What is the difference between pvb and eva in laminated glass? What are the characteristics of PVB laminated glass intermediate film

Glass has good transmission and light transmission performance, high chemical stability, and can obtain strong mechanical strength and heat insulation effect according to different processing methods. It can even make glass change color independently and isolate excessive light, so it is often used in all walks of life to meet different needs. Next, please see what is meant by pvb in laminated glass, and what are the characteristics of pvb laminated glass, so as to increase your understanding.

• What is the difference between pvb and eva in laminated glass

The laminated glass is divided into pvb and eva laminated glass,

PVB lamination requires a series of equipment, such as autoclave, roller press, film processor, etc. The cost of investment is high, and the autoclave with a smaller autoclave costs four or five million yuan. The autoclave mainly includes four steps: cleaning, laminating, prepressing, and entering the autoclave

Principle: Not much about cleaning and laminating. Pre pressing is to compress the air between the two pieces of glass and the PVB in the middle into small bubbles through a roller press to make the two pieces of glass stick together through the PVB; Entering the autoclave is to compress the bubbles in the autoclave until they are invisible to the naked eye through more than ten atmospheres. It is characterized by high strength and is mainly used for front windshield of automobiles

EVA laminating only needs laminating furnace, mainly including cleaning, laminating and feeding

The principle is to pre pump the air between the two pieces of glass by vacuum pump to form a vacuum in the silicone bag, and then put the EVA film into the furnace to reach the melting state under high temperature to bond the two pieces of glass together. It is characterized by good adhesion and good light transmittance. EVA film is characterized by relatively low investment capital cost, about 10 million pieces of equipment. It is mainly used on building glass, such as curtain wall, daylighting roof, canopy and other interlayer

• What are the characteristics of PVB laminated glass intermediate film

1. PVB is the abbreviation of polyvinyl butyral; EVA is the abbreviation of ethylene vinyl acetate copolymer

2. Processing and storage conditions; The requirements for processing and storage conditions of EVA are relatively low, the temperature shall not exceed 30 ℃, the humidity shall be lower than 80%, and the requirements for the equipment for laminating are also low, the vacuum degree shall be ≥ 700mmHg (0.092Mpa), and the temperature shall be 100-110 ℃; PVB lamination process is more complex than EVA, takes longer and consumes more energy

3. Features: PVB has stronger aging resistance than EVA, and its impact resistance is also stronger than EVA

4. Use: PVB is more used outdoors, such as building curtain wall, car windshield, etc. EVA is more used for interior decoration

Related concepts

Glass

Glass is an amorphous inorganic non-metallic material, which is generally made of a variety of inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc.) as the main raw materials, with a small amount of auxiliary raw materials added. Its main components are silicon dioxide and other oxides. The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O · CaO · 6SiO2, etc. The main component is silicate double salt, which is an amorphous solid with irregular structure. It is widely used in buildings to isolate wind and light, and belongs to mixture. In addition, colored glass mixed with some metal oxides or salts to show color, and tempered glass made by physical or chemical methods. Sometimes some transparent plastics (such as polymethyl methacrylate) are also called agricultural production system glass.

PVB

Polyvinyl butyral (PVB) is a kind of commonly used support. It has strong adhesion, high optical clarity, easy adhesion to various surfaces, high toughness and high elasticity. It is prepared by reacting polyvinyl alcohol with butyraldehyde. The main applications are safety laminated glass and automobile windshield.