Medical Fluid Management & Filtration

An open-cell reticulated polyurethane in an ISO 10993-referenced grade. To absorb, wick, and distribute a fluid you need a through-porous open-cell structure that lets the fluid in and moves it by capillary action, which a closed-cell foam or a solid material cannot do. An ISO 10993-referenced reticulated polyurethane (FilterPore class) is the usual choice where the foam contacts a sample or reagent, in a pore grade tuned to the absorbency and the wicking rate you need.

The pore grade is the controlling property: a finer pore holds more fluid and wicks more strongly but passes flow more slowly, a coarser pore passes more flow and wicks more weakly. State the absorbency, the wicking rate, and the fluid contact on the drawing, and H-O the pad to your cartridge geometry. Grades are referenced to ISO 10993 and USP Class VI by designation; pore and density are reported per ASTM D3574.

Match the pore grade to the trade-off between flow and filtration or wicking. Pore grade is measured in pores per inch (PPI): a finer pore (higher PPI) filters smaller particulate, holds more fluid, and wicks more strongly, but passes flow more slowly and can clog if the particulate load is high; a coarser pore (lower PPI) passes more flow and resists clogging, but filters less and wicks more weakly.

You cannot maximize flow and filtration (or flow and absorbency) at once, so decide which the application needs more and select the grade from the maker pore range to suit, then verify on the maker TDS. Where a bare pore is not enough, a coated reticulated foam adds a barrier or a directional control on one face. Remember the media is a reticulated foam, not an absolute or sterile filter, so any absolute or sterility rating belongs to the device maker's validated filter.

Pore and density are reported per ASTM D3574.

Use a low-extractable, chemically compatible material in a non-porous (solid or closed-cell) form. A fluid-path seal must block the fluid and must not leach substances into a sample or reagent or degrade in the fluid, so a low-extractable material is preferred.

A platinum-cured medical silicone (BISCO MS-1600) leaves no peroxide cure by-products and is the low-extractable, high-purity choice for a clean fluid path; an FFKM perfluoroelastomer handles aggressive solvents and reagents an elastomer would not; an FDA pharmaceutical butyl suits a pharmaceutical or low-permeability closure; and an FDA-grade white or translucent elastomer is the general fluid-contact seal.

Match the material to the fluid chemistry and the purity requirement. The device maker owns the extractables and leachables assessment for the finished fluid path; H-O references a low-extractable grade and provides the material documentation, with grades referenced to the medical designations by the maker. Durometer is reported per ASTM D2240.

Decide by what the part does to the fluid. An open-cell foam is through-porous, so the cells connect and a fluid passes through; you need open-cell to absorb, wick, distribute, filter, or diffuse a fluid. A closed-cell foam (or a solid material) has sealed cells that block fluid passage; you need closed-cell or solid to seal a fluid path or to make a moisture seal.

So if the job is to move or hold a fluid, choose open-cell (reticulated polyurethane); if the job is to keep a fluid out or in, choose closed-cell or solid (a medical or FDA-grade elastomer). Two foams can look similar but have opposite cell structures, so verify the cell type on the maker TDS rather than by appearance. State the fluid job clearly on the drawing, manage versus seal, and the cell type follows.

Foam properties are reported per ASTM D3574.

Yes, if the adhesive is placed where it does not seal the functional face. A device-side pressure-sensitive adhesive applied across an absorbent or filtration surface seals the pores it touches and blocks the fluid path the foam was chosen to provide, so the rule is to keep the adhesive off the functional face. H-O can put the adhesive on a non-functional edge or a backer face, laminate a backer away from the absorbent surface, or leave the pad adhesive-free and let the assembly hold it mechanically.

Tell H-O which face is functional (the one that contacts and moves the fluid) and how the pad is held, and the converted construction keeps the fluid path open while still locating the part. For a multi-layer part, the lamination and kiss-cut-on-liner are arranged so the absorbent face stays open. State the functional face on the drawing.

H-O references material grades by designation and assembles documentation aligned to your requirements. State the fluid contact (the fluid it touches and whether that fluid reaches the patient), the duration, and the basis you need, ISO 10993 endpoints (for example cytotoxicity), a USP Class VI designation, or an FDA contact basis, and H-O sources a grade whose maker evaluates it against those frameworks and provides the material TDS, certificate of conformance, and lot traceability.

The key distinction is who owns what: the material maker evaluates the grade at the material level, and the device maker owns the finished-device biocompatibility and the extractables and leachables assessment for the actual fluid path. H-O is an ISO 9001:2015 certified converter; it does not independently certify materials and does not certify finished devices, and it does not claim an ISO 13485 certification, an FDA device registration, or a cleanroom certification.

Customer-specified compliance packages are assembled on request.

