Five steps to choose ideal bonding solution
There are many reasons to choose liquid adhesives or tape for material joining tasks. Different chemical compositions offer endless possibilities in terms of flexibility, speed, strength, or conformity with industrial specifications.
3M has developed a method called ASPEC to cover all the important considerations that will help you choose the best product for your needs.
ASPEC is an acronym for the five factors that determine the selection of an appropriate bonding solution – assembly, substrate, process, end use, and cost. This method covers issues such as joint design, surface requirements, and adhesive chemical composition to help you choose a solution that is the best option for your assembly.
Step 1: Identify the type of assembly
Most joining processes can be represented by one of the following six common types:
Five steps to choose the ideal bonding solution
- large-area lamination,
- mounting and cutting attachment,
- small joint assembly,
- gasket attachment,
- sealing, filling, and encapsulation.
These are common applications where adhesives and tapes have been proven to work well. These operations are part of various design solutions in many markets and industries. Identifying the closest type of assembly for your application will help narrow down the choice of available tape and adhesive families that are suitable, based on joint geometry and typical production methods.
Step 2: Choose substrate materials
One of the advantages of adhesive tapes and glues is the ability to bond a wide range of substrates. Different substrates have different characteristics that affect the ability of the adhesive or tape to bond.
Surface energy, texture, roughness, and cleanliness are substrate conditions that can influence the choice of adhesive or tape. Knowing the materials you are working with is one of the key steps in the selection process.
Step 3: Identify production steps
Understanding how the part will be assembled can narrow down the selection of bonding tapes or adhesive formats. The careful selection here can help improve flowability or productivity compared to other joining methods, helping to reduce the number of steps, processing, and labor costs.
Adhesives and tapes can be applied manually or be part of automated dosing solutions and often involve lower capital investments compared to other joining methods.
Step 4: Define the end use
The final use of the product also affects which type of joint is the best choice for the intended product design. It is important to consider how the end user will use the product and what external conditions it will be exposed to. UV radiation, extreme temperatures, moisture, immersion, and exposure to chemicals are common end-use considerations that should be kept in mind, and many solutions can withstand these conditions.
Some common design advantages of adhesives and tapes are the ability to distribute pressure evenly, simultaneous bonding and sealing, energy absorption or transfer through the joint, metal insulation to prevent galvanic corrosion, and the ability to bond different materials.
Step 5: Costs and Benefits
When considering the total cost of materials and production for a given assembly, adhesives, and tapes often have numerous advantages. In terms of material cost, bonding can allow for lighter, thinner, or cheaper substrates to be part of the assembly due to enabling the bonding of different materials, as well as eliminating the need for drilling holes and mechanical fastening.
When it comes to production, this method realizes savings compared to welding or fastening, due to the reduced number of processing steps, including grinding of welded joints and repairing damaged surfaces. Labor costs for applying tapes and adhesives are often lower and require minimal training, as well as capital equipment costs that may be lower compared to other assembly methods such as welding.
Certainly, the cost of liquid adhesive or tape is also important. Liquid adhesives are generally cheaper than tapes, but it should be kept in mind that there may be compromises in curing time, drying, or hardening. The chemical composition and performance level of the adhesive or tape will also affect its price. Generally, the more extreme the conditions that the tape or adhesive can withstand, the higher the price. During the selection process, it is mandatory to keep in mind the end uses that are required and choose based on what is needed for the application.