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Questions tagged [molding]

30 questions
6
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1 answer

How are non-continuous internal threads plastic injection molded?

I'm trying to figure out how the heck some of these plastic bottle caps are injection molded. By having the thread on the inside of a cap, this obviously creates an undercut. Now I've watched some videos on Youtube on the process, and I can see…
Davbog
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1 answer

Purpose and name of fine pitch marks on a cast metal part

I have seen this kind of mark on various cast metal parts. This is an image of the base casting of a hard disk drive made by HGST. What are these marks for? What are they called?
Alec Martin
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3
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0 answers

Glass bottle with a prolonged neck that continues into the inner space

Is it possible to create following two shapes from glass using currently known glass mass production techniques? Shape #1: bottle with a prolonged neck that continues into the inner space, like this (cross section): | | | | /| |\ /…
user1876484
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3
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2 answers

Molding thermoplastic over sensitive components

I have an electronic assembly that is heat sensitive. Due to the incorporation of a CR3032 coin cell battery, it can survive being heated to a maximum of 60 degrees C. I want to coat this assembly in a biocompatible, waterproof plastic. This layer…
stanged
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2
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5 answers

Low cost molds. Can such molds be produced?

I recently found the following link https://anglingai.com/224b-4-4-blood-line-swim-bait-mold/. There you will see that they sale hundreds of different aluminum molds related to fishing. These molds are really inexpensive (from 50 up to 200 USD). How…
Efthymios Kalyviotis
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1
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1 answer

Why does the cylinder/barrel on an injection moulding machine have such thick walls?

When you look at the cylinder on injection moulders, for instance on DIY ones on YouTube, they are all thick walled. The piston has say a 20mm diameter and the cylinder has like a 40mm diameter in which plastic is heated to 250C. Could you get away…
Lewis Kelsey
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Pressure bag moulding Vs Vacuum bag moulding

What are there pro and cons of each method? In which industries were/are these molding techniques used? Why has vacuum bag molding supplanted pressure bag molding?
Cubedspartan
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How can we tell if a press mold need more stages?

I was asked to design a simple press mold for a 0.5mm sheet metal part. It has some small but rather deep sinks (5-7mm) which has made me wondering if it can be done in a single stage or it needs more stages. I guess there should be a table to help…
2012User
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Can I use polymer clay to make a mold and then melt HDPE plastic in it in the oven?

Can I use polymer clay to make a mold and then melt HDPE plastic in it in the oven? My goal is to be able to dig a fairly uncomplicated shape in a polymer clay block and then fill that mold with small HDPE plastic filaments. I'm hoping that the…
JingleBells
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Can wooden mold be used for blow molding?

I should have produced a custom designed bottle, but metal molds are some expensive and because we don't require too many products (we just need 100-200 piece), I need a way to reduce the cost. So I thought that, maybe I can use wooden mold for…
Alper
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1
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Rc Car BodyShell created

Growing up I would have these RC Car, they had the cover which eiher a cover of a truck or any brand of cars, I could take this cover off and then change the batteries of the rc car or just check the components. These covers came with the car, had…
E199504
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Designing an injection molding mold for a part with a certain parting line and ejector pin location

How do you design a mold to create that part? The only way I can think of is to make the parting line horizontal to the part instead of vertical. But is there any way to design the mold so that the parting line is vertical like in the picture?
SVS
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3 answers

(moulded) cast properties of the untreated surface

While my research about the untreated surface of moulded cast I read that the properties such as tensile strength, 0,2% proof stress and so on are different (much smaller) from the properties you can find in the tables. That’s because the samples…
tueftla
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Push button design for small gadget

I'm looking at designing a small gadget (think something like a Fitbit in size) where the case has a couple of buttons on it. For various reasons the buttons have to be around the narrow side (edge) of the case. I am fairly lost as to what the…
Alex I
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Is it possible to replicate a motorcycle engine cylinder head?

Is it possible to create a mold of an aluminium motorcycle cylinder head so that you can create an exact replica with melted aluminium?
A C Marston
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