The main materials of basement membrane are chlorinated polypropylene, OPP, BOPP, polyethylene, polyester, polyvinyl chloride and MOPP.
CPP (cast polypropylene) film, also known as unstretched polypropylene film. CPP is a polypropylene (PP) film produced by casting and extrusion in plastic industry. This kind of film is different from BOPP film and belongs to non-oriented film. Strictly speaking, cast polypropylene only has a certain orientation in the machine direction (MD), which is mainly due to the nature of the process. Excellent transparency and smoothness are formed on the film by rapid cooling on the cold casting roll.
OPP movie, BOPP movie. They are all raw materials of polypropylene film. Because the production process is multi-layer extrusion, they are called * * * extruded oriented polypropylene films. If there is a process of biaxial stretching in processing, it is called biaxial stretching oriented polypropylene film.
PE (polyethylene) film is a thermoplastic resin polymerized from ethylene. In industry, it also includes * * * polymers of ethylene and a small amount of α-olefins. Polyethylene is odorless and non-toxic, feels like wax, has excellent low temperature resistance (the service temperature can reach -70 ~- 100℃), good chemical stability, resistance to most acid and alkali corrosion (oxidation acid resistance), insolubility in general solvents at room temperature, low water absorption and excellent electrical insulation performance.
PET (polyester fiber) film is a kind of packaging film with wide performance. Has good transparency and luster; Good air tightness and fragrance retention; The moisture resistance is moderate, and the moisture permeability decreases at low temperature. PET film has excellent mechanical properties, its strength and toughness are better than all thermoplastics, and its tensile strength and impact strength are much higher than ordinary films. Suitable for secondary processing such as printing and paper bags. PET film also has excellent heat resistance, cold resistance, chemical resistance and oil resistance. But not resistant to strong alkali; Easy to carry static electricity.
PVC film can be divided into soft PVC film and hard PVC film. Among them, hard PVC accounts for about 2/3 of the market and soft PVC accounts for 1/3. Soft PVC is generally used for floors, ceilings and leather surfaces, but its application is limited because it contains softener (which is also the difference between soft PVC and hard PVC), which is easy to become brittle and difficult to store. Rigid PVC contains no softener, so it is flexible and easy to form, not fragile, non-toxic and pollution-free, and has long storage time, which is of great development and application value.
MOPP can be divided into two types: one is metallized BOPP film, that is, aluminizing the surface of BOPP film again; The other is a dull BOPP film, which is a dull BOPP film. The surface becomes rough and scattered by light, resulting in a dull effect.
Glue materials are mainly divided into: water glue, oil glue, hot melt adhesive, natural rubber and synthetic rubber.
Water glue: water-based coating glue is made by emulsifying acrylic acid or ester resin with water as solvent; Advantages: various types, environmental protection and low cost; Disadvantages: poor film forming and fastness, PU can't stick hot air adhesive and can't withstand low temperature.
Gum: made of acrylic acid or polyurethane dissolved in oily solvent (toluene, DMF, butanone); Advantages: good film-forming property and fastness, PU can be attached with hot air adhesive, which is commonly used in the market; Disadvantages: high cost and high environmental protection requirements.
Hot melt adhesive: plastic adhesive whose physical state changes with temperature; Advantages: environmental protection chemical products, no degumming, strong adhesion and corrosion resistance; Disadvantages: high cost, limited temperature range, need special application equipment, and strength is limited by viscosity and temperature range.
Natural rubber: (NR) is a natural polymer compound with polyisoprene as the main component, and 9 1% ~ 94% is rubber hydrocarbon. Natural rubber is a widely used universal rubber. Generally speaking, natural rubber refers to the natural latex collected from rubber trees in Brazil, which is an elastic solid made by solidification, drying and other processing procedures.
Synthetic rubber: Synthetic rubber, also known as synthetic elastomer, is a synthetic polymer with high elasticity and one of the three major synthetic materials. Its output is only lower than that of synthetic resin (or plastic) and synthetic fiber.