Here's how copper electrical cables are made from scrap cables

Watch some old lengths of copper cables get recycled into new ones.
Christopher McFadden

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Electrical cables are an essential component for many aspects of our modern lives. Whether they be used to transmit electrical power from the source to your home or help you make that long-distance phone call to your friends and family on another continent, electrical cables will be behind the scenes somewhere in the chain of communications.

But, while you never normally see them, and probably never give them a second thought, they are very important and interesting things. Let's take a look at the journey from raw materials to the final product of some of these vital parts of our telecommunications and power distribution networks, shall we? 

electric cables complete
Source: Interesting Engineering

Step 1: Getting some copper

Most large electrical cables, though not all, tend to use copper as the main conductive material. This can either be sourced as new, raw copper wire or, as in this case, recycled from old and spent cables. 

For the latter, this particular cable manufacturer takes in piles of old cables first. These are stored in a warehouse until ready for processing. 

electrical cables cutting
Source: Interesting Engineering

When the time comes, a series of powered claws are used to cut the old cables down to size to make processing them further easier. Much like cutting small electrical wires with pliers, these tools are used to also help trim off the rubber insulation that normally covers old cables. 

Once the rubber is removed, the raw copper calling inside is exposed and isolated. 

electrical cables copper
Source: Interesting Engineering

With the copper now in hand, the next step is to begin to make the new cables. 

Step 2: Processing the copper wiring

Bundles of loose copper wire are then fed into a special machine ready to process them into new lengths of copper wire. This machine chops up the old copper wiring into standardized shards of copper to make it easier to handle them later. 

This has to be done, as full lengths of the old copper wiring often vary in size and length so can't be reused as they are. However, some longer lengths can be used, but are usually crushed into blocks of coiled copper ready for melting. 

electrical cables copper bits
Source: Interesting Engineering

The shards of chopped-up copper are then exhausted from the machine onto a conveyor belt and deposited in large sacks ready for the next part of their journey.

Step 3: Melting the copper

The compressed blocks of copper wire and macerated copper are then fed into a large furnace in order to melt them down. 

electric cables melting
Source: Interesting Engineering

The furnace needs to get to temperatures in excess of 1000 degrees Celsius, or more than 1,832 degrees Fahrenheit, in order to force the solid copper to melt.

This stage also serves to burn off impurities that may have built upon the copper including bits of old insulation, if any. These will form an impurity on the surface that can be skimmed off to leave the pure copper underneath. 

That is incredibly hot, so workers need to use special long tools to manipulate the copper into the furnace and stir it around.

Step 4: Making the new cables

Once melted, the molten copper is then drawn from the furnace and formed into lengths of new copper wire. 

These new wires are then stretched along a series of spindles to allow them to cool and form the correct diameter needed for the final electrical cables. 

electrical cables new wires
Source: Interesting Engineering

These new lengths of copper wire are then wound into large rolls of copper wire ready for further processing into new lengths of electrical cabling.

With that complete, the wires are then fed into another series of machine to unwind the rolls of copper and pass them through a series of chemical treatments to prepare them further for being turned into new electrical cables. 

electrical cables cleaning
Source: Interesting Engineering

Once treated, the wires are then further fed by a series of spindles and drums until they are wrapped around large rolls of copper wire once again. 

With that done, the rubber insulating coating is prepared ready to coat the wires. This first requires the rubber to be heated and made more pliable.

This is done in a special machine that then extrudes the rubber in a similar fashion to playdough toys. 

electric cables rubber
Source: Interesting Engineering

The rubber strands are then cooled in a pool of water and strung out to form lengths of cooled rubber lengths. 

The rubber strands are then further heated and encased around the copper lengths to form new cables. The degree to which this occurs depends entirely on the final specifications for the new wire. 

With that done, the new electrical cables are wound, once again, into large rolls of wire ready for shipping. 

And that's a wrap, so to speak!

If you enjoyed watching this industrial process, you might enjoy watching another product being made in a factory? How about, for example, seeing how LPG tanks are made

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