Laminate flooring: Which layer is the most important?
Dr. Fu: Currently on the market, reinforced wood flooring is generally composed of four layers of composite materials, namely wear layer, decorative layer, substrate layer and moisture barrier layer.
The bottom layer of the laminate wood floor is a moisture-proof layer, which is usually made of polyester material. The base material layer is the main part of the laminate wood flooring. The density board is used as the base material; the base material layer is the decoration layer, that is, the pattern layer. The first layer is made of a specially processed paper; the wear layer is a layer of anti-wear agent uniformly pressed on the surface of the laminate floor.
In the four layers, the base layer is the most important. It is the core component of laminate flooring. It uses pine wood and fast-growing species as the main raw material. After peeling and screening, it is mechanically separated and chemically processed using wood or plant fibers. , Incorporating adhesives and water repellents, and then paving, forming and high temperature, high pressure pressure. Because the wood fiber is added to the adhesive through high temperature and high pressure, the density is relatively uniform, and the mechanical properties are close to that of wood, which is currently a more popular artificial plate in the world.
Generally, there are several ways to check the substrate : First, look at the degree of fineness of the substrate fiber, whether it is uniform, with or without impurities; secondly look at its color, the base material of pine wood as raw material, and the pine wood is retained. The color, darker color, longer growth cycle of pine wood, complete development of wood fiber, physical properties, better than the white substrate, the use of fast-growing species, fast-growing tree species of wood fiber development is not complete, physical performance is poor. Second, smell, see if there is no smell of the substrate. Third, cook, can take the different brands of the floor in the same container, soaked in water at 100 °C for 30 minutes, take out the look, the higher the expansion coefficient shows the quality of the more times, the lower the coefficient of expansion the better the quality.
Nature floor del floor decoration
The disc of the wafer butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of the butterfly valve body, the disc-shaped disc rotates around the axis, and the rotation angle is between 0° and 90°, which can play the role of flow regulation. When the disc rotates to 90°, the valve reaches the maximum opening.
Compared with the gate valve, the wafer butterfly valve has the characteristics of simple structure, small volume and light weight.
It consists of only a few parts. And it only needs to rotate 90° to open and close quickly, the operation is simple, and the valve has good fluid control characteristics.
When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has better flow control characteristics. Butterfly valve has two types of sealing type: elastic soft seal and metal seal. Elastic soft sealing valve, the sealing ring can be embedded on the valve body or attached to the periphery of the disc.
Valves with metal seals generally have a longer life than those with elastic seals, but it is difficult to achieve complete sealing. Metal seals can adapt to higher operating temperatures, while elastic soft seals have the defect of being limited by temperature.
When the project is used and installed, the double-headed butterfly valve is connected between the two pipeline Flanges with stud bolts, and the flanges at both ends of the valve are connected to the pipeline flange with bolts.
The wafer butterfly valve has good sealing performance, light operation, secondary corrosion, high temperature resistance, convenient operation, flexibility, safe and reliable use, and has been widely used.
Widely used in cooling water systems of petroleum, gas, chemical, water treatment, thermal power stations, and SO2, steam, air, gas, ammonia, CO2, oil, water in chemical, petrochemical, smelting, pharmaceutical, food and other industries , Brine, lye, seawater, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and other media pipelines are used as adjustment and interception devices.
Divided by structure
(1) Center sealing butterfly valve (2) Single eccentric sealing butterfly valve (3) Double eccentric sealing butterfly valve (4) Triple eccentric sealing butterfly valve
According to the sealing surface material is divided into
(1) Soft sealing butterfly valve.
1) The sealing surface is composed of non-metallic soft material to non-metallic soft material.
2) The sealing surface is composed of metal hard material and non-metal soft material.
(2) Metal hard sealing butterfly valve.
The sealing surface is composed of metal hard material to metal hard material.
Divided by material: cast iron, cast steel, stainless steel
Butterfly Valves,Ss Butterfly Valve,Stainless Steel Butterfly Valve,Stainless Butterfly Valve
Inner Mongolia Overseas.Trade co.,LTD , https://www.flangevalvejoint.com