December 6, 2024 – The selection of color masterbatches plays a pivotal role in the production of PE cast films, as their properties directly influence the quality and final application effects of the films. This article provides an in-depth analysis of the considerations for choosing color masterbatches for PE cast films.
Firstly, given the high requirement for resin melt fluidity in the casting process, processing temperatures often reach as high as 300°C, and can even be higher when combined with cotton fabric in lamination processes. Therefore, the pigments in the color masterbatches must possess excellent heat resistance to ensure color stability and unaffected application performance at these high temperatures. This is a crucial indicator that cannot be ignored when selecting color masterbatches.
Secondly, the lamination strength of cast composite films is directly related to the sealability of the packaged liquids. Inadequate lamination strength can lead to serious issues such as liquid leakage. In the formulation design of color masterbatches, special attention should be paid to the control of wetting and lubricating agent dosages, as well as the selection of carrier resins, to ensure sufficient strength and stability of the composite films.
Moreover, cast films are typically thin, especially the color layers of multilayer co-extruded cast films, which are extremely thin. To achieve vivid colors and sufficient color depth on such thin color layers, the pigment loading must be increased. However, this also places extremely high demands on pigment dispersion. Only by ensuring uniform dispersion of the pigments within the color masterbatches can smooth processing and excellent product quality be guaranteed.
According to industry sources, the pigment migration resistance is also one of the key factors to consider when selecting color masterbatches. This is important both from a production perspective to avoid contamination between products and between products and equipment, and from an application perspective to ensure that packaging materials do not contaminate the packaged goods, particularly in terms of food packaging safety requirements.
For outdoor cast film/laminated products such as tarpaulins, sunshades, and fence color stripes, the light and weather resistance of the pigments become critical considerations. These products are exposed to natural environments for extended periods, so the pigments must resist UV radiation and harsh weather conditions to maintain the color and performance stability of the products.
Lastly, safety is the bottom line that cannot be overlooked when selecting color masterbatches. As a large number of cast film/laminated products are used for packaging food, beverages, and dairy products, they must comply with strict food safety standards. Both domestic and export markets require adherence to corresponding food safety regulations and requirements to ensure the safety of packaging materials.
In summary, when selecting color masterbatches for PE cast films, multiple aspects such as heat resistance, lamination strength, dispersion, migration resistance, light and weather resistance, and safety must be comprehensively considered to ensure the quality and application effects of the final products.