Polyvinyl Chloride (PVC) is one of the most widely used thermoplastic materials in various industries due to its feature due to its durability, flexibility, and versatility . For example such as plastics pipes, cables, medical devices, profiles, flooring, blood bags, tubing , clothing, footwear ,electrical wiring , packaging for films and bottle etc.
However , before PVC compounds are used in mass production, formulation testing must be gone through ,so that evaluate material properties.
So in laboratory R&D setting , one of this laboratory testing equipment for PVC is laboratory two-roll mill machine.
This compact two roll mill machine is a small-scale open mixing mill designed for PVC compounding, blending, and testing under controlled conditions ,it is used in the plastics and rubber industries for compounding PVC with additives like pigments and stabilizers.
This laboratory equipment allows engineers, researchers, and product developers to mix, plasticize, and test PVC materials under controlled conditions.
Here ,in this blog ,let us explore how do the laboratory two roll mill work for PVC compound testing ?
1. What Is a Lab Two-Roll Mill?
A laboratory two-roll mill is a compact lab version of an industrial open-type mixing mill machine. It consists of two horizontally placed cylinder steel rolls rotating towards each other at different speeds in opposite direction . Its rotating action generate intensive force to the compound material , in order to knead, blend, and homogenize PVC materials homogenized and evenly.
The lab two roll mills provide precise control for small-batch testing and material evaluation, allowing operators to evaluate and adjust the dispersion of color and physical changing of property .
2. How Does a Lab Two-Roll Mill Work for PVC Material?
The process of PVC on lab two-roll mill for PVC is actually mechanical shearing, kneading and compression repeatedly . The PVC material need to put in the gap of roll , kneading, stretching, and folding again and again between the gap of these two rotating rolls ,so that the mixture can be mixed and plasticized uniformly and evenly.
Here ,let us tell the working process clearly step by step as follows:
Step 1: Preheating the Rolls
Firstly , the PVC materials need to be heated in controlled temperature, in order to achieve plasticity.
As the same time , the rolls of this machine need to be preheated as well via electric heaters or oil circulation systems. It depends on which kind of laboratory mixing mill equipment are you using or want to purchase which kinds of equipment.
Generally ,the temperature to process PVC compound material need to controlled at range between 150°C and 190°C, as to what degress temperature you need to adjust, it depends on your specific formulation.
Step 2: Feeding PVC + Additives
Secondly ,the PVC material are fed onto the gap of two roll , if we want to add other additives , resin, plasticizer, stabilizers, colorants, and fillers etc ,they are also added manually on the mixing process .
On the process , we can adjust the nip of two roll ,so that adjust and control the thickness of sheet material and mixing intensity.
Step 3: Mixing & Kneading
The two rolls rotate at different speeds in opposite direction, we need to adjust their friction ratio ~1:1.2 or 1:1.3 usually. Through the rotating rolls ,they create strong shearing and blending action on the PVC compound to achieve uniform dispersion of additives ,homogeneous mixing and controlled plasticization .
Step 4: Material Formation
The processed PVC mixture by the process of kneading and mixing ,and finally it forms a thin, hot sheet on the rolls.
The PVC sheets can be peeled off using a scraper knife and re-fed for multiple passes in order to achieve thorough mixing completely.
Step 5: Cooling
After sufficient mixing and kneading repeatedly, the PVC sheet achieve the purpose of being homogenized and blended fully , it then can be removed and cooled as final sample for reference .
The PVC sheet samples are then used for testing of material for several purpose ,such as:
* Tensile strength testing
* Impact resistance measurement
* Thermal stability evaluation
* Color uniformity checks
3. Why Use a Lab Two-Roll Mill for PVC Processing
PVC processing requires accurate formulation control, efficient material blending, and stable testing conditions.
While a lab two-roll mill equipment offers several advantages that make it ideal for PVC compound research and quality control.
For example :
* Precise temperature control —- prevents PVC degradation
* Small-batch processing —- Testing new formulations for material analysis , Or preparing small PVC for further evaluation.
* Uniform plasticization —- better material performance evaluation
* Repeatability —- Since just a little sample testing ,it can be process and tested repeatedly ,ensures consistent test results
* Versatility —- PVC is widely used due to its sturdiness and resistance to chemicals and moisture , thus suitable for rigid, semi-rigid, and flexible PVC compounds.
In conclusion , no matter for laboratories or manufacturers, if you need to process or handle with PVC compounds, a lab two-roll mill machine is an essential equipment . The two roll mill become indispensible lab tool for R&D, formulation testing, and quality control ,because it offers precise control, efficient mixing, and consistent sample preparation, invaluable.
By using a lab two-roll mill for PVC , engineers and researchers can optimize PVC formulations, improve product performance, and reduce development costs, thus with laboratory mixing mill ,it would provide you better-quality PVC products.
At Simptek , we specialize in manufacturing high-precision laboratory two-roll mills designed for PVC compounding and R&D.
To learn the advantage of laboratory mixing mill equipment ,welcome to visit our blog here for more…