Podcast – How Can You Improve the Material Utilization Rate in Injection Molding?

Close-up of an injection molding machine producing plastic parts
How Can You Improve the Material Utilization Rate in Injection Molding?
Nov 08 - MoldAll - Explore expert tutorials, case studies, and guides on mold design and injection molding. Learn hands-on skills to enhance your craft at MoldAll.

All right, let's dive into the world of injection molding. We're going deep on how manufacturers are getting smarter about using less material. And I think you'll be surprised at what we find.
It's pretty cool stuff.
It is. And our guide for this deep dive is a piece called how can you improve the material utilization rate in injection molding?
That's a good one.
It is. It's full of strategies companies are using to cut down on waste, which is, of course, good for the planet, but also, you know, good for their bottom line.
Yeah. And sometimes it's these small tweaks that make a huge difference, like mold design. We often think of it as just shaping the final part.
Right.
But it's so much more than that.
The article really hammered that point home. It's not just about the part. It's about how that plastic gets to the part. And that's where this whole hot runner versus cold runner thing just blew my mind.
Yeah, Huge for efficiency.
Yeah.
I mean, think of cold runners like, you know, old plumbing systems, pipes going everywhere, wasting mach material.
Okay, so hot runners are like the new efficient plumbing.
Exactly. Everything's streamlined and optimized.
So with cold runners, you get those chunks of solid plastic waste like the sprues you get with model kits.
Yeah. Gotta toss them. Hot runners keep the plastic melted and.
Reusable, which is, of course, less waste.
Way less.
The article actually put some numbers to. It said switching to hot runners can cut waste by up to 20%, sometimes even more.
It's crazy.
And that's not just good for the environment. We're talking serious cost savings for companies. And bonus, they can often speed up production too.
Oh, yeah. It's a win, win, win.
Okay, so I'm starting to see why companies are making the switch. Even though I imagine the upfront cost is a little bit more.
It can be. Yeah. But the long term benefits. Wow.
Really add up for sure.
And it's not just about, like the type of runner system. The article also gets into how the size and layout of those runners have to be just right.
Oh, so it's gotta be fine tuned.
Yeah. You need just the right amount of everything. Kind of like a chef perfecting a recipe.
Okay, so you're saying it's like finding that Goldilocks zone for the runners. Not too big, not too small.
Yeah, exactly. Too big, and you're wasting material too small, you risk not filling the mold right. And then you've got defects and that's more waste.
So it's about balancing material flow with part quality 100%. And then there's the cavity itself. A heart of the mold where the part takes shape.
Right.
The article mentions that the number of cavities has to match the machine's power. I mean, that makes sense, right?
Oh, absolutely. You don't want to overload the machine and end up with a bunch of messed up parts.
And the design of the part itself matters too, right?
Totally. Simpler designs often use less material. It's something to keep in mind right from the start.
So you're saying those super intricate parts might actually be material hogs?
Not always. But you gotta be mindful. Sometimes a simpler design can do the job just as well with less material.
So it's that balance between looks, function, and of course, not wasting resources.
Right. Gotta weigh it all.
Okay. So we've got our perfectly designed mold ready to pump out amazing parts. But the journey doesn't end there, does it?
Nope. The article goes deep into the actual molding process itself, and there's a lot of science involved.
Yeah. Making sure that process is as efficient as possible.
For sure. And that's where those process parameters come into play. Things like injection pressure, speed, temperature, all of that can make or break how efficient the whole operation is.
So it's not just a set it and forget it kind of thing.
Yeah.
You have to be constantly monitoring and adjusting these parameters pretty much.
Especially when you're dealing with different types of plastics.
Oh, right. Because each one's going to have its own. Its own quirks.
They do. Each plastic has its. Its own sweet spot when it comes to temperature.
Okay.
Too hot and some plastics will degrade. Kind of like burnt toast.
Yeah.
Too cold, they won't flow properly. It'd be like trying to spread cold butter on bread.
I can picture that. Yeah. A gloppy mess. So getting that temperature just right is crucial.
Absolutely crucial. And then you think about things like thin walled parts versus thick walled parts.
Right.
The thin ones, they need higher injection speed and pressure to make sure those cavities fill completely. But if you use those same settings for a thicker part, you might end up with problems.
