What are the requirements for color masterbatch in blow molded products?

Plastic blow molding is a common method of forming thermoplastic materials. It involves placing the semi molten embryo obtained by extrusion or injection molding into various shaped molds, expanding it in the mold through compressed air and utilizing internal and external differences to adhere closely to the mold cavity wall, giving it a specific shape and size, and then cooling and demolding to obtain the product. Plastic blow molding is the third largest plastic processing and molding technology after extrusion molding and injection molding.

Blow molding processing technology is simple, low energy consumption, high production efficiency, and can be produced in large quantities. The products have diversity. This molding processing technology can produce hollow containers such as bottles, barrels, pots, and cans with different shapes and capacities, daily necessities, transportation facilities, and children's toys. It can also produce industrial hollow products for different purposes, which are widely used in industries such as chemical, food, pharmaceutical, automotive, transportation, fisheries, sports, water facilities, military, and home appliances.

Requirements for color masterbatch in blow molded products:

Almost all thermoplastic resins can be used for the manufacturing of hollow blow molded products, among which the most important resins include polyethylene, polyester, polypropylene, polyvinyl chloride, polyamide, polycarbonate, etc. The color masterbatch products used for blow molding processing need to pay attention to many properties, among which the properties that need special attention mainly include: chemical resistance, light/weather resistance, heat resistance, safety, etc.

01 Chemical resistance

Plastic containers used for packaging raw materials and products, especially chemical products, in industrial and agricultural production must ensure that the substances contained in the container itself do not react chemically with the packaged substances. Therefore, special attention should be paid to the tolerance of pigments for the packaged content, such as acid/alkali resistance, solvent resistance, water resistance, oil resistance, etc. Higher requirements are placed on packaging containers for strong oxidant chemicals.

02 Safety

Numerous plastic containers are used for packaging food, beverages, and other cosmetics or kitchen cleaning products that come into contact with the human body. All raw materials used in the production of these plastic containers, including pigments, must comply with relevant chemical safety regulations and usage permits.

03 Heat resistance

Under different process temperature conditions for hollow blow molding of resins, pigments need to be able to maintain color stability and proper performance.

04 Light resistance/Weather resistance

Hollow blow molding products are often used outdoors, so attention should be paid to the light resistance of pigments, especially for some oils and cosmetics stored in outdoor display windows, which may have special light resistance requirements for brand promotion.

05 Migration resistance

Hollow blow molding products are mainly used as liquid packaging containers. If the pigments used in them have migration resistance, the migrated colors will migrate to the liquid in contact with them, causing contamination.