Recycling does indeed cause some more pollution.
When you recycle things it takes fuel to transport the recycles, to sort the recycles using machines, then transport the recyclables to a recycling plant.
Then it causes pollution to melt those recyclables such as plastic, tin, iron etc into new materials.
So you do pollute the earth when you recycle materials.
But it does save the earths natural resources such as the iron ore, aluminum ore, copper ore, oil to make plastics etc.
There's also though a plant derived plastic.
Some brands of disposable diapers are made from plant based plastics which are much better for the environment because those plant based plastics are renewable.
Diapers will always have some plastic to them because it needs a plastic backing behind the cloth backing so that it holds in the wetness.
If you take a disposable diaper and remove the outer cover you'll notice a plastic diaper underneath it.