Material Selection - Elo TouchSystems IntelliTouch Ultra Product Manual

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Chapter 4 - Component Installation Chapter 4 - Component Installation

Material Selection

Material Selection
Many materials may be used to create a seal for an IntelliTouch system. Relatively Many materials may be used to create a seal for an IntelliTouch system. Relatively
hard seal materials are preferred, such as metal, hard plastics and high-durometer hard seal materials are preferred, such as metal, hard plastics and high-durometer
rubber. Adhesives and elastomers that actually bond to the touchscreen should be rubber. Adhesives and elastomers that actually bond to the touchscreen should be
avoided. Elo has sealing materials available for a variety of mechanical avoided. Elo has sealing materials available for a variety of mechanical
configurations. configurations.
The easiest seal is produced by allowing the bezel of the display to contact the The easiest seal is produced by allowing the bezel of the display to contact the
surface of the touchscreen. This method is typically used in systems where the surface of the touchscreen. This method is typically used in systems where the
system requirement is for a dust seal. Most CRT-based displays have bezels that system requirement is for a dust seal. Most CRT-based displays have bezels that
are made of a blend of polyvinyl chloride (PVC) and acetyl butyl styrene (ABS), are made of a blend of polyvinyl chloride (PVC) and acetyl butyl styrene (ABS),
and are generally acceptable for contact with the touchscreen or reflector arrays. and are generally acceptable for contact with the touchscreen or reflector arrays.
Spacers for the CRT-touchscreen combination should be chosen to distribute Spacers for the CRT-touchscreen combination should be chosen to distribute
contact along the entire periphery of the bezel opening without excessive pressure. contact along the entire periphery of the bezel opening without excessive pressure.
If a custom bezel is to be designed for the display and touchscreen, a blade-type If a custom bezel is to be designed for the display and touchscreen, a blade-type
profile in contact with the touchscreen can be utilized to produce an excellent seal profile in contact with the touchscreen can be utilized to produce an excellent seal
with essentially no signal attenuation. Considerable pressure may be applied to the with essentially no signal attenuation. Considerable pressure may be applied to the
touchscreen by the bezel, and a near-watertight seal may be achieved using this touchscreen by the bezel, and a near-watertight seal may be achieved using this
method. method.
Open-cell urethane and polystyrene foam materials make excellent dust seals and Open-cell urethane and polystyrene foam materials make excellent dust seals and
provide some degree of water resistance. These foams have very high compliance provide some degree of water resistance. These foams have very high compliance
and can take up wide variations in space between the touchscreen and display. If and can take up wide variations in space between the touchscreen and display. If
dust is severe in the application environment, the pores in the material may clog dust is severe in the application environment, the pores in the material may clog
up over a long period of time, reducing its effectiveness. These foams may also be up over a long period of time, reducing its effectiveness. These foams may also be
used in situations where seal contact with the reflectors is necessary. As noted used in situations where seal contact with the reflectors is necessary. As noted
above, use the least possible amount of contact with the reflectors. above, use the least possible amount of contact with the reflectors.
Watertight seals are achievable with several different materials. A fluorocarbon Watertight seals are achievable with several different materials. A fluorocarbon
material available through Elo produces a watertight seal with very little signal material available through Elo produces a watertight seal with very little signal
attenuation. attenuation.
Crosslinked polyolefin closed-cell foams also produce an excellent seal. Use Crosslinked polyolefin closed-cell foams also produce an excellent seal. Use
Volara, manufactured by Voltek, in 2A, 2E, 4A, or 4E weights For a flame- Volara, manufactured by Voltek, in 2A, 2E, 4A, or 4E weights For a flame-
retardant seal, use 2AF weight. Black is recommended. retardant seal, use 2AF weight. Black is recommended.
Cellular urethanes are a closed cell material with good compliance and little set, Cellular urethanes are a closed cell material with good compliance and little set,
and can make a good seal. and can make a good seal.