Weather also plays a critical role in your windshield wiper blades' deterioration. Freezing temperatures make the rubber in your wiper blades hard and brittle, which increases their tendency to crack or tear. Hot weather warps the rubber and prevents the blade from wiping your windshield cleanly. Heavy use is hard on the wipers because dust, abrasives, road grime and bug juice wear away the cutting edge the blade needs to wipe cleanly. Even road dirt acts like an abrasive to wear away the flat surface necessary for a good squeegee effect.
Rubber also deteriorates over time.
As blades age, they lose their flexibility and are less able to wipe cleanly. They may develop a permanent set or curvature which prevents full contact with your windshield. Bosch Micro Edge and Micro Edge Excel wiper blades feature added contact points to increase blade contact pressure at all driving speeds. This pinned joint design also provides superior flexibility to maintain proper blade contact with the windshield. Bosch Micro Edge and Micro Edge Excel wiper blades are manufactured using a unique synthetic compound that provides superior blade flip-over flexibility in hot and cold weather extremes.