Focus on Process Time

When working to optimize a manufacturing process, engineers have to balance the goals of Health & Safety, Environmental Impact, Product Quality, and Process Time. Our June newsletter focuses on the last of these, which is often a major driver of technology acquisition decisions.

Process Time Overview
One way to look at surface prep process time is to consider the elapsed time from when the surface is available for sanding to when the workpiece is ready for paint. Every minute in between is spent with the sander (or grinder, etc.) either on or off. Optimizing the process requires both that you maximize the efficiency of the time spent with the tool on, and minimize the percent of the total time spent with the tool off. Besides all the sanding steps required – which may include scuffing bare composite, sanding filler, reactivating primer, etc. – one should also consider time required for any rework or repair and any time used inefficiently because of schedule conflicts or task gaps. We will start our conversation by examining the process time components in more detail:

Trigger-On Time

At the most basic level, process time during surface preparation operations is divided into “trigger on” time and “trigger off” time – either the tool is on and abrading the surface or it isn’t. In general, the greater the percent of time spent trigger-on, the more efficient the process.

Trigger-Off Time

One of the more obvious components of trigger-off time is abrasive changes whenever the disc becomes loaded with dust or the grains become dull. Other reasons to turn off the tool include:



Scheduled Breaks (lunch, meetings, etc.)

Unscheduled Breaks (called away to help elsewhere, etc.)

Operator Repositioning (walking or climbing to a new position)

Equipment Repositioning (moving a scissor lift, scaffolding, or hoses)

Part Repositioning (to accommodate reach restrictions)

Fatigue (short break to shake out hands and shoulders, stretch, etc.)

Mid-Process Clean Up (wiping part surface for inspection, emptying vacuum, etc.)

Inspection / Supervision (whenever operator stops to check the surface or confer with quality assurance personnel)

EMMA and Process Time 

With this in mind, it follows that there are two main paths to reduce process time:

1] Improving the tool /abrasive effectiveness
     e.g. a more powerful tool or an abrasive that cuts more aggressively allows the operator to move the tool across the surface faster (increased feed rate)

2] Minimizing the amount of time the tool spends off the surface.
     e.g. an abrasive that lasts longer means fewer sheets per surface and less time spent changing paper

Temple Allen keeps both of these paths in mind when discussing how we can help clients reduce process time. Among the relevant characteristics of our equipment are the following:



Additional process optimization can be the result of other factors such as:

• EMMA's improved ergonomics allow otherwise restricted-duty personnel to perform sanding operations and  contribute more to task completion
• EMMA's ability to control the sweep rate and contact force generate more consistency among operators in both finish quality and task time - and this makes it possible to produce a reliable and efficient schedule -  minimizing the need to adjust resources on the fly
• EMMA's greater consistency and fatigue prevention also yields a reduction in parts that need rework or repair, as well as the inventory holding costs associated with delays in the production schedule