Did you know that only 30% of plastics is being recycled within the EU? The rest either ends up in landfill or is incinerated with the Waste to Energy scheme. Even though power is derived from burning waste (including plastic), recycling plastic waste saves more energy than when it's burned as there are more virgin materials needed to produce new items.
Before you recycle your items, you need to make sure that your council has the capabilities to send them off to the recycling plants. You also need to make sure the items are (reasonably) clean, free of food and it's best to tear off all the labels. If a batch of recycled goods is too contaminated, the tip might decide to dump it in landfill or send it to be incinerated.
There are many different types of polymers and the current system divides them up is seven different categories of plastic - most of your packaging will have a number to indicate which type of plastic it is. You should check with your council to see which numbers you can recycle (and if they take lids, as some councils don't take that category of plastic).
Once your recycled waste arrives at the plant, all items will be sorted, and all plastics sorted into their polymer type. They are then shredded, washed, melted and pelletized. The pellets are sold to other companies who use these to mold new products from them.
Recycling plastic doesn't only save virgin fossil fuels from being extracted, the process will also save a huge amount of CO2 emissions entering our atmosphere. The British Plastic Federation has analyzed that recycling a tonne of plastic saves 1200kg of CO2 in comparison to producing it from virgin materials. This is the equivalent of transporting a tonne of plastic from London to Milan in a lorry.