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

4. Whiteness:

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

7. Brittleness

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