Are you looking for butyl tape or sealing solutions that will retain their performance for years without losing their properties? Crosslinked compounds manufactured by Almara represent a new generation of industrial solutions — backed by laboratory testing that clearly demonstrates their superiority over standard products available on the market.
What Is Crosslinking and Why Does It Matter?
Crosslinking is a chemical process in which polymer molecules bond together to form a three-dimensional molecular network. In practice, this means that crosslinked materials maintain their mechanical properties across a much wider range of temperatures and loads than conventional compounds.
Products from Almara marked with the “N” designation (e.g., T1EN, T2EN, C1EN) are crosslinked materials — and the difference compared to their non-crosslinked equivalents (T1E, T2E, C1E) as well as competing products is measurable and significant.
Higher Shear Resistance – FINAT FTM 8 Test Results
The static shear resistance test according to FINAT FTM 8 involves loading a sample adhered to a standard surface and measuring the time until failure. The longer the time, the better the adhesive performance.
Test results at 20°C (sample size: 45 × 50 mm)
| Material | Shear Resistance Time |
|---|---|
| Competitor I | 00:37:27 |
| Competitor II | 01:46:52 |
| Competitor III | 01:56:49 |
| Competitor IV | 03:15:44 |
| C1E (non-crosslinked) | 03:38:09 |
| T2E (non-crosslinked) | 09:15:08 |
| T1E (non-crosslinked) | 10:02:12 |
| C1EN (crosslinked) | 28:58:33 |
| T1EN (crosslinked) | >168 hours |
| T2EN (crosslinked) | >168 hours |
The T1EN and T2EN products did not fail even after 168 hours of testing — the test was terminated before the samples showed any signs of degradation. No competing product came close to achieving similar results.
Shear Resistance as a Function of Temperature
Crosslinked compounds from Almara maintain their advantage at every tested temperature. Comparison of C1E and C1EN:
| Temperature | C1E | C1EN |
|---|---|---|
| 15°C | 20:28:28 | 43:45:45 |
| 20°C | 6:59:14 | 22:22:13 |
| 25°C | 5:41:54 | 7:44:03 |
| 30°C | 3:50:10 | 4:16:09 |
The lower the temperature, the greater the difference between the crosslinked and non-crosslinked material. This means that under harsh winter conditions, Almara’s crosslinked compounds maintain high performance, while standard products lose adhesive properties much faster.
Practical Importance
Butyl tapes used outdoors, on pipelines, and in installations exposed to temperature fluctuations must withstand stresses caused by thermal expansion of materials. Low shear resistance increases the risk of adhesive failure and costly system breakdowns.
Higher Peel Strength – ISO 8510-2 and FINAT FTM 1 Tests
The peel resistance test measures the force required to remove an adhered material at a 90° angle at a speed of 10 mm/min.
Results
| Material | Peel Strength [N/25 mm] |
|---|---|
| T2E (non-crosslinked) | 4 N/25 mm |
| T2EN (crosslinked) | 14 N/25 mm |
The crosslinked T2EN product demonstrates a peel strength 3.5 times higher than its non-crosslinked counterpart. In practice, this means significantly stronger adhesion to protected surfaces — especially important for anti-corrosion pipe wrapping and installations exposed to vibration or thermal movement.
Lower Penetration = Greater Shape Stability
The penetration test according to ISO 2137 measures material hardness and cohesion — the lower the penetration value, the harder and more deformation-resistant the material. Results are expressed in 1/10 mm units.
Penetration vs. Temperature
| Temperature | T1E (non-crosslinked) | T1EN (crosslinked) |
|---|---|---|
| 5°C | 44 | 44 |
| 10°C | 49 | 47 |
| 15°C | 55 | 48 |
| 20°C | 61 | 48 |
| 25°C | 65 | 55 |
| 30°C | 67 | 55 |
As temperature increases, the non-crosslinked material becomes noticeably softer and more susceptible to deformation. The crosslinked T1EN maintains significantly more stable hardness — the difference between 10°C and 30°C is only 8 units, compared to 18 units for T1E.
Why Is This Important?
A material that softens during summer conditions may flow out from beneath the tape or joint, losing its sealing properties. Crosslinked compounds from Almara ensure predictable and stable performance throughout the year.
Aging Resistance – ASTM C772 Test
Samples were subjected to accelerated aging in an oven at 100°C for 168 hours, simulating many years of service conditions.
Results for Almara Products
- Increased flexibility
- Higher tackiness
- Smooth, glossy surface
Results for Competing Products
- Cracking and delamination — permanent material degradation
Competing products failed the aging test. Both crosslinked and non-crosslinked compounds from Almara retained their structural integrity, demonstrating the high quality of the raw materials and manufacturing process.
Who Are Almara Crosslinked Compounds Designed For?
Crosslinked products are particularly recommended for applications requiring:
- Long-term sealing performance — water, gas, and sewage systems
- Corrosion protection of pipelines — oil, chemical, and district heating industries
- Operation in changing temperatures — building façades, roofs, and outdoor installations
- High mechanical loads — joints exposed to vibration and shear stress
- Compliance with standards and certification requirements — projects where documented technical parameters are essential
Summary – Crosslinking Is an Investment in Durability
Laboratory testing clearly confirms that Almara crosslinked butyl compounds (EN series) outperform both the company’s own non-crosslinked products and competing solutions in all key performance areas:
- Shear resistance — over 168 hours (competition: max. 3 h 15 min)
- Peel strength — 3.5× higher than standard products
- Stability under temperature changes — lower penetration and reduced temperature sensitivity
- Aging resistance — no cracking or delamination after 168 h at 100°C
By choosing crosslinked compounds from Almara, you are choosing products supported by hard data — not marketing promises.