TECHNICAL NOTES

Rev. 3 – 06.02.1

Aim and content of the document

The document contains technical notes which should be adhered to, in order to facilitate the processing of items.

Dimensions of items

Standard dimensions for pieces to be coated are limited to being able to be placed in a cylinder D 900mm x H 1350mm. In special cases, it may be possible to cover items with larger dimensions, which will be evaluated on a case-by-case basis also depending on what type of coating is required. Our Technical Office is available to determine the technical viability based on the above criteria.

Surface characteristics

  • Surfaces must be free of burnishing, vaporisation, Teflon and anodizing.
  • There must not be present any residue from anodizing, thermal treatment, worked materials (e.g. plastic, rubber, other metals etc.), glues, paints or adhesive tape.
  • The cutting edges must be free of any burns or burring.
  • Do not use marker pens to indicate the area to be coated: always attach technical drawings of the operational area. If no zones are highlighted, Lafer reserves the right to cover other areas.
  • It is advised that the surface should be protected with a light covering of oil (e.g. Chemetal Gardolube L8255 oil or equivalent) in order to avoid corrosion.
  • Photoengraved surfaces are suitable for coating.
  • Nitrided surfaces must me free of the “white layer”, to be removed by grinding.
  • The item to be covered should have holes or threads so that it can be fixed to the coating equipment.
  • Hardened pieces must have a tempering temperature greater than that of the coating.
  • Steel items must be sent already demagnetised.

Surface polishing

  • Surface roughness should be lower than Ra 0.2 micron (compatible with the characteristics of the mold/tool/component). If this is not possible to fulfil this requirement, a tailored Lafer Polishing process can be performed in Lafer.
  • Do not polish surfaces with rubber grinding wheels.
  • Diamond paste polishing must not cause absorption of particles into the piece, avoid using pastes with granulometry finer than 3 micron.

Brazing

Brazed alloys must be resistant to high vacuum pressure ((x10-6 mbar), not contain cadmium and zinc (or elements with low melting points in general), and must be able to withstand temperatures of at least 600C without degassing.

De-coating

STEEL:

it is possible to completely remove any PVD coating from any kind of tools, molds and components made of steel. This is strongly recommended before any re-coating for gearing hobs (TiN, Hyperlox and Tigral) and aluminium diecasting pins (Superlattice, Tigral)

HARD METAL (HM):

it is possible to completely remove TiAIN (titanium-aluminium) coatings from tools and hard metal surfaces. It is possible to remove titanium based PVD coatings (only titanium). It is not possible to carry out de-coating on brazed tools (e.g. cutting edge in hard metal and body/support on steel).

TITANIUM ALLOYS:

It is not possible to remove titanium based PVD coatings from titanium alloy surfaces. It is not possible to chemically remove chromium based PVD coatings (CrN, Newchrome, Superlattice) from the following substrates:

  • Any type of Hard Metal
  • Nickel alloys or surfaces with chemical / galvanic Nickel deposition
  • Chromium alloys or surfaces with galvanic chrome deposition (e.g. Stelliti).

Preparation of molds and assembled parts

All mounted parts of molds must be disassembled. If it is not possible to disassemble some parts, provide the assembly instructions of the parts. In this case, an additional phase of preparation, called “Degas”, will be required with a dedicated quotation.
Cooling and lubrication holes and channels must be opened and cleaned with solvents. Unscrew the cooling / lubrication channel plugs, or alternatively close these channels with copper seal plugs.
Attach the following information to the material to be covered:

  • design drawing or sketch, indicating the surface to be covered and the geometric tolerances
  • type of material and thermal treatment (temperture of hardening and tempering)
  • material of the molded contact or counterpart
  • molding conditions (e.g. dry, lubricated etc).

Extend the finishing process beyond the operational area to adjacent surfaces to guarantee uniformity of adhesion of the coating.
For molds for plastic molding, carry out this process before creating final profiles and relative final adjustments. After preparation, prevent oxidisation of the surfaces by applying a thin layer of oil (e.g. Chemetal Gardolube L8255 or equivalent). Do not use any type of grease.
In case of soldering to restore profiles, always use filler material the same as the base material.

Packaging and shipping

  • packages exceeding 30kg must be delivered on pallets
  • packages must have maximum dimensions equal to a Europallet (1200x800xH100mm) and a maximum weight of 500 kg in order to fit our motorised conveyor belt transporter.
  • prepare packages well in order to avoid damage in transit. The same packaging will be used for the return delivery. For repeat delivery, Lafer has plastic containers available for use.
  • do not use bubble wrap material in direct contact with the tool surfaces. Please use paper to separate.
  • goods travel at the customer’s own risk, even if carriage free shipped.