|
Material
|
Type
|
Examples
of usage
|
Smell/appearance/feel
|
Typical
density (g/cm3)
|
| Polyvinyl chloride
(PVC) and PVC blends |
Solid or cellular
(thermoplastic) |
As TR above,
also industrial footwear including Wellingtons. |
A glossy feel
and appearance. Cut surface are shiny unlike rubber. Familiar plastic
smell. All colours possible including clear translucents (usually
brown tint). Hardness is usually moderate. Moulded into soles with
or without tread pattern. Mould flow lines sometimes evident Occasionally
painted to resemble leather. Cellular PVC has an irregular cell
structure (large and small) visible with the naked eye, and is solid
close to the surface (1-2 mm). |
Solid:1.15-1.30
Cellular: 0.70-0.90 |
| Polyurethane
(PU) Reaction Moulded |
Cellular Solid
(on 2 density sole) |
Casual/everyday
and fashion footwear including women's wedge sandals. Industrial
and military footwear. Sports midsoles. |
An expanded
or cellular material although this is rarely visually evident as
the moulding process produced a thin solid skin over the underlaying
cell strucuture and moulded soles do not usually have cut edges.
Soles arelightweight and moulded with or without tread patterns.
Cleat edges and fine detail in tread pattern often have small surface
voids caused by air bubbles trapped in mould. Surface may feel greasy
due to residual mould release. Heavier than EVA. All colours possible.
Has own charcteristic smell. Casual footwear soles often spray of
dip painted. A cut edge viewed with a 10x magnifier will show the
cellular structure. |
Cellular: 0.40-0.60
Solid:(on 2 density sole) 0.90-1.15 |
| Thermoplastic
PU |
Solid (thermoplastic) |
Everyday shoes,
football soles, women's top-pieces. |
On everyday
footwear can be difficult to distinguish visually from PVC but the
charcteristic smell of PVCwill be absent and there is no other noticeable
smell. Moulding definition is usually very good and mouldings often
have a matt finish. Feels smooth and not rubbery. Top-piece grades
are relatively hard. |
1.21-1.26 |
| Ethylnc vinyl
acetate (EVA) Crosslinked and EVA blends |
Cellular |
Casual/everyday
and fashion footwear, sports midsoles, poolside shoes and flip-flops. |
Main feature
is extremely light weight despite usually being thicker than other
soles. Tread pattern is often shallow (eg mesh type) and moulded
soles often have cut edges exporsing the cellular structure. Usually
microcellular (visible with 10x mignifier) but occasionally the
cell size can be up to 1 mm. Tread pattern definitioin better than
PU (no small voids). Available in all colours. Very soft, can make
finger impression. Characteristic smell. |
0.20-0.40 |
| Microcellular
rubber |
Cellular |
Casual/everyday
and fashion footwear |
Similar in
appearance and typical thickness to EVA but heavier and with strong
rubbery smell and feel. Also harder than EVA. Similar weight to
cellular PU but very different in appearance and smell Uncommon
relative to EVA. |
at least 0.50 |
| Leather |
Solid (fibrous) |
Smart dressshoes,
welted footwear, specialised footwear. |
Unmistakable
smell. Nearly always labelled as 'Leather', often with the hide
mark. Sometimes combined with moulded polymeric inserts eg forepart
treads or heels. Colour rnages from buff through mid-tan to dark
brown and red shades. Usually a smooth lightly glossed surface and
the hair shaft openings are visible under magnification as tiny
pin pricks. Sometimes the grain is raised to give a very fine sueded
feel. |
0.95-1.05 |
| Valcanised
rubber (Crosslinked/ Composition) including resin rubber. |
Solid |
Sports, deckshoes,
industrial, military, hiking, welted soles, men's top-pieces, resin
rubber for court shoes. |
Familiar rubber
smell and feel. Good, even matt appearance with excellent definitin
of edges and fine detail. All colours possible including translucent.
Mouldable into patterns, can be soft to hard. Resin rubber form
is hard, thin sheet, usually black or buff in colour (resembling
leather). Its high hardness creates a sharp snappy sound when the
soles are tapped against each other. |
1.05-1.40 |
| Crepe rubber |
Solid |
Casual/everyday
and fashion footwear. |
Unique 'sweet'
smell, unlike vulcanised rubber. Soles are always laminated from
sheets with corrugated or plain, rough feeling surface (never any
thread pattern). A soft material, usually off-white, honey or brown
colours, sometimes black. Feels very rubbery (grippy). Clean, fresh
crepe will readily stick to itself. Cut edges show a layered effect
at about 1 mm intervals throughout. |
0.88 |
| Thermoplastic
rubber TR or TPR |
Solid
(thermoplastic) |
Casual
everyday and fashion footear including children's shoes, slipper
soles. |
Very
rubbery feel often quite soft with dull or matt finish, like vulcanised
rubber. Smell is not commonly encountered elsewhere and distinctive
from vulcanised rubber and is sometimes masked with a vanilla fragrance.
All colours possible. Moulded into sole with or without tread pattern.
Lighter in weight than vulcanised rubber or PVC. Mould flow lines
sometimes evident, also sometimes 'swirl' or 'fish-scale pearl'
effect. |
0.90-1.06 |
