UHMWPE is below. When two different materials are pressed or rubbed together, the surface of one material will generally steal some electrons from the surface of the other material. At this low surface force (typical of industrial conditions), the absolute ranking of charge affinity of various insulating materials was self-consistent. If contaminated by dust, high-speed air can charge surfaces, but this charge comes from contact with the dust, not the air. Sometimes inaccurately called “neoprene” (see below). Cellophane Tape. Polyurethane foam +60 +N All materials are good insulators (>1000 T ohm cm) unless noted. For example, when adhesive tape is removed from a roll, a certain amount of energy per cm2 (of tape removed) must be expended in order to separate the adhesive from the backing material. Conductive. (10 T ohm cm). Several clear tape adhesives are have an affinity almost identical to acrylic, even though various compositions are listed. The amount of transferred charge can be found by first subtracting the two table entries: 30 nC/J – [-190 nC/J] = 220 nC/J. Acrylic (polymethyl methacrylate) and adhesive side of clear carton-sealing and office tape. UHMWPE is below. Click here to see meters for measuring static electricity, 3005 South 300 West Salt Lake City, Utah 84115 USA. This is therefore a good reason to select contacting materials such that their affinity difference is small. All samples needed to be sanded or scraped clean before testing; any thin layer of grease of oil (organic or synthetic) was generally highly positive and would thus distort the values. Sorbothane +58 -W Slightly conductive. Two materials that are this close to each other in the triboelectric series never seem to reach a charge difference as high as 2 nC/cm2, no matter how much they are rubbed together. Col.2: Charge affinity in nC/J (nano ampsec/wattsec of friction). In gaseous form, air is generally unable to impart any charge to or from solids, even at very high pressure or speed. Table below gives such a series for some conventional materials. The triboelectric series is a list that ranks materials according to their tendency to gain or lose electrons. This table can be used to select materials that will minimize static charging. Col.3: Charge acquired if rubbed with metal (W=weak, N=normal, or consistent with the affinity). Read the list. negative and how strong the effect will be. The series was further expanded by Shaw22 and Henniker3 by including natural and synthetic polymers, and showed the alteration in the sequence depending on surface and environ-mental conditions. Filled rubber will usually conduct. (Of course the other material will have an equal amount of positive charge.) If chilled to a solid or liquid, air is expected to be slightly negative, not positive. Slightly conductive if filled (1.5 T ohm cm). Resistivities were measured with an AlphaLab High Resistance Meter Model HR2. Column 1 (this col.): Insulator name. A letter “N” (normal) in this column means the charge affinity against metal is roughly consistent with the column 2 value. All materials are good insulators (>1000 T ohm cm) unless noted. Becomes more negative if sanded down to the BOPP film. Non-sticky side. The level of charge is linked to a material’s placement in this series (Table 1). Skin is conductive. For insulators, the table below can be used to predict which will become positive v.s.