Model:MHST/MHST-A
Medium Wall Heat Shrinkable Tubing with Adhesive (MHST-A)
MHST-A is a premium medium-wall heat shrinkable tubing featuring an integrated hot-melt adhesive layer. It delivers excellent electrical insulation, environmental sealing, and superior resistance to impact and abrasion. With a 3:1 shrink ratio, it easily conforms to irregular shapes and large connectors, making it the ideal solution for sealing and protecting electrical splices, cable terminations, and joints in demanding environments.
Key Features & Benefits
- 3:1 High Shrink Ratio: Easily fits over irregular shapes, large connectors, and bulky splices without wrinkling.
- Superior Environmental Sealing: The integrated hot-melt adhesive provides a permanent, waterproof, and moisture-resistant barrier against harsh elements.
- High Electrical Insulation: Excellent dielectric strength and volume resistivity ensure reliable performance in medium-voltage applications.
- Robust Mechanical Protection: Highly resistant to UV radiation, impact, abrasion, and environmental stress cracking.
- Flexible Options: Available with adhesive (MHST-A) or without adhesive (MHST), and custom cutting lengths are supported upon request.
Common Applications
- Electrical splices, cable terminations, and underground joints
- Telecommunication and power cable repairs
- Protection for busbars and connectors in harsh or corrosive environments
- Automotive, marine, and railway wiring harnesses
Product Specifications & Technical Data
- Model: MHST-A (Non-adhesive MHST available upon request)
- Shrink Ratio: 3:1
- Operating Temperature: -55°C to +110°C
- Minimum Fully Recovery Temperature: 120°C
- Standard Color: Black (Other colors available on request)
Technical Properties
| Item | Test Method | Value |
|---|---|---|
| Operating temperature | IEC 60216 | -55°C to +110°C |
| Tensile strength | ASTM D 2671 | ≥ 14 MPa |
| Tensile strength after aging (150°C / 168 hrs.) | ASTM D 2671 | ≥ 12 MPa |
| Elongation at break | ASTM D 2671 | ≥ 400% |
| Elongation at break after aging (150°C / 168 hrs.) | ASTM D 2671 | ≥ 300% |
| Density | ASTM D 792 | 1.05 g/cm³ |
| Longitudinal shrinkage | UL 224 | 0 to -10% |
| Dielectric strength | IEC 60243 | ≥ 20 kV/mm |
| Volume resistivity | IEC 60093 | > 1014 Ω·cm |
| Eccentricity | ASTM D 2671 | < 30% |
| Copper stability | ASTM D 2671 | Pass (Non-corrosive) |
| Resistance to stress cracking (50°C) | ASTM D 1693 | No cracking |
| Water absorption (Jacket, 23°C / 14 days) | ISO 62 | < 0.15% |
| Water absorption (Adhesive) | ISO 62 | < 0.2% |
| Softening point (Adhesive) | ASTM E28 | 85°C |
| Peel strength (to PE) | DIN 30672 | ≥ 4 N/cm |
| Resistance to fungus and decay | ISO 846 | Pass |
Dimensions & Specifications
| Size (mm) | As Supplied I.D. (mm) Min | After Recovery I.D. (mm) Max | After Recovery W.T. (mm) Min | Standard Length (mm) |
|---|---|---|---|---|
| 8/2 | 8 | 2 | 1.7 | 1220 |
| 12/3 | 12 | 3 | 2.0 | 1220 |
| 16/5 | 16 | 5 | 2.2 | 1220 |
| 19/5 | 19 | 5 | 2.5 | 1220 |
| 22/6 | 22 | 6 | 2.5 | 1220 |
| 28/6 | 28 | 6 | 2.5 | 1220 |
| 33/8 | 33 | 8 | 2.5 | 1220 |
| 40/12 | 40 | 12 | 2.5 | 1220 |
| 55/16 | 55 | 16 | 2.7 | 1220 |
| 65/19 | 65 | 19 | 2.8 | 1220 |
| 75/22 | 75 | 22 | 3.0 | 1220 |
| 85/25 | 85 | 25 | 3.0 | 1220 |
| 95/25 | 95 | 25 | 3.0 | 1220 |
| 115/34 | 115 | 34 | 3.0 | 1220 |
| 140/42 | 140 | 42 | 3.0 | 1220 |
| 160/50 | 160 | 50 | 3.0 | 1220 |
| 180/58 | 180 | 58 | 3.0 | 1220 |
| 205/65 | 205 | 65 | 3.0 | 1220 |
| 235/65 | 235 | 65 | 3.0 | 1220 |
| 265/75 | 265 | 75 | 3.0 | 1220 |
| 300/85 | 300 | 85 | 3.0 | 1220 |
| 350/100 | 350 | 100 | 3.0 | 1220 |
| Remarks: 1. MHST-A includes hot-melt adhesive. Non-adhesive version (MHST) is available upon request. 2. Custom cutting pieces and specific lengths are available on request. 3. Adhesive Application: Available in Coated Adhesive (standard) and Spiral Adhesive. Please note that Spiral Adhesive is custom-made and available upon request. |
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Frequently Asked Questions (FAQ)
Q: What is the difference between MHST-A (Medium Wall) and DHST (Dual Wall) tubing?
A: Both feature a hot-melt adhesive inner layer for waterproof sealing. However, MHST-A has a thicker, medium wall (up to 3.0mm) designed for heavy-duty mechanical protection and higher voltage insulation. If your application primarily involves standard wire splices, connectors, or cable bundles where extreme thickness isn’t required, our DHST dual wall tubing might be a more flexible and cost-effective choice.
Q: Can MHST-A be used for high-voltage busbar insulation?
A: MHST-A is excellent for medium-voltage applications and general electrical insulation. However, if you are insulating copper or aluminum busbars in switchgear or substations (1kV to 35kV), we highly recommend our specialized HBBT high-voltage busbar tubing, which is specifically engineered to reduce phase-to-phase clearance and resist electrical tracking.
Q: Do I need the adhesive version (MHST-A) or the non-adhesive version (MHST)?
A: If your application is exposed to moisture, water, or corrosive environments (like underground or marine installations), the adhesive version (MHST-A) is essential to create a permanent, waterproof seal. If you only need electrical insulation, color coding, or mechanical protection in a dry indoor environment, the non-adhesive version will suffice.
Q: How does the 3:1 shrink ratio benefit my installation?
A: A 3:1 shrink ratio means the tubing will shrink to one-third of its original supplied diameter. This high ratio allows a single size of tubing to easily slide over bulky connectors, irregular shapes, or large cable splices, and then shrink down tightly to form a secure, void-free seal.
Q: What is the recommended heating method for installing MHST-A?
A: We recommend using a professional hot air gun or a propane torch with a soft flame. Heat the tubing evenly, starting from the center and moving outward toward the ends. This technique allows trapped air to escape and ensures the adhesive flows uniformly to create a perfect seal without scorching the material.
Q: Do you supply custom cut lengths or specific colors for project orders?
A: Yes. While our standard offering is black tubing in 1220 mm lengths, we can provide custom cutting pieces, specific lengths, and alternative colors (such as Red, Yellow, Green, or Blue for phase identification) upon request for bulk or specialized project orders.