06-21-2013, 07:34 AM
Join Date: May 2010
Location: Ponte Vedra Beach, FL / London, UK
My Ride: Jaguar XKE
What exactly is 'Finished leather'?
Automotive OEM technology is becoming more and more complex requiring educated and skilled technicians to work on them. As the materials used are constantly changing we must maintain our knowledge base and utilize the correct products and application methodologies to keep up with emerging technologies.
Automobile manufacturers have blurred the distinguishing lines on what exactly leather is. There are many so-called 'leathers' that are actually the bottom split (the fibrous part of the hide) which are covered with a vinyl or urethane coating. Diagnosis is the key, not guess work. Before deciding on what products to use, you need to ascertain the grade of leather and the type of leather finish applied
The leather used for automotive upholstery is finished leather; the 'finish' applied to the leather hide is a urethane protective layer and an abrasion resistant topcoat.
Be cognizant that the leather and finishes used for automotive upholstery varies from leather industry standard descriptions and although the names are similar the type of leather, pigmentation and finish are often very different. Si it is very important to be able to recognise the various finishes and materials used by OEM's as they all require different methodologies and products for proper care and maintenance.
Automobile model ranges use different materials for their vehicles interiors; leather upholstery like Aniline Immersion Dyed, Aniline Micro Pigmented, (Urethane) Finished, Artificial leather such as MB-Tex and unfinished materials like Synthetics and Alcantara, and sometimes combinations of products (Alcantara seat inserts on leather seating) as well as various grades of leather hide, full-grain, top-grain and split -grain (which is protected with urethane) all of which require different products and applications methods.
Using any product not specifically designed for your leather type can cause staining and permanent damage to the leather.
During the finishing processes - the final stages of the tanning process, various finishes can be added to the surface to make it more serviceable or to hide defects and scars in the hide's surface.
a) Leather pigmentation or color is applied to the leather usually as a coloured urethane coating.
b) Leather dye is applied by soaking the hide in the desired colour so that it permeates the hide.
Finished leather consists of a soft acrylic pigment (colour) coating under a urethane clear coating (for durability). These resins create a film that protects the leather, providing both abrasion and stain resistance; these are often called pigment coated leather.
A simple test - place a drop of moisture on the surface of the leather - if it soaks into the leather you have unfinished leather (sometimes called aniline style)
If there is a very light color or clear coat on top of aniline-dyed leather, it is often referred to as "semi-aniline." Semi-aniline leather offers modest protection while retaining much of the aesthetic beauty of unfinished aniline-dyed leather but still remain absorbent to moisture. If the moisture sits on the surface and does not soak in and darken the material you have finished leather.
Section through finished leather - Diagram by Advanced Leather Solutions
Automotive leather and finished leather surfaces have undergone major technological improvements over the past decade. The leather used for automotive upholstery is finished leather; the 'finish' applied to the leather hide is a pigmented (colour) urethane protective layer and a clear abrasion resistant topcoat.
This type of leather has an aqueous (water- based) urethane pigmented (coloured) coating, think of it as a urethane paint applied on top of the leather, and then a clear top coat is applied, o you are not actually touching the leather. The coating gives the leather more durability and protection. It is also much easier to clean. Finished leathers make up almost all auto leathers. Just because leather has a top coat doesn't mean it is any less desirable.
It also has micro-pores that allow transpiration, i.e. evaporation and hydration (the passage of water vapour through a membrane or pore) they are not sealed per se
Pigmented leather won't absorb liquids because of the protective properties of the finish making for easier clean-up. Since the leather hide has a clear coat finish, when treating the leather, so you are in fact dealing with a urethane (to all intents and purposes, a ~150 µ (micron) thick plastic surface coating, about the same thickness as automobile clear coat paint; that simply needs to be kept clean and hydrated...it really is that simple.
TOGWT® Autopia Detailing Wiki Articles
1. "Leather Upholstery Type Surface Identification" - http://www.autopia.org/forum/autopia...fication.html#
2. "Leather Articles Hyperlinks" -http://www.autopia.org/forum/autopia...yperlinks.html
If you have any questions about automotive leather, its care or renovation techniques, please let me know
Last edited by TOGWT; 06-21-2013 at 05:18 PM.
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