Quality control is a multifaceted process that requires a balance of numerous factors to produce consistent, high-quality injection molded parts and products. Several design decisions early in product development can impact final part dimension tolerances and other important quality characteristics.
For example, determining the ideal location for a gate (the opening through which plastic flows into the mold) helps ensure even fill distributions and proper cooling. Similarly, ejector pin placement influences product dimensions.
Design for Manufacturability (DFM)
Quality isn’t just about avoiding defective products in today’s competitive market. It’s about ensuring issues are found in the product design process as early as possible. This is where Design for Manufacturability (DFM) comes in.
DFM is a concept that enables OEMs to make product manufacturing a seamless and efficient process. By analyzing potential problems with production processes during the conceptualization of a product, engineers can ensure that the final product will be easy to produce.
DFM aims to minimize production costs without sacrificing product performance or quality. Several factors achieve this.
Some of the most important include minimizing the amount of secondary operations needed, limiting part tolerances, and selecting readily available materials. Additionally, engineers should consider whether a product can be sterilized or requires biocompatible materials. This can also be accomplished by designing the product with its intended operating conditions in mind. DFM also involves reducing the size of parts to reduce the required material.
In injection molding, precision is critical for ensuring accurate product dimensions. However, achieving 100% tolerance in injection molded parts is difficult due to the process and material constraints. Tolerance is determined by several factors, including gate placement (the aperture through which resin flows into the mold) and the ejector pins that control part removal.
Tolerance is also impacted by the material injected into the mold, which has different shrink rates. A high-quality injection mold will be designed to reduce warping and shrinking by maximizing wall thickness and determining the best location for the gate. Moreover, mold manufacturers utilize cutting-edge technology and expertise to create molds that meet the stringent requirements of diverse industries, ensuring precision and quality in production processes.
In addition to minimizing human error, process controls help to monitor and adjust machine settings automatically. This allows for long-term data warehousing and analysis, which can be used to determine the source of any problems that may arise. This helps to identify the issue and make necessary changes. This ensures that production processes run smoothly and to the highest possible standard.
The injection mold is the tool that takes on the shape of your final product. It consists of two parts: the core and cavity and the runners. The runner allows the hot molten plastic materials to pass to the body and cavity. Ejector pins remove The molded parts from the mold once they’re cool. Some tools have several holes, referred to as a multi-shot mold.
Each type of plastic has a different shrink rate, so your molding tool must be designed with this in mind to ensure that your finished product meets strict tolerance standards. Using support ribs in places where thickness transitions occur can also minimize the occurrence of stress concentrations and sinks.
Engineers review the drawings before a tool is built to ensure they meet construction standards. Then, the device goes through an initial sampling process, where it is tested for production viability, quality, and characteristics. Once the sample passes, the mold enters a regular production maintenance schedule.
Generally speaking, measurement is the act of comparing an unknown quantity with a known or standard amount. The results of this process are often expressed in terms of values and symbols.
A quality control (QC) program relies on four main types of measurement: control charts, product quality control, process quality control, and acceptance sampling. These techniques help establish and implement operational processes to deliver quality products.
For instance, ensuring that injection molds are designed to hold tight tolerances may involve adding support ribs or increasing draft angles. Appropriate draft angles, however, vary based on part design and desired surface finish.
Ultimately, consistent process controls ensure that a finished part meets QC standards. These standards also help ensure that products or services adhere to regulatory guidelines and industry standards, reducing liability. They can also boost a brand’s reputation for delivering high-quality products or services. This is especially important for businesses with a global customer base.