In an effort to reduce production costs, manufacturers of PVC products are increasingly turning to highly filled formulations. Calcium carbonate (chalk) is rightly regarded as the leading filler. However, while an economist may see chalk as simply “low-cost volume,” a technologist sees a complex component that fundamentally changes melt rheology and product properties.
Switching to highly filled formulations always involves risk. An error in lubricant or modifier dosage can be very costly if it is tested directly on a production line. It is much more efficient and safer to refine the formulation in the laboratory. This is precisely why Revada Plastic offers a range of Hapro laboratory equipment.
Hapro: the laboratory instead of the production line
Testing every new formulation or raw material batch on production equipment involves considerable costs: material consumption, equipment downtime, waste and the risk of producing tonnes of scrap. A professional approach is to move all research to the laboratory.
Hapro equipment makes it possible to simulate actual processing operations, such as extrusion, mixing and calendering, with high accuracy. Instead of loading tonnes of material into a production extruder, you can start a trial with just a few kilograms, rule out unsuccessful options and take a fully developed and tested solution to the line.
The key advantages of this approach:
- Resource savings: you do not waste expensive raw materials or stop production.
- Speed: rapid comparison of several formulations or raw materials from different suppliers.
- Accuracy and predictability: you can establish a direct correlation between compound behavior in the laboratory and on the production line, making it possible to predict the outcome.
- Risk reduction: problems are identified at an early stage, before production begins.
A basic setup for studying chalk loading
For a comprehensive study of the behavior of chalk-filled PVC compounds, the following Hapro equipment setup is recommended:
Hapro plastograph
Purpose: evaluation of compound fusion, thermal stability and processability under heat and shear. It is an ideal tool for the initial evaluation of formulations.
Key parameters: working volume of 60 ml (200 and 300 ml chambers are available), temperature up to 350 °C. The air-cooled version provides more precise control of the temperature profile and allows work with materials sensitive to overheating.
Hapro laboratory twin-screw extruder
Purpose: simulation of an actual extrusion process. It allows the evaluation of melt behavior, pressure stability and filler dispersion quality, and the production of samples (sheets, pipes and strands) for further testing.
Key parameters: screw diameter of 25 mm, L/D of 28:1, speed up to 200 rpm and throughput of 1-10 kg/h. It is equipped with pressure sensors (up to 5) for monitoring the process along its entire length.
Laboratory two-roll mills
Purpose: used to evaluate thermal stability and the risk of color deviations (“yellowing”) when the melt comes into contact with hot metal, as well as to produce film samples.
Hapro laboratory equipment is therefore more than an expense: it is a strategic investment in the stability and safety of your production. The ability to simulate highly filled processing on a small scale allows your technologists to carry out dozens of trials without the risk of shutting down the plant or producing tonnes of scrap.
Testing a formulation in the laboratory gives you confidence that you will achieve exactly the result you expected when moving to the production line. With Hapro, you gain the freedom to innovate, while additives from Revada Plastic provide a guarantee that these innovations will be successful and cost-effective.
