America’s manufacturers may have a bigger image problem than they thought.

Factory bosses have long griped that they’re falsely viewed as operators of dank workhouses, when in fact their operations are more likely to be sparkling clean — with more brain than brawn required to run their computerized machinery. But what if that’s a problem too?

Earlier this year, Rockwell Automation Inc., a Milwaukee-based maker of factory automation equipment, decided to fund a survey for an industry group it supports called the Smart Manufacturing Coalition. The coalition was formed last fall to among other things encourage government support for the development of advanced factory technology. John Bernaden, a Rockwell spokesman and vice-chairman of the coalition, says the results were shockingly bad.

When asked to describe the impact on the economy of modernizing factories with advanced technology and automation, nearly two-thirds of respondents said it either made no difference or actually hurt the economy. The percentage who thought it was bad — 37% of the total — rose with lower household income and among those with less education.