Here the 5 steps to produce Lurex® :
1. METALLISATION : The principle of vacuum metallization is to pass a plastic or cellulose film into a vacuum chamber. This film is placed on uncoiling cylinders inside the closed metallisation chamber in order to obtain vacuum conditions (99.9999% of the air is rejected). The film passes over a cooling cylinder while vaporised aluminium at a temperature of 1500 °C is condensed onto the film as it passes over the cooling cylinder. The aluminium layer deposited on the film corresponds to approximately 300-500 Angstroms (i.e., 1/250 of the thickness of an aluminium foil). To give you an idea of the performance, 1kg of aluminium would be enough to cover two football fields after metallisation! Once the metallisation process is completed, the vacuum conditions are evacuated, the chamber open and the metallised film recovered.
2. COATING : After metallisation, the film passes through an on-line coating process which will, depending on the needs, provide the colours and technical characteristics of the yarn (resistance to dyes, for example). It is at this stage that the different effects are given to the thread, such as a high gloss or a matt appearance. During this step, the film can also be laminated with another film for specific applications.
3. SLITTING AND WINDING ONTO SUPPORTS : This step involves slitting the Lurex® metallised film with a high precision cutting system. It can be slit up to 0.10 mm wide. At this stage, the yarn is labelled “slit” (flat aspect) or “unsupported”. It is then presented on reels or bicones.
4. ASSEMBLY : Unreinforced Lurex® is sold for certain applications, such as weaving or spinning. But it can also be reinforced with other fibres, such as polyamide, polyester, viscose or cotton. The thread is then called "supported" and is used most often for knitting, weaving, lace or embroidery.
5. QUALITY CONTROL : Throughout the production process, the thread is checked and tested to ensure maximum quality. The last check is done in Lurex® quality laboratories in England before shipment.