Cable Shielding
JHC supports a range of products to assist cable assembly shielding requirements.
CHO-SORB® EMI Attenuators
Reduce radiated emissions on data and power cables without affecting data transmission.
Cost effective CHO-SORB EMI ferrites reduce radiated emissions on signal lines and power cables without affecting data transmission. Parker Chomerics CHO-SORB attenuators are made of specially formulated soft ferrite material, which is a chemical composition of various metallic oxides, primarily nickel zinc. They possess two principle characteristics useful for controlling emissions: high magnetic permeability, which concentrates magnetic fields, and high electrical resistivity, which limits the flow of electrical current in the field. The properties of CHO-SORB ferrite materials can be found in Table 1. CHO-SORB ferrite attenuators allow desired signals to pass through cables or circuits while absorbing extraneous and unwanted energy. Low frequency and DC see only the conductor and are unimpeded. High frequency energy couples with the CHO-SORB attenuator, creating an impedance with inductive and resistive qualities. When a radiating conductor is surrounded by a ferrite attenuator, low frequency signals are transmitted without any loss. High frequency signals encounter inductive resistance due to the ferrite material’s permeability. This resistance reduces the conducted current and introduces an insertion loss. At still higher frequencies, the permeability of the ferrite material decreases and the inductive resistance falls. Here, the resistive characteristics dominate and the resistive quality of the ferrite assumes control of providing the insertion loss for dissipating EMI.
CHO-SHRINK® 1120
Commercial Grade Conductive Heat Shrinkable EMI Cable Shielding System
Chomerics’ Silver Plated Copper CHO-SHRINK 1120 is formulated and manufactured for commercial EMI cable shielding applications to provide a low cost, light weight, 360° EMI shielding for cables, transitions, connectors and terminations. CHO-SHRINK’s ease of application reduces assembly costs and provides a reliable, professional looking EMI cable shielding solution for electronic equipment. CHO-SHRINK also provides an effective shielding solution which simplifies connector and termination designs. The product consists of polyolefin heat shrinkable tubing, connector boots, and transition pieces that are coated with Chomerics’ unique silver-plated copper filled coating system.
ZIP-EX-2® Cable Shielding
ZIP-EX-2 cable shielding provides convenient, inexpensive EMI and EMP shielding of cable harnesses for computers, communications equipment and other interference-sensitive electronic systems. It can be opened and closed quickly, before or after the cable is installed. The shielding medium is 4 ply 2 strand 0.0045” wire diameter Ferrex® knitted wire mesh with the option of a Black Vinyl or Fire Retardant/ Anti-Static PE protective covering, a combination that provides flexibility and durability as well as positive shielding. A conductive Velcro® fastening system provides continuous closure. It consists of nylon hook & loop tapes impregnated with silver. This system also allows ease of opening and closing.
SHIELD WRAP™ Knitted Wire Mesh Tape
SHIELD WRAP wire mesh EMI/EMP shielding tape is produced as a two-ply flattened cylinder of varying widths, loop spacings, wire sizes and metals. SHIELD WRAP mesh is designed to wrap easily (50% overlap recommended) around cables and harnesses, and will reduce corona discharge in addition to providing EMI shielding. It has excellent flexibility and conforms easily to irregular and complex surfaces. Under rising temperatures, the wire’s knitted loops enlarge into each other instead of bulging away from wrapped surfaces, as do straight wires of woven mesh. Although not intended as a substitute for braided grounding straps, SHIELD WRAP mesh becomes especially useful for grounding when considerable flexibility is required. Standard SHIELD WRAP mesh is available in either Monel* or Ferrex**, in wire diameters of 0.0035 in. (0.09 mm) and 0.0045 in. (0.11 mm), and widths from 3/4 in. (19.1 mm) to 2 in. (50.8 mm). Openings per linear in. are from 8 to 14 for these materials.