Development

When development is done by the customer, Techné engineers provide advice in order to optimise the profile depending on chosen manufacturing process. Parting lines, materials, tolerances are reviewed with the customer.

Thanks to its experience and process knowledge, Techné will position the parting lines in areas with little or no impact for the sealing. Techné production drawing is then submitted to customer approval.

Rubber parts are toleranced according to the chosen process, and the appropriate international standard. Warning: Elastomers are flexible and deformable; therefore standards and regulations defined for plastic and metal parts mau under no circumstances apply to them.

Centering: when creating the drawing, it is highly recommended to use centered tolerances. Due to the moulding process (we do not strat from a raw part), the mould production, and the material shrinkage, there will not be any material savings if tolerances are note centered.

For the production of the moulding tools Techné's technical department prefers to work with 3D CAD models with centered dimensions: *.stp files.

There are so many different elastomers types, crosslinking agents, hardness, compression set, etc. Each compound has it own characteristics.

Depending on the application, environment, and the required mechanical properties, Techné will select the appropriate compound for your application.

When the customer has a clear idea to what profile he needs, Techné will then provide its expertise.

• A complete revision of the required specifications (environment, dynamic/static, temperature, pressure, standards and certifications, etc.)
• Optimisation of the seal's profile.

• Study of customers' specification sheet
• Proposal of one or more sealing solutions
• Prototype and production quotation

The prototype aims to determine sealing, to save time on the design and to avoid any modification on serial production moulding tool.

Techné offers various prototype manufacturing processes.

To be machined, a prototype must meet the following criteria:

• High hardness 83 IRHD for rubber. 90 to 95 IRHD for thermoplastics
• Revolution parts (milling, drilling, tapping can be done)
• Minimum radius of 0.4mm.

In its cutting division (Chromex), Techné manufactures sealing parts by automatic cutting process. This process, which is well suitable for gaskets, allows most 2D profiles from thickness 1 to 15mm depending on the material.

Techné offers prototypes using a silicone mould obtained by stereolithography. The finished parts are made in PU resin or silicone material. These materials have a similar mechanical properties to elastomers. This process allows manufacturing of complex 3D and 2D profiles.

The prototype tool is made for compression process and has a reduced number of cavities. It offers the following advantages:

• Better representation of mass production parts
• Use of same compounds as the one for mass production
• Approval of cross linking parameters
• Economical, flexible and faster realisation

On request Techné can provide the following certificates together with the delivery of the parts (NF EN-10204):

• 2.1 Declaration of compliance with the order without mentioning inspection results
• 2.2 Declaration of compliance with the order mentionning inspection results on incoming batch
• 3.1 Declaration of compliance with the order mentionning inspection results on each delivery

The initial samples are the first parts coming out from the mass production tool. They are used for the approval/qualification of the tool and process. These initial samples can be delivered with PPAP.

Depending on the criticity of the parts, a PPAP requirement level (1, 2 or 3) is agreed together with the customer. Techné provides on request, a folder that can contain the following documents: