A guide to Professional Cookware - page 10-11

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Thermodiffusion base and induction
The steel pots are endowed with a so-called
“thermodiffusing” base
, which makes up for the
scarce heat conduction characteristic of this metal.
The procedure consists of applying a thick aluminum
disk (6-7mm.) on the base of the pot, making it adhere
using braze welding.
It is possible to apply a second disk over this disk, but
this time a steel one, onto which a heavy pressure is
placed, at a high temperature, aiding adhesion; this is
where the name “sandwich bottom” comes from.The
ferrite composition of this supplementary disk makes
the pot suitable also for induction cooking.With a
different method, coining, it is also possible
to mount a ferrite steel disk on the external base of an
aluminum pot, making it also suitable for use on the
modern electromagnetic induction
heat sources.
Anti-stick coatings
Some vessels can be coated internally with
a film of plastic material (PTFE)
which confers an anti-
stick property; such that it allows less fat to be used in cooking and makes it easier to wash. Processing
involves an initial phase of preparation of the metal onto which the coating is to be applied:
cleaning
or removal of grease, sanding.
Subsequently there is the application phase, normally of more than one layer, until a thickness is
reached which allows it to perform to its maximum in terms of resistance against friction but also in
terms of duration over time.
Today two distinct methods of application are used, which give very different results in
terms of quality:
ROLLED:
Consists of applying the coating directly by
passing the disk through rollers
, before the
pot has taken on its definitive shape.This allows savings on the cost of processing, but lessens the quality
and the duration of the product.
In addition, during pressing it is possible that the coating can become weak at certain points and can
fall off.This type of working is used solely for products destined for domestic use. It can be easily
recognised by the horizontal streaks present on the surface.
SPEAYED:
Is applied by spraying the material,
using the relevant device, directly onto the
inside of the body which has already been pressed into its definitive shape
, thus preventing
any further work from compromising the sticking. Is the most efficient technique for obtaining
the maximum possible quality, and it is also fundamental in the production of articles destined for
professional use.The uniformity of the surface, which is almost granular, makes it distinguishable in
appearance.
The creation of coatings containing particles of hard minerals has also significantly increased the
resistance against the abrasive action of normal metallic utensils, therefore prolonging the duration of
the products by up to ten times compared to the traditional ones. In any case, if the coating should
wear out or become damaged with use, it must be substituted.
Tinning of copper
Copper is normally coated with an inert material: tin,
which is a good conductor of heat.
The best method
of tinning is still handcrafting, on the forge,
using virgin tin
. Processing requires that the surface
is first of all brushed, to facilitate the adhesion of the
tin to the heated copper.
The recipient is then placed on the forge until the tin
reaches its melting temperature, then “pig tin” is passed
over the internal surface, which melts like a piece of
butter. Finally the tin is evenly distributed over the
walls, removing the excess with a ball of cotton-wool.
The tinned vessel is then immersed in a bath of
boiling water to clean it and to allow the coating to
fix.Tinning can be done repeatedly over time and
therefore the pot lasts an eternity.
Tinning
Sprayed non-stick coating
A guide to professional cookware
THE PRODUCTION STAGES OF A POT
1,2-3,4-5,6-7,8-9 12-13,14-15,16-17,18-19,20-21,22-23,24-25,26-27,28-29,30-31,...92
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