Customized Liquid Filter Bag Solution for Precision Applications SFFILTECH – Engineering Filtration Excellence

Customized Nylon and Polypropylene Filter Bags for Liquid Filtration Systems

During this project, the customer required a series of non-standard liquid filter bags, mostly in nylon, with a very specific size — inner diameter 85 mm, outer 85.5 mm, and length 305 mm.

These are smaller than the standard size 1/2 bags, so the first step for us was to design and open a new plastic ring mold to match their system.

1. Project Background

In precision liquid filtration applications such as coating, cooling, and cleaning systems, customers often require non-standard filter bag dimensions with special diameter, length, or sealing structure.

To meet these customized demands, SFFILTECH provides engineering-grade filtration solutions, covering mold development, frame welding, and material performance testing.

2.Inquiried Product Scope

Customized Nylon Bag Filters

All filters are double-layer nylon mesh (PA) with heat-sealed or thermo-welded plastic frames, designed for fine particle removal and high flow performance.

Product	Micron Rating	Internal Diameter	External Diameter	Length	Construction	Sealing Type
Nylon Bag Filter	5 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic frame – Heat sealed
Nylon Bag Filter	10 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic frame – Heat sealed
Nylon Bag Filter	25 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic frame – Thermo-welded
Nylon Bag Filter	50 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic ring – Heat sealed
Nylon Bag Filter	100 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic frame – Thermo-welded
Nylon Bag Filter	150 µm	85 mm	85.5 mm	305 mm	Double-layer nylon	Plastic frame – Thermo-welded

Termination characteristic code: P"x"***

Customization: Full OEM available upon technical drawing or sample.

Polypropylene (PP) Filter Bags for Liquid Filtration

Product	Micron Rating	Diameter	Length	Material	Special Feature
PP Filter Bag	5 µm	178 mm	813 mm	Polypropylene	Standard heat-sealed
PP Filter Bag	10 µm	178 mm	813 mm	Polypropylene	Standard heat-sealed
PP Filter Bag	25 µm	178 mm	813 mm	Polypropylene	Standard heat-sealed
PP Filter Bag (Anti-Oil)	25 µm	178 mm	813 mm	PP Anti-Oil Fabric	Heat-sealed

Filter Blanket Materials

Type	Material	Width	Weight	Thickness
Large Blanket Filter	PP / PE	705 mm	35 g/m²	0.3 mm
Small Blanket Filter	PP / PE	505 mm	35 g/m²	0.3 mm

3. Engineering Process

How we make the liquid filter bag for them in professional way?

How we offer one formal quotation in professional way?

Step 1: Mold Design & Development

Because the nylon filter bags required a special 85 mm plastic frame (non-standard size),

SFFILTECH’s engineering team designed and opened a custom injection mold to ensure precise fitting and smooth sealing edge.

We optimized:

Ring thickness and diameter tolerance

Groove geometry for welding compatibility

Matching with customer’s existing filter housing system

Step 2: Plastic Frame Welding & Assembly

Each filter bag is thermo-welded using controlled temperature fusion to achieve:

Uniform sealing with zero leakage

Firm bonding between frame and double-layer mesh

Long-term stability under flow and temperature fluctuation

Step 3: Material & Technical Validation

All nylon filter fabrics (5–150 microns) and polypropylene felts were tested for:

Air permeability

Bursting strength

Micron retention accuracy

Thermal resistance (up to 120°C)

Chemical compatibility with coolant and coating media

Technical datasheets were provided for client approval before mass production.

Step 4: keypoint:Quotation & Sample Delivery

After confirming the design and technical validation,

SFFILTECH supplied:

Engineering drawing (STEP format) of liquid filter bag top and whole filter bag drawing for customer reference

Material datasheet (PP / Nylon) for this liquid filter bag

Customized quotation for small-batch trial order

Optional support for filter media roll supply (hot air cotton / melt-blown layer) for assembly testing

4. Why they prefer to Choose SFFILTECH

For me, i think total five reason:

Full Engineering Support – from drawing to mold and finished product

Precision Manufacturing – strict quality control for dimension & sealing accuracy

Flexible Customization – small-batch OEM accepted

Fast Prototyping – mold opening and sample delivery within 10–15 days

Global Experience – filtration supply for automotive, paint, and chemical industries

5. Technical Parameters Summary

Parameter	Value
Micron Range	5–150 µm
Bag Length	305 mm / 813 mm
Ring Type	Plastic (custom 85 mm mold)
Sealing	Heat sealed / Thermo-welded
Media	Nylon / Polypropylene / Polyester
Temperature Resistance	120°C (continuous)
Chemical Resistance	Acid, alkali, oil, solvent
Flow Direction	From inside to outside

We have confidence to offer right liquid filter bag for you, if you come to us.

Application Products

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