Vibram Technical Information

VIBRAM COMPOUNDS

Not one compound is suitable for all physical activities. However, these key characteristics are common to most uses:
• Resistance to wear, which is defined as abrasion resistance.
• Lightness, which is defined as density.
• Softness, which is defined as hardness. Vibram compounds offer a wide range of hardness levels. All levels have excellent wear resistance.
• Elasticity, which is measured by the percentage of elongation at break. Some Vibram compounds can stretch as much as six times their original length.
• Tenacity, which is measured by stress at break.

Foam Compounds

Compact Compounds

GLUEING THEORY AND TECHNIQUES

Knowledge of adhesive techniques is FUNDAMENTAL for a Master Cobbler in order to provide the best service to your customers, ensuring that the best soles in the world can provide optimal performances in total safety. Vibram Sole Factor Mobile Lab technicians, in cooperation with technicians adhesive manufacturers, have prepared a list of required processes and guidelines, regardless the brand of the glue, which establish tried and tested working method.

Steps of processing:

• Recognition of the materials which compose the shoe and the sole.
• Preparation of the surfaces to be glued on the shoe.
• Preparation of the surfaces to be glued on the VIBRAM sole chosen for resoling/customising.
• Application of chemical primers to both the shoe and the sole.
• Application of glue to both surfaces.
• Reactivation of glues on the surfaces to be glued with a hot air gun or infra-red oven.
• Assembly of the sole and shoe with the use of a cushioned sole press.
• Allowing the adhesives the necessary time to create a permanent bond between the shoe and the sole.
• Trimming, finishing and cleaning of the shoe.

The work of the Cobbler begins with an analysis of the shoe to be re-soled and which kind of material is made of.

Here is a list of the most common used materials:

• EVA is typically used as a shock absorber in the insole for running shoes.
• PVC is generally used for the production of soles for acid-resistant work shoes which, over the time, has become a fashion icon.
• NYLON is generally used to create inserts of varying levels of elasticity, used above all in sportswear.
• POLYURETHANES are generally used for the production of insoles/heels of sports shoes or for the production of mid/low-range shoes. If exposed to particular weather conditions, the phenomenon of hydrolysis can occur, which causes the crumbling of the soles.
• Various THERMOPLASTIC materials such as polyethylene, polypropylene etc. are used for the production of inserts and parts of high-range sports shoes.
• RUBBER typically used for the production of soles and crepe sheets.
• PARA, a derivative of solidified rubber latex, it is used for the production of some soles.
• LEATHER

After identifying the types of materials that can be typically re-soled, let’s examine the main compounds which have recently been developed and that at Vibram, we love defining as TECHNOLOGIES.

MEGAGRIP
A compact rubber which guarantees maximum grip in OUTDOORS sports activities, above all in the wet conditions.

ARCTIC GRIP AGAT
A soft rubber which guarantees durability, associated with special inserts in loaded rubber which guarantee the best possible grip on wet ice.

XS CITY
A medium-soft rubber that, in addition to durability, guarantees maximum grip on urban surfaces, especially on wet and greasy ones. XS City also resists heat caused by contact with surfaces.

LITE BASE
A combination of a synthetic support and MEGAGRIP rubber allow for soles which are 30% lighter without renouncing in terms of duration or grip on wet surfaces.

Below you will find the methods used by Vibram Sole Factor Mobile Lab technicians on 4 recently-developed technologies.

Before moving forward, we would like to emphasize that:
• Primer refers to any substance used to prepare the surface to be glued.
• Activators or cross-linking agents are substances which increase the reaction speed of the glueing process, if added in a precise percentage, generally recommended by the manufacturer.
• Carding and/or scraping the surfaces to be glued, as well as removing any impurities, increases the surface on which the glue will act, thus improving the final result. This operation is always carried out with appropriate equipment, according to the type of surface to be treated.

Taking these assumptions in mind, here few simple instructions for obtaining the best results with 4 new VIBRAM technologies:

MEGAGRIP
• treat the surface of the sole with a primer for EVA/SBR-based expanded materials, adding 5% cross-linker for solvent adhesives after 25 minutes;
• apply a single-component polyurethane adhesive, again with the addition of 5% cross-linker for solvent adhesives. After 20 minutes reactivate the surface with heat (hot air gun or IR oven) and press

ARCTIC GRIP
• treat the surface of the sole with a primer for EVA/SBR-based expanded materials, adding 5% cross-linker for solvent adhesives after 25 minutes;
• apply a single-component polyurethane adhesive, again with the addition of 5% cross-linker for solvent adhesives. After 20 minutes, reactivate the surface with heat (hot air gun or IR oven) and press.

XS CITY
• Treat the surface of the sole with a halogenating agent for vulcanised rubber after 45 minutes;
• apply a single-component polyurethane adhesive, adding 5% polyisocyanate cross-linker for solvent adhesives. After 20 minutes reactivate the surface with heat (hot air gun or IR oven) and press.

LITE BASE
• For information regarding soles in Vibram LITE BASE, please consult the dedicated guide “HOW TO LITE BASE” which is available on request from

Please remember that:
When using a halogenating agent for vulcanised rubber and TR, a polyurethane glue must always be used. On the contrary, when a polychloroprene primer for EVA/SBR-based expanded materials is used, polychloroprene based adhesives can also be employed