The main goal of mold design is to create a product with high manufacturability—a high-quality process that is simple and efficient, long-lasting, easy to operate and maintain, and that meets all customer specifications at the lowest possible cost. Fulfilling these expectations depends on designing the best tooling option for each customer’s needs.
To accomplish this, mold decisions must be made in the earliest design stages. The mold-maker must be involved as early as possible to provide a realistic machining perspective on product design, requested tolerances, tool design, selected materials, and associated costs. Taking this step up front is the best way to eliminate wasted effort and rework, which adds significant cost to the mold budget. Part design and mold design are dependent on each other and thus should be done concurrently whenever possible.
For good reason, customers are always concerned about cost. After all, mold-making is one of the highest expenses in the production process. Properly designing, building, and using tooling for each part requires a highly skilled team of engineers and technicians utilizing the latest in sophisticated design and manufacturing technologies. Labor cost can be optimized, however, by working closely with an experienced, efficient tooling team that makes wise decisions on material selection and design tradeoffs, early in the design process.
In an effort to save costs up front, some companies shop mold according to price, looking for the lowest bid. There is usually a not-so-good reason behind lowball machining/tooling bids, including poor quality, poor repeatability, inferior mold, improper materials, low operational skills, and waste/rework.
Other companies trying to beat a deadline may select a mold vendor quickly, hoping “things turn out right.” Typically, however, lack of due diligence leads to oversights or cut corners that take much longer to straighten out. Although rushing might get the first shots completed quickly, chances are the final submittal won’t be any faster.
The best way to get maximum value for your mold budget is to consider lifecycle costs, not up-front costs. The ultimate goal is quality and repeatability. This is achieved by working with an experienced injection molder that takes the time to completely understand the customer’s needs, goals for the product, and production expectations and designs the best possible mold package to meet those needs. Up-front costs for quality tooling may be higher compared to cheaper vendors or offshore suppliers, but the payback come quickly in higher quality, fewer defects, greater throughput, longer-lasting equipment, and over better return on your tooling investment—leading, ultimately, to higher customer satisfaction and loyalty.
Injection molding is one of the leading processes for manufacturing plastics. It is widely used for mass-producing identical parts with tight tolerances. It is a cost-effective and extremely repeatable technology that yields high-quality parts for large series production.
It is a fast, intensive process where high heat and pressure are involved to inject molten material inside a mold. The molten material depends on the scope of the manufacturing project. The most popular materials are various thermoplastics, such as ABS, PS, PE, PC, PP, or TPU, but metals and ceramics can be injection molded as well. The mold consists of a cavity that accommodates the injected molten material and is designed to closely mirror the final features of a part.
Normally, the main cost driver in injection molding is the cost of the mold, also known as the tooling cost. The cost of designing and building a mold depends on the required production volume, the complexity of the part design, mold material, and the process used to create the mold.
Simple low-volume 3D printed molds can cost as little as $100, while the cost of designing and manufacturing complex molds for high-volume production may hit the $100,000 mark. Despite the considerable fixed start-up costs, the injection molding process has low variable costs due to the inexpensive thermoplastics materials, short cycle times, and the labor needs decrease progressively due to automation and economies of scale. This means that the variable costs of production are low and the process becomes more efficient and the cost per part decreases at higher volumes as the costs get distributed among hundreds or thousands of parts.