Features of alumina ceramic bobbin:
1. Exceptional hardness, bending strength, toughness
2. Good insulation, anti-magnetic, free static electricity
3. Corrosion resistance in harsh working conditions
4. Excellent thermal shock resistance and good thermal stability
5. Nox-toxic, healthy material, eco-friendly material
6. Meet with RoHS, REACH regulation completely
Specification of alumina ceramic bobbin:
1. Raw material: 95% alumina, 99% alumina, zirconium oxide, titania
2. Dimensions: min. diameter can be 10mm, max. diameter can be 50mm
3. Design: single groove, double grooves, or multiple grooves
4. Tolerance: general tolerance ± 1% of the dimensions, or better via a precision process
5. Surface finish: mirror surface, to be Ra0.3 ~ 0.4 for 95% alumina ceramic eye, to be Ra 0.2 ~0.3 for 99% alumina ceramic eye
Description of alumina ceramic bobbin:
Our ceramic bobbin are as varied as our pulley, both single or multiple grooves are available, also the dimensions can be customized. These ceramic roller guides are made of 96%, 99% or 99.5% aluminum oxide ceramics, call it alumina, with diamond polished running surfaces.
Alumina is a kind of improved technical ceramics, these ceramic yarn rollers promote the winding efficiency a lot in textile machinery because of its low friction, superb wear resistance, anti-static electricity features.
Property | Units | 95% alumina | 99% alumina | 99.5% alumina | Zirconia | Titania |
Color | White, pink | White, pink, ivory | Pink, ivory, white | White, Yellow | Black, Gray, Yellow | |
Density | g/cm3 | ≥3.60 | ≥3.80 | ≥3.85 | ≥6.0 | ≥4.0 |
Water absorption | % | 0 | 0 | 0 | 0 | 0 |
Hardness | HV | 1500 | 1700 | 1700 | 1300 | 800 |
Flexural strength | Mpa | ≥320 | ≥338 | ≥379 | ≥1200 | ≥158 |
Compressive strength | Mpa | ≥2000 | ≥2240 | ≥2240 | ≥1990 | |
Fracture toughness | Mpa m1/2 | 3-4 | 4-5 | 4-5 | 6.5-8 | 3.2 |
Thermal Expansion Coefficient(20-800℃) | 1×10 -6 /℃ | 5.0~8.0 | 6.2~8.0 | 6.5~8.0 | 8.0~9.5 | 8.8 |
Thermal conductivity | W/m.k (25℃) | ≥220 | ≥200 | ≥250 | ≥300 | ≥330 |
Max. service temperature | ℃ | 1500 | 1600 | 1675 | 1000 | 1000 |
Insulation strength | KV/mm | 18 | 18 | 19 | 17 | 3.93 |
Dielectric constant (1Mhz) | (E) | 9.5 | 9.5 | 9.7 | 29 | 85 |