From the March 2015 issue of Car and Driver Leather is available on nearly every car for sale today. But this is no mere cowhide we’re talking about. Unlike leather luggage or jackets, automotive leather has to be durable enough to resist stains and fading and survive your butt sliding across it thousands of times.
Leather, as noted above, comes from cows. But for some brands, such as Bentley, bulls are preferred for their slightly thicker and more durable hides. For premium leathers, far-northern climates are favored because they tend to have fewer biting pests, which leaves the hides with fewer scars. Free from major blemishes, these leathers retain their natural finishes throughout the tanning process. The graining you see is just how the cow made it.
Less-costly hides usually have more imperfections, including scars from barbed-wire fencing, but embossing the leather with a grain pattern can hide these flaws, give the leather a consistent appearance, and make it easier to pass durability requirements. By embossing the cheaper cuts, more of a hide can be used, thus reducing costs. In contrast, a Bentley Mulsanne’s interior takes 14 hides, though only about half the material is consumed.
Tanning is what takes the leather from bovine wrapping to car-seat covering. Chrome tanning (so-called because of the chromium sulfate used in the process) is by far the most popular technique, favored for its lower cost and greater durability. The process starts with a lime bath that removes the hair and water and breaks down the collagen proteins, thus making the leather more pliable. A dip in water rehydrates the leather before it is immersed in a chromium-sulfate acidic-salt bath. After a few hours of soaking, the leather softens, becomes stretchable, gains a consistent finish and color, and becomes water-repellent. A blue-hued hide, called “wet blue,” emerges from the process ready to be dyed and finished.
- First Drive Review: 2015 Bentley Mulsanne Speed
- We Visit Recaro’s Michigan Factory, Witness the Camaro Z/28’s Seats Being Assembled
- 8 Reasons Why a Bentley Mulsanne Costs $300,000
In general, the premium leathers you find in many luxury cars get additional tanning to further enhance their feel. Chrome tanning fosters some of the scent associated with leather interiors, but the retanning process, which often involves natural tannins made from tree bark, can enrich the bouquet. The vegetable tanning process, common in furniture and luggage, is what Bentley uses for its leather headliners and instrument panels; it’s a lengthier ordeal that results in more-flexible leather that isn’t quite as durable as chrome-tanned leather.
Why all the fuss? Because while vinyl and cloth can look great, leather’s scent can’t be synthesized. No, for that whiff of authenticity, you need to hit the stockyard.
from Car and Driver Blog http://ift.tt/1FoY8nl
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