Leading Hollow Fiber Membrane Spinning Machine and Spinneret Manufacturer - Trustech

Hollow fiber membrane spinnerets

Hollow fiber membrane spinnerets are the core components for producing hollow fiber membranes. Their structural design, performance, and manufacturing precision directly determine the fiber's concentricity, wall thickness uniformity, pore size distribution, mechanical strength, and separation performance.

Product advantages

● High Reliability
● Extended Service Life
● Robust Needle Design
● Integrated Spinneret Core
● Easy Cleaning and Maintenance
● Convenient Maintenance for MBR Braided Tube Coating Spinneret
● Modular Design with Separate Spinneret Core and Flow Channel Plate

Inquiry

Write a Review

Structural Features

Coaxial dual-channel design: The outer channel delivers the polymer solution (e.g., PES, PAN), while the inner channel injects the bore fluid (e.g., pure water, solvent, or gas), forming a "tube-in-tube" structure. The inner and outer diameters of the spinneret orifices determine the membrane's inner diameter, outer diameter, and wall thickness.

Working Principle

In dry-wet or wet spinning, the polymer solution is extruded from the outer annular gap, while the bore fluid is injected through the central channel. They meet at the spinneret outlet. The polymer solution contacts the external coagulation bath and the internal bore fluid, undergoes phase separation, and solidifies to form a hollow fiber membrane with a skin layer and finger-like or sponge-like pore structure.

1-1-wet-spinning-spinneret_03b

1-1-wet-spinning-spinneret_04b

1-1-wet-spinning-spinneret_02b

1-1-wet-spinning-spinneret_01b

Trustech Spinneret Key Design Elements Trustech

These parameters are fundamental to spinneret design and directly determine the membrane's final performance:

Parameter	Description	Influence on membrane performance
Flow channel (R)	The runner for transporting, buffering, and distributing the dope and bore fluids.	Different structures should be optimized according to material properties, viscosity, spinneret orifice size, and hole quantities to achieve optimal spinning performance.
Annular gap width (d)	The gap (thickness) of the dope flow channel.	It primarily determines the hollow fiber wall thickness. Narrower gaps yield thinner walls and lower mass-transfer resistance, but may reduce mechanical strength.
Bore tube outer diameter (d₁)	The outer diameter of the central tube forming the inner wall of the annular gap.	Together with the outer sleeve inner diameter, it defines the annular gap width.
Outer sleeve inner diameter (d₂)	The inner diameter of the spinneret outer sleeve forming the outer wall of the annular gap.	Together with the bore tube outer diameter, it defines the annular gap width and the fiber outer diameter.
Central tube inner diameter (d₃)	The diameter of the bore fluid channel.	It primarily determines the fiber inner diameter. The inner diameter affects membrane module packing density and the pressure drop of fluid inside the fiber.
Length-to-gap ratio (L/d)	The ratio of the flow channel length (L) to the annular gap width (d).	It affects spinning stability. Designing an appropriate L/d according to material properties and process conditions helps stabilize flow and eliminate entry effects, resulting in more uniform extruded fibers membrane.
Concentricity	The coaxial alignment among the dope layer inner diameter at the spinneret outlet and the bore tube inner and outer diameters.	It affects wall-thickness uniformity and bubble point pressure.
Extrusion face geometry	The foremost geometry of the spinneret, such as flat or micro-tapered.	It influences draw-down and deformation after extrusion, especially important for the air-gap segment in dry-wet spinning.

The Advantages of Trustech FCT Spinneret Trustech

The spinneret design covers a wide dope viscosity range, offers strong versatility, high spinning stability, and effectively reduces issues such as filament breaks.

Hollow fiber membrane spinnerets 9 Modular Design with Separate Spinneret Core and Flow Channel Plate: No positioning pins needed, making assembly and disassembly as simple as using a screw.

Hollow fiber membrane spinnerets 10 Integrated Spinneret Core: High precision and good concentricity.

Hollow fiber membrane spinnerets 11 Robust Needle Design: The Bore liquid needle is not easily damaged.

Hollow fiber membrane spinnerets 12 Easy Cleaning and Maintenance: User-friendly cleaning and maintenance ,friendly for non-professional operators

Hollow fiber membrane spinnerets 13 High Reliability: Stable and consistent performance.

Hollow fiber membrane spinnerets 14 Extended Service Life: Longer operational lifespan.

Hollow fiber membrane spinnerets 15 Convenient Maintenance for MBR Braided Tube Coating Spinneret: Spinneret cores can be easily taken out and cleaned without disassembling the flow channel plate.

Product Parameters

Brand	Trustech	Application	NIPS
Material	SUS304, SUS630, SUS316L	Holes/Pack	1-32
Dope inlet Thread	G1/8, BSP1/8, NPT1/8	Minimum membrane OD	0.20mm
Bore liquid inlet thread	G1/8, BSP1/8, NPT1/8	Customize thread	Yes
Precision	±0.002mm	Concentricity	0.003mm
Design	FCT, conventional	Connections	Standard
Viscosity application	1000-300000cp	Roughness	Ra0.2-0.8

Suitable Materials

PVDF (Polyvinylidene Fluoride), CA (cellulose acetate), PVC (Polyvinyl chloride), PES (Polyethersulfone), PSF/PSU (Polysulfone), PA (Nylon, Polyamide), PAN (polyacrylonitrile)

FCT Design

We can offer FCT designs that allow the spinneret core to be removed, replacing conventional designs where each spinneret hole cannot be independently replaced or disassembled. If one hole has a quality issue, the entire spinneret traditionally needs repair or scrapping. Our FCT spinnerets are independently designed so each hole can be individually replaced if needed. The FCT 6th-generation spinneret enables independent on/off control of the dope feed for each spinneret core, and the 8th-generation FCT spinneret cores can be changed online within a few minute down to 50 seconds when problems occur, to ensure continuous production without downtime.

Conventional design

FCT design

Common Specifications

General Specification	Application	Design Type	Type
0.36/0.28/0.15	NIPS	Independent design	Single-aperture/ Multi-aperture
0.5/0.28/0.15	NIPS	Independent design	Single-aperture/ Multi-aperture
0.6/0.4/0.2	NIPS	Independent design	Single-aperture/ Multi-aperture
0.8/0.4/0.2	NIPS	Conventional design	Single-aperture/ Multi-aperture
1.3/0.7/0.4	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
1.4/0.9/0.6	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
1.5/0.9/0.6	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
1.6/0.7/0.4	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
1.8/0.9/0.5	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
1.8/1.2/0.6	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
2.0/1.0/0.7	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture
3.1/1.8/1.5	NIPS	Conventional design/ Independent design	Single-aperture/ Multi-aperture

Customer Membrane Examples