All right, let's kick off another deep dive.
Sounds good.
Today we're going to be tackling something pretty cool.
Okay.
We're looking at injection molding, but we're going even deeper.
Okay.
We're focusing on a specific mechanism called core pulling.
Right.
And I think this is going to be a fun one because, you know, we all use products every single day that are made using this process, but we probably don't ever think about how it's done.
No.
And, you know, when you start to think about how these intricate features are created, it's pretty mind blowing.
It is.
So we've got some technical excerpts here from some articles and textbooks.
Okay.
And we're going to try to break it down and see if we can explain it in a way that makes sense to everybody.
I think it'll be fun to see how they make these crazy shapes and cavities, you know, in these everyday objects.
Absolutely. Like, you know, you look at something like a bottle cap and you think, oh, that's a simple little thing.
Right.
But, you know, those threads on the inside, those had to be formed somehow. And how do you get that hollow space in there?
Right.
So that's what core pulling is all about.
Exactly. It's allowing manufacturers to create those really complex features.
Right.
You know, whether it's the inside of a bottle cap or, you know, like you said, those little buttons on your electronics, all those little details.
Yeah. So let's start with the basics. Then what? Exactly. This process.
So core pulling, it's basically a technique that's used in injection bolding to make these, like, internal and lateral shapes in a plastic part. Okay, so let's go back to that bottle cap example.
Yeah.
You need those threads inside the cap so it can screw onto the bottle. And to create that space, a core is inserted into the mold.
Okay.
So you have the mold cavity.
Right.
And then you have this core that's shaped to create that empty space for the threads. And then after the plastic is injected and it cools and hardens, that core needs to be pulled out.
Yeah.
And that's where the core pulling comes in.
Right.
And that's what lets you eject the finished cap without damaging those threads.
I see. So you're protecting those delicate threads by pulling out that core.
Exactly.
That makes sense.
Yeah.
So are there different ways to pull out these cores?
You're right. There are.
I imagine it's not all, you know, big factories with robots doing all the work.
Yeah, you're right.
Yeah.
There are different types of core pulling mechanisms, each with Their own pros and cons.
Yeah.
Okay, so let's start with most basic.
Okay.
Which is manual core pulling.
All right.
This is kind of like the old school way where the core is actually pulled out by hand.
Oh, wow.
Yeah. So it's very simple. It's cost effective.
All right.
But it's also very labor intensive.
Right.
And not very efficient.
Yeah. Especially if you're doing large scale production.
Exactly. It's slow.
Okay. So that would be better for smaller batches.
Yeah, definitely for smaller batches.
Or maybe like, prototypes.
Prototypes. Where you're just trying to test things out, Right?
Yeah.
Almost like, I don't know, like the difference between handcrafting pottery versus like, mass production with the mold.
Yeah, that's a great analogy.
Yeah.
So once you need to start producing those parts quickly and at a larger scale, you probably want to switch to something more automated.
Okay.
Like a motorized core pulling system.
Okay. So that's where you're bringing in motors and things to help speed up the process.
Yep. A motor to automate it, make it more efficient and consistent.
Okay.
And one of the most common methods there is the inclined guide pin mechanism.
Okay. Inclined guide pins.
Yep.
So what does that even.
So you can imagine this if you're.
Making something like a toy with little side buckles.
Okay. Like little snaps or something.
Exactly. So those buckles are formed using side cores.
Okay.
And the inclined guide pin mechanism uses inclined guide pins.
Right.
That are attached to the core.
Okay.
And then as the mold opens, those pins, they slide along an angle track.
Okay.
And that pulls the core out laterally.
Oh. So it's like a. It's like a tiny little dance happening inside the mold.
It's like a perfectly choreographed little ballet.
Wow. That's amazing to picture.
It is pretty cool when you think about it.
So you got these little pins moving and sliding and pulling things out.
Yeah. All working together.
Wow. Okay.
Yeah.
So what about when you need even more force?
Okay.
Like, say, for a car bumper, something really big and complex.
So for complex designs like that, you need even more power and precision.
Right.
That's when you start using hydraulic and pneumatic systems.
Oh, okay. So these are like the big heavy hitters.
The heavy hitters.
Yeah.
They use hydraulic fluid or compressed air to generate a lot of force.
Okay.
And so they can pull these larger cores or cores that need a greater degree of force to extract them.
So for something like a car bumper.
Exactly.
That would be necessary.
Yeah. You need that extra power.
Wow. Okay, so. But I imagine that comes at a higher cost too.
You're right. It's a trade off.
Yeah.
