It is a common practice to create items from molds. Most kitchens have a range of cookie cutters, cake cans or jelly molds. The products made by molds are full of our families, cars and hospitals. They are also essential for aerospace and national defense projects. Therefore, molds are very common for household products and spacecraft parts.
Manufacturers use injection molding to manufacture parts for many consumer and industrial applications. The method includes melting the raw material and injecting it into the mold under high pressure. In large batches, injection molding provides low cost and relatively competitive speed. For parts requiring higher accuracy, such as medical devices or parts commonly used in national defense and aerospace applications, other manufacturing methods may provide better results.
CNC machining
In these cases, consider CNC or CNC machining. CNC machining workshops use software controlled milling, turning and drilling equipment to manufacture plastic parts, which can remove materials layer by layer from solid blocks. This method has obvious advantages in terms of time, cost, accuracy and performance of the products you design.
The advantages and disadvantages of CNC processing and injection molding are described in detail below to help you make the best choice for the production of the next prototype or part.
Advantages and disadvantages of injection molding
To compare and contrast injection molding and NC machining, first of all, we should understand the advantages and disadvantages of injection molding.
Advantages of injection molding
When manufacturing a large number of almost identical parts, most manufacturers choose injection molding. This process supports everything from toys to car engine parts - anything that needs to be mass produced with moldable plastic.
Injection molding provides a variety of materials, and more materials are being created regularly to meet the demand for high-performance plastic parts. Although CNC processing cannot adapt to soft parts requiring TPE or rubber materials, injection molding can.
Plastic CNC processing
Disadvantages of injection molding
When the batch size is large, the single piece price of injection molding is low. The costs associated with manufacturing the actual molds for injection molding drive up start-up costs. Certain materials, such as glass fiber reinforced plastics, require molds made of hardened tool steel to cope with increased pressure.
Another disadvantage of injection molding involves costs associated with part replacement, which often requires the production of new tools or molds. In addition, the mold consists of two halves that must be placed together for injection, resulting in potential surface defects. The injection system will introduce bubbles into the material, causing further defects.
There are many good reasons to use injection molding, especially in the mass production of parts. According to your product use, material specification and required quantity, CNC processing may provide a better solution for purchasing high-quality plastic parts.
Advantages of CNC processing and precision parts injection molding
When evaluating injection molding and plastic CNC processing, the following four aspects need to be considered:
Quantity: Generally, CNC machining can provide faster delivery speed and lower cost to reduce the number of parts. The exact number threshold for cost reduction in injection molding depends on part size, part complexity, and material selection.
Speed and cost: CNC processing provides higher speed for small batches. Or rapid prototyping or limited part production runs without breaking your development budget, and machining provides faster turnaround time at lower costs. For tens of thousands or hundreds of thousands of production, injection molding is usually more meaningful.
Precision: machined parts provide you with more control and fewer variables when dealing with precision tolerances. Machining focuses on the precise specification of the part itself, rather than injection molding, which considers the tolerance of the mold rather than the part. When absolute precision is required for the final product, especially for aerospace, medical and defense applications, CNC machining usually provides more accurate results.
Performance: For high-performance hard plastics that cannot be molded, the manufacturer selects CNC for processing. Some applications require hard plastics that must be processed. Melting and re hardening of plastic in injection molding may bring undesirable changes to the material properties of final parts.
Plastic cnc processing
Injection molding and cnc processing both provide high-quality methods to produce the best possible products. each method has its own advantages and disadvantages. Many end products include combinations of components made by each method. To make the best choice for your production needs, seek the help of the manufacturing experts who best understand these methods.
Choose the right approach for your next project
The machine shop will see various parts requirements and understand the capabilities of different manufacturing processes. They have first-hand experience in using various materials and make wise choices for your products. With this knowledge and experience, experts will advise on the best methods for your components.