1
abstract
Magnesite composite corrugated colored tile, referred to as magnesite tile for short, is an energy-saving roofing material made of magnesium oxychloride cement as the base material and crop straw or sawdust as the filling material. This product has the advantages of light weight, rich colors, good waterproof performance, simple construction and moderate price, and is an ideal substitute for asbestos tiles, cement tiles, colored steel tiles and other products.
At present, in the domestic market, magnesite tiles are mixed, and most production enterprises do not pay attention to scientific production. Most products have problems such as salt water return, frosting and poor water resistance. Especially in hot and humid summer, "heavy rain outside and light rain inside" often occurs, which seriously affects the promotion and service life of magnesite tiles. Jinan Meichen Building Materials Machinery Co., Ltd. adopted reasonable production technology and advanced modification technology, which effectively solved this technical problem and greatly improved the physical and mechanical properties of Pomegranate tile.
According to the current market survey of ceramic tile products, the author summarizes the differences between magnesite tile and ceramic tile products made of other materials, as shown in Table L. It can be seen that magnesite colored tiles are not only the most ideal products for building factories, warehouses, houses, markets and sheds, but also the best and most economical materials for decorating urban and rural buildings.
2
Production technology of magnesite tile
2. 1 production equipment and appliances
According to the effective working time of 8 hours per day, the daily output is 1500 tiles, and the required mechanical equipment and production tools are as follows:
(1) One brick-making machine production line, with power of 4kW and speed regulating motor power of 0 ~1200r/min;
(2) L cutting machines, ***6 motors, 4kW ×4, 0.75kW× 2;
(3) L polishing machine with power of 5.5 kW x 1; o . 75kw× 1；
(4) Magnesite mixer: horizontal double-shaft paddle mixer, with a mixing weight of 800 ~ 1000 kg and a power of 10kW.
(5) Cement pool (10× 5x2.2) m (disconnected in the middle);
(6) 10 plastic bucket;
(7) 5 scissors;
(8) There are 6-8 trolleys, as shown in Figure L.
2.2 raw materials for production
(1) light burned powder: 85-grade fine powder is required, with activity ≥ 60%, Cao ≤ 1.5%, loss on ignition (7-9)% and fineness ≥ 180 mesh. Origin: Haicheng, Liaoning, dashiqiao city.
(2) Halogen tablets: the main components are MgCl2 ≥ 45%, Na+ ≤0.5%%, K+≤ 0.7% and SO2-4 ≤ 3%. The manufacturer is Jinan Meichen Building Materials Machinery Co., Ltd. ..
(3) Sawdust or plant fiber: no mildew and deterioration, fineness of 20-80 meshes, moisture content ≤ 1o%, mud content ≤ 1%.
(4) Stone powder or fly ash: 50-60 mesh;
(5) Glass fiber cloth: medium alkali glass fiber cloth.
(6) Modifiers: all are produced and provided by Jinan Meichen Building Materials Machinery Co., Ltd., and the specific dosage and function are shown in Table 2.
(7) Polyester film: 6-8 filaments thick;
(8) Weighing tools: scales, bench scales, etc.
2.4 Installation and construction technology of magnesite colored tile
(1) Preparation and working conditions before construction
① Magnesite tiles have neat edges, uniform thickness, no holes, cracks, deformation and other defects on the surface, and each tile has the same size.
(2) Magnesite tiles can be laid on the roof base. The base should be hard, dry, dust-free and oil-free. The protruding parts should be leveled, and the cracks and depressions should be leveled with polymer mortar. The suitable slope of magnesite tile roof is 20 ~ 60%.
(3) Magnesite tile and its supporting fixture, cold water mud, etc. The materials needed for construction have entered the site as planned.
(4) When the magnesite tile is bonded and fixed with cold cementing material, it shall conform to the construction conditions of cementing material or coating, and shall not be used in rainy days, snowy days and environments with wind force above 5.