It's kind of like comparing a basic car to a high performance race car.
Right. So you get all the bells and whistles.
Exactly. You get all the power. But it comes at a price.
Yeah. And more. I imagine it's more complex to maintain.
Absolutely. It requires more expertise.
Okay. All right. So we're starting to see there's a lot of variety in these approaches to core pulling.
A whole spectrum.
Is there anything else we need to consider when designing these mechanisms?
So designing these mechanisms is really a delicate balance. You have to think about how far the core needs to travel.
Okay.
The force required to pull it out.
Right.
And then you have to design the whole system.
Okay.
The sliders, the guide groups, everything to handle those forces smoothly and accurately.
It sounds very precise.
It is.
Yeah.
It's like you're designing these tiny little machines that are working together.
Yeah. It's fascinating how, you know, these seemingly simple objects require this level of engineering.
It is, yeah.
Okay, so what about the materials?
Oh, yeah, materials are huge.
Do they play a big role in this?
Absolutely.
Okay.
Different plastics have different properties.
Okay.
Some are more rigid.
Right.
Some are more flexible.
Yeah.
Some shrink more than others as they cool.
Okay. So that's a factor too.
Yeah. All those things need to be considered when you're designing the core pulling mechanism.
So, like, if you're, for example, if.
You'Re working with a really rigid material.
Right.
Like polycarbonate, that's going to require a lot more force to pull that core than, say, a flexible material like polyethylene.
Okay.
So the material really dictates.
Yeah.
How you approach this.
So it's not just the mechanism itself, it's the material you're working with.
The material, the design, everything has to work together.
Wow. Okay, so is there like an ideal material?
I wouldn't say there's one ideal material.
Okay.
It really depends on the application and the desired properties of that final product.
So it could be rigid, it could be flexible.
Exactly.
It could be anything.
Yeah. It all depends on what you need.
So this is where material science comes into play.
That's a whole other field that plays a huge role in manufacturing.
Right. And it sounds like it's closely tied to this process as well.
Yeah. You can't separate them.
So what we're seeing here is that there's no one size fits all approach.
Not at all.
To core pulling. You really have to think about the material, the design, the type of mechanism.
Exactly. It all has to be tailored and.
Put it all together.
Yeah. To create the final product.
Okay. And it's not just about.
And don't forget.
Yeah.
It's not just about making those intricate details. It's also about protecting them.
Okay.
During that whole molding process.
Right. Because if you try to eject the part without pulling the core out, if.
You didn't pull that core out first.
Yeah.
You could break those delicate features.
Oh, wow.
Yeah.
So it's kind of a double whammy.
It is.
It creates the feature and it protects it.
Exactly.
Okay, cool.
Yeah.
Now, you mentioned before about calculating.
Right.
The core pulling distance and force. Can you elaborate on that a little bit?
Of course. So it's really important.
Okay.
To get those calculations just right. If you don't pull the core far enough.
Right.
You risk damaging the part.
Okay.
And if you pull it too far.
Yeah.
You could create other problems.
Okay. Like what kind of problems?
Like, you could have flash, where the plastic kind of squishes out.
Right.
Or you could have misaligned features.
Oh, okay.
So it really needs to be precise.
Right.
Not too much, not too little.
Yes.
But just. Right.
Goldilocks.
Exactly.
Yeah.
And I imagine the materials play into that as well.
Oh, absolutely.
Okay.
Some plastics are more rigid.
Right.
So they need more force to pull that core.
Okay.
While others are more flexible. So you might need a gentler approach.
Okay.
And then there's the shrinkage to consider.
Oh, right.
Most plastics shrink as they cool.
Right. Right.
So you have to account for that shrinkage.
Okay. When you're calculating that distance.
So you need to kind of predict.
Exactly. You need to know how much that plastic is going to shrink and how that's going to affect that whole process.
That sounds like a real challenge.
It can be.
Yeah.
That's why experience is so valuable in this field.
Right.
You need to know how different materials behave under heat and pressure, how they're going to shrink, how they're going to interact with other materials.
So you're like a chemist and an engineer. A little bit of everything all rolled into one.
It's a multidisciplinary field. For sure.
That's pretty cool.
Yeah, it's fun.
All right, so let's talk a little bit more about those motorized systems.
Okay.
You know, you mentioned those before.
Yeah. Those are much more common in larger scale production.
Right. Because they're Exactly.
Much more efficient.
Yeah. Okay, so tell me more about how those work.
All right. So within the world of motorized systems, there are a few different methods.
Okay.
One that we touched on earlier is the inclined guide pin mechanism.