So it's like a balancing act for each part. You need the experience, you need the knowledge of the materials.
For sure. For sure.
But what about technology? Can technology help us out here at all?
Oh, 100%. Technology is playing a huge role in modern injection molding. Imagine sensors embedded in the mold just constantly monitoring things like temperature, pressure, all that.
So they're like little spies sending back intel on how things are going inside the mold.
Exactly. And that Data is used to adjust the machine settings in real time. So if the temperature starts to climb too high. Boom. The system dials it back down, prevents defects, and ultimately saves material.
So it's like having a co pilot who's constantly monitoring the instruments and making sure everything's running smoothly.
Exactly. It's the power of automation at work. Takes a lot of the guesswork out of it, allowing for more precision and efficiency.
I love that. So we've talked about the mold, we've talked about the molding process itself, but obviously there's another crucial piece here, the material itself.
Of course, you gotta start with the right stuff.
Right. It all starts with those little plastic pellets. And I'm guessing there's more to it than just tossing them into the machine.
You bet there is. Choosing the right plastic for the job is essential. Sometimes a stronger plastic, a more durable one, means you can use less of it overall. It's about picking the material that's gonna perform best for that particular thing.
So not always about just the cheapest option. Right?
Right. Like using the right tool for the job. You wouldn't use a hammer to screw in a light bulb.
I get you. Quality over quantity.
There you go.
And there must be a ton of different factors to think about when choosing that plastic.
Oh, yeah. And one of the most important ones, believe it or not, is making sure those pellets are properly dried before they go into the machine.
Really? Moisture can cause that much trouble?
You wouldn't believe it. Think bubbles, voids, all sorts of defects that can just ruin the final product.
So even a little bit of moisture can sabotage the whole thing?
It can. And the article actually gives this really helpful table that lays out different drying techniques depending on what kind of plastic you're using. Some plastics are fine with, like, a simple oven drying method, while others, like some of those fancy engineering plastics, they need those special dehumidifying dryers or even vacuum drying.
So it's not a one size fits all approach. Drying is a whole science.
Oh, absolutely. And don't forget about the human element. Proper handling of the material is crucial, which is where employee training comes in.
Right. You don't want someone accidentally, like, contaminating the plastic or spilling a whole batch of pellets all over the floor.
Exactly. Even little mistakes can add up to a lot of wasted material. So investing in good training is key.
Okay, so we've covered choosing the right plastic, drying it properly, making sure people know how to handle it. Anything else we can do to squeeze out every ounce of efficiency from this process, I feel like we've covered everything from the tiniest little pellet to the giant molding machine.
We've covered a lot. But there's one big piece of the puzzle left. How the whole production process is managed.
Ah, okay, so now we're zooming out to the entire factory floor. Everything from when those plastic pellets arrive to when the finished product is rolling off the line.
Exactly. And a key element here is, you guessed it, well trained employees.
But this is training beyond just handling the material.
Right. We're talking training on the entire injection molding process. Start to finish, start to finish. The more they understand, the fewer mistakes they make, which means less waste. You got it.
It's a chain reaction of efficiency.
It really is.
Okay, what else falls under production management?
Quality management systems. Think of them as the watchdogs, constantly monitoring and catching defects early on.
So like quality control inspectors, but maybe with some high tech tools to help them out.
Yeah, they use all kinds of tools and techniques to make sure each part meets the specs. And this is important for material efficiency because if you catch a defect early, you avoid making a whole batch of bad parts.
Ah, so you're not using up all that material on something that's just going to be scrapped.
Exactly, yeah. Preventing waste at every stage.
Okay. Any other production management tricks up your sleeve?
Production scheduling. It's about optimizing the workflow to cut down on waste. You don't want to constantly switch between different molds and materials because that causes downtime. And downtime means a waste. Right. So you got to be smart about it. Group similar jobs together. It's like when you plan your errands so you're not driving all over town and wasting gas.
Makes sense.
Smart planning.
So it seems like every stage plays a part in reducing that material waste, from how the mold is designed to how the whole production line is running. It's all connected.
It's a whole system working together.
This is all super insightful. But now I'm curious to see how these ideas actually play out in the real world. Like, can you give me some examples of companies that are really putting these principles into action? I want to see how these concepts translate to real results.
