Home > Products and Services > Products by Type > Titanium Dioxide - Plastics > Market Applications Masterbatch/Color Concentrate - Films One of the most prevalent polymer fabrication methods for the conversion of molten polymer into a usable product is film processing. The industry convention dictates that film is .010" in thickness or less. A flat layflat produced thicker than .010" is considered sheet. Certain aspects of processing and end use requirements for film may dictate the use of a specific grade of TiO2 in whites or colors to achieve optimal processabilty and performance. Blown Film: The vast majority of blown film comprises polyethylene (LDPE, LLDPE, HDPE) produced for in-line or out of line bagmaking. The nature of the blown film process includes minimization of melt temperature to reduce the cooling load, which is often rate limiting, and maximize melt strength for bubble stability. Thin final gage and high drawdown rates from the die gap make dispersion critical to avoid die lines and holes that can cause air loss from the bubble. If the TiO2 is not effectively dispersed by the (typical) single screw extruder, it can result in agglomerates of nibs in the film which are aesthetically undesirable, reduce overall opacity by minimizing light scattering sites, and can cause processing/quality problems resulting in downtime and rejects. A general purpose TiO2 performs well for most general purpose film applications by providing excellent dispersion and less blue reflectance from thicker film and more blue transmission from thinner film. When dispersion is extremely critical or when using a very highly (80% +) loaded concentrate, a high performance TiO2 may be desirable. Be sure to review the FDA status of the TiO2 used for food packaging applications. Since the majority of thin film relies on low final TiO2 loading levels (1-3%) to achieve adequate opacity, the dispersion, particle size, and particle size distribution must be optimized to achieve the most efficient light scattering and opacity. This property is measured by tinting strength. When processing film for semi-durable applications (agricultural, mulch, construction, auto overwrap films) a durable TiO2 product is required. In addition to having the proper inorganic treatment for durability, the TiO2 product requires an organic treatment for dispersion to provide processabilty and adequate UV protection. Cast Film: TiO2 requirements in cast film are somewhat similar to blown film with the exception that the process runs at much higher temperature and throughput due to the more efficient chill roll cooling (vs. air with blown film) and typically narrower die gaps (higher shear). This process is less dependent upon the melt strength of the polymer and, due to the high temperatures, more prone to lacing and die lip build-up problems. These result in downtime and quality problems. For high temperature cast film (>550F) we would advise high performance TiO2 due to excellent thermal stability and low die lip build-up. Printing, heat sealing, or interlayer bonding in coextruded structures should not be adversely impacted. About Us | Products & Services | Safety, Health & Environment News & Events | Contact Us | Search | Site Map | Careers