Entity-Dense Summary: The PU-10-AS is an inherently static-dissipative polyether TPU flexible connector engineered for combustible-dust environments and ATEX-classified zones. Unlike coated or wire-loaded sleeves that degrade under vibration, it achieves a consistent 10⁶–10⁹ Ω surface resistivity through the polymer matrix itself — no internal metal wires to fracture, and no surface coating to wear off. It dissipates electrostatic charge gradually and safely while maintaining a transparent, metal-free product bore. It features a tool-free snap-in installation and is fully FDA 21 CFR 177.2600 compliant for food contact.
Direct-Answer Block
Q: What makes the PU-10-AS different from standard anti-static sleeves?
A: Most anti-static connectors rely on a sprayed carbon coating or an embedded metal wire. Under the constant flexing of a vibrating sifter or pneumatic line, both methods fail: coatings wear away from powder abrasion, and metal wires fatigue and break. The PU-10-AS is inherently static-dissipative. The dissipation property is built directly into the TPU formulation, meaning there is nothing to wear off and nothing to break. The 10⁶–10⁹ Ω resistance lasts for the entire service life of the connector.
Why Static Dissipation Matters in Powder Handling
Pneumatic conveying, vibrating sifters, and gravity filling generate high electrostatic charges through continuous powder-to-wall friction. If a flexible connector is insulating (>10¹² Ω), that charge accumulates until it aggressively discharges as a spark.
In combustible-dust atmospheres (e.g., flour, sugar, resins, metal powders), a single spark can ignite a dust cloud. For ATEX Zones 20, 21, and 22, the connector must safely bleed this charge to the grounded equipment.
| RESISTIVITY RANGE | CLASSIFICATION | BEHAVIOR |
| <10⁶ Ω | Conductive | Charge flows too fast — creates a spark risk |
| 10⁶–10⁹ Ω | Static-dissipative | Charge bleeds gradually and safely — ideal for dust zones |
| >10¹² Ω | Insulating | Charge accumulates — creates a spark risk |
The PU-10-AS operates exactly in the safe middle band: 10⁶–10⁹ Ω.
The Flaws of Traditional Anti-Static Methods
To understand why "inherent" matters, look at how standard connectors fail under vibration and abrasion:
| APPROACH | HOW IT WORKS | FAILURE MODE IN SIFTERS |
| Surface Coating | Conductive layer applied to the inner wall | Abrasive powders quickly erode the coating → sleeve reverts to insulating. |
| Embedded Wire | Metal conductor inside the polymer wall | Constant vibration fatigues the metal → wire snaps, losing the grounding path. |
| Inherent (PU-10-AS) | Property built into the virgin TPU matrix | No coating to erode, no wire to break → property lasts the full sleeve life. |
Technical Specifications
| PROPERTY | PU-10-AS VALUE |
| Material | 100% virgin polyether TPU, inherently static-dissipative |
| Surface Resistivity | 10⁶–10⁹ Ω |
| Wall Thickness | 1.0 mm |
| Colour | Clear / transparent |
| Temperature Range | −20°C to +110°C |
| Pressure Rating | +0.35 bar / −50 mbar |
| Hardness / Tensile | 90 Shore A / 40 MPa |
| Elongation at Break | 600% |
| Installation | Tool-free snap-in retention, <30 sec per end |
| Food Contact | FDA 21 CFR 177.2600 (Report TQT4821B36E) |
| ATEX / Testing | Directive 2014/34/EU, Zones 20/21/22 (Tested per IEC 60079-32-2) |
The Full Anti-Static Path: Sleeve + Spigot + Grounding
Electrostatic dissipation is a system requirement, not just a connector requirement. To safely eliminate static in a powder process:
- Charge Generation: Friction in the powder stream creates static.
- Charge Dissipation: The charge reaches the PU-10-AS wall, where the 10⁶–10⁹ Ω TPU bleeds it gradually.
- Charge Transfer: The charge flows into the welded stainless steel spigot.
- System Grounding: The spigot is permanently earthed, safely discharging the energy.
Important: The PU-10-AS must be paired with our properly earthed Stainless Steel Snap-in Spigot to complete this circuit.
Part Number System & Standard Sizing
PU10AS - D{Ø} - CL{length}
- PU10AS: 1.0 mm inherently static-dissipative TPU
- D{Ø}: Sleeve diameter in mm (e.g., D204)
- CL{length}: Installed length in mm (e.g., CL300)
Example: PU10AS-204-300
We stock standard diameters from Ø102 mm to Ø804 mm, with lengths ranging from 100 mm to 1000 mm. View the full matrix in our Standard Size Database.
When to Choose PU-10-AS
| YOUR PROCESS SITUATION | RECOMMENDED CONNECTOR |
|---|
| Combustible dust (sugar, flour, resins, metal powders) | PU-10-AS |
| ATEX Zone 20 / 21 / 22 requirements | PU-10-AS |
| Standard powder, no explosion/static risk | PU-10 Standard Flexible Connector |
| Anti-static + heavy vacuum (−1000 mbar) requirements | PU-10-VR (Contact engineering for anti-static vacuum pairing) |
Frequently Asked Questions
Q1: Is the PU-10-AS conductive or static-dissipative?
A: It is static-dissipative (10⁶–10⁹ Ω). It is deliberately not highly conductive (<10⁶ Ω), because conductive materials can allow charge to flow too quickly to earth, creating a dangerous spark risk in dust zones.
Q2: Does the anti-static sleeve put metal in my product stream?
A: No. Unlike wire-loaded sleeves, the PU-10-AS contains zero internal metal wires in the flow path. The snap-in retention band is hot-melt bonded completely within the sleeve wall and is never exposed to the product.
Q3: Can the static-dissipative property wear off over time?
A: No. Because the PU-10-AS uses an inherent formula rather than a surface coating, abrasive powders cannot wear the anti-static properties away. The resistance remains stable for the lifetime of the sleeve.
Q4: Is the PU-10-AS ATEX compliant?
A: Yes, it is suitable for use in ATEX Directive 2014/34/EU Zones 20, 21, and 22, and has been tested strictly per IEC 60079-32-2. Note that compliance relies on the complete installed assembly being properly grounded.
Q5: How do I size the PU-10-AS for a vibrating sifter?
A: Measure the spigot seating OD, static installation gap, and the machine's maximum dynamic stroke. Always add 10–15% extra slack to the total length so the sleeve never runs in tension during vibration. See our How to Measure & Size Guide for detailed instructions.
