Those who frequently work with epoxy resin, whether for sticker doming, parts bonding, or operating equipment like Visual Dispensing Machines and AB Glue Dispensers, have likely encountered a frustrating problem – epoxy resin failing to adhere to certain materials. It's not that the epoxy itself is defective, but rather that some materials are inherently incompatible with it. Today, let's discuss which materials epoxy resin won't adhere to, or won't adhere to securely.
First and foremost is silicone. Whether it's soft silicone products or silicone-coated surfaces, epoxy resin has great difficulty adhering to them. A friend once used an
Epoxy Doming Machine to apply epoxy to silicone stickers, but the epoxy peeled off after curing – this is the reason. Silicone surfaces are extremely smooth and chemically stable; epoxy resin simply cannot penetrate and form a strong bond with it. Unless special surface treatment is applied beforehand, don't waste glue and time.
Next is polytetrafluoroethylene (PTFE, also known as Teflon). This material is familiar to most people; it's the coating used in non-stick pans. Its characteristic is "non-stick to everything." Not only does epoxy resin not adhere to it, but most adhesives are ineffective as well. If you need to use an
ab glue dispenser machine to apply adhesive to Teflon parts, the adhesive alone is completely useless. You need to perform special surface treatments such as sanding and etching to roughen the surface before you can achieve even a slightly improved adhesion.
Polyethylene (PE) and polypropylene (PP) plastics are also "enemies" of epoxy resin. These two plastics are commonly used in daily life and industry, such as in plastic containers, pipes, and parts. They have very low surface tension; when epoxy resin is applied, it automatically shrinks into droplets, making even adhesion impossible, let alone a strong bond after curing. A customer once asked why their
AB glue Epoxy dispensing Machine couldn't bond PP plastic parts securely; the problem was with the material itself, not the machine operation.
Additionally, materials with oily, dusty, or waxy surfaces will also prevent epoxy resin from adhering. Although this isn't a problem with the material itself, it's one of the most easily overlooked aspects in practical application. Whether you're using a
sticker doming machine to apply epoxy resin to stickers or using ordinary AB glue to bond parts, if the material surface has oil, dust, or has been waxed, the epoxy resin will only adhere to these impurities and won't bond with the base material. It will easily peel off after curing. Therefore, it's crucial to clean the surface thoroughly before operation, ensuring degreasing and dust removal are completed.
Some particularly smooth metal surfaces, such as polished stainless steel and aluminum products, also exhibit poor adhesion with epoxy resin. While not completely non-adhesive like Teflon, the bonding strength after curing is insufficient, and the bond can easily break under stress. In this case, in addition to cleaning the surface, you can lightly sand it to create fine textures, helping the epoxy resin to "grip" the material better.
In summary, although epoxy resin has strong adhesive properties and can handle most situations when used with equipment like Visual Dispensing Machines and Epoxy Doming Machines, it becomes "ineffective" when dealing with silicone, Teflon, PE/PP plastics, and materials with unclean or excessively smooth surfaces. Before starting work, always confirm the material and perform necessary surface treatment to avoid wasted effort.
