Washable Activated Carbon Sponge Filter for Odor Removal

The Oltaven washable activated carbon sponge filter is a flexible, reusable filter that combines coarse particle capture with adsorption of formaldehyde, benzene, ammonia and other odorous gases. It is made from polyurethane sponge loaded with specially fixed activated carbon, and it is designed for air purifier pre-filters, fresh air systems, car cabin filters, central air return grilles and industrial vacuum cleaners. Oltaven supplies the finished filter in custom thicknesses, pore densities and shapes, not just the raw media.

From Media to Finished Filter

Activated carbon is good at trapping gas molecules, but on its own it is a powder or fine granule that is difficult to handle and easy to lose in an air stream. The finished filter solves that by fixing the carbon inside an open-cell polyurethane sponge. The sponge holds the carbon in place, gives the filter a stable three-dimensional shape, and lets air pass through with low resistance. The result is a filter that can be washed, cut and fitted into compact equipment without shedding carbon.

The choice of sponge and carbon grade sets the starting point, but the finished performance comes from how the two are combined and formed. A higher carbon loading generally gives more adsorption sites, while a more open sponge structure keeps resistance low. Oltaven balances these factors for each application, so the filter delivers the intended airflow and odour control in the device where it will be used.

What Decides Finished Performance

Three things decide how a carbon sponge filter performs in practice: the media, the forming, and the way it is sealed into its housing.

Media choice. The activated carbon grade and loading determine how much gas the filter can adsorb. The sponge’s pore density, measured in pores per inch (PPI), affects both airflow and the amount of carbon that can be held. A denser sponge may hold more carbon but can raise resistance, so the right balance depends on the fan and the space available.

Pleating and shaping. Unlike pleated paper filters, this product is a flexible sponge. Forming therefore means cutting, stamping or die-cutting the sponge to the required outline and thickness. Oltaven can supply thicknesses from 3 mm to 50 mm and can produce circular, rectangular or irregular shapes. The forming step also sets the effective surface area exposed to the air stream, which influences both particle capture and gas adsorption.

Framing and sealing. A finished filter needs to sit securely in its housing so that air passes through the media rather than around it. Oltaven can add frames or edge treatments where required, and the sponge can be supplied with or without a frame depending on the application. The sealing method is chosen to suit the device, so the filter stays in place during use and can still be removed for washing.

Because Oltaven controls these steps in-house, we can adjust the finished filter’s efficiency, resistance and capacity to match a specific device. That is why two filters of the same size can behave differently: the difference lies in the carbon loading, the sponge structure, the forming accuracy and the sealing, not just the outer dimensions.

Applications

The washable activated carbon sponge filter is used wherever coarse dust and odours need to be handled together in a compact space. Typical applications include:

• Air purifier pre-filters, where it captures hair and dust before the main filter and adds odour control.
• Fresh air ventilation systems, as a pre-filter that reduces dust and odorous gases entering the system.
• Car cabin air filters, where it helps adsorb exhaust and environmental odours.
• Central air conditioning return grilles, for coarse filtration and odour reduction.
• Industrial vacuum cleaners, where it protects the motor and reduces odours from collected dust.

In each case, the filter can be washed and reused, which reduces consumable costs compared with disposable carbon filters. Its flexible sponge construction also makes it easy to fit into irregular spaces.

Technical Specifications

The Oltaven Factory and Certifications

Oltaven is a filter manufacturer with more than 20 years of experience in filter development and production. We support OEM/ODM projects and have developed more than 1,000 filter solutions for customers. Our plant covers 50,000 m², including six cleanrooms totalling 20,000 m², where filters for sensitive applications are produced.

Our in-house laboratory is CNAS-accredited and can issue test reports for filtration efficiency, dust-holding capacity and resistance. The company holds IATF 16949 certification (obtained in 2024) and ISO 9001, ISO 14001 and ISO 45001 system certifications. Products comply with REACH and RoHS requirements, and compliance documents can be provided. We have been exporting to Europe, the United States, Japan, Korea and other markets for over 20 years.

OEM/ODM Workflow

1. Inquiry and requirements. Share your device or vehicle model, required size or drawing, airflow or water flow, operating conditions and estimated quantity.
2. Evaluation and proposal. Our team reviews the requirements and recommends a suitable sponge grade, carbon loading, thickness and PPI.
3. Sampling. We produce samples for your testing, typically within 5–7 working days for custom designs.
4. Validation. You test the samples in your device; we adjust the design if needed.
5. Production. After sample approval, we manufacture the order on automated lines with IQC, IPQC and OQC checks.
6. Delivery. Finished filters are packed to your requirements and shipped by sea, air or express.

Start a Custom Project

To receive a quotation or sample, please tell us your device or vehicle model, the required size or a drawing, the airflow or water flow, the operating conditions, and the quantity you expect to order. With those details, Oltaven can propose a finished filter that matches your performance and cost targets. Contact our team to begin.