Yeah.
So let's Explore that one a little further.
All right, I'm ready to hear more about that one.
All right, so remember, those inclined guide pins.
Okay.
Are attached to the core.
Right.
And they slide along an angled track.
Oh, yeah.
As the mold opens.
Right.
And this angled movement pulls the core out laterally.
Right.
Which is what lets manufacturers create those side holes or buckles that we talked about earlier.
So it's like a tiny little train on a track.
I like that.
But instead of going forward, it's going sideways.
Yeah, exactly.
Okay.
So this mechanism is really popular. Okay.
Why is that?
Because it's pretty simple and reliable.
Oh, okay.
Those inclined guide pins provide really consistent pulling force and distance.
So you know exactly what you're going to get.
Exactly.
Time.
Yeah.
Okay.
Which is really important for making sure that the core is removed cleanly.
Yeah. If you're doing mass production and you want it to be the same every.
Time, you want consistency.
Yeah.
You don't want to be damaging the part every other time.
Yeah. Okay. So it sounds ideal for that kind of. It is high volume production.
Perfect for high volume.
Are there any other benefits to it?
Yeah, absolutely.
Okay.
The incline guide pin mechanism is also relatively easy to maintain.
Oh, okay. So that's a plus.
Yeah.
So you don't have to.
You're not constantly shutting down the production line to replace parts.
That makes sense.
Yeah.
Okay, so incline guide pins are good for that.
Yep. Definitely a good option.
What about. Are there other motorized systems?
Yeah, there's another type of motorized core pulling called the bent pin mechanism.
Okay. Bent pin.
Yeah.
How's that one different?
So instead of using incline guide pins.
Okay.
The bent pin mechanism uses bent pins.
Okay.
That are attached to the core.
So the pins are actually bent.
They are. They're bent.
Oh, wow. Okay.
Yeah. And as the mold opens.
Right.
Those bent pins are pulled straight.
Oh, okay. So they straighten out.
They straighten out as they're pulled. Yeah. And that pulls the core out laterally.
So they're bent when they're at rest.
Exactly.
And then they straighten, and that pulls the core.
That's how it works.
Wow, that's. That's interesting.
It's a clever little mechanism.
Yeah. It sounds counterintuitive.
It does, but it works. It does. It's very effective.
Okay. And what are the advantages of that one?
One of the big advantages is that it can generate a lot of pulling force.
Oh, wow. So it.
So if you have a core that's really stuck or difficult to extract.
Okay.
This is a good option.
Okay. So it's like the real muscle the muscle.
Yeah, exactly.
Okay. Are there any other benefits to that?
Yeah. Another advantage is that it can accommodate longer pulling distances.
Oh, okay. So like, if you have a part with a really deep side hole or.
Something, if you have a really deep internal feature or a long core, this is a good option.
All right, so we've talked about manual incline guide pins, bent pins.
Right.
Is there another category?
There is one more category that we should talk about, which is hydraulic and pneumatic systems.
Okay. So this is like the next level up.
These are the big ones.
Yeah.
The heavy hitters.
Like when you really need to get serious.
Exactly.
Yeah.
These are for those complex molds.
Okay.
With really large cores.
Right.
Or parts that require a lot of force for extraction.
So we were talking about like a car bumper.
Exactly. Like a car bumper. All those curves and details.
You need some serious power.
You need serious power.
Yeah.
And that's where these systems really shine.
Okay.
They use either hydraulic fluid or compressed air to generate that power. Wow.
Okay. And they can pull.
Yeah, they can pull those really large cores or cores that require a lot of force.
And are they.
And they're also really good for precise movements.
Okay. So you can really.
You can control the speed and the force very precisely.
That makes sense.
Yeah. So for those really intricate parts where you need a lot of accuracy, these are the way to go.
So it's like comparing. It is, I don't know, like a hand operated car jack to a big hydraulic lift.
Exactly. At a mechanic shop, you get so much more power.
Yeah.
But it also comes with a higher cost.
Right. And it's probably more.
More complexity.
Yeah, yeah.
You need to know.
You need to know how to use it.
How to use it properly.
Yeah.
How to maintain it.
Yeah. So probably not something you do.
Not a DIY project.
Yeah.
But for large manufacturers.
Right.
Who are producing complex parts in high volumes, these are essential.
Okay. All right. So it sounds like there's a whole range of options when it comes to core pulling.
A whole spectrum.
You've got everything from simple manual methods to these high powered hydraulic systems.
Exactly.
And choosing the right one depends on.
Yeah, it all depends on the part, the volume you're producing and, of course, the budget.
