While composites inspection takes place after parts are manufactured, the plans for such inspections are developed based on work completed well before the piece or product is fabricated. Inspection is a multi-faceted process that typically starts with the engineering drawing. It takes into consideration what the designer determines is most important – the surface plane, mating surfaces, hole location, attachment points, material performance and so on.
Inspection techniques range in difficulty according to the method. Some of the more common techniques include visual, measurement, destructive testing and non-destructive testing. Each of these techniques require skilled inspectors. Without proper inspections, you risk shipping substandard or non-conforming products to the final customer.
No matter what method is ultimately used, the path to creating an inspection plan is similar and relates to an effective quality system. ACMA’s Certified Composites Technician (CCT) program notes four basic elements of an effective quality system: expectation, specification, verification and progression. Following this model, the first step toward creating an inspection plan is to define the product. What is it? What is it used for? Next, establish the necessary specifications to provide the customer with an acceptable product. Those specifications include visual, aesthetic and physical requirements.
In this column, the word “method” will refer to the procedure or way an inspection is accomplished, while “technique” will refer to the ability or skill required to complete the inspection. In creating an inspection plan, the methods of evaluating the product and process must be defined first, then the various techniques can be established. From my experience assisting companies in establishing quality systems, it’s more difficult to determine what needs to be inspected than how to inspect it.
Once you’ve defined the product and established specifications, then it’s time to choose inspection methods and techniques – as well as members of your team that can handle the inspection or be properly trained to do so.
Let’s take a very simplistic look at what is needed to select inspection methods and techniques to verify compliance and provide for continual improvement – the verification and progression parts of an effective quality system. Keep in mind that the main purpose of inspection is to determine whether the components and/or the product conform to the specifications as provided. Once the product has been defined and the specifications established, the manufacturing process must be charted. This is a step-by-step diagram including all necessary steps, from receipt of raw materials through manufacturing to final packaging and product shipment.