Plastic is used to make doors and is most commonly called a upvc door these types of doors usually use cylinders.
How to change lock on upvc front door.
How to change a upvc door lock.
Only remove the key from the lock once the retaining screw is secured back into place.
Do you need to change a upvc door lock.
Test the lock by turning the key both right and left a few times and gently tug on the key when it is turned to both.
Door locks and mechanisms can be purchased from upvc spares 4 repairs.
A video tutorial on how to replace a full length door lock on a upvc or composite door.