Acrylic chemical name is polymethylmethacrylate. It is an important plastic polymer material developed earlier. It has good transparency, chemical stability and weather resistance, easy dyeing, easy processing and beautiful appearance. It is widely used in the construction industry. Plexiglass products can usually be divided into pouring board, Extrusion board and molding plastic.
In the field of cosmetic bottle packaging, acrylic bottles are widely used in cosmetics packaging such as high-grade cream, lotion, etc., and are deeply welcomed by the market. Acrylic bottle not only has the characteristics of plastic: falling resistance, light weight, easy coloring, easy processing, low cost, but also has the characteristics of glass bottle, beautiful appearance and high-grade texture. It allows cosmetic manufacturers to obtain the appearance of glass bottles at the cost of plastic bottles, and also has the advantages of falling resistance and convenient transportation. Acrylic packaging bottles have a wide variety, rich colors and extremely excellent comprehensive performance, providing designers with a variety of choices, which can be dyed, and the surface can be painted, silk screen printed or vacuum coated. At present, the place where domestic manufacturers of acrylic cosmetic bottles are concentrated is Shangyu, Zhejiang Province. The manufacturers here are also the first batch to start the production of acrylic packaging in China, and their products are exported to the European and American cosmetic bottle packaging market.
Acrylic packaging bottle has excellent transparency, light transmittance of more than 92%, good anti-aging performance, and can be used safely outdoors. Although acrylic bottles have achieved great success in the cosmetics market, they have not been widely used in food, medicine and other packaging fields, which is also a field worthy of exploration and exploration by acrylic bottle manufacturers.
Casting molding is used to form profiles such as plexiglass plates and bars, that is, profiles are formed by bulk polymerization. The cast products need post-treatment. The post-treatment conditions are heat preservation for 2h at 60 ℃ and heat preservation for 2h at 120 ℃.
Injection molding adopts the granular material prepared by suspension polymerization, and the molding is carried out on the ordinary plunger or screw injection molding machine. Injection molded products also need post-treatment to eliminate internal stress. The treatment is carried out in a 70-80 ℃ hot air circulation drying oven. The treatment time generally takes about 4H depending on the thickness of the product.
Polymethylmethacrylate can also be extruded to prepare plexiglass plate, bar, pipe, sheet, etc. with the granular material produced by suspension polymerization. However, the profile prepared in this way, especially the plate, has the advantage of high production efficiency, especially for the mold of pipe and other pouring methods, because the molecular weight of the polymer is small and the mechanical properties, heat resistance and solvent resistance are not as good as the profile formed by pouring. Difficult to manufacture profiles. Single stage or double stage exhaust extruder can be used for extrusion molding, and the length diameter ratio of screw is generally 20-25. Table 2 shows the typical process conditions of extrusion molding.
Thermoforming is the process of making plexiglass plate or sheet into products of various sizes and shapes. The blank cut into the required size is clamped on the mold frame, heated to soften it, and then pressurized to make it close to the mold surface to obtain the same shape as the mold surface. After cooling and shaping, the edge is trimmed to obtain the product. The method of vacuum drawing or direct pressurization of punch with profile can be adopted for pressurization. The thermoforming temperature can refer to the temperature range recommended in Table 3. When using rapid vacuum low draft forming products, it is appropriate to adopt the temperature close to the lower limit. When forming deep draft products with complex shape, it is appropriate to adopt the temperature close to the upper limit. Generally, the normal temperature is adopted.
It is mainly aimed at hollowing out and carving of formed acrylic or colored acrylic materials. Ordinary laser engraving and cutting machine can meet the engraving and hollowing needs of most acrylic products.
Post time: May-06-2022