Every plant is different, however, Aircrete production technology is always the same – simple and reliable. Our production process does not use cake tilting, therefore Aircrete plant can expect no sticking and no separation of products. Our trademark production technology allows for flexible product portfolio and efficient plant operation.
1. AAC Raw Materials Mixing and Mould Casting
Sand (or fly-ash) is grinded with water in a ball mill to produce sand slurry. Other dry materials (lime, cement, gypsum & additives) are transported to the silos located in the mixing tower. Aluminum powder is dosed using an Aircrete ALU-Safe System for maximum safety and dosing precision. An accurate and reliable Aircrete dosing and mixing system uses an intelligent software control system to measure with high precision. Once weighed and dosed, the Aircrete Mixer (low speed mixer) ensures perfectly homogeneous distribution of raw materials in the mix. Once casted into the freshly cleaned and oiled mould, the mix is additionally vibrated to eliminate air pockets and ensure the quality of end products.
2. Reinforcement - option
If Aircrete plant is designed to produce load-bearing wall-floor-roof panels and lintels, a reinforcement station is installed. Before introducing the steel reinforcement in the mix, an assembled steel mesh (for partition panels) or ready cage (for reinforced panels and elements) is dipped into anti-corrosion treatment. After a mix is poured into a mould the reinforcement is immediately inserted into a mould. Precise AAC formula design and control over the cake rising process are especially important in panel production.
Aircrete flat-cake production technology is largely recognized as the best for reinforced elements production. The greatest advantage of AAC panel production in the flat-cake Aircrete system is that it reduces handling, cake cracks and other damages (mainly sticking) the element can suffer during the production process. Aircrete factories comply to the latest EN regulations for reinforced AAC production.
3. Aircrete Flat Cake Cutting Technology
Cutting Line represents the heart of an Aircrete plant, defining its product portfolio and ensuring high-quality of the AAC products. Aircrete’s innovative cutting process involves a horizontally positioned cake.
Once the cake rises and is ready for cutting, the mould automatically opens from all four sides and the grabbing crane picks up the entire green cake. Just after pick up, the optional profiling can be made in the bottom of the cake. 100% of the rest material is mixed with water and used in the next cycle. The cake lifting with the grabbing crane is the only step in our process where the cake is mechanically handled; that limits the risk of its damaging and eliminates tilting related problems. The cross cut is made with oscillating and pneumatically spanned steel wires resulting in a precise cut. A recent innovation is the inclined cross cut frame. After the cross-cut, the ‘pusher’ advances and gently rolls the cake on its frame bars (or strip bed) towards the High Speed Cutting Frame (HSCF). The Aircrete Cutting System uses two wires (the first cutting wire is followed by a smoothening towing wire) which oscillate at high speed. Thanks to this unique technology the final AAC products have a SUPER SMOOTH surface. At the same time an oscillating horizontal wire cuts the cake to required height. Since the products are cut in a flat/horizontal position, the openings between the products are created eliminating sticking problems known from the tilt-cake systems. No separating or tilting machines are used in Aircrete plants.
The top of the cake can be also profiled with special knives- it can be applied to either blocks for ‘tongue and groove’ profiling, or panels – the panel profile depends on the panel’s application, i.e. wall or floor or roof. The outermost vertical wires remove the green cake’s side waste, leaving a smooth surface.
Once cut, the cake is then rolled under the vacuum crane, where the top, front and end side crust are removed and 100% recycled back into the production process.
4. Curing (Autoclaving)
The cake leaves the cutting line already on an autoclaving frame, without mechanical handling of the cake (no tilting). The curing frames with cakes are stacked vertically (2 or 3 high) and transported directly to the autoclaves (32 m long).
The complete curing cycle time is between 10 and 14 hours (depending on product type, density, reinforcement used). In Aircrete Autoclave Control System, steam is transfered between autoclaves to minimize energy consumption and costs.
After curing process is completed, the double/triple stack is removed from the autoclaves and the white cakes are de-stacked by a de-stacker.
5. Unloading and Packaging
In the unloading area a semi-automatic crane takes the complete white cake and one-by-one transfers it from the frame onto the pallet table. Elements are then automatically placed on the pallets and transported by a conveyor system to the quality inspection and sorting place. After this station the pallets are ready for final packaging e.g. stretch hood, shrink hood of foil, and eventually strapping.
In a similar manner, reinforced wall, floor, roof panels and lintels can be packed and strapped automatically or manually. Aircrete plants can have different packing line designs depending on the sales market.