What is main differences between precipitated calcium carbonate/PCC
and ground calcium carbonate/GCC?
1. Settlement volume and true density
The sedimentation volume of GCC is 2.4-2.8 mL/g and GCC is 1.1-1.4 mL/g. So the same weight of PCC
and GCC, PCC packaging bigger than GCC. But in fact, The true density of GCC is 2.6-2.9g/cm3, PCC
is 2.4-2.6g/cm3.So this is small diffence, Calcium carbonate reflects true density by fill in plastics.
2. Powder characteristics
GCC particles are irregular in shape and large in size. The average particle size is usually 5-10 um, and
the distribution is wide.but PCC particles are regular in shape and small in size. The average size of GCC
is generally 1-3 um, and the distribution is narrow.
3 oil absorption value
The oil absorption value of PCC is 60-90 ml/100 mg, GCC is 40-60ml/100mg
activation additives (plasticizers, lubricants) of filler GCC is less than PCC, So soft plastics better use GCC
Becaus content more impurities of GCC, the whiteness of GCC is generally 89%-93%, and very few products
can reach 95%. Because of chemical synthesis, PCC remove many impurities. The purity of products is very
high, so the whiteness of products is 92%-95%, and some products can reach 96%-97%. This is also the
main reason why PCC are mostly used for filling high-grade or light-colored products.
5. Production efficiency
Because PCC is fluffy ,if filling ratio is more than 25%, it is easy to build a bridge in the hopper, the
flowing is not smooth. It seriously affects the production efficiency. GCC is more suitable for high filling
because of its loose particles and better fluidity after mixing with PVC materials.
6. Different modification functions
GCC has better tensile strength, PCC has better impact strength and rigidity. Generally, the surface of
plastics added PCC is smoother and its density is lower. The processing fluidity of heavy GCC is better
Because of the loose and irregular shape particles of GCC, the stress of the GCC combined with plastic
polymers is small and the brittleness of the products is large. For plastic products filled with the same
proportion of calcium carbonate, the flexibility plastic filled with PCC is better than GCC
8. Different sales measurements
Using GCC instead of PCC has obvious advantages for products sold based on weight, but if the products
are sold by length, area or number, PCC more better than GCC