A NEW TECHNICAL CALCIUM CARBONATE FOR THE PRODUCTION OF WHITE MASTERBATCH

In short, we define a white masterbatch as:

• A Calcium Carbonate concentrate: with a content of up to 85% of our ultra-white calcium carbonates;
• A white masterbatch: containing just TiO2 (60-80%) or a combination of TiO2 and calcium carbonate.

The aim of producing a white masterbatch is to obtain higher productivity and the highest filler levels in the compound compatible with the lowest energy consumption (kWh/kg) and good quality grains (uniform shape and size, good filler dispersion, etc.).

The first thing that comes to mind when we want to maximise productivity and filler levels in producing grains is to adjust the process parameters (rpm of the spindle / rotor, temperature profile, spindle configuration, etc.).

However, the contribution of calcium carbonate in terms of productivity and grain filler level should not be underestimated, as it is a unique opportunity to delay the need for major investment in both new machinery and modifications of production processes.

That is why Reverté, a company that specialises in the production of Technical Calcium Carbonates, has decided to take a step forward by launching a new technical calcium carbonate called Calcipore 80T AL on the market, which is specifically designed to offer maximum productivity and the highest level of filler in the grain.

The main benefits of Calcipore 80T AL in the production of white masterbatch are as follows:

• For compound manufacturers:
  • • Higher productivity and filler level in Co-rotating Twin-Screw Extruders and Continuous Mixers.
    • Improved dispersion: lower pressure values in the filter test.
    • Reduction of additives in the compound’s formulation.
    • Greater reduction of TiO2 in white masterbatch due to the greater extending power of TiO2.

• For processors:
  • • Higher filler level in the finished product due to the improvement in chemical properties.
    • Lower filter change frequency during processing of the grain.

EXPERIMENTAL DATA

The tables below show the higher productivity obtained with the new Calcipore 80T AL for both Twin-Screw and Continuous Mixers compared with other calcium carbonate of the same average particle size (D50 = 1.1 micra)

In Continuous Mixers (for example: Farrell CP 2500) it has been found to eliminate undissolved particles, as shown by the low pressure values in the filter test.

CONCLUSIONS:

The new Calcipore 80T AL Calcium Carbonate offers the following advantages to manufacturers of compounds and polyolefin processors:

1. Maximum productivity and filler level in the production of calcium carbonate concentrates (grains) in both Twin-Screw Extruders and Continuous Mixers.
2. Maximum substitution of TiO2 in white masterbatch.
3. Higher level of use of calcium carbonate concentrate in the end product.

PRODUCTIVITY AND FILLER LEVEL OBTAINED WITH TWO CALCIUM CARBONATES OF THE SAME D50
Máquina Extrusora: Extruder: Leistritz Co-TSE ZSE 87 MAXX

PRODUCTIVITY AND FILLER LEVEL OBTAINED WITH TWO CALCIUM CARBONATES OF THE SAME D50
Máquina : Machine: Farrel CP 2500