In 1973 the real best-seller of Serrature Meroni made its appearance in the market under the brand name PremiApri (literally PressOpen), an exclusive patent that won recognition in the Industrial Design sector.

Amongst the different models of PremiApri locks, today a new solution has created: "Combina". The Combina solution, in order to keep up with the times, is created by using special thermoplastic materials, representing an intelligent balance of tradition and technology.

LATI has worked together with the original idea of Serrature Meroni supplying its engineering thermoplastics suitable for the design requirements and the technical aspects of the project.

The chassis, the structural frame of the knob lock, is made of metal and is now also available in LATI’s thermoplastic version. The metal version is made of die-cast Zamak (an alloy of Zinc, Aluminium and Magnesium), one of the most proven and reliable materials used in architectural design and furniture industry. This material, stiff and solid, provides not only the requested mechanical properties, but also the best surface quality.

On the other hand, the thermoplastic version, meeting the same level of expectations, is made by injection moulding, using a new and innovative special formulation developed by LATI, LATIGLOSS, named after its outstanding aesthetics in spite of its high fibre glass content.

Also studied for the door hardware and furniture industry, this polymer is a compound of nylon 66 reinforced with 50% glass fibre, blended with special additives providing a superb surface gloss.

Indeed one of the typical limitations of glass reinforced thermoplastics is the finishing quality: the glass fibre normally appears on the external surface, causing uneven colour effect or, in the worst case, visible flow lines. To avoid this behaviour, the mould engineers have to set high cycle times or time-consuming pre-heat operations.

On the contrary Latigloss, without a significant increase in the moulding cycle time, provides high-end mechanical properties (similar to metal) and a top-class surface smoothness and brilliance, consequently reducing friction, noise and improving metallisation, if needed.

The door knob upper cap is also made of KELON, a thermoplastic resin produced by LATI. Kelon (an acronym of Keramic + Nylon) is a nylon 6 based polymer, reinforced with special fillers and heat stabilised.

The presence of this special blend of isotropic and anisotropic fillers and the thermal stabilisation, imparts to the material high values of resilience (the ability to maintain the rigid shape and the elastic response), in conjunction with a uniform high-gloss surface quality.

LATIGLOSS is also available in a special antimicrobial formulation with proven antibacterial properties that, without any further treatment, greatly reduces the bacterial growth and propagation. This special formulation has been tested according to the international standards ISO 22196:2007, "Plastics – Measurement of antibacterial activity on plastics surfaces" as well as EN ISO 846 "Plastics – Evaluation of the Action of Microorganisms".

All the most well known post-finishing operations are allowed with this nylon based material, giving the final customers a wide variety of colours and effect choice.

Simply put, the "Combina" door knobs match tradition and advanced technology bringing together a worldwide known metal alloy with a selected combination of "intelligent polymers".


The "Combina" door knob is currently proposed in a wide variety of colours and finishing along with all its typical functions, and is suitable for several demanding applications such as hospitals, nurseries, clinics, operating theatres, passageways, bathrooms, entrances and offices, classrooms and hotel rooms.