for determining material properties such as flexural modulus, creep, tensile strength, etc. In other words, it helps you to see whether the plastic should be stiff or a bit bendy, you can also see how the finish you envisioned will work in real life (e.g. you can easily see fingerprints and scratches on certain gloss finishes, maybe you want matte instead).

Unless you're 100% sure that your design is perfect and that you can easily sell several thousand units of your product I strongly urge you to do some reasearch using the knowledge people are providing here.

 

[Ultralite]

I just ran across this website while I was reading random articles about manufacturing: https://www.dragoninnovation.com/
It's a company that helps people who have no manufacturing experience make their products.

In their videos section, they teach some stuff mostly from 2 textbooks:
Product design for manufacturing and assembly by geoffrey boothroyd
designing plastic parts for assembly by paul tres

I'll be checking out these books myself later. Take a look, it could be useful.

 

[SEBASTlAN]

If you provide the information I requested in reply to your PM I might be able to identify the best process,and maybe the appropriate material and that could help those two be more specific, but I won't reveal anything unless you give the OK.

All good. It's a custom toothbrush - I believe we wanted to go with polypropylene.


Thanks a bunch @Ultra Magnus - just downloaded it. PM'd you [HASHTAG]#nowhere[/HASHTAG]

 

Dislike ads? Remove them and support the forum: Subscribe to Fastlane Insiders.