You Like to Talk About Injection Molding? I Like to Talk About Injection Molding

DMS General
1

That’s actually kind of interesting, I’m wondering what kind of scale they’re doing injection molding on because most of the injection molding that I was privy to use Mexico as a springboard to go to China for China pricing, back in the late '90s.
Definitely not trying to open up any kind of bullshit topic about that, I was just around (not directly involved with) that industry when all that started happening.

I do know around the 2006/2007 time frame a lot of these smaller injection molding factories started moving into a small batch, fast turnover model for smaller orders.
I never really did find out how that worked out, but with a local Plastics injection molder, I would imagine it didn’t do too awful bad.

With all that being said, I’m not highly interested in taking a tour just because of the negative Nostalgia for me, however, anyone that’s actually interested in the electrical side, automation, Etc would love this tour.

I do remember being around these machines as a kid and seeing them cycle. It was always really interesting to watch how a bag of plastic pellets, whether it was abs, glass for nylon, etc, could go into a hopper at the top, melted, shot into a multicavity mold, coolant ran through the mold to cool the parts and dropped out the bottom in such a rapid cycle. Especially on 120 ton machines that had between 7 and up to 20 cavities in the molds.
It was definitely mesmerizing to watch, even as a young child.

That being said, I do wonder what machines are in use anymore because of the time that I was aware of all of this, the big ones were Newberry, Cincinnati Milacron and Sandretto.

So I say this, anyone that’s interested in automation, fluid hydraulics, electronics, go check it out. It is definitely worth it.

1 Like
2

Shipping cost is a factor, providing large parts an advantage.

Precision often reduces cycle times. This can be an advantage for local vendors.

Regulatory requirements can often be met more easily by local specialized suppliers.

Ii see a lot of local supplies operating with any of these or a combination applying.

3

I’m going to be pleasant as I can here so I will say this, from what I understand you’re an electrical engineer and you seem to be very good at it. I’m not going to deny that.

However, everything you just said really seems like you read it in a book or an online journal and you have no real world experience with on the floor manufacturing and what truly happens and the actual costs on a lot of that.

Shipping costs on large parts are always going to be higher. It doesn’t matter if it’s local or international, the cost of shipping a hood is always going to be more than shipping 100 window switches that take up the same amount of space.
The cost may be the same but you’re talking one part versus 100 parts which brings the cost down.

This is completely false, which is why such a thing is quality control exist. The Precision comes into making the mold, especially when you get into injection molding as we are talking about now. The quality control comes in because anything could have gotten into the mold, something could have happened, Etc so quality control exists. And if foreign material or something happening that messes up a batch of parts Could Happen whether or not it’s in the us, china, Taiwan or anywhere else in the world.
Precision can sometimes make a higher quality part, but it doesn’t make things faster.
When you manufacture things, you’ve got quality, fast or cheap. You can pick two but you cannot have all three.

Also false. When companies in the US send their designs and blueprints to companies in China to produce, they’ve already passed the regulatory requirements, so nobody has an advantage there. Unless Parts get painted with a lead-based paint which is rare.

Of course you do, because they are required to.

4

No floor experience, just as a customer. It’s true this is what I hear from suppliers and not based on first hand experience.

As to “Precision often reduces cycle times.” I misspoke, I meant cycle rates. That comment was based on getting quotes on a large assembly with optical features. Several suppliers indicated that meeting our specs would require more time in mold and made this general statement.

5

And right there is the issue.

You can’t make a generalized statement based on a one-off with extra specifications on a mass produce, plastic injection molded subject.

You were getting quotes on something custom, then trying to apply it to a mass production supplier, as a generalization.

To completely and separate animals with much, much different involvement and implications. Especially on overall cost.

6

Well, now that this threads highjack over some bullshit is over…

Who else wants to go on a tour!?

7

I am an ME and have designed and sourced a lot of injection molded parts. The main drivers in my experience for choosing a Chinse injection molding shop are tooling cost and lead times.

Tooling from domestic shops is often an order of magnitude more expensive and domestic lead times tend to be terrible even taking shipping into account. I can send a part to a Chinse vendor get it tooled and have samples in hand in less than 6 weeks, if you really push them I have gotten sample parts in 4 weeks. Full production time will vary based on total volume.

I have largely given up on quoting with domestic vendors as getting a quote reply back in less than a week is rare. I have never gotten a quoted lead time of less than 8 weeks (I was quoted 16 weeks once) for samples from domestic vendors.

Admittedly I tend to work on low/medium (10,000 to 50,000) quantity parts and many US vendors
really only want to deal with 100,000+ quantity.

2 Likes