Selecting Masterbatches for Injection Molding

Injection molding is a manufacturing process in which differently shaped and sized components are formed by injecting materials into a mold. Masterbatches are used in plastic manufacturing for coloring and imparting other properties to the plastic products. Masterbatch is an additive; it may be in solid or liquid form and is added to polymers for coloration and to improve certain functional properties.

Masterbatches are basically concentrated mixture of pigments or additives encapsulated in a carrier resin by means of a heat process. This carrier resin is first cooled and then cut into granular shapes. These additives allow the processor to color the raw polymer in an economic manner during the plastics manufacturing process.

There is a wide of variety of Masterbatches in use in plastic industry. Different additives are attributed with specific properties, and thus they need to be sorted and selected to meet the specific requirements in an application. Masterbatches that are designed for injection molding are required to fulfill certain important performance criteria. The key performance criteria for Masterbatches include dilution, compatibility, dispersion and temperature stability. These key performance criteria are briefly explained below.

Selecting Masterbatches for Injection Molding

• Dilution – This determines the ease with which the Masterbatches mix and distribute them throughout the fabricator’s polymer resin. The dilution is dependent on Masterbatches’ viscosity, so it is preferable that the melt flow index of the Masterbatches is somewhat near to that of the fabricator’s polymer resin. Additives with high melt flow index should therefore be used for injection molding.
• Compatibility – There should be compatibility between the fabricator’s polymer resins and Masterbatch carrier resins. Ideally the amount of polymer resins and carrier resin should be same but in some cases; it is not possible due to the range of resins processed. In such cases universal Masterbatches should be used.
• Dispersion – It is the level to which the pigments and additives are wetted and de- agglomerated within the Masterbatches carrier resin. Good dispersion characteristics are desired in applications which require high mechanical properties and weathering performance.

For the finest grade Masterbatches, you can contact Universal Colorant Company. Based in Gujarat, the company is a prominent Manufacturer, Supplier and Exporter of a wide range of Masterbatches and Color Concentrates. Its offerings include Colorant Pigments, Black Masterbatch, Universal Masterbatch, White Masterbatch, Additive Masterbatch, Rubber Masterbatch, Special Effect Masterbatch, PVC Masterbatch and many others. It is also counted amongst the most trusted Plastic Pigments Manufacturers in India. To place your orders or to know more about the company, please log on to http://www.univcol.com/.

Author is representing this article on the behalf of Universal Colorant Company, a prominent Additive Masterbatch