Park seats are being placed in more and more public places for people to relax and entertain. So, how many types of park seats are there?
Xiaobian will take everyone to understand, park seats are divided into several categories:
First, the legs of the park seat:
1. Steel feet are made of steel plates or steel pipes by stamping and welding. These types of chairs have high strength, simple and modern shapes, and the surface of the steel structure has been improved by pickling, phosphating, and plastic spraying. But the useful life is shorter.
2. Cast iron feet are mostly made of gray cast iron. There are also some ductile iron bench legs. After processing, the surface is a bit rough and the surface coating technology is slightly poor. Usually five to ten years.
3. Cast aluminum feet, due to the injection molding process, the product surface is relatively delicate, lightweight, assembly accuracy is higher than cast iron feet, anti-corrosion and rust, is a high-end product in the chair feet.
Second, the material of the foundry park bench chair strip:
1. Plastic-wood chair strip: one-time molding free of paint, plastic-wood strip has no corrosion and aging, no cracking, no maintenance, recyclable, and it has been proved that the service life can be more than ten years.
2. Resin chair strip: resin-coated steel core, resin in the outer layer, and hollow square steel tube in the inner layer, with a typical service life of more than 10 years.
3. Anticorrosive wood:
a. The specifications required for turning the logs into chair bars are dried. (Natural drying or steam drying) after a series of treatments to ensure the flatness of the chair bar before painting.
b. The paint treatment is roughly as follows: The wood is sprayed with primer several times before being sanded. Use sanding equipment to remove burrs on the surface of the wood, and then spray the topcoat. The topcoat must be uniform.
Foundry Park Bench Chair
Ductile iron is the same as other material castings. During the forming process, stresses are generated inside the casting due to the difference in cooling speed between different parts of the casting and the change in phase change volume. In addition, the shot blasting method is used to clean the casting, and the cutting force of the harness and the part tightening force during the machining of the casting will also cause additional internal stress to the casting. It is inevitable that nodular cast iron parts generate internal stress during the production process. The internal stress of the casting will be gradually released in an unconstrained environment. When released, the size and shape of the casting will change. Under constrained conditions (such as fixing the casting with screws or other methods), new internal stresses will be generated in the casting, which will increase the internal stress level of ductile iron, and even cause damage to the casting. The internal stress reduction treatment of the ductile iron lighting pole before use can significantly reduce the residual internal stress level.
Aging can be used to reduce the internal stress of castings. According to different treatment methods, there are natural aging treatment, vibration aging treatment or annealing treatment to reduce internal stress. The natural aging treatment requires that the casting be placed in the open air. After cold and heat, the casting should be released slowly. This treatment takes a long time, but the internal stress relief is relatively thorough. This kind of aging treatment method is often used for castings that need to maintain precise dimensions for a long time after processing such as machine tool rails.