I've got some great examples lined up, and that's exactly what we're going to be diving into in the next part of our deep dive. Get ready to be inspired by how companies are truly making a difference.
I'm ready.
Welcome back. Ready for some real world examples of companies putting these principles into action.
Oh, I am all Ears. Hit me with them.
Let's start with a company that makes reusable water bottles.
Okay.
They were using a traditional cold runner system, which meant a lot of wasted plastic. Those sprues we were talking about?
Yeah.
So they decided to make the switch, invest in a hot runner system.
I remember you compared cold runners to old plumbing.
Yeah.
So it makes sense to upgrade. But was it worth it?
Big time. They saw a huge drop in material waste, which of course saved them money. But it also helped them meet their sustainability goals. So it's a win win. Right.
Less plastic in landfills and a healthier bottom line.
Exactly.
Do you have any idea how much material they actually saved?
They reported a 15% reduction in material usage, which works out to thousands of pounds of plastic every year.
Wow.
And that's not all. Their cycle times decreased by 10%. So they could make more bottles in the same amount of time.
Talk about a boost in efficiency.
For sure. That upfront investment really paid off.
It did. Okay, what about another example? Different industry maybe?
Sure. How about the automotive industry? This company makes car parts and they were having trouble with one particular part. It had a very thin wall design.
Oh, I remember us talking about those thin walls being tricky.
They can be.
It's like trying to get cake batter into all those tiny little spaces in a Bundt pan. You know, you need the right pressure, the right speed to make sure it fills everything without making a mess.
Perfect analogy. This company was having a really high scrap rate because those parts weren't filling right, which meant they were wasting a ton of material. So they had to take a closer look at their process parameters.
I bet those sensors we talked about played a role here.
Don't know it. They used sensors to watch the injection pressure and speed in real time.
Okay.
And by looking at that data, they were able to zero in on the exact adjustments they needed to make.
So they use data to fine tune things.
Like a chef tweaking a recipe.
Exactly. So what happened? Did it work?
Oh, yeah. Their scrap rate plummeted. They were wasting way less material.
Great.
And the quality of their parts went way up. Plus they were actually able to use a slightly cheaper type of plastic because they had optimized everything so well.
Okay, so they saved material, improved quality and reduced costs.
Flip will win.
That's amazing. It shows how interconnected all of these things are for sure. Efficiency, quality, sustainability, it all works together.
It does. And it's not always about high tech solutions either. Sometimes you gotta go back to basics. Let's talk about a toy company.
Okay. Toys.
They were really passionate about being eco friendly and they realized material selection was key.
Oh, right. It's not just about how you mold the plastic. It's about choosing the right type to begin with.
100%. They started looking closely at the plastics they were using.
Makes sense.
Seeing if there were more sustainable options out there.
And we're there. I mean, finding sustainable plastics that are also safe and durable for toys can't be easy.
It wasn't easy, but they were determined.
Good for them.
And for some of their toys, they found they could actually switch to a bio based plastic made from renewable resources.
Oh, wow. Like plants.
Yeah. A little pricier than traditional plastics, but for them it was worth it to be more sustainable.
I can see how that would appeal to a lot of parents.
Absolutely.
But I imagine there were some challenges making that switch. Bio based plastics, they must behave differently.
They do. They had to adjust their molding parameters a bit, even tweak some of their mold designs. But they were committed and they figured it out.
That's awesome.
It was.
What about drying? I'm remembering our conversation about those pellets needing to be bone dry.
You have a great memory. That was one of their biggest learning curves, actually.
Really?
Yeah. They had some problems with inconsistent drying at first and that led to some defect.
Oh, moisture. That sneaky culprit.
Right. You gotta watch out for it. So they ended up investing in a special drying system made just for bio based plastics.
So there's a constant learning process in this field.
There is.
You gotta be adaptable, willing to invest in the right equipment.
It's true. But the big takeaway here is that this company was proactive. They found potential problems early on and took care of them. Yeah. They understood that even the small stuff like drying can have a big impact.
It all adds up.
It does.
