What Are the Different Types of Raw Materials for Construction?

[cái liào]

Materials are those substances that humans use to make articles, devices, components, machines, or other products.

Materials are substances, but not all substances are called materials. Fuel and chemical raw materials, industrial chemicals, food and pharmaceuticals are generally not counted as materials and are often referred to as raw materials. However, this definition is not strict, such as explosives and solid rocket propellants, which are generally called "energetic materials" because they are part of artillery or rockets. Materials are always associated with a certain use case and can be composed of one or several substances. The same substance, due to different preparation methods or processing methods, can become different types and properties of materials with very different uses.

Materials are the material basis on which human beings live and develop. In the 1970s, information, materials and energy were hailed as the three pillars of contemporary civilization. In the 1980s, the new technological revolution represented by high-tech clusters also listed new materials, information technology, and biotechnology as important signs of the new technological revolution, because materials are closely related to national economic construction, national defense construction, and people's lives. ^[1]

Material English name: Material

Materials are the material basis on which human beings live and develop. In the 1970s, people put information,

Divided by physical and chemical properties:

It can be divided into

Matters to pay attention to when selecting materials

Attention to selecting materials in the process of designing plastic formulations-According to a statistical data, in the statistical investigation of injection products failure, 23% are errors in selecting materials and 9% are errors in selecting additives. This shows the importance of selecting materials. It is generally required that the cost of materials is reduced and the performance of materials is increased. At the same time, the appearance and durability of the era must be considered, so it is difficult to choose a suitable material that can meet all performance requirements. For example, when producing transparent containers by injection molding, in general, two materials, polystyrene or polymethyl methacrylate, can be selected. However, if cheapness is the first requirement, then polystyrene should be selected; on the other hand, if weather resistance is emphasized, polymethyl methacrylate (that is, plexiglass) must be selected. If it is also necessary to add good impact resistance, it is necessary to exclude the above two materials and choose polycarbonate, of course, the cost must be increased. Generally, the following should be considered in the selection: whether the material to be selected can withstand the highest and lowest temperature changes in the use environment, whether the material can be deformed within this temperature range, is prone to cracking, and how resistant to impact . If it does not meet the user's requirements, it is necessary to change the existing plastic variety, choose another new variety, or modify it. In addition, other factors in the use environment of the material to be designed also need to be considered. When good dimensional stability of the product is required, factors such as the thermal expansion coefficient of the resin, the thermal expansion coefficient of the resin, the shrinkage change in the early and late molding stages, and hygroscopicity should also be considered. In general, it is impossible to meet all the conditions, as long as the main conditions are met. Regarding the grasp of quality standards, the following conditions are generally determined.

(1) Whether it can withstand changes in the use environment's overflow, the influence of sunlight, and changes in load during use.

(2) Whether the product meets sanitary standards and safety.

(3) Whether the bending strength, tensile strength, impact strength, electrical insulation, arc resistance, fire resistance, water resistance, oil resistance, and electrical properties comply with national standards, and mechanical and mechanical properties such as solvent resistance and enterprise standards.

(4) How about dimensional stability, optical performance, anti-toxic and anti-humidity anti-bacterial performance.

(5) Whether the appearance, economic cost, and special requirements can meet the requirements.

For long-term use of plastic materials and products, repair and maintenance costs must be considered. If the maintenance costs can be significantly reduced, even if the initial investment is large, it is still beneficial to the overall material. In addition, it is necessary to consider the forming processability and the ease of secondary processability, and the change of the material in the mold. When designing and manufacturing important components such as bearings and gears, physical and mechanical performance inspection and analysis should also be performed; when making transparent materials, optical tests and corrections should also be performed.