The steady, silent accumulation of fabric particles that get beyond your lint screen will not only decrease your dryer's performance, it creates a fire hazard. Cleaning your lint trap after every load will slow this process, but cannot prevent it. As your vent gradually becomes caked with lint, your dryer's airflow decreases. This not only prevents your dryer from drying as it should, it can cause it to overheat and ignite the highly flammable lint.
(Template) Service Roundtable has invested in the proper tools to clean your dryer vent quickly and without the mess.
If you haven't cleaned or checked your vent in the last four years, you should do it now.