Moulding Process: The Four Stages Of Injection Molding

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Process number 1 :- Injection Moulding.

Injection moulding is a cheap, efficient and environmentally friendly way of precisely replicating a mould or plastic components.

Here’s the 4 stages of injection moulding...

Stage 1
Thermoplastics in a granulated or powdered form are fed into a hopper which leads into the machine.
This hopper is blowed with warm air which eliminates any moisture in the mould, if moisture were to get into the mould, the product produced by the mould would most likely have faults.

Stage 2
The injection moulding machine is made of a steel barrel, this barrel containing a large rotating screw, technically known as an archimidial screw, carries the plastic pellets or powder along the barrel to the mould.
While being
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This forces the molten plastic through a sprue into a moulding cavity. A good example of the leftovers of a sprue would be the bottom of a plastic bottle, where a small filed down dot will be visible.
The mould is temporarily warmed by heaters while the plastic is injected into the mould, this is to prevent the plastic from prematurely hardening inside the mould, disallowing the mould to be completely filled, creating a defective
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Hand Soldering

Hand Soldering is the oldest and “easiest” type of soldering there is, it’s a rather simple process, but an extremely time consuming one.

Different components are placed into 1mm thick holes on an unpopulated PCB, the components are loosely placed into these hole and the PCB is then turned over.
Solder is then applied to the legs with a soldering iron and a ribbon of solder.
The solder then cools and solidifies, setting the component into place and keeping it steady and fixed.

This process has to be repeated for every component of the PCB and takes a huge amount of time. Hand soldering is usually done for small or one off jobs, but for cheaper products with smaller circuits, (like the screwdriver we’ve been investigating) the PCBs used for controlling the screwdriver are hand soldered by labourers in mostly third world countries.
Children and the poor are usually employed in sweatshops and are usually paid minimal amounts of money (usually a couple of dollars per day) meaning manufacturing prices are incredibly low, this helps with making the screwdriver be sold for less, but this way of production is considered incredibly

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