Asbestos board is also called asbestos fiber cement plate. Its production and processing raw materials carefully select excellent asbestos, glass fiber, pottery and other raw materials, according to the proportion of processing. The product has strong tension, high pressure, high temperature resistance up to 1400 C, light weight. It can be used in industrial boilers, metallurgy, chemical industry, and other large factories to play the role of insulation and thermal insulation.
In order to ensure product quality, the state stipulates that every month asbestos boards should be inspected for physical properties of sealing materials such as asbestos rubber boards in accordance with the national GB/T3985-2008 standard, and the physical properties of products can be judged by the solution of inspection, and the unqualified products can be returned to the factory for re-work. The purpose of doing so is to protect the rights and interests of consumers, and at the same time implement the concept of honest management of manufacturers.
The detection process is divided into the following steps:
At first, the inspectors need to change their work clothes and wear gloves to enter the laboratory; secondly, a sample of pleasant 25*30CM is randomly sampled from the asbestos board stack head to be inspected and cut with a knife; the qualified samples are drawn with an angle ruler and a pen, and the density of the samples should be 34*4cm, 3*4cm, 3*3cm compression rate and 6 tension aging samples. Calipers measure the thickness and width of each piece and record it in the experimental record book; turn on the heating switch of aging chamber and turn off the heating switch at 100 C, then turn on the constant temperature controller; put the sample in the aging chamber for drying for 1 hour, then take out the sample, keep the aging sample at 100 C, and put the remaining sample in the drying bottle for 30 minutes; test the load-bearing capacity of the sample and the loss of ignition, and use the analytical balance to measure the lateral weight of the sample. The tension sample of early evaluation is taken out and put into the testing and adjusting fixture of the tension machine to open the equipment to record the transverse tensile strength when breaking; the resilience and compression tests need to place the asbestos board and the asbestos rubber board in the center of the anvil, apply the initial load to keep the recording thickness for 15 seconds, apply the second time slowly to achieve the total value within 10 seconds and record the thickness for 1 minute after the main load is removed. Thickness, the springback rate and compression rate can be calculated by synthesizing three data.
With the rapid rise of modern industries, people have improved their material performance and quality in stages. Take the commonly used asbestos board sealing materials for example, the early asbestos board can meet people's needs only by sealing, but with the increasing degree of modernization, the working environment and sealed materials have changed, asbestos board may not achieve the desired effect, but consumers are also hopeful about this product. At this time, the production enterprises need to improve product adaptability.
In view of the current market, in the process of choosing and purchasing products, consumers pay more attention to: whether the sealing performance meets the standards, whether there is leakage problem; whether the mechanical strength and hardness meet the requirements; how resilient, whether extruded will be deformed; how working at high temperature, whether decomposition, whether low temperature will lead to material vulnerability; corrosion resistance, chemical resistance. How to affect the product sealing, the service life of the product, the convenience of use and the price of the product.
Next, let's look at the two characteristics of asbestos board:
1. Physical properties: the tensile strength of asbestos internal structure is very strong, but not this week, after several bending stretching capacity will decline; the water content of asbestos fiber structure is 10-15%, when the asbestos is heated to 700 C, the water precipitates out, the asbestos structure will be damaged, the quality will become brittle, the applied force component, the color will change, and the thermal conductivity will drop to about 0.104-0.260, which is very important. Excellent insulation material, strong heat resistance.
2. Chemical properties: asbestos has excellent alkali resistance and is basically not corroded by alkaline substances, but its acid resistance is slightly poor, and its strength will decrease after being corroded by acid substances.
In the selection and use of asbestos boards, asbestos boards are not only required to have excellent heat preservation and energy saving type, but also to have corresponding fire protection capability. Recently, fire incidents of building exterior wall insulation materials occur frequently, and because of dry weather in Hebei, it is very easy to induce fire. This is often overlooked by some consumers. The same is true of other kinds of inorganic thermal insulation materials for exterior wall fireproofing.
At present, the representative products are rock wool and slag wool products, which have very low thermal conductivity, non-polar silicate, non-flammable, up to A-grade fire protection standards, excellent thermal insulation performance.