Vital Aspects of Plastic Surface Pretreatments
You should know that plastic adhesion problems are a major issue across the globe when it comes to plastics. The major contributor to these problems is that chemicals plastics have non porous surfaces which are known to have low tension. The other problem is that plastics are known to be chemically inert. You can conclude that plastics are naturally hydrophobic and, therefore, cannot get wet at all. These properties make secondary assembly and decoration of plastics a major issue. It is also hard to paint, to bond, to coat, and to print plastic materials because of this problem. When you have plastic surface pretreatments, you will not have a problem when it comes to solving plastic adhesion problems. You are also able to increase the bond strength of plastics using plastic surface pretreatments.
When you are carrying out surface pretreatments, it is vital for you to make sure that you your plastic surface is clean. A clean plastic surface will enable you get the best pretreatment and optimal adhesion. Some of the contaminants that may make surface pretreatment difficult are dirt, oils, grease, dust, fingerprints, among others. You also have to make sure that the plastic that is supposed to be treated is pure with no other elements that may inhibit the success of pretreatments.
You also need to know the conditions that can make a pretreatment last for long. There are a number of factors you should consider, for example, the formulation, the resin, and the general storage environment. Low molecular weight oxidized materials such as plasticizers, colorants, stabilizers, and others, have the ability to limit the life of a treated surface. High temperatures will also make a pretreated plastic surface revert back to being inert. This is because high temperatures are responsible for increased molecular chain mobility. When molecular chains move, the treatment bond moves away from the plastic surface thus destroying the treatment and you have to treat it again. The best thing for you to do is paint, coat, bond, and do other things to the plastic as soon as you finish the pretreatment procedure for the best results.
There are a variety of pretreatment processes you can use. Most of them are gas -phase oxidation plastic surface pretreatments. Examples include the low pressure cold gas plasma, the electrical pretreatment, and the flame plasma. These methods are applied differently. Cold gas plasma pretreatment method is applied in thin films, plasma enhanced chemical vapor deposition, and active microcircuits. The corona discharge or the electrical pretreatment method is applied in bottles, pens, containers, automotive parts, and non-active electronic components. The flame plasma pretreatment process is applied pens, bottles, and containers. All these processes have their particular advantages and disadvantages. They have one property in common, they can be able to generate gas plasma which is a very reactive gas that contains positive ions, free electrons, and other chemicals. These chemicals are the ones that react at high energy that can break molecular bonds on plastic surfaces thus making the plastic surface able to get wet. It is vital that you understand the pretreat methods properly so that you get the best outcome even for high volume productions that demand state of the art surface pretreatment systems.