Membrane Filter Holders Singapore
A filter holder is a simple piece of equipment that decides whether a filtration takes ten minutes or two hours. The membrane does the separating, but the holder decides the active area, the pressure the membrane can take, the material the sample touches and how much of the sample is lost on the walls.
At JW RESEARCH SUPPLY, we supply vacuum and pressure membrane filter holders in glass, PTFE and stainless steel to laboratories, water testing teams and quality departments across Singapore, together with membranes, prefilters and support discs to match. This guide explains how to choose one.
Membrane Filter Holder Types Compared
| Type | Typical Membrane | Drive | Best For |
|---|---|---|---|
| Syringe filter holder | 13 – 25 mm | Manual syringe | Small samples, HPLC preparation |
| Vacuum filter holder, glass | 25 / 47 mm | Vacuum flask | Microbiology, sterility testing |
| Vacuum filter holder, stainless | 47 / 90 mm | Vacuum or pressure | Rugged daily use, high flow |
| Pressure filter holder | 47 / 90 / 142 mm | Compressed gas | Viscous samples, solvent filtration |
| PTFE filter holder | 25 / 47 mm | Vacuum or pressure | Aggressive solvents, trace analysis |
| Multi-place manifold | 47 mm × 3 or 6 | Vacuum | Batch microbiological testing |
Selection Data and Handling Guide
| Parameter | Typical Range | Why It Matters |
|---|---|---|
| Membrane diameter | 13, 25, 47, 90, 142 mm | Sets active area, flow rate and capacity |
| Funnel volume | 15 mL to 1000 mL | Fewer refills, less sample handling |
| Body material | Borosilicate glass, PTFE, 316 stainless | Chemical compatibility and extractables |
| Support | Fritted glass or perforated screen | Frit blocks less, screen flows faster |
| Clamp | Aluminium spring or screw clamp | Even sealing without cracking glass |
| Pressure limit | Vacuum to about 3 – 7 bar | Glass units are not for high pressure |
| Autoclavable | 121 °C, 15 – 20 min | Required for sterile filtration work |
Choosing the Right Holder
- Sampling a few millilitres? Use 25 mm — Small active area suits microscopy and clean-up.
- Routine aqueous work? Use 47 mm glass — The general-purpose size in most laboratories.
- Several litres at a time? Step up to 90 mm — More area means far less blinding.
- Aggressive solvents? Use PTFE — Lowest extractables and almost universal inertness.
- High throughput or pressure? Use stainless steel — Tough, fast and safe under load.
- Batch microbiology? Use a manifold — Three or six places in one vacuum run.
Running a Filtration Properly
Seat a fresh membrane centrally on the support, wetting hydrophobic membranes with a little compatible solvent if the manufacturer recommends it, and close the clamp evenly so the seal is uniform rather than over-tight at one point. Use a vacuum that suits the membrane's bubble point and apply pressure slowly: a sudden full vacuum can rupture a membrane or pull a slug of sample past the seal and into the filtrate. Match the prefilter to the load, because when a sample is heavy with solids it is far cheaper to replace a coarse glass fibre disc than a fine membrane. For sterile work, assemble and sterilise the unit as one item, open sterile packaging in the cleanest zone available, and never reach over an open funnel. Cold or viscous solutions filter slowly by nature, so warm or dilute them before blaming the hardware, and note that a head of liquid above the membrane helps flow just as much as extra vacuum. After every run, dismantle, clean and dry the unit fully; dried sample on a fritted support is the most common cause of a holder that slowly stops working.
Why Choose JWRESEARCH for Filter Holders in Singapore?
- Complete filtration range — Holders, membranes, prefilters, support discs and flasks.
- Materials matched to your chemistry — Glass, PTFE and stainless steel options.
- Consistent stock — Matching membranes always available alongside the hardware.
- Fast local delivery — Quick dispatch across Singapore so work never waits.
