Introduction and production process of PVC foam boardIntroduction and production process of PVC foam board
The definition of foaming materials is also called foamed plastics. It is based on plastics and contains many bubbles. It can be said that it is a composite material filled with gas. The classification of foamed sheet material can be divided into high foaming and low foaming according to different foaming ratios, and can be divided into hard, semi-rigid and flexible foams according to the softness and hardness of the foam body texture. According to the cell structure, it can be divided into closed-cell foam and open-cell foam. The common common PVC foam sheets are classified as hard closed-cell low foam sheets.
Use of PVC foam sheet PVC foam sheet has the advantages of chemical resistance, weather resistance, flame retardancy, etc. It is widely used in many aspects, including display panels, symbols, billboards, partitions, construction panels, furniture Use plates, etc.
Comment on the key factors of foam sheet quality For foam materials, the size and uniformity of the cells are the key factors that affect the quality of the sheet. For low-expansion foamed sheets, the cells are small and uniform, the foamed sheets have good tolerance, high strength and good surface quality. From the perspective of decreasing the density of the foamed sheet, as long as the cells are small and uniform, there is a possibility of further decreasing the density. If the cells are large and scattered, it is difficult to further reduce the density.
The key point of PVC foaming process control Plastic foaming is divided into three processes: the formation of bubble core, the expansion of bubble core and the solidification of bubble body. Regarding the PVC foam sheet with added chemical foaming agent, the expansion of the bubble core has a decisive influence on the quality of the foam sheet. PVC is attributed to straight-chain molecules. The molecular chain is short and the melt strength is low. During the expansion of the bubble core to form a bubble, the melt is not enough to cover the bubble. The gas is easy to overflow and merge into a large bubble, which reduces the quality of the foamed sheet product. .