An open mixing mill also called a two-roll mill, it is are essential equipment widely used in the rubber and plastic industries, including for processing PVC (polyvinyl chloride), color master batch ,polymer etc. Today, open mixing mill equipment are indispensable in plastic rubber industries that require high-volume production of rubber and plastic products, such as tire manufacturing, automotive parts, and consumer goods.
As we know ,this automated, efficient, and precise two roll mixing mill machines are specially designed to mix and blend raw materials with fillers, stabilizers, and colorants into a uniform mixture, such as PVC, rubber compounds, plastics, and additives ,so that create homogeneous mixtures that are crucial for manufacturing high-quality products.
Here let us talk how this two roll open mixing mill work in PVC industry as follows:
1. Precise Mixing & Homogenization
This two roll mixing mill allows thorough dispersion of additives (like stabilizers, plasticizers, fillers, pigments) into the PVC base.
The shearing action between the two counter-rotating steel drums rolls ,which are heated or cooled to control processing temperature ,so that ensures uniform mixing of the compound.
The PVC compound (often dry blend or plastisol) material is fed into the nip (space between the rolls )of the two rolls.
2. Gelation Control
PVC material requires controlled thermal and mechanical energy to initiate plasticization ,which is also named as gelation.
The open mixing mill allow the operator visually monitor the PVC material and adjust temperature and mixing time accordingly ,so that achieve proper gelation without over-degrading the PVC.
3. Small Batch Flexibility
From the laboratory mixing mill , factories find the suitable formulation through smal batch lab testing , it is ideal for trial batches, formulation development, or R&D in both labs and production lines.
With this lab two rolll mill ,you can quickly test new PVC formulations before scaling up to extrusion or calendaring.
Sometimes some additives like plasticizers, stabilizers, and fillers may be added directly on the two roll mill.
4. Sheet Formation
After mixing and kneading, the PVC material can be formed into sheets by adjusting the nip gap.
The two rolls open mixing mill can also form the PVC compound into sheets, which are needed for pre-processing steps or direct use in calendaring machines or extrusion machine . This mechanical energy helps mix the components uniformly and initiate gelation/plasticization of PVC.
5. Easy to Operate
The lab PVC two roll mill offers manual control over nip gap, friction ratio, and roll temperature—helpful for sensitive PVC formulations.
The operators can observe texture, temperature ,color, and consistency in real time. Careful control of temperature is critical to avoid PVC degradation (usually kept under ~160–180°C).
So here let us conclude ,Why need to Use an Open Mill for PVC Material ?
1. Great for small batch testing or custom formulation
2. Easy visual monitoring of mixing progress
3. Manual control allows flexibility in mixing time and additives
If you’re targeting high-precision PVC products like cables, films, or specialty sheets, an open mixing mill equipment can be a very valuable part of the process.
Want a comparison between open mill and internal mixer for PVC?