Filter Bags in Standard Nominal Rated Felt

Polypropylene (PP) and polyester (PE) are two common materials used in bag filter media for liquid filtration, and they have several differences:

Chemical Resistance:

Polypropylene (PP): PP offers excellent chemical resistance to a wide range of acids, alkalis, and organic solvents. It is particularly suitable for applications involving aggressive chemicals.

Polyester (PE): Polyester also provides good chemical resistance but may not be as resistant to certain aggressive chemicals compared to PP. However, it offers better resistance to higher temperatures. (Please fer to datasheets for Maximum Temperatures

Temperature Resistance:

Polypropylene (PP): PP has lower temperature resistance compared to polyester. It is typically suitable for applications with temperatures up to around 200°F (93°C).

Polyester (PE): Polyester can withstand higher temperatures than PP, making it suitable for applications where elevated temperatures are present, typically up to 300°F (149°C) or higher.

Mechanical Strength:

Polypropylene (PP): PP has good mechanical strength and is resistant to tearing and puncturing, making it durable for filtration applications.

Polyester (PE): Polyester also has good mechanical strength and can withstand higher stress and strain compared to PP.

Mechanical Strength is generally only a concern when a filter bag is being used in an open filtration application. When installed in a vessel the bag is supported by a stainless steel perforated basket.

Micron Rating and Filtration Efficiency:

Both PP and PE can be manufactured to various micron ratings to meet specific filtration requirements. The micron rating indicates the particle size that the filter media can effectively capture. Both materials can achieve high filtration efficiency.

Standard Felt Fiter Bags are Nominal Rated, approx. 70% to 80% removal efficiency at the stated micron size per pass. The actual result will be influenced by the solids loading and the article size distribution.

Cost:

Polypropylene (PP): PP is generally more cost-effective compared to polyester, making it a preferred choice for applications where cost is a significant factor.

Polyester (PE): Polyester tends to be slightly more expensive than PP due to its higher manufacturing costs and superior temperature resistance.

In summary

The choice between polypropylene (PP) and polyester (PE) bag filter media depends on factors such as chemical compatibility, temperature requirements, and cost considerations specific to the filtration application.