There are many properties of plastics that need modifying to suit specific applications. We call these “functional” additives because they are developed to function in a unique way when added to polymer materials. Here we’ll continue our Q&A discussion about functional additives
Q: What is static electricity?
A: Static electricity is electricity generated by an unbalance of the molecular construction of relatively non-conductive insulators such as plastics and other non-conductive materials. While static electricity as such is relatively harmless to humans, one report shows that static electricity costs industry billions of dollars per year.
Q: What causes static electricity?
A: The unbalance of atoms is the cause. A “balanced” atom contains positive charges that are present in the nucleus of the atom. An equal amount of negative charges orbits this nucleus in the form of electrons. Both charges are equal and, therefore, the overall charge of a balanced atom is zero. If this configuration is disturbed and several electrons removed from the atom, a greater positive charge the nucleus results along with a deficiency of electrons. Conversely, adding a few extra electrons results in an overall negative charge.
Q: How does this develop in plastics?
A: Plastic materials such as Polypropylene, PVC (Vinyl), Teflon, and Silicone tend to collect electrons and become negatively charged.
Q: What can be done to prevent static electricity build-up in plastics?
A: One of the most effective ways is the active method of static control called “ionization.” While static electricity cannot be entirely eliminated, the conductivity of most plastic materials are so low that electricity cannot flow to ground, or remain “static.” Ionization or active static control must be utilized.
Q: What is an Antistatic additive?
A: Antistatic additives have static dissipative qualities that prevent static charges that build up on the surface of plastic products. Static can attract dust and dirt, cause clinging or sticking, as well as even be a fire or explosion hazard if a static charge sparks in the presence of flammable liquids. While there are various antistatic sprays that can be applied to the surface of parts, the optimum method of tackling this problem is through at antistatic additive that becomes an inherent part of the plastic material.
Q: What are some of the applications for Antistatic additives?
A: Antistatic additives are used in various types of packaging applications because brand owners want the packaging to stay clear and shiny, and static in the plastics can attract dust and dirt. One of the major areas of applications is in the electronics industry. There many electrical and electronic products molded with polymers that have antistatic additives in them to prevent an electrical discharge. Many electronic and electrical assembly plants use carrier trays and totes molded from polymers with antistatic additives to prevent static build-up on the plastic carrier trays from discharging harming the electronic components.