Monroe Electronics Electrostatic Fieldmeter - Static Monitor - model 177A - Manual (Page 54)

APNE-0015 53
I. Introduction
Why Is It Important To Understand, Measure And Control Static Electricity In Web
Coating, Converting, And Printing?
Statically charged materials on the converting machine, the web, or both may attract
or repel the web to itself or to the machine. This material misbehavior can adversely
affect the manufacturing process by causing jams and downtime, reduced
productivity, and/or poor product quality.
Static on the web can attract contamination such as dust and other particulates,
resulting in coating or printing defects.
Static shocks received by operators can cause dangerous physical reactions by the
persons receiving the shocks, possibly resulting in injuries or death from moving
machinery.
Static sparks in hazardous operations such as solvent-based coating or printing can
cause fires and explosions, possibly resulting in injuries or death to people,
destruction of the equipment or facility, and lost production.
Overall Review Of Static Generation, Measurement, And Continuous Control Of
Static In Web Handling Operations
This document provides the reader with a review of web static charging
mechanisms, web and machine factors most involved in static charging, typical
locations of web static charging, and techniques to minimize web charging.
Generation and control of static in web converting depends upon many varying
conditions in the web material, the converting machine, the surrounding
atmosphere, and the static control measures used on the machine. It is impossible
to predict and control all of these conditions because they can change without one
realizing it until a statically caused event occurs. Changing conditions can alter the
amount of static charge accumulation, so although static is under control today, it
may not be under control tomorrow.
The keys to continuous static control are (1) the correct determination of critical
areas of the machine to monitor for static charge accumulation, (2) application of
static countermeasures and devices that prevent or control static charge
accumulation, and (3) continuous electric field measurement in these critical areas
using permanent fieldmeters, which are alarmed to warn or shutdown the operation
when web static charge levels increase beyond predetermined set points.