Right. Budget's always a factor.
Always a factor.
Okay, so it sounds like.
So it really emphasizes how important it is to get those design considerations. Right.
Right.
And we talked about the core pulling distance and the force and the design of those sliders and guide grooves. All of those details. They're really important.
Yeah. Because even the smallest.
Yeah, even the smallest Detail.
Yeah.
Can have a big impact on whether that core pulling process is successful.
Right.
For example, the angle of those guide grooves has to be just right.
Right.
To make sure the core slides out smoothly.
Okay.
And it doesn't bind or stick.
So it's like all these little tiny components working together. It's like a. Yeah.
Like a.
Almost like a watch.
Like a watch.
You know, all the little.
Yeah. With all the little gears.
Yeah. All the little gears have to be.
Yeah.
In the right place.
We all have to be perfect.
Yeah. For it to work.
Exactly.
Okay. And I imagine you also have to use.
And you also have to use the right materials.
Right. For those different components.
For all those components.
Because they're going to be under a lot of.
Exactly. They're going to be under a lot of heat.
Right. Heat and pressure.
Pressure. Friction.
Yep. Yep.
So the material really matters.
Right. Wow. Okay. So materials are a factor. They are key in, like, every aspect of this, it seems.
They are.
It's really interesting.
It is.
So understanding material science is absolutely. Is really important.
Yeah. You need to know.
Yeah.
How those plastics behave.
Right.
Under those conditions.
Yep.
Heat, pressure, peakage, shrinkage.
Yeah.
How they interact with other materials.
Yeah.
It's a lot to consider.
Wow. So it really is like being a chemist and an engineer.
It's a multidisciplinary field for sure.
And a little bit of an artist, maybe.
Yeah. A little bit of artistry in there.
Too, to put it all together.
Yeah.
It's pretty cool.
It is.
Think about how much complexity it is.
Fascinating.
It's hidden behind all these.
Behind all these everyday objects.
Yeah. The things that we just use without even thinking about it.
We take it for granted.
Yeah.
Yeah.
Okay. All right. Well, we've talked about how they're made.
Yeah.
But I'm curious, what kind of products actually use this process?
Oh, so many.
Yeah.
Think about, like, the housings for your electronics.
Okay.
Your phone.
Right.
Your laptop.
My laptop case.
Yeah. Your TV remote. They all have those intricate internal features. The side holes all created using core pulling.
Yeah. And all those little buttons.
The buttons wouldn't be possible without it.
That's true.
Yeah.
What about more complex applications?
Oh, yeah. You've got automotive parts.
Okay.
Think about the dashboard of your car.
Right.
The air vents, the door handles.
Yeah.
Even some engine components.
Wow. I didn't realize that.
Yeah. A lot of those are made using injection molding and core pulling.
So it's everywhere.
It really is.
What about the medical field?
Oh, the medical field uses it extensively. Syringes.
Right.
4V connectors. Medical implants.
Wow.
Yeah. They all often require those intricate internal features and precise dimensions that are achieved with core pulling.
So it really is amazing how this one technology can be used.
Yeah.
It's pretty amazing in so many different ways.
Yeah. Very versatile. From, you know, from everyday objects.
Yeah.
To life saving medical devices.
It's incredible.
It's pretty amazing.
Okay, so.
Yeah.
What does the future hold?
That's a good question. So like any technology, there's always room for improvement.
Right.
So one area of research is focused on developing new materials.
Okay.
That are even more durable.
Right. Even better material.
Even better materials.
Yeah.
More resistant to wear and tear.
Okay. So that would.
So that would mean longer life for those sliders and guide pins.
Right. And less downtime.
Less downtime, less maintenance costs.
That makes sense.
Yeah. It's all about efficiency.
What else are they looking at?
Another area of innovation is in developing more sophisticated control systems.
Oh, okay.
For those hydraulic and pneumatic core pulling mechanisms.
So they're getting even more.
Exactly. More precise, more control over the process.
That's really cool.
It is pretty cool.
All right, so as we're wrapping up here.
Yeah.
What are some key takeaways?
So I hope our listeners have gained a new appreciation.
Right.
For the complexity expert speaker. For all the thought and engineering that goes into these everyday plastic objects.
It really is. It's like we've been given a glimpse into the secret world of makers and creators.
A whole world behind the scenes.
Yeah, exactly.
Yeah.
Okay. So I hope they also learned that core pulling, it's more than just, you.
Know, it's not just yanking something out. It's more than just pulling a core out of a mold.
Yeah. It's a whole process.
