|
To facilitate the communication with our
customers we would like to inform a bit about galvanic plating.
|
In the process of electroplating, the
product to be coated is placed in a bath (containing a salt of the coating metal) and is
connected to the negative terminal of the external source of electricity. Another
conductor, often composed of the coating metal is connected to the positive terminal of
the electric source. (anodes connected + on a rectifier).
A normal galvanic treatment consists of
multiple steps that differs from one metal to another. To ensure a strong and close bond
between the object to be plated and the plating material, the object must be cleaned
thoroughly and be without temperings.
A normal procedure consists of following
steps:
|
|
|
- Alkaline degreasing at high temperatures
- Rinsing
- Acid pickling, which removes temperings
- Rinsing
- Electrolytical degreasing in a strong
alkaline solution, which removes the last impurities
- Rinsing
- Acid dip, which prevents transfer of
degreaser to the plating baths
- Rinsing
- Galvanic coating
- Rinsing (In lots of cases the object needs
more coats, for instance nickel-plating and gold-plating)
- Drying
- Control
- Packing and sending.
To treat the object we have to place it on
fitted racks or if it is a small object which is sturdy, we can treat it in a barrel or a vibratory unit.
Essentiel information.
To ensure the right treatment to your
products it is essential that we get following information from you:
What is the product made of ? (*1)
How thick a coat is wanted ?..
Which margins are to be accepted ? (*2)
On which part of the product should these margins be fulfilled ?.
Where can the eventual marks of the racks be placed?.
Is the edges and corners of the product fragile so that we can treat the metal in a
barrel?
A drawing of the product is often a big advantage.
If you have an exact calculation of the surface of the product it is very usable for us.
Re-treatment
Unfortunately mistakes sometimes happend so that the result is not satisfactory.
In lots of these cases we can remove the coating and restart the proces.
Quotation request.
In order to give you the best service and make an estimate for you it is
essentiel that we receive a drawing with the information stated above, and total no. of
pieces per order and eventually An estimate of monthly or yearly consumption. If
possible we would like to receive a number of samples. This is due to the fact that with a
challenging product it can be necessary to perform tests, before we can make an exact
quotation.
If the products are very tempered or dirty at receival and this is not mentioned in your
order we reserve the right to refuse treatment of the product at the quoted price. We will
in that case inform you immediately and we will of course do our best to find a reasonable
way to treat the product.
*(1) It is
important that you inform us of any changes to the parent metal. Lots of the alloys
resemble eachother, but it is not certain that we can perform the same treatment, if the
metal has been changed. Another very important fact is whether the metal has been hardened
before we receive it. It is often quite difficult to remove the layer that appears on the
product when it has been hardened.
*(2) As galvano
technics has it's natural limits we can't always fulfill the wishes of our
customers. But as long as we know in advance what your demands are, we can normally state
whether it is possible and inform you before the treatment if we find the margins too
narrow. A typical example is small machine screws with a delicate thread. The galvano
process will put more coating at the end than at the middle of the screw and it is
therefore important to be careful and especially with nickel, which is often used for
coating.
|
