Published

Cleaning Tips for Beginners

PCx showed that some shops are using patchwork cleaning processes.
#basics

Share

At the Parts Cleaning Expo (PCx) earlier this year in Columbus, Ohio, we couldn’t help but notice that at least some of you are limping along with informal, patchwork cleaning processes. Problems that go along with ineffective, inconsistent cleaning include variable yield, increased rejects, high labor costs and excessive chemical and waste management costs.

 

Inefficient Cleaning Processes

Signs that it’s time to switch to a cleaning process that works can vary. If your shop’s parts are held under the tap and scrubbed with a brush or dunked in grimy buckets filled with mysterious, murky liquids, it’s time for a new cleaning process. If dirt is removed with stacks and stacks of shop towels that litter work surfaces and overflow trash cans or laundry containers, it’s time for a new cleaning process.

If there are dozens of industrial aerosol and spray bottles as well as household cleaners that are good for kitchens or floors that festoon the assembly area, and/or your cleaning products have a poorly defined and ever-changing assortment of ingredients, then it’s time for a new cleaning process. It’s impossible to have decent process control if you don’t pin down what your cleaning process is.

Do your workers have well-developed biceps on their dominant side because they hand-slosh containers of parts to separate metal fines from product, and the process degrades as physical fatigue sets in? If so, your company needs a better physical fitness plan.

 

Product and Soil Changes

Manufacturing activities often change gradually. When production volume increases, the impact on cleaning activities may only be considered when failures increase. The product itself may change qualitatively. Smaller parts with tight spacing may need cleaning agents that do a better job of wetting. Changes in the mix of metals may mean that the cleaning process that used to work is no longer successful.

Also, the soils may change. Lubricants and other metalworking fluids have gradually been reformulated nationwide, in part to avoid environmental impact on air quality. The process of machining can change the properties of metalworking fluids, too. The altered fluids can combine

with other soils to form an adherent residue.

 

Costs

We always start with this advice: First, don’t clean if you don’t have to. Second, understand what you are trying to accomplish in cleaning. Third, clean right away; cured-on or dried-on soil is difficult to remove. A simple immersion process right after machining can reduce or even eliminate the need for cleaning later.

Cleaning costs money. If you need to clean, consider the adage attributed to W.E. Deming: In God we trust, all others must bring data. Suppliers of cleaning agents and cleaning equipment can provide useful information, but look at that information critically in the context of what you need. One manufacturer commented that they abandoned plans for new cleaning equipment when they found it cost more than $100,000, that it took up a lot of space and that it did not work for their entire product line. Therefore, they didn’t set up a formal cleaning process. Let’s think of some other approaches. In the first place, less expensive, compact cleaning equipment could be evaluated. While it is rare that one cleaning process works for everything, you can usually find something that works for most of your product line. In any event, always invoke the concept of quality.

 

Keep Learning

Uncontrolled cleaning results in high costs and unfortunate consequences to product quality, so dip a toe into the murky waters of cleaning process development.  The best way to learn what works is hands-on testing to determine what does and, even more important, what doesn’t work. Some of you came up to us at PCx with tests you were conducting yourselves. Good work! Speaking of hands-on testing, Sam Houston State University and BFK Solutions are partnering to present a practical Product Quality Workshop in cleaning processes and operations in May 2018.  We’ll include a lot of demonstrations, so you can experience the joys of failure and success in surface prep.  

RELATED CONTENT

  • The Difference Between Ra and Rz

    While it is best to measure using the parameter specified in the print, there are rules of thumb available that can help clear up the confusion and convert Ra to Rz or Rz to Ra.

  • Understanding CNC Collet Chucks

    Workholding for turning is usually fairly basic: The selection comes down to chucks or collets. This article looks at when to consider the collet chuck and what kind might be best for a given application.

  • Deal Differently with Certainty, Risk and Uncertainty

    Let's take a look at the differences between certainty, risk and uncertainty, examples of each, and how we make decisions when faced with these situations.