Elastic pressure sensitive tape

With all kinds of intelligent electronic products against falling, deformation resistance, waterproof and dust requirements are more and more stringent, hardware manufacturers urgently need high-performance cushioning and energy-absorbing materials to achieve the above functions. At present, most of the pressure sensitive tape with buffering properties on the market is foam tape.

Foam tape is a kind of tape product made of foam as the base material. This tape is thicker than ordinary tape and has better sealing and damping effect. It can be used in a variety of occasions. Common foam materials are polyolefin or polyurethane foam materials. The polyolefin or polyurethane is heated and shear to high temperature melting state through screw machine and other equipment, and then blended with the electron beam excited foaming agent.

After extrusion molding, irradiation foaming, cutting shaping and other processes, the final strip foam manufacturing is completed. Foam tape is generally coated with pressure-sensitive glue on the release film, and then bonded to the foam after curing.

Due to the characteristics of the foam strip used, this kind of foam tape often has some inherent shortcomings in manufacturing and application: (1) Because the foam material is made of polyolefin or polyurethane material, which has poor heat resistance, there will be different degrees of shrinkage, camping and other deformation at 80℃ when there is no sufficient external tension support, which leads to the foam strip can not go through the high temperature process, which means that the foam tape can not be made by directly coating the foam surface with glue: Solvent-based glue needs high temperature to remove solvent and curing, UV glue in the long time UV curing process will also produce high temperature, both will lead to foam deformation, so only by the pressure sensitive glue coated on the release film and then fitted to the foam method to manufacture foam tape.

The surface energy of the foam is mostly below 32 dyns, which leads to the manufacturing of the foam tape, it is necessary to improve the surface energy of the foam by corona, pre-coated adhesion enhancer and other methods, in order to ensure that the pressure sensitive adhesive layer can be and the surface of the foam after bonding strength is enough, the process is complex, high manufacturing cost. (2) Before the foam tape is assembled into the intelligent electronic products, it is necessary to process buffer devices of various shapes through die cutting process. In the die cutting process, polyolefin or polyurethane itself is brittle and prone to dust, and electronic products have a high requirement on cleanliness, which makes it necessary to always pay attention to whether the devices with foam tape produce dust. Increased the cost of quality. (3) The bubble structure formed in the foaming process of foam, once destroyed in the die-cutting process, there will be a permanent open structure, which leads to water vapor, dust is very easy to invade from these open structures inside the foam, and along the porous structure inside the foam through the foam, As a result, many precision devices with strict limits on water vapor and dust need to increase the sealing structure to avoid pollution, increasing the cost of structure.