A whole process.
You got to think about the materials.
Absolutely.
The design.
The design, the mechanism, the specific mechanism, the forces involved.
Yeah.
It's a lot to consider.
And it sounds like the best method really depends on the project at hand.
There's no one size fits all.
Yeah.
Each project has its own unique challenges.
So there's no magic bullet.
Nope.
You can't just say, oh, this is the way to do it.
You gotta analyze it every time. You gotta figure out what's best for that particular situation.
So the next time our listeners, you know, encounter a plastic object, whether it's something simple like a bottle cap or something complex.
Right.
Like a car bumper.
A car part.
Yeah. I hope they'll maybe pause for a.
Second, take a moment and think about all that.
All the engineering.
Yeah. All the engineering that went into it.
Into making it.
Yeah. It' it's really amazing when you stop and think about it.
It's pretty cool.
Yeah. Okay.
Yeah.
And I'm also hoping that maybe this deep dive will inspire, I hope so. Some of our listeners to maybe explore the world of manufacturing, get into the.
Field, get hands on and engineering. Yeah. It's a fascinating field.
It is. There's so much to learn.
And it's so important.
It's so important.
You know, it's shaping the world around us.
Shapes everything around us.
Yeah, exactly. So thanks for joining us. Thanks for having me on this journey into the heart.
Yeah. This was fun.
How things are made.
I enjoyed it.
Yeah. And we'll be back soon.
All right.
With another deep dive.
Looking forward to it.
To a fascinating topic.
Sounds good.
Until then, keep exploring.
Yes.
Keep questioning, stay curious, and keep that curiosity burning bright.
Absolutely.
Yeah.
Yeah. It's pretty amazing.
It is.
It is.
Okay, so what does the future hold?
That's a good question for core polling. So, like any technology, there's always room for improvement.
Right.
So one area of research is focused on developing new materials.
Okay.
That are even more durable.
Right. Even better materials.
Even better materials.
Yeah.
More resistant to wear and tear.
Oh, okay.
So that would mean longer life for those sliders and guide pins.
Right. And less downtime.
Less downtime, Less maintenance costs.
That makes sense.
Yeah. It's all about efficiency.
What else are they looking at?
Another area of innovation is in developing more sophisticated control systems for those hydraulic and pneumatic or pulling mechanisms.
So they're getting even more.
Exactly.
Precise.
More precise. More control over the process.
Yeah. That's really cool.
It is pretty cool.
All right, so as we're wrapping up here.
Yeah.
What are some key takeaways?
So I hope our listeners have gained a new appreciation for the complexity, for all the thought and engineering that goes into these everyday plastic objects.
It really is. It's like we've been given a glimpse into this secret world of makers and creators.
A whole world behind the scenes.
Yeah, exactly. Okay. So I hope they also learned that core pulling, it's more than just, you.
Know, it's not just yanking something out. It's more than just pulling a core out of a mold.
Yeah. It's a whole process.
It's a whole process.
You gotta think about the materials.
Absolutely. Design.
The design mechanism. The mechanism.
The specific mechanism.
Yeah. The forces involved.
Yeah.
It's a lot to consider.
And it sounds like the best method really depends on the project at hand.
There's no one size fits all.
Yeah.
Each project has its own unique challenges.
So there's no magic bullet. You can't just say, oh, this is the way to do it. You gotta analyze it every time.
You gotta figure out what's best for that particular situation.
So the next time our listeners, you know.
Yeah.
Encounter a plastic object, whether it's something simple like a bottle cap or something complex.
Right.
Like a car bumper, a car part. Yeah.
Yeah.
I hope they'll maybe pause for a.
Second, take a moment and appreciate.
Think about all that. Yeah.
All the engineering.
Yeah. All the engineering that went into it.
That went into making it.
Yeah. It's really amazing.
It is.
When you stop and think about it, it's pretty cool. Yeah.
Yeah.
And I'm also hoping that maybe this deep dive will inspire some of our listeners to maybe explore the world of manufacturing field.
Get hands on engineering.
Yeah. It's a fascinating field.
It is. There's so much to learn and it's so important.
It's so important.
You know, it's shaping the world around us.
It shapes everything around us.
Yeah, exactly. So thanks for joining us. Thanks for having me on this journey into the heart.
Yeah. This was fun.
Of how things are made.
I enjoyed it.
Yeah. And we'll be back soon.
All right.
With another deep dive.
Looking forward to it.
Into a fascinating topic.
Sounds good.
Until then, keep exploring.
Yes.
Keep questioning, stay curious and keep that curiosity burning bright.