These stories are really encouraging. It's amazing to see how companies are getting creative, figuring out ways to reduce waste and becoming more efficient. It's exciting, but I have to ask, is there a downside? I mean, it sounds like a win win, but are there any trade offs we should be aware of?
That's a great question. And it's something we're going to dig into. In the final part of our deep dive, we'll explore some of the challenges, the potential downsides, and what the future might hold for this whole idea of sustainable injection molding.
Sounds intriguing. I can't wait. Okay, so we're back and ready to tackle the big question.
Yeah.
Is there a downside to all this efficiency? It sounds like a Win, win. But I'm guessing there are always trade offs.
Yeah, you gotta be careful. It's rarely that simple. I mean, the push for efficiency and injection molding, it's definitely a good thing.
Right.
But there are a few potential downsides to keep in mind.
Okay, lay it on me. What kind of downsides?
Well, one of the biggest hurdles is usually that initial cost.
Why?
Yeah, upgrading to more efficient equipment like those hot runner systems or fancy drying systems, it can be expensive.
Makes sense. Those cutting edge systems probably don't come cheap.
They don't. And even setting up a really good quality management system, you know, training software, personnel, it adds up.
So for a smaller company, that cost could be a real barrier.
It can be. Yeah. And it's not just about the money. There's the complexity, too. More sophisticated equipment. You need specialized knowledge to run it, to maintain it. So maybe you have to train your staff or even hire new people.
So it's not enough to just buy the new machine. You need people who know what they're doing.
Exactly. And even the mold design itself, it can get more complicated when you're going for maximum efficiency. We talked about those runners, how they have to be just the right size and layout. Well, that can lead to some pretty complex mold designs, which are more expensive to make.
So it's like a chain reaction. One efficiency measure might lead to a cost somewhere else.
It can? Yeah.
You really have to weigh the pros and cons.
You do. And here's something that might surprise you. Sometimes increasing efficiency in one area can actually cause problems in other areas.
Oh, really? That's interesting. How so?
Well, let's say a company gets really good at scheduling production to minimize mold changes.
Okay.
Less downtime, less waste. Sounds good, right? Yeah. But what if the schedule becomes too rigid?
Oh, I see.
They might not be able to react quickly if there's a sudden change in demand.
So if a big order comes in, they're stuck.
Exactly. It's that balance between efficiency and being flexible, being able to adapt.
So there's no magic bullet.
Nope.
You have to find what works best for your situation.
That's the key. It's not just about chasing efficiency for the sake of it. It's about making smart choices, understanding the potential downsides, and finding solutions that make sense financially and environmentally.
And it's not just about companies doing their part either.
Oh, absolutely not.
Consumers have a role to play too.
Big time. We can support companies that are trying to be sustainable, choosing products made with recycled materials. You know, things like that.
Right. Supporting the companies that are making an effort.
Exactly. Our choices as consumers, they make a difference.
They do. Okay, so as we wrap up this deep dive, I'm curious, what do you think the future holds for all of this? What's next for material efficiency and sustainability in injection molding?
I think we're going to see even more automation, better data analytics. Imagine systems that can predict problems before they even happen.
Wow. So it's like having a crystal ball that can see into the future of.
The process pretty much. Less waste, better quality. And I think we'll see some really cool new materials being developed. Materials that are both high performing A and D sustainable, like bio based plastics from plants, or even recycled plastics that can be used to make high quality products.
It sounds like the future of injection molding is bright.
It is. And this is just the beginning. The ideas we talked about, they apply to way more than just injection molding. Any manufacturing process where materials are being used, really?
So it's a bigger shift in how we think about things.
Exactly. Focusing on efficiency and sustainability every step of the way. From the design phase all the way through production and beyond.
Always asking, how can we do better?
Yeah. How can we use less? How can we waste less? How can we make products that are both good and good for the planet?
That's a great takeaway. So as we've learned from our deep dives into injection molding, there's a lot to think about. There is, but by embracing new ideas and staying informed, we can all help create a more sustainable future.
Couldn't have said it better myself. It's been great exploring this with you.
Thanks for joining us on this deep dive into the world of injection molding. We learned a lot about the challenges and the opportunities out there.
And remember, keep learning, keep asking questions, and keep pushing for a more sustainable future.
That's a great note to end on. Thanks for listening, everyone, and we'll catch you on our next deep