Scientific Molding: High in Demand, Hard to Find

Posted by Ben Harrison on Aug 9, 2011 1:30:00 PM
Ben Harrison

blank.pngIn this age of global competitiveness and tough regulation, quality is the name of the game—superior quality will differentiate you from the competition and increase your market share.

OEMs in various industries are designing increasingly complex components, products, and devices that require higher tolerances—but are still expected to meet high quality standards, comply with regulations, and be cost-effective. This can be achieved by having the best designed and controlled manufacturing process possible—which is what scientific molding is all about.

More manufacturers want scientific molding because it gives them a competitive advantage in the marketplace when it comes to critical-use, complex parts and devices, or precision-molded plastic parts (standard molding, which can be more “trial and error,” works fine for simple parts and products—things like food-storage containers, toys, or other basic molded parts).

Scientific molding relies on material science and precise measurement to completely understand, down to the molecular level, what’s happening during every stage of the injection molding process. By fully understanding how all the different parameters interact in detail, we can maintain high precision across multiple production runs. Because all the data is recorded, we can easily replicate the manufacturing process as needed—even when production is transferred from one machine to another—saving a tremendous amount of setup time.

Scientific molding engineers develop a hypothesis about the best design and process, test it, refine it, and perfect it until the results are reproducible many times. Then we can build a tightly controlled and repeatable manufacturing process that makes parts consistently free of defects. Sophisticated software and sensors are used to collect data that documents every phase of the manufacturing process: design and building of the tool, debugging of the tool, material selection, and the injection-molding process.

Highly-trained engineers know how to use scientific molding data—they understand exactly what is happening with the material inside the mold at every step of the process; they know how small changes in pressure, temperature, and flow rate impact quality of the final product. By recording data when the machine is producing at peak efficiency (top productivity with minimal scrap), engineers create a template by which process parameters can be replicated, or easily adjusted if deviations are noticed (always in real time).

Scientific molding engineers are often specialized in a particular phase of product development: tool design and construction, molding production, and process conformation, for example. They have deep knowledge of how all the process variables react in certain ways according to temperature, pressure, material flow rate, material chemistry, cooling time and rate, material moisture rate, fill time, and mold conductivity. Cooling time, for example, is influenced by the heat level in the material, the conductivity of the tool steel, and the geometry of the part. Since engineers have been trained to consider everything from the perspective of the plastic, they know exactly how to manipulate the variables back to peak efficiency.

Even the slight fluctuations can result in scrap, so control is incredibly important. Engineers monitor process parameters according to the “peak” template with ongoing quality testing and inspection. Some testing and monitoring tools used during tool development and production include rheology curves (or viscosity curves), velocity profiling, cavity pressure readings, and gate seal (or gate freeze) studies.

Successful scientific molding requires a combination of deep knowledge, experience, analytical skills, and the highest-quality equipment and tools. Through their expert analysis and interpretation of the collected process data, engineers use scientific molding to design and document a robust and repeatable process that delivers consistently defect-free parts—maximizing profits by increasing quality and saving time and money.