Barrier Tubing
Solvent, Gas, and UV Barriers — Three Variants
Junkosha barrier tubing puts a fluoropolymer wetted surface inside every variant — then adds a purpose-built outer layer: flexible polymer for solvent/moisture barrier (HB1), gas-barrier polymer for oxygen exclusion (HB2), or UV-shielding polymer for photosensitive fluid protection (HB3). All three are flexible where pure fluoropolymer is not.
Standard Fluoropolymer Stops Chemical Attack. It Doesn't Stop Permeation.
When ink, paint, or solvent passes through a standard ETFE-lined tube, the fluid composition changes — because ETFE allows vapor transmission in both directions. Over time the solvent component evaporates through the wall, the fluid concentration shifts, and the downstream process sees a different fluid than was specified. For UV-curable inks, the problem is more acute: ambient light penetrating a clear tube can begin polymerization inside the line.
HB1 reduces solvent and moisture permeation to a fraction of ETFE tubes. HB2 adds a gas-barrier polymer layer that keeps dissolved oxygen below process-critical thresholds. HB3 adds UV-shielding without sacrificing the visual transparency needed to monitor flow.
Three Barrier Variants
Fluoropolymer inner + flexible polymer outer. Strong solvent and moisture barrier — suppresses changes in composition of fluid inside the tube. Flexibility 1/3 of competitor ETFE inner layer tubes at tight bend radii.
- • Transfer tubes for paint, ink, and solvents
- • LCD and organic EL display production
- • Food color, binder, and pure water transfer
| Part No. | ID × OD | Max Working Pressure | Min Bend Radius |
|---|---|---|---|
| HB1-0320 | 2.0 × 3.0 mm | 0.50 MPa | 19 mm |
| HB1-0430 | 3.0 × 4.0 mm | 0.35 MPa | 36 mm |
| HB1-0640 | 4.0 × 6.0 mm | 0.50 MPa | 33 mm |
| HB1-0860 | 6.0 × 8.0 mm | 0.35 MPa | 78 mm |
Fluoropolymer inner + gas barrier polymer intermediate + polyolefin outer. Suppresses dissolved oxygen in fluid — demonstrated to hold O₂ concentration below 2 mg/L where competitor EVOH multi-layer tubes rise to 8 mg/L.
- • Transfer tubes for paint, ink, and solvents
- • Metallic paste transfer requiring oxidation prevention
- • Tubes requiring no O₂ or gas dissolution into fluid
- • Food & pharmaceutical manufacturing systems
| Part No. | ID × OD | Max Working Pressure | Min Bend Radius |
|---|---|---|---|
| HB2-0320 | 2.0 × 3.0 mm | 0.50 MPa | 28 mm |
| HB2-0430 | 3.0 × 4.0 mm | 0.35 MPa | 45 mm |
| HB2-0640 | 4.0 × 6.0 mm | 0.50 MPa | 45 mm |
| HB2-0860 | 6.0 × 8.0 mm | 0.35 MPa | 90 mm |
Fluoropolymer inner + special UV shielding polymer outer. Shields long-wave UV (365 nm) while maintaining transparency — ink inside does not solidify, unlike black or non-shielding tubes.
- • UV-curable paint and ink transfer
- • Tubes requiring UV protection without losing flow visibility
| Part No. | ID × OD | Max Working Pressure | Min Bend Radius |
|---|---|---|---|
| HB3-0430 | 3.0 × 4.0 mm | 0.35 MPa | 35 mm |
| HB3-0640 | 4.0 × 6.0 mm | 0.50 MPa | 37 mm |
| HB3-0860 | 6.0 × 8.0 mm | 0.35 MPa | 77 mm |
Chemical Resistance — Inner Layer vs. Outer Layers
◎ Unaffected | ○ Highly resistant | ▲ Resistance degrades | × Affected. Inner layer is fluoropolymer with barrier properties for all three types.
| Chemical | Inner Layer | HB1 Outer | HB2 Outer | HB3 Outer |
|---|---|---|---|---|
| Hydrochloric acid | ◎ | × | ○ | ○ |
| Sulfuric acid | ○ | × | ○ | ○ |
| Nitric acid | ◎ | × | × | ○ |
| Sodium hydroxide | ◎ | ○ | ○ | ○ |
| Benzene | ◎ | ▲ | × | × |
| Toluene | ◎ | ▲ | × | × |
| Mineral oil | ◎ | ○ | × | × |
| Water | ◎ | ◎ | ◎ | ◎ |
| Methanol | ◎ | × | ○ | ○ |
| Acetone | ◎ | ▲ | ○ | ○ |
Full table including ester, ketone, ether, and alcohol groups available in catalog.
Request a Quote
Specify variant (HB1/HB2/HB3), ID × OD, and required length. Koto will respond within one business day.
Contact UsDownload Full Catalog
Barrier performance test data, full chemical resistance tables, and flexibility comparison graphs.
Junkosha-ITFEE.pdf