(2)
Construction process, Figure 2
Check at the grass-roots level → Line dividing and elastic line laying → Magnesite brick laying → Flat and oblique ridge making → Acceptance.
(1) Pop-up the laying control line according to the roof slope length and magnesite tile specifications on the solid and flat base.
(2) Each magnesite tile should be fixed, and it can be fixed on the concrete base with special cement steel nails or cold cement; Steel nails should be nailed flat, and it is forbidden to expose the nail cap on the magnesite tile.
③ Magnesite tiles are laid upward from the eaves.
When laying, it is required that the first row of tiles should be flush with the cornice, the cutting groove should point upward to the roof and be fixed with steel nails; The second row of Wache grooves points downward to the cornice and is stacked on the first row of tiles for fixing; The third row of tiles covers the previous layer of tiles, and the second row of Wache grooves is exposed for a certain distance; Subsequent magnesite tiles are nailed in turn.
(4) Divide the magnesite tile into four pieces at intervals along the cutting groove as roof tiles, and each roof tile is fixed with two steel nails.
3 analysis of common problems
3. 1 Moisture absorption and halogen return
(1) reason
Magnesium chloride, as a admixture, is one of the basic raw materials of magnesia cementitious materials. At the same time, magnesium chloride is also a hygroscopic agent, which is the key to moisture absorption and halogen return. Unqualified raw materials, improper proportioning or modification, and unreasonable process will all lead to the residual supercritical amount of free magnesium chloride or excessive alkali metal impurity ions in solidified magnesium cement. In high temperature and high humidity environment, water vapor will quickly penetrate the capillary channels in solidified magnesium chloride and excessive alkali metal impurity ions, migrate to the surface of solidified magnesium chloride and accumulate in large quantities. Due to the strong hygroscopicity of salt ions, condensation and sweating will occur on the surface of solidified magnesium cement.
(2) Prevention and control measures
① Control the quality of raw materials. Before use, the true contents of active magnesium oxide (MgO) and effective magnesium chloride (MgCl2) in raw materials must be detected. Do not have the test conditions, but also through the raw material suppliers to learn more about its true content.
② Scientific dynamic proportioning. The ratio can be appropriately adjusted according to the actual production environment, and the same ratio should not be changed all the year round.
③ Necessary and effective modifications. The modifier GX- 1# GX-4# GX-8# developed and produced by Jinan Meichen Building Materials Machinery Co., Ltd. can significantly improve the halogen resistance of products.
④ Correct and standardized technological process. The batching process should be clear and strictly follow the operation sequence; Attention should be paid to temperature and humidity in the curing process of products, so that the later curing reaction can proceed smoothly and the physical and chemical properties of products have been achieved.
(3) Poor water resistance
1) reason
(1) Adding some organic fillers, such as sawdust or plant fiber, in the batching process leads to
There are some capillary channels in the curing process of magnesite tile, and the density is too poor, which leads to water seepage.
(2) The light burned powder particles are too coarse, and the density of magnesite tile is not enough when it participates in the reaction, and the capillary channels increase.
A lot.
2) Preventive and control measures
Give priority to the selection of qualified raw materials, pay attention to scientific and dynamic proportioning, and at the same time, make magnesite.
The product is effectively modified. Especially for magnesite tiles filled with coarse aggregate,
Jinan Meichen Building Materials Machinery Co., Ltd. can add halogen-resistant reinforcing agent at the same time.
The developed GX-5# defoaming and color retention agent can improve the softening coefficient of products, thus improving
Water resistance.
4. Conclusion
To sum up, magnesite tile is a new waterproof building material with energy saving and waste utilization.
Correct selection can solve the problems of moisture absorption, halogen return and poor water resistance in the application process.
Selection of raw materials, scientific proportion, advanced modification technology and standardized and reasonable production and installation.
Technology has greatly broadened its application scope and has great market development potential.