GRAVITON COMBI

GRAVITON COMBI is a fully insulated combined static oven tower designed for drying natural-stone slabs before resin application and curing them after resin treatment. The machine combines two independent thermal processes within one compact vertical structure. One chamber is dedicated to slab drying, while the second chamber provides the controlled conditions required for epoxy or polyester resin polymerisation. The number of drying and curing levels is configured according to the customer's required production capacity, process times and resin-line architecture. A typical arrangement may include 15 drying levels and 30 curing levels, while alternatives such as 10+20 or other customer-specific combinations can be developed. By combining drying and curing capacity in a single oven tower, GRAVITON COMBI reduces the installation footprint while providing the controlled residence time required at each stage of the slab treatment process. The drying and curing sections are physically separated and operate as independent thermal chambers. The drying chamber removes residual moisture from the slab before resin application, helping prepare the stone surface and internal fissures for effective resin penetration. The curing chamber maintains the controlled temperature required after resin application, allowing polymerisation to progress before the slab moves to the next processing stage. Each chamber is equipped with its own heating and air-circulation system. This enables the drying and curing temperatures to be regulated independently according to the stone, resin formulation and production recipe. GRAVITON COMBI does not have one fixed drying-to-curing capacity ratio. The number of levels in each chamber is selected according to required slabs per hour, slab-drying time, resin-curing time, selected resin formulation, stone characteristics, slab dimensions and weight, upstream and downstream machine capacity, available factory space and height.

GRAVITON COMBI can be supplied with either electric-resistance heating or a natural-gas-fired heating system. Heat is distributed through recirculating hot-air systems engineered to maintain stable conditions across the different tray levels. Internal diffusers direct the heated air towards the slabs, while steel airflow guides retain it within the treatment area. The controlled circulation system supports consistent heat transfer along the slab surface and between the different levels of each chamber. Combined with the fully insulated construction, this limits unnecessary thermal loss and enables efficient use of the installed heating capacity.

The external structure is fully insulated using high-density panels and additional thermal insulation materials. The temperature inside each chamber is continuously monitored by electronic sensors. Humidity conditions within the drying section are also monitored, and moisture-laden air is extracted from the chamber when required. GRAVITON COMBI is controlled through an industrial automation system incorporating an industrial PC, variable-frequency drives, sensors and automatic process controls. The control architecture can be integrated into the wider resin-line automation system and connected production environment.

A vertical elevator positioned outside the oven tower aligns with the selected drying or curing level. A motorised shuttle travels between the elevator and the oven chamber, inserting the slab tray into the selected position or retrieving it when the programmed treatment period has been completed. The shuttle is mounted on a monorail located at the centre of the elevator. Pneumatically operated chamber hatches open during tray transfer and close immediately afterwards to limit heat loss. The elevator platform is raised and lowered by two synchronised chain systems positioned on opposite sides of the supporting structure. Both sides are driven through a coordinated geared-motor system to maintain balanced lifting and accurate alignment with each tray level.

The HeadStart function schedules oven preheating before the production shift begins. The drying and curing chambers can therefore reach their required operating temperatures before the first slabs enter the line, avoiding start-up delays and enabling production to begin under stable process conditions.