Canadian Plastics

Can Robots Save Manufacturing in North America

Industrial robotic applications in molding operations are becoming increasingly flexible, proficient and powerful. At the Plast-Ex Show in May an unattended work cell consisting of an all-electric injection molding machine and two robots was used...

August 1, 2004   By Michael Legault, editor



Industrial robotic applications in molding operations are becoming increasingly flexible, proficient and powerful. At the Plast-Ex Show in May an unattended work cell consisting of an all-electric injection molding machine and two robots was used to mold and assemble a tool caddy (June issue, p. 7). Our current issue features stories (among others) about a fully automated Delphi plant running with an average of one operator per 15 machines (p. 13) and new automated methods of handling and assembling blow molded fuel tanks (p.10).

It is clear that these new, advanced robotic applications are the result of not only continuous improvement in robotic hardware and software, but also a result of progress in supporting technologies–end of arm tooling, vision systems, welding technologies, sensors, part delivery systems and programming/interface software.

It is also clear that many processors view robotics as the last line in the sand between them and low-cost foreign competition. In the words of one company president quoted in the cover story on robotics, “This (automation) is our vision of how you compete with China.”

One is inclined to applaud this attitude–why sit and wait for the business to be taken from you, after all? Yet in terms of rational business strategy and cost/benefit analysis, how realistic is the hope that automation is the cure for all that ails processors, especially given that in some cases parts made in China are being priced below the cost of the raw materials to make them?

Advertisement

No doubt, for certain applications, the impact on the bottom line can be dramatic. Robot suppliers say that in addition to lowering labor costs, robots can increase machine utilization by as much as 15 to 20%, and improve cycle time through quicker part extraction. The relatively new ability to program a robot off-line, while it is still running, is also improving the efficiency of robots.

Factoring in these savings, one engineering study calculated the payback time on a $100,000 robotic installation to be 3.6 years for one shift and 1.9 years for two shifts.

These are decent numbers. Industrial processes, however, are often limited by a built-in process interval–in the case of injection molding, the time it takes to inject and freeze a plastic melt. Because of this, one especially exciting development is the growing use of a single robot to carry out multiple functions, such as part extraction, applying a label and packing the part for shipment. Another trend helping expand robotics applications is the growing use of low-cost robotics systems for routine tasks in low-volume or smaller custom molding operations.

Understandably, robot suppliers prefer to downplay the sensitive issue of savings arising from reduced labor and employee headcount. Suppliers argue that processors usually capitalize on a robot installation by reallocating labor to more value-added tasks, rather than laying-off personnel. This is probably true, although there is no doubt automation would be expected to have some impact on the creation of future jobs, as it gives a company the ability to do more with less. Perhaps the increase in automation among North American companies is a contributing factor in the so-called jobless recovery we’re experiencing. If so, it hardly justifies whining. Some jobs are better than no jobs.