JWRESEARCH supplies glass, PTFE and stainless steel membrane filter holders, syringe holders, vacuum manifolds, membranes and prefilters to laboratories across Singapore. Contact us for sizes, materials and volume pricing.
📞 +65 8039 3660 | ✉️ SINGAPORE@JWSHY.COM
🌐 www.jwresearch.cn
Frequently Asked Questions
Q: What size membrane filter holder should I choose?
Match the holder to the volume you filter and to the membrane diameter you already stock. A 25 mm holder is intended for small volumes, typically a few millilitres up to about 20 millilitres, and is convenient for syringe-scale work, small sample clean-up and looking at a single filter under the microscope, where the small active area is an advantage. A 47 mm holder is the general laboratory workhorse: it accepts 47 mm membranes, handles roughly 100 millilitres to a litre in one pass and gives enough active area that flow does not stall on a moderately loaded sample. A 90 mm or 142 mm holder is chosen for large-volume work, particulate surveys, and any application where a single filter must collect a visible amount of solids from several litres. As a rule, do not force a large volume through a small holder: the membrane blinds, flow collapses and the run takes far longer than it would with the right diameter.
Q: Should I buy a glass, PTFE or stainless steel filter holder?
Glass is the usual first choice because it is chemically inert to most aqueous solutions and most common solvents, it can be autoclaved, and the filtration progress is visible through the funnel. Borosilicate glass with a fritted glass support is excellent for microbiology, sterility testing and general aqueous filtration, but it is fragile and should not be used with hydrofluoric acid or hot concentrated alkali, and a sintered glass support needs careful cleaning to keep its pores open. PTFE bodies are chosen where the sample attacks glass or where the lowest possible extractables matter, such as trace analysis and aggressive solvent work; they are inert to almost everything, autoclavable and non-wetting, but they are softer and must not be over-tightened. Stainless steel is the choice for pressure-driven work, high flow rates, reverse-flush cleaning and rugged daily use, and it tolerates pressure far better than glass, but it is opaque and must be checked for corrosion if halogenated or chloride-rich solutions are used. Many laboratories keep one glass vacuum unit for routine work and one stainless steel pressure unit for viscous or high-throughput jobs.
Q: Why is my filtration suddenly very slow?
In most cases the membrane has blinded, not the holder. As solids build on the surface, the effective pore area falls away sharply, and flow that starts briskly becomes a drip within minutes. Prefilter the sample through a coarser glass fibre disc or a coarser membrane stacked above the fine one, reduce the volume loaded, or split the sample across several filters. Check the obvious mechanical causes as well: an air leak at the clamp or the vacuum hose, a partly blocked fritted support, a membrane seated off-centre so that only part of it is in the flow path, or a vacuum that has dropped because the pump trap is full or the pump itself is worn. Very viscous samples, cold samples and samples with a high dissolved solids content all filter slowly by nature, and slightly warming the solution or diluting it will do more good than any change of hardware. Finally, confirm the membrane is the right material: a hydrophobic membrane will resist water entirely and can look like a blockage when it simply needs pre-wetting.
Q: How should a filter holder be cleaned and sterilised?
Dismantle the holder completely after every use, remove the membrane and the support, and clean each part separately so that no sample dries in the clamp area or on the frit. Wash with a warm neutral detergent, rinse thoroughly with tap water and then with distilled or deionised water, and finish with a solvent rinse that is compatible with the material, working from the cleanest solvent to the dirtiest use and back again. For microbiology work, autoclave glass and stainless steel units at 121 degrees Celsius for 15 to 20 minutes according to your validated cycle, or sterilise them in a hot air oven where the manufacturer allows it; PTFE parts may be autoclaved but must be left loose so that they do not distort. Never autoclave a unit with a membrane clamped in place unless the procedure requires it, never use abrasive cleaners on a fritted support, and store dry parts in a dust-free container so that airborne particles do not become your next blank.