Expertise

From a desire to amaze and seduce the customer with a new product, to its creation... Like real "glass houses", literally and figuratively, Arc International and Luminarc divulge all their manufacturing secret...

Creating the material

Making glass requires the addition of cullet (broken glass) to the three main raw materials that are sand, soda and lime.
Mixed in exact proportions, the mixture is then transferred to the furnace until the materials are fused and refined in order to obtain the fluid and homogeneous paste expert glassmakers will be able to work with.

Invention

The original model of an item comes out of the fertile imagination of the designers (in collaboration with the brand managers), always at the leading edge of current trends. In the Creative Studio of Arc International their initial sketches give birth to the realisation of a prototype model. This allows a better visualisation of the product as well as the possibility of correcting any mistakes before the project is sent off to the technical departments in charge of finalising the whole thing.
There, once it has been validated, the prototype is used for the development of the moulds, later used in the –mass–production of the object.

Manufacturing

The molten glass is then conveyed and maintained at the correct temperature by feeders to the various production lines.
It is then shaped with two methods:

• Pressed process

  A drop of previously calibrated incandescent glass is accurately directed towards the mould of a pressing machine. The object takes its shape. It is then cooled down before being extracted from the mould. Finally the item passes in front of burners in order to be polished by the flame: the result is perfectly smooth edges and a brilliant, shiny finish.

• Blown process

  A drop of molten glass is given its first rough shape with a press – this means that a mold gives it its initial shape. The blank is immediately blown into a finishing mold that gives it its final shape. At this point the object is still surmounted with a ‘neck’: that excess glass is removed when the glass is reheated then cut at the rim whilst it is still hot (for a thick rim) or once it has cooled down (fine rim).

Whether pressed or blown, the item must go through a final manufacturing phase called annealing: the object is reheated before being cooled down very slowly. This process contributes to the elimination of internal stresses within the glass. In order to increase its thermal and mechanical resistance, the item might be tempered, which means that it will be cooled down rapidly, in a controlled manner, with the help of ventilation.
All the Luminarc plates, for example, are manufactured this way in order to become two to three times more resistant than items of a similar thickness.

N. B. : Only stemmed glass require two further operation: the fusion of the bowl to the stem and the flattening of
the base of the foot