Home > Notre information

The selection of adhesives
Date:2010-8-4

With the rapid development of adhesive technology, there are a variety of excellent choices for different usage. Different adhesive have different performance characteristics, technological conditions and the scope of application. Even the same adhesive, it would have different performance and usage with different using methods. Faced with thousands of adhesive, is not a casual adhesive can be used for any purpose of bonding. The success or failure of bonding is depend on what kind adhesive that you choose. Therefore, reasonable choice of adhesive is a key point. Magpow's is happy to provide this information as a service to you.
The basic principle for adhesive selection as following:
1, Should familiar with the adhesive performances:
Different adhesives have different performances, including the state, viscosity, guarantee period, curing conditions, bonding process, adhesive strength, temperature, shrinkage rate, the linear expansion coefficient, corrosion resistance, water & oil resistant, medium-resistant and anti-aging and so on, these are factors must be taken into account for adhesives.
2. Should consider the viscosity of materials and nature:
Materials was divided into metal materials, non-metallic and composite materials. Metals and metal alloys have high strength and generally have be pressed structure, should use epoxy glue or acrylic glue. Even the same metal have different natures. Steel, iron, copper are the three very easy-oxides. Within stainless steel, the nickel, aluminum and cadmium are easy to passivate, while tin, aluminum are soft texture, the adhesive performances are different. Steel and aluminum alloy cast iron relatively easy to bond, on the contrary, stainless steel, nickel, chromium, cadmium are hard to bond, we must make chemical treatment, remove the passivation layer.
Of the non-metallic materials, the pottery, glass, stone and concrete are small linear expansion coefficient and small contractibility materials, these super hardness and brittleness should use epoxy glue. While, neoprene, polyurethane glue and SBS glue are suitable for the rubber, leather, cotton fabric, polyester fabric, foam rubber, foam those porous materials and cattle imitation leather.
3. Should consider the purpose and usage of bonding:
Bonding’s efficacy including connecting, sealing, fixing, orientating, repairing, filling, plugging, tumbling, anti-corrosion, perfusion, polish etc. Therefore, should choose different types of adhesives according to the bonding purpose and usage .
4. Should consider the joint object’s force:
Bonding parts should be pressed or clamped in processs. Generally speaking, there are four types, extending, shearing, tearing and peeling.
 For example: rubber and rubber, rubber and metal bonding should main consider its peel stress and tear strengthen.
The tensile shear strengthen of epoxy glues is above 15 Mpa, but with low peel stress. Neoprene glue and SBS glue have high peel stress and tear strengthen.
5. Consider the bonding environment --- temperature, moisture, outdoor use and other media.
(1) Our epoxy adhesive can be cured in general -30 ℃ -100 ℃ temperature. Neoprene generally cured below 80 ℃. If use above 150 ℃ or below -70 ℃ in the long-term, should select high or ultra-low temperature adhesives.
(2) Moisture and water is disadvantage to the stability of adhesive interface. Our epoxy glue and neoprene glue are not suitable to be bond in the humid environment. Except for the underwater curing adhesive, 30 minutes curing adhesive and acrylic glue. However, the epoxy adhesive that after curing can anti-humid, water-resistant. But the water-resistant of neoprene glue is poor.
(3)The outdoor use should bear the wind, rain, sun and cold, heat, light, oxygen. Epoxy adhesive can be used indoors for five years, while less than a year in outdoors. Therefore, outdoors should choose atmospheric resistance and anti-aging adhesive. Such as NBR modified epoxy.
6, consider the possibility of process.
At present, our adhesives can cure with pressure at room temperature. In general, heating curing performance is much better than curing at room temperature. Therefore, if require high strength, durability, and media-resistant adhesive should use the high-temperature curing adhesive.
Adhesive selection can not only focus on high strength, good performance, should also consider technological conditions. It is better to use fast-curing adhesive in production lines, Those require curing time, such as fast-curing epoxy glue and acrylic glue. For large areas of glue that need a long time should not choose fast-curing adhesive. Such as rubber, electrical components, thermoplastics, which can’t stand high temperature, should avoid using high-temperature curing adhesive. Extremely thin rubber parts must avoid use pressurized curing. And room temperature curing adhesive or low-temperature fast-curing glue are for outdoors application.
7, cost requirements
Use bonding technology has a big benefit. A little glue will solve serious problems, saving a lot of materials. Don't use too much - a thin coat usually works best. Use cheap adhesive with better performance.
8,non-toxicity and safety requirements
In order to protect the environment, reduce pollution and poisoning, and ensure health and safety, it would be better to use non- solvent or less solvent adhesive.
Adhesive selection attentions
1,Should not pursue high-intensity blindly, high-strength adhesive didn’t mean firmly bond.
2,Do not just attach importance to initial curing strength, should consider good durability more.
 3, The performance of high temperature curing adhesive is much better than room temperature ones. If you require high strength and durability, high-temperature curing adhesive would be your best choice.
4, Except for small or emergency repair and continuous production line, do not use room temperature fast-curing epoxy adhesive.
5, Wood glue can not be used for metal bond.
6, Polyurethane adhesive, transparent epoxy glue, unsaturated polyester adhesive, polyvinyl acetal glue suit for require transparency ones.
7, adhesive should not be mordant. For example: polystyrene foam can self-adhesive, so can not use solvent-based neoprene glue. But polystyrene foam can stick with metal. Coat neoprene glue on the metal surface, can be bond with polystyrene foam after drying.