What Is The Production Line Process For Making Large Terrazzo Slabs?

The production line process for large terrazzo slabs usually includes main steps such as raw material preparation, batching and mixing, molding and pressing, curing and solidification, grinding and polishing, as well as quality inspection and packaging for storage. The following is a detailed introduction:

Raw material preparation

Cement: As the binding material for terrazzo slabs, cement with high strength grade and stable performance is usually selected, such as 42.5 grade or above Portland cement and ordinary Portland cement, to ensure the strength and durability of the slabs.

Aggregates: including coarse aggregates (such as gravel and pebbles) and fine aggregates (such as river sand). The particle size of coarse aggregate is generally controlled between 5-20mm, and the fineness modulus of fine aggregate should be within the range of 2.3-3.0. The aggregate should be hard, clean, and free of impurities.

Pigments: Used to give various colors to terrazzo boards, inorganic or organic pigments with good light resistance, weather resistance, and chemical stability should be selected to ensure that the colors are not easily faded during use.

Water: Use clean tap water or qualified drinking water, and avoid using water containing harmful substances or excessive impurities to avoid affecting the quality of the board.

Mixing of ingredients

Weighing ingredients: Based on pre designed mix proportions, precise electronic weighing equipment is used to accurately weigh raw materials such as cement, aggregates, pigments, and water. Ensure that the proportions of various raw materials meet the requirements to ensure the performance and color consistency of the board.

Mixing: Place the weighed raw materials into a forced mixer for thorough mixing. The mixing time should be determined based on the characteristics of the raw materials and the performance of the mixer, generally not less than 3-5 minutes, to evenly mix various raw materials and form a uniform mixture.

Forming and pressing

Fabric: Spread the mixed material evenly in the molding mold. The fabric process can be done manually or mechanically to ensure that the mixture is evenly distributed within the mold, without any voids or shortages.

Compression molding: Use a hydraulic press or vibrating press to press and shape the mixture inside the mold. The pressing pressure should be adjusted according to the specifications and requirements of the board, generally controlled between 10-30MPa. During the pressing process, it is necessary to ensure uniform and stable pressure to achieve the specified density and strength of the board.

Curing and curing

Demoulding: After being pressed and formed, the sheet is cured in the mold for a period of time until it has a certain strength, and then the demolding operation is carried out. Caution should be taken during demolding to avoid damaging the edges and surfaces of the board.

Natural or steam curing:

Natural maintenance: Place the demolded board in a well ventilated and dry area for natural maintenance. During the maintenance period, the surface of the board should be kept moist and regularly watered for maintenance. The maintenance time is generally not less than 7 days.

Steam curing: Place the board in a steam curing kiln to accelerate the hydration reaction of cement and improve the early strength of the board by controlling temperature and humidity. The temperature for steam curing is generally controlled at 60-80 ℃, and the curing time is 4-6 hours.

Grinding and polishing

Rough grinding: Use a rough grinding machine to preliminarily grind the surface of the cured board, remove the protrusions, burrs, and uneven parts of the board surface, and make the board surface basically flat. Coarse grinding generally uses grinding heads with coarser particle sizes, such as 60-120 mesh diamond grinding heads.

Medium grinding: On the basis of rough grinding, use a medium grinding machine to further grind the surface of the board, improving the flatness and smoothness of the board surface. The particle size of the grinding head used during intermediate grinding is generally 180-240 mesh.

Fine grinding: Fine grinding is a key process to achieve high smoothness on the surface of the board. A fine grinding machine is used in conjunction with a finer grained grinding head (such as 320-600 mesh) to finely grind the surface of the board, eliminating the fine grinding marks left after intermediate grinding and making the surface of the board smoother.

Polishing: Polishing is the final grinding process in the production of terrazzo slabs, using a polishing machine and polishing paste to polish the surface of the slab, giving it a mirror like luster. The surface smoothness of the polished board should meet the specified standards.

Quality inspection and packaging storage

Quality inspection: Conduct a comprehensive quality inspection of the terrazzo board after grinding and polishing, including appearance quality, dimensional deviation, flatness, glossiness, strength and other indicators. The appearance quality requires that the surface of the board be free of defects such as cracks, missing edges and corners, color differences, etc; Dimensional deviation should comply with relevant standard requirements; The flatness and glossiness should reach the specified level; The strength should meet the design requirements.

Packaging and storage: Qualified boards should be properly packaged using wooden frames or cardboard boxes to prevent damage during transportation and storage. Packaged boards should be classified and stored according to specifications, colors, and grades, and labeled before being stored in the warehouse.