Environmental Impact and Sustainability of GCC and PCC Production
While it is inescapable that calcium carbonate filler production depletes resources and consumes energy, it must be looked at in a more holistic way. The fillers replace polymers in the final products, and life cycle analysis has shown that in most cases production of the filler is less detrimental to the environment than that of the polymer it is replacing.
Ground (natural) calcium carbonates (GCC) is a critical and functional mineral for plastics, and there is no doubt that it will continue to be one of the principal fillers used by the polymer industry. Developments in grinding are likely to result in even finer forms and increased opportunities. As an example, it has recently expanded into a new market, fibers and nonwovens, and this opens up a large potential market in polyolefins. Imerys has engineered an innovative mineral additive for fibers and nonwovens based on GCC known as FiberLink®. This new technology is incorporated into the polymer during extrusion and is dispersed in the fiber. It can be added directly to powdered polymer or as a masterbatch with pelletized resins for fiber, spunlace, spunmelt (SMS), and meltblown applications. FiberLink increases softness, reduces luster, improves opacity, and improves tensile strength of the fabric/ web. For example, in diaper and hygiene products, adding FiberLink to the spunbond layers of SMS increases the strength in core wrap and leg cuffs. In addition to the optical and mechanical property benefits, FiberLink enables faster throughput or reduced processing temperatures leading to increased productivity or energy savings. An image of a polypropylene nonwoven fiber containing a FibreLink surface-treated GCC is given in Fig. 5.
The picture for PCC is less clear. While it will remain a major filler in paper applications, where the ability to manipulate shape and crystal form and the possibility to introduce satellite production installations utilizing the waste CO2 from the papermaking process protect it from encroachment by GCC to some extent, the use in polymers is expected to remain relatively minor.
Fig. 5 Polypropylene nonwoven fibers containing a surface-treated GCC
IMERYS COMPO 20.0kV 10#im WO 13.0mm
- ? Particulate Fillers, Selection, and Use in Polymer Composites
- ? Surface Modifiers for Use with Particulate Fillers
Khanna YP, Xanthos M (2010) Calcium carbonate, Chapter 16. In: Xanthos M (ed) Functional fillers for plastics, 2nd edn. Wiley-VCH, Weinheim, pp 291-306 Rothon RN (2010) Functional polymers and other modifiers, Chapter 6. In: Xanthos M (ed) Functional fillers for plastics, 2nd edn. Wiley-VCH, Weinheim, pp 115-140