Adhesive technology has come a long way and has helped people overcome the common problems and limitations of older adhesive products. Adhesives that are reliable for attaching, securing, sealing, and bonding make tasks easier, whether professional or DIY. With advantages like simplified assembly, creating an evenly distributed bond, improved appearance, and cost-effectiveness, it is no surprise that adhesives are helpful in so many applications.
There are many types of adhesives for different uses, and you must find the best solution for your application. Here are the key considerations to narrow down your choices.
The Material/Substrate
The first thing you should ask yourself before looking for an ideal adhesive is the type of material you want to use the glue on. Do you want to bond metal, wood, plastic, ceramic, glass, fabric, stainless steel, paper, or rubber? Keep in mind that some adhesives adhere better to some materials than others which explains why there are different types in the market.
Knowing the exact material is key to finding a well-suited adhesive. Also, the type of glue matters; for instance, special plastic adhesives have different procedures for application. Some need acid to etch and achieve a proper bond, while others only need alcohol cleaning to adhere.
Surface Condition
Another critical consideration when choosing an adhesive, especially for DIY projects, is surface condition. Is it smooth or rough, coated or uncoated? Is it rigid or flexible? Such aspects can impact the bond. For instance, flexible adhesives are suitable for surfaces of different thermal expansions or substrates subjected to thermal shock, peel, and impact. Opt for rigid adhesives if you want to achieve creep resistance, chemical resistance, and tensile strength.
Thermal Cure or UV Cure
You should determine the proper cure schedule to ensure you achieve optimal adhesive performance on your application. Thermal cure adhesives are curable at room temperature or with heat. If the adhesive is labelled as a heat-cured thermal adhesive, it requires high temperatures to cure, which is detrimental to some materials.
In contrast, UV cure adhesives require exposure to UV light to cure; therefore, one of the substrates should allow UV light transmission. These are ideal for materials like glass and plastic that can transfer UV or visible light to the bond line. The advantage is that UV cure adhesives cure faster.
Surface Cleanliness
It is crucial to prep a surface before applying adhesive to achieve a solid and long-lasting bond. Most adhesives require different substrate prepping. While some require simple cleaning with water, others require complex preparation processes like plasma treatment, abrasion, chemical etching, etc.
Additionally, you must ensure that the adhesive adequately wets out the surface to be bonded. That means the adhesive flows to cover enough surface area on the material to maximize the contact area and the forces of the adhesive and substrate.
Environmental Conditions
Environmental conditions also impact the strength of a bond, as they could degrade the adhesive. When choosing an adhesive, you should consider the environmental conditions: chemical fluids, temperature, moisture, and outdoor weather impact different adhesives. If you are using the glue in an environment with possible degrading elements, it is advisable to test it first under simulated conditions.
Configuration of the Joint and Load
The dimensions of parts and how they fit together are critical when choosing an adhesive. Some adhesives are designed to work better with thinner gaps, while thicker cracks may require a slower cure to reduce shrinkage.
The Takeaway
Choosing the right adhesive for your application requires careful thought. Testing the glue before applying it to the main substrate is advisable to find the ideal solution.
