Permabond 268 Instant Adhesive-Fast-Set,-Gap Filling for Difficult Plastics & Rubbers
Permabond 268 Cyanoacrylate Super Glue Instant Adhesive is a one component, medium-high viscosity, instant setting adhesive that is used for bonding rough surfaces, passivated metals, rubber, ceramics, plastics, and large gap applications. It provides faster set times and improved gap-filling capability compared to conventional cyanoacrylates. The adhesive bonds to a wide range of substrates including metals, ceramics, plastics and elastomers. It is excellent for bonding difficult-to-bond plastics such as polyacetals. It can also be used on passivated metal surfaces. Surfaces should be clean, dry and grease-free before applying the adhesive. Use a suitable solvent (such as acetone or isopropanol) for the degreasing of surfaces. Some metals such as aluminium, copper and its alloys will benefit from light abrasion with emery cloth (or similar), to remove the oxide layer.
Features and Benefits
- Versatile and general purpose
- Good gap fill ability
- Instant setting
Approved to MIL-A-46050C Type II Class 3 (existing designs)
Physical Properties of Uncured Adhesive
| Chemical Composition | Ethyl Cyanoacrylate |
| Appearance | Colorless/Clear |
| Viscosity @ 25°C | 1,200-2,400 mPa.s (cP) |
| Specific Gravity | 1.1 |
Typical Curing Properties
| Maximum gap fill | 0.43 mm (0.017 in) |
| Fixture/Handling time *
(0.3 N/mm^2 shear strength is achieved) |
5-10 seconds (Steel)
5-10 seconds (Buna N Rubber) 5-10 seconds (Phenolic) |
| Full strength | 24 hours |
*Handling times can be affected by temperature, humidity and specific surfaces being bonded. Larger gaps or acidic surfaces will also reduce cure speed but this can be overcome by the use of Permabond C Surface Activator (CSA) or Permabond QFS 16.
Typical Performance of Cured Adhesive
| Shear strength*
(ISO4587) |
Steel: 20-22 N/mm² (2900-3200 psi) |
| Impact strength
(ASTM D-950) |
3-5 kJ/m² (1.4-2.4 ft-lb/in²) |
| Coefficient of thermal expansion | 90 x 10^-6 mm/mm/°C |
| Coefficient of thermal conductivity | 0.1 W/(m.K) |
| Hardness
(ISO868) |
85 Shore D |
*Strength results will vary depending on the level of surface preparation and gap.