Leading Hollow Fiber Membrane Spinning Machine and Spinneret Manufacturer - Trustech

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 1

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 2

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret

A dry-jet wet spinning spinneret is the core forming component tailored to the Dry-Jet Wet Spinning process for producing hollow fiber membranes. THis spining spinneret primary function is to precisely co-extrude a polymer casting dope and a bore fluid through coaxial flow channels, so that the extruded "liquid filament" first passes through an air gap which calls dry zone for partial solvent evaporation and initial drawing, then enters a coagulation bath which calls wet zone for phase separation and solidification, ultimately forming hollow fibers membrane with specified structures and properties. The spinning spinneret must be designed to accommodate both "liquid filament stability in the air gap" and "initiation of phase separation in the coagulation bath,"acting as the critical bridge between dry state drawing and wet state solidification.

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Structural features

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 3 Dual concentric needle, annular orifice

The center needle delivers the bore fluid (or N₂), while the outer annular slit extrudes the high viscosity spinning dope to form the hollow lumen.

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 4 Short conical inlet channel

L/D ≈ 1–2 with a cone angle of 60–90°, suppressing spinneret orifice swell and mitigating abrupt velocity gradients.

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 5 Heatable spinneret body

Equipped with 60–120°C circulating oil or cartridge heaters to ensure that high viscosity solutions >1000 Pa·s exhibit low viscosity and uniform flow at the orifice.

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 6 Adjustable air gap distance

Continuously adjustable 3–50 mm between the spinneret face and the coagulation bath surface, enabling optimization of the draw ratio,up to 20times.

Trustech hollow spinneret single hole FCT 5th Gene

Trustech hollow fiber spinneret price 02 (4)

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.
Central tube inner diameter (d₃)	The diameter of the bore fluid channel.
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.
Concentricity
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.

Trustech hollow spinneret single hole FCT 5th Gene (3)

The Advantages of Trustech FCT Dry Jet Wet Spinning Spinneret Trustech

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 10 Wear resistant and anti-clogging, compatible with high solids slurries: Nozzles and liners made from ultra-hard materials (zirconia, tungsten carbide, sapphire), with polished surfaces and anti-wear coatings, resist particle abrasion and clogging, ensuring stable delivery of high solids, viscous sols/slurries.

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 11 Low shear and rapid gel-forming: Gently curved distribution channels and a coaxial external gelling agent flow or short air-gap design significantly reduce shear stress to prevent premature gel aggregation; rapid gelation at the nozzle exit forms a robust green fiber wall, avoiding collapse and ovalization.

Polymer Fiber Spinning, Dry Jet Wet Spinning Spinneret 12 Multilayer co-extrusion with controlled shrinkage compensation: Supports multilayer co-extrusion (dense skin + porous support), producing composite ceramic/metal/glass hollow fibers in a single pass; spinneret dimensions and wall-thickness are pre-compensated for 10–40% drying/sintering shrinkage, maintaining dimensional accuracy and structural integrity after high-temperature sintering (400 - 1200°C).

Product Parameters

Brand	Trustech	Application	Dry-jet wet spinning
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	Conventional design	Connections	Standard
Viscosity application	1000-300000cp	Roughness	Ra0.2-0.8
Solvent	DMAC, DMF, NMP	Temperature	150℃

Suitable Materials

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

Process characteristics

High positive drawing at the spinneret: low resistance in the air gap allows spinning speeds of 600 - 1200 m min⁻¹, which is 3–5 times that of pure wet spinning.

Uniform fiber structure: pre-solidification in the air gap forms a dense skin; bidirectional diffusion in the coagulation bath is moderated, reducing skin - core differences and overall porosity.

Suitable for high solids, high viscosity dopes: stable extrusion even at 18 - 30% solids and zero-shear viscosities of 2000–3000 Pa·s.

Flexible hole count: Spinning spinneret extend 1–6 holes for lab use, and 4-32 holes for industrial plates.

Conventional design

FCT design

Common Specifications

No.	General Specification	Application	Design Type	Type
1	1.3/0.7/0.4	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
2	1.3/0.8/0.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
3	1.3/1.0/0.7	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
4	1.4/0.7/0.4	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
5	1.4/0.9/0.6	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
6	1.4/1.0/0.8	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
7	1.6/0.8/0.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
8	1.6/0.9/0.6	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
9	1.8/0.9/0.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
10	1.8/1.2/0.6	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
11	1.8/1.2/0.8	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
12	2.3/1.5/1.0	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
13	2.3/1.5/1.2	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
14	2.7/1.5/1.2	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
15	2.2/1.7/1.4	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
16	2.7/2.2/1.9	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
17	2.8/2.0/1.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
18	2.8/2.2/1.9	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
19	2.8/2.3/2.0	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
20	2.9/1.4/1.1	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
21	2.9/1.8/1.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
22	2.9/1.9/1.6	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
23	3.0/2.3/1.9	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
24	3.0/2.3/2.0	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
25	3.1/2.8/2.5	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
26	3.2/2.2/1.8	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
27	3.4/1.7/1.4	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
28	3.4/2.2/1.8	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
29	3.7/1.9/1.6	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
30	3.8/2.2/1.9	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture
31	3.8/2.3/2.0	dry-jet wet spinning	Conventional design	Single-aperture/ Multi-aperture

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