Prior to extrusion each aluminium extrusion die has to be prepared to be placed on the press line. VIAS Ltd. has a qualified Extrusion Dies Department where our specialists are preparing, correcting and cleaning every die before and after extrusion. We collaborate only with the best die producers on the market and we use high quality die correcting tools.
The extrusion dies are nitride with the latest generation fully automatic NITREX nitriding system. All process stages – purging, heating, nitriding and cooling are performed in one uninterrupted cycle. The nitriding furnace is equipped with multiple separate heating zones for accurate temperature control. The installation has its own personalized N-EXTTM control system.
The new press line includes:
• system with 5 zones for heating of the aluminium billets;
• system for conical heating of the billets with up to 50oC tolerance in both ends;
• induction heating system for the extrusion dies;
• 7 inch 18 MN front loading press line with automatic billet feeder;
We are using only high quality aluminium alloys from which the most frequently used is EN AW-6063.
Each batch of aluminium billets arrives with its own inspection certificate and declaration of conformity, as well as a laboratory analysis indicating the exact ration of the chemical composition.
The press line allows extrusion of profiles with dimensions from 8 mm to 220 mm for open profiles and from 10mm to 220 mm for closed type profiles. The weight can be from 0.05 kg/m up to 8.5 kg/m. The length of the profiles varies from 2100 mm to 8000 mm (the standard length is 6000 mm).
The production of aluminium profiles complies with the following standards:
• EN 573 – Aluminium and Aluminium Alloys — Chemical Composition and Form of Wrought Products;
• EN 755 – Aluminium and aluminiums alloys — Extruded rod/bar, tube and profiles;
• EN 12020 – Aluminium and aluminum alloys — Extruded precision profiles in alloys EN AW- 6060 and EN AW-6063;
• ISO 2768 – Mechanical parts, tolerances, other dimensions and deviations. (Applied to parts with metal removing treatment — cutting, milling, punching).
The 18MN, 7 inch front loading press is equipped with the patented energy saving system PE.E.S.S., which can have an energy savings of 25%, depending on the profile being produced. The PE Manager system automatically manages the furnace temperature, press parameters and puller force to simplify the operation of the stretcher, automatically adjusting the parameters according to each new profile. The users with the relevant access rights log in the software application at any time and from anywhere in the world via internet connection to track the production plan of the press line and see in real time which production order is currently in extrusion, what profiles has been produced before that and what is scheduled next for production. All this information is also automatically transferred in the accounting software of the company.
The production plant is also equipped with Presezzi-developed monitoring system to track the service life of the entire press line. This allows the service department to check on the current status of the plant, as well as make comparisons to the plant status from minutes, hours, months, or even as far back as years ago. The monitoring system makes it possible for the service department to advise in real time the operator or maintenance staff as to what parts needs to be checked and replaced.
Once the profiles are extruded and cut to 6m length they go through an ageing oven, where they are heated in order to accelerate the separation of the secondary phases until the desired hardness is reached (the standard is T6 WBS). The profiles are heated up to 195оС for a period of 4 hours after stabilization. During this kind of heat treatment the copper-saturated solid aluminium solution is decomposing, which results in alloy hardening.
The aging oven’s capacity is 16 baskets. The oven is equipped with automatic charging conveyor, a stacker and de-stacker. Usually the profiles are tempered to hardness T6 WBS, but it is possible to achieve other hardness rates if needed (T4, T5, T66). The capacity of the ageing oven is 60 tons per day on average.
During the extrusion cycle the profiles are a subject of strict quality control. Their dimensions are measured to check whether they are within the acceptable tolerances, their surface is checked for imperfections. Their hardness is also measured.