I'm going to disagree with most of these comments. They don't protect the prong so much as they protect the cord or other objects in the cords vicinity (painted surfaces, fragile surfaces, etc). The little plastic cap that covers tire stems on cars and bikes , while keeping it clean when installed, are primary to prevent chaffing issue on the inner tube whike shipped and stored; same thing with this prong shroud. They have holes in them as to not retain moisture I imagine.
Long story short, the prongs are metal and have corners. They are the strongest, "sharpest" thing in the box. The plastic isn't protecting the prongs from us, it's protecting us from the prongs.
You commonly get plastic protectors like that with UK plugs which have squarish metal pins with hard corners - example - but I don't remember ever seeing any such things coming with EU plugs, of which there are two two types but both with all pins having round tips - example.
This is consistent with the explanation that those plastic covers are to protect everything else from the plug pins, hence why they come on plugs whose pins have tips with hard corners that more easilly perforate or shred things but not on those with tips which are rounded.
In the specific example of this post, two of the pins are have hard corners and although the other does not, the plastic protector covers all 3 probably because it's just a more stable fit (and it looks better) if it slots in all 3 than in only the more dangerous 2 even if it's not doing much for the round pin.
I believe it's to protect the prongs from getting damaged during shipping - and if the container gets rained on or something, it could provide some protection from that
I’m of the opinion that it’s just to improve the perception of package quality. I don’t see those cheap plastic pieces as keeping the prongs from accidentally warping or bending but I guess they could keep moisture away. I’ve never received a corroded set of prongs before their use though so my theory stands as they are upping the packaging visual aesthetics.
Could it be to protect the rest of the item from getting scratched by the prongs? Especially a screen, or some soft/glossy plastic case that would be prone to scratches.
I've been buying electrical and electronic things for years (okay decades), and the toys and computers I got as a kid never had these. The cords are always nicely coiled in their own cavity of the box too, so already protected well enough.
All in all it just seems like a solution to a non-existent problem.
It looks very easy to produce, what if it's for the illusion of higher quality? In which case the small increase in production cost is worth it for better sales (or allows them to sell the item at a higher price).
Same idea as the unnecessary packaging on fruits at the store
The plastic adds enough rigidity overall to help resist bending. The combination of the metal inside and the overall thickness of the added plastic is pretty good. It won't resist a Hulk smash or a tank rolling over it. But it should, hopefully, resist routine bending forces during packaging and shipping. Goof around with it the next time you receive one, and you'll see what I mean.
I think it's just to stop the prongs from scuffing other things in the same package compartment. Usually you'll get the cord in a bag or with the plastic but not both. With the cord is in a section of the packaging with other items it keeps them from getting scratched.
It's to protect the prongs during shipping or whatnot so they don't get bent, or to protect other things in the package from the prongs scratching them up. Might also protect them from corrosion.
It’s designed to make sure that the contact point with the back plate is reinforced.
That’s the point you don’t want to have fatigue or stress during shipping, etc since it breaking off there when it’s plugged into your wall would be a pain.
I suspect it’s mainly there for the shipment from the cord manufacturer to the company that made the product and there’s little benefit in removing it on their end when they can then ship it, cover and all, to their end consumer.
It's probably not for shipping of the final product at all. Cords for a product are going to be purchased in-bulk. There will be thousands of these cords with sharp and semi-fragile ends all packed together and then handled throughout the product build. This cap both protects the prongs from shipping/handling/assembly processes and protects equipment/handlers while products are being assembled. There's no good reason to remove the cap after assembly, so it stays on the final product to the consumer.