Effective wiper blades are a crucial part of your car and car maintenance yet they are often overlooked.
Windscreen wipers are repeatedly dragged across the glass countless times a year, in all weathers. If they’re not clearing bird droppings, wipers are usually busy all year; clearing bugs in the summer and snow in winter. A thin piece of rubber moving back and forth thousands of times a year, in often extreme temperatures, wipers degrade slowly and we often do not notice how ineffective they have become until they need replacing, yet despite the noise they can make when they’re worn, or the increased smearing, many motorists ignore this part of essential – and required – car maintenance.
Replacing worn wiper blades can be a revelation, instantly making your vision clearer and reducing that irritating judder.
Wiper blades are like squeegees. The arms of the wiper drag a thin (usually) rubber strip across the windscreen to clear away the water. When the blade is new, the rubber is clean and smooth thus gives the windscreen a judder and smear-free wipe on each sweep. A new or effective wiper blade squeegees the water away without leaving any streaks. As a wiper blade ages, and with extensive use, the rubber edge making contact with the windscreen loses its effectiveness as the once watertight ‘seal’ against the glass is compromised. This comes as a direct result of a few factors:
- the buildup of road grime;
- exposure to UV light and extreme temperatures;
- airborne dust particles and road grit;
- repeated sweeps over a pitted or chipped windscreen;
- low quality wiper blades;
- incorrect wiper blade type (in relation to curvature of windscreen).
There are two main types of wiper blade; the conventional (and most common) blade, and the ‘beam’ blade:
By comparison, the most noticeable difference is in the design of the blade itself. Modern windscreens are much more curved than their flatter predecessors. The evolution of windscreens and curved glass has dictated that wipers matched the older, flatter design. Beam blades are designed to match the curvature of modern-day windscreens leading to better contact and coverage between wiper blade and glass. Wiper coverage on a windscreen is based on various contact, or pressure points. The more pressure points, the greater the wiper pressure. Conventional or traditional wiper blades are designed with only six to eight contact points while beam blades feature an infinite number of pressure points. This ensures the entire length of the wiper blade will remain in contact with the glass providing evenly applied pressure.
Despite its many strengths, natural rubber is not the ideal material for windscreen wipers. Given wipers will spend most of their life stationary in ‘parked’ mode, natural rubber wiper blades tend to permanently ‘set’ to one side. However, to be effective, windscreen wipers need to flip as the wiping mechanism switches direction. A ‘set’ blade cannot flip, and the result is squeaking blades which do not clear as effectively.
Synthetic (Ethylene Propylene Diene Methylene, or EPDM) wipers don’t set’ they also perform better than natural rubbers in terms of thermal aging, and overall resistance to ultraviolet light. Natural rubber does, though, perform better than synthetic rubbers in colder conditions. As a result, manufacturers have advanced their processes by combining natural and EPDM rubber materials through a coextrusion process for superior performance in all weather conditions.
Whatever the choice of material, both natural and synthetic rubbers will still slowly deteriorate over time. An effective process to negate this issue is with the addition of coatings. Coatings reduce friction between the blade and the windscreen and they also preserve ‘sweep’ quality over the life of the blade as well as reduce noise.
Telltale signs your wiper blades need replacing:
- Streaking – occurs when the wiper blade is damaged, worn or coated with grime or debris.
- Skipping or Juddering – this happens when the wiper blade has been ‘set’ in one position preventing the blade from performing a ‘flip’ movement between sweeps. This is usually a symptom of under use.
- Squeaking – caused by incorrect assembly, usually remedied by tweaking the wiper arm angle.
- Smearing – the most obvious sign that your wiper blades are in desperate need of replacing.
The longer you use work or incorrect wiper blades to clear your windscreen, the more road film your glass will attract thus exasperating the issue of a greasy windscreen that just will not clear. Can you see a rainbow effect on your glass after the wiper has swept? That’ll be a sure sign of neglect.
A clear view of the road ahead is paramount not only for driver – and passive – safety, but also for something that can make driving a pleasurable experience.
Why wouldn’t you always have good wiper blades?