No. A reticulated polyurethane is a through-porous foam that filters and diffuses by its pore structure, catching particulate above a size set by the pore grade and controlling the flow, but it is not an absolute filter (which has a defined, validated retention rating) and it is not a sterile filter (which has a validated sterilizing-grade rating).

The reticulated foam is well suited to coarse-to-medium particulate filtration, diffusion, and flow control, and to wicking and absorption, but where the application needs an absolute retention rating or a sterilizing-grade filter, that is a different, validated filter media that the device maker specifies and validates.

On this page the reticulated foam is framed as a fluid-management and diffusion media, not as a sterile or absolute filter, and any such rating belongs to the device maker. State the particulate and flow you need, and H-O recommends the pore grade; the validated filter rating is the device maker's.

An FFKM perfluoroelastomer is the broad-chemistry choice. Where a fluid path carries an aggressive solvent or reagent that would swell or attack a silicone or an FDA-grade elastomer, a perfluoroelastomer (FFKM) in a USP Class VI / FDA medical grade gives broad chemical resistance and low extractables, so it holds up where other elastomers fail. It is the premium fluid-seal material, so reserve it for the chemistry that needs it rather than as a default.

For a moderately demanding chemistry a platinum-cured medical silicone may suffice, and an FDA pharmaceutical butyl suits a pharmaceutical or low-permeability closure. The deciding input is the specific fluid chemistry and its concentration, so state the fluids the seal contacts on the drawing, and H-O recommends a grade and provides the material chemical-compatibility data from the maker TDS. The device maker confirms the compatibility and the extractables for the finished fluid path.

Durometer is reported per ASTM D2240.

Often single-use, but it depends on the grade and the method. Reticulated polyurethane absorbent and filtration foams are frequently used in single-use consumables, and a chosen sterilization method may limit how the foam can be reused, so the reuse question must be checked on the maker TDS for the grade and method. By contrast, the silicone seals on this page (cellular sponge and solid medical silicone) broadly tolerate steam, ethylene oxide, gamma, and e-beam as a family and suit a reusable seal — verify the specific grade and cycle count on the maker TDS.

The practical approach is to state whether the part is single-use in a consumable or reused across cycles, and the sterilization method, on the drawing, because a single-use absorbent pad has a wider material choice than a seal autoclaved daily. Where gamma is used on silicone, verify the dose limit, since high-dose gamma stiffens silicone. This is a material-level property; H-O references the grade and defers the method-specific limits to the TDS on file.

Yes. H-O laminates a reticulated foam pad to a film backer, a coated barrier, or an adhesive layer and the assembly as one part, which is common for fluid-management constructions: a wick pad on a film backer that directs the fluid, a foam with a coated face that adds a partial barrier, or a pad with an adhesive on a non-functional face for placement.

The lamination is arranged so the absorbent or filtration face stays open and the fluid path is preserved. Tell H-O the layer stack (the foam grade and pore, the backer or coating, any adhesive and which face), the functional face that must stay open, and the part geometry, and supply the drawing. H-O laminates the layers, the pad or media to the path geometry, and kiss-cuts it on liner where the line peels and places it.

The lamination and die-cutting are standard converting operations.

No. H-O Products is a precision converter: it makes the fluid-management parts (absorbent and wicking pads, filtration media, fluid-path and cartridge seals, lab-equipment seals) to your drawing from material grades commonly used in medical-device and life-science fluidics, under an ISO 9001:2015 quality management system. H-O is an ISO 9001:2015 certified organization; that certification governs the converting process, not a device clearance.

H-O does not make finished medical devices and does not claim an ISO 13485 certification, an FDA device registration or clearance, or a cleanroom certification.

Material grades are referenced by designation to ISO 10993, USP Class VI, and FDA composition frameworks at the material level, where the material maker performs the evaluation. The finished-device biocompatibility, the fluid extractables and leachables assessment, the filter validation, and the regulatory file belong to the device maker. H-O supplies the converted parts, the material documentation, and lot traceability aligned to your requirements.

Send the part drawing or a sample and five things: what the part does to the fluid (absorb or wick, filter or diffuse, or seal), the flow or chemistry detail (the absorbency and wicking or the pore for a foam, the fluid chemistry and purity for a seal), the fluid contact (contacts a reagent or sample, contacts the patient, or no fluid contact), the geometry (the pad, wick, media, or seal outline, the gauge, the functional face, and any lamination or adhesive), and whether the part is single-use or reused and the sterilization method.

If a contact basis applies, state the ISO 10993 endpoints, the USP Class VI designation, or the FDA contact basis. Add the prototype and annual volume. With that, engineering returns a material family and pore or grade, a converted-part approach, prototype lead time, and the documentation that can be aligned to your requirements. The quote form below has fields for each of these.

Samples typically ship in 3 to 5 business days; standard production in about 2 weeks.