A hot melt adhesive, also known as a hot glue, is the name given to a polymer-based glue which is solid at room temperature and is applied in a molten state.
There are three principal levels to the process of a hot melt adhesive bonding collectively materials. Firstly, the solid adhesive is heated until it reaches its softening point, at which stage it will turn to liquid. The molten adhesive is then applied and wets the substrate. The interval available to make the bond between applying the thermoplastic adhesive and bringing in the secondary material is called the open time. Lastly, cooling time will then occur. This typically varies from just a couple of seconds to as much as 5 minutes, and through which the hot melt will solidify and really quickly build up power and stability. This fast turn round permits for a quick processing time and speedy assembly.
Most important Elements of Hot Melt Adhesives:
Polymers: These help to give the adhesive power and flexibility, as well as heat and impact resistance.
Resins: Control the wetting of the adhesive (how lengthy it remains a liquid whilst involved with the substrate).
Wax: Primarily controls the open time, and how lengthy the bond takes to form. It additionally helps thin the adhesive for application. The higher the wax content current within a hot melt, the higher viscosity and greater flexibility the bond will have. High levels of wax additionally enable for a quicker bond.
Antioxidants: These are used primarily to help preserve the material during its shelf life.
Advantages of Hot Melt Adhesives:
Good for hard to reach areas: Because the adhesive is utilized in a purely liquid form, it permits for straightforward application to more obscure places or surfaces which different glue or adhesive products can’t do as well. Many glue guns and nozzles are manufactured to distribute the glue into these small complicated places guaranteeing your entire chosen surface is attainable and covered which in turn, allows for stronger bonds.
Speed and ease: As the whole process of using hot melt adhesives is quick, this lowers assembly time and allows for optimum productivity with a fast turnaround.
Bonds number of substrates: Hot melt adhesives are specially formulated for particular tasks. A wide number of supplies could be bonded, resembling wood or corrugated cardboard. Heat sensitive materials resembling foam and even some plastics and metal can also be bonded utilizing hot melt adhesive when disbursed at a lower temperature. They can also bond both porous and non-porous surfaces.
Neat Application: The bond which forms from a hot melt adhesive is practically invisible which provides an general pleasing aesthetic. This is particularly useful when used for items resembling signs, displays and even furniture.
Lengthy shelf life: Hot melt adhesives have excellent moisture resistance and don’t need refrigeration which means they remain firmly bonded for an in depth period.
Challenges of hot melt adhesives:
As with most adhesive products, alongsideside the benefits, hot melt adhesives have a couple of limitations. The temperature at which hot melt adhesives are set at is crucial to the application process.
As soon as molten, the adhesive must be hot sufficient for assembly. If the adhesive isn’t hot sufficient at this stage, a weak bond could also be formed which is also known as a cold bond.
Nevertheless, if the hot melt adhesive is applied in a molten state at too high a temperature, it will stay in a liquid state for too long and end in a soft bond being formed. Any stress or weight on this bond will cause a weakening which may fail immediately.
Unlike different adhesives, if hot melts bonds are re-heated to their softening level temperature, the earlier adhesion caused by the cooling process could be reversed. Although this does make hot melt adhesives more flexible and simpler to repeatedly change, it can cause a hindrance should this be utilized to a substrate which will undergo or survive in an environment with higher temperatures. Nevertheless, many hot melts at the moment are being manufactured with higher levels of heat resistance to fight this.
If you have any inquiries pertaining to where and ways to utilize reactive Polyurethane PUR hot melt glue, you can contact us at our own web site.