A few dirt particles may have little significance in everyday life, but they can cause critical failures when making aviation fuel or chemotherapy drugs. Food, transportation and medical manufacturers must take extraordinary measures to ensure the purity of their products. How do they prevent particulate contamination along every part of the supply chain?
What Is Particulate Contamination?
Representative product samples containing foreign particles like metal shavings, cotton fibers or insect debris are considered contaminated. Technicians use particle size analysis to determine the mean size of the fragments in a liquid or powder sample. This allows them to detect any outliers that may come from a foreign source.
Particulate contamination is detrimental to products like hydraulic fuel and lubrication because it can lead to wear, failure and clogging, shortening vehicle life. In the medical field, matter on surgical tools can transfer foreign material into a patient’s body. Rough surfaces in food processing plants make it harder to clean the workspace, increasing the risk of foodborne illness.
In addition to contaminating products, particulate matter can negatively affect factory machinery function. Debris can slow or break mechanical equipment, leading to costly repairs and lengthy downtime.
Particulate matter can come from multiple sources along the production line, starting with salts left in the mix at the factory. Additionally, materials can be contaminated by coming in contact with water and steel during transportation — leading to rust — or by being left outside where pollen can enter the container. Pests can also cause contamination.
How to Ensure Product Purity
Because so much is at stake, manufacturers take several steps to reduce particulate contamination and ensure product purity.
1. Inspection
It’s often easier to prevent particulate contamination than to try to undo it later. Early in the manufacturing process, machinery parts can break down and allow metal shavings or fragments to enter the material. Regular inspections enable manufacturers to check for broken or malfunctioning filters, ensure moving parts are well-lubricated and replace damaged parts.
2. Storage
A 210-liter metal drum is one of the most common containers for storing and shipping materials such as oil or lubricants. Keeping them outside can lead to rusting that contaminates the material. Temperature changes can cause them to expand and contract, compromising their integrity. Manufacturers must take several steps to keep their storage area clean, cool and dry.
Manufacturers often use multiple barriers to protect barrels stored outside, ensuring the bungs are tight and the seams intact. They use roofs or secondary containers to keep the drums dry because water can cause temperature and pressure changes. It’s also helpful to lay oil drums on their side to ensure the internal contents are above the bung level, stopping the seals from drying out.
Manufacturers must thoroughly clean containers — especially around the bungs — to prevent particulate contamination from insects, dirt, rust or water when taking the material out of storage.
3. Preventing Internal Contamination
Some internal particulate contamination is expected when manufacturing, storing or using a material. It can stem from an issue with the machinery and includes any particles causing contamination once placed into a closed system.
Wear particles and seal material in oil are some examples of internal contamination. It comes from the car itself but may still indicate a defective product. Technicians that detect a high particle count on tests despite a well-controlled external environment could find particulate contamination inside the machinery.
Technicians employ various techniques to check particle counts. For example, they may use a test that operates on a light blockage method to count the total number of particles, regardless of origin, and catalog their sizes. They must take action if they detect a high count.
Many manufacturers use filters inside their machinery or storage containers to achieve target cleanliness levels. Technicians take representative samples of the material before and after using the filters to test their effectiveness.
Instead of filtering, manufacturers may also manually drain and discard any contaminated material. Another technique, called cryogenic grinding, allows for more accurate particle size distribution to identify contamination sources. It’s up to the manufacturer to decide which method is the most effective and affordable.
4. Training
Simple user errors can lead to contamination. Manufacturers train workers to keep testing equipment clean, use it properly and take accurate sample measurements. They emphasize maintaining a sanitary work environment and properly labeling materials and tools. Regular refresher courses ensure employees remember their training. In addition to preventing contamination, education also improves workplace safety and prevents dangerous accidents.
5. Pest Control
Mice, insects and even-smaller pests — like mites — can find their way into a product by mistake. Manufacturers check for holes, leaks and air drafts that might allow pests to enter the building or infiltrate storage containers, then take corrective action. Employing exterminators also helps keep them at bay.
Additionally, manufacturers can enforce rules about where employees may eat and drink to minimize infestations. Having a dedicated breakroom for lunch and instructing staff to clean up after themselves goes a long way.
6. Electropolishing
Having a clean, polished indoor workspace also helps prevent contamination. Electropolishing strips off a layer of metal to remove contaminants from a surface, such as on machinery or countertops. Parts are dipped in an electrolyte solution and attached to a positively charged metal bar. An electric current then runs through and removes excess material.
This process reduces bacterial buildup, creates a sanitary finish, improves corrosion resistance and prevents products from sticking to the surface. Electropolishing makes it easier for manufacturers to clean surfaces and can even help machinery parts function more smoothly.
High Standards, High Quality
Maintaining strict particulate matter levels isn’t just a matter of cleanliness. In some industries, like pharmaceuticals and aviation, it can save lives.
Faulty equipment, user error and poor storage techniques contribute to contamination, but there are numerous ways to prevent and correct the problem. Employing these methods is vital for the best outcomes. Proper training, periodic inspections, pest control, filtering and electropolishing are just a few of the main techniques manufacturers use to protect their products and customers.
Emily Newton is a technology and industrial journalist. She is also the Editor in Chief of Revolutionized. She has over five years covering stories about warehousing, logistics and distribution.
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