Many CBD oil extraction machine do come equipped with built-in filtration systems or steps to remove impurities, but the specifics can vary depending on the type of extraction method used and the design of the machine. Here's an overview of what you might find:

CO2 Extraction Machines:

Built-in Filtration: These machines often include multi-stage filtration systems to separate the desired cannabinoids from unwanted plant material, waxes, and chlorophyll.

Winterization: Some CO2 systems integrate winterization, a process that involves mixing the crude extract with ethanol and freezing it to precipitate out fats and waxes, followed by filtration.

Ethanol Extraction Machines:

In-Line Filtration: Ethanol extraction machines frequently have in-line filtration to remove plant particles during the extraction process.

Winterization: Similar to CO2 extraction, ethanol systems may include a winterization step, either within the same machine or as part of a multi-machine setup.

Hydrocarbon Extraction Machines:

Filtration and Purging: These machines typically have filtration systems to remove impurities, and they often include a purging process to eliminate residual solvents, ensuring that the final product is free from contaminants.

Supercritical Fluid Extraction (SFE) Machines:

Precision Filtration: SFE machines, which often use supercritical CO2, can incorporate precision filtration steps to ensure that only the desired cannabinoids and terpenes are extracted, leaving behind unwanted materials.

Post-Extraction Filtration:

In some cases, filtration is performed post-extraction, using additional equipment to remove impurities and refine the oil further.

It's important to review the specifications of the specific machine you're considering to understand the exact filtration capabilities and whether any additional post-processing steps are required to achieve the purity level you need.