The lint filter is used to collect the lint that comes out of the clothes when they are drying. In order for the dryer to work properly, the user needs to clean the filter after each load. If you let the lint accumulate in the filter, the airflow will be restricted and the dryer will not dry properly. It will take too long to dry a load of clothes.
So , if your dryer is taking too long to dry the clothes make sure that the first thing you do is to clean the lint collecting filter.
Below are the links to the parts needed for this repair.