Advantages of Plastic Injection Molds
The plastic injection molding process is highly efficient. It allows for parts to be produced with minimal or no post-production finishing, saving time and money.
Unlike 3D printing, which takes hours to create one part, plastic injection molds most injection molding cycles last just minutes. This high speed makes it possible to produce hundreds of identical parts per hour at a low cost.
High-Speed Production
Plastic injection molds allow for high production rates due to automation, which saves both time and money. With less human labor, the process is more reliable, reducing the likelihood of errors that would require rework and potentially lower quality.
During the injection process, the thermoplastic undergoes a melting process and is injected into the mold via a nozzle. Then, the molded product is cooled and solidified to take its final shape. Within one mold, a core and cavity can be designed for multiple parts, making it possible to create multiple components in a single injection cycle.
The injection molding process requires precise control of temperature and pressure in order to produce accurate, high-quality parts. Variables like injection speed and cooling rate have a significant impact on the final product’s dimensional accuracy, surface quality, and strength. Different thermoplastics also have varying melt points and flow characteristics, requiring adjustments in the injection machine’s heating system. They may also have different shrinkage rates, requiring adjustments in the machine’s cooling cycle. This allows manufacturers to closely monitor the performance of their equipment and make any necessary modifications to ensure a quality product.
Durability
Plastic injection molding produces durable parts that are lightweight, impact resistant, and compliant with all relevant environmental standards. This technology offers many customization options to meet the desired product traits, including strength, stiffness, and color. Glass fibers can be added to increase structural integrity, while specialized resins offer UV protection. There are over 25,000 engineered materials that can be used with injection molding processes.
Regular maintenance and preventive maintenance practices can help to extend the lifespan of an injection mold. Undue thermal stress can be the leading cause of mold failure, and a proper maintenance protocol can reduce this risk.
The length of production cycles can also impact injection mold longevity. Longer cycle times expose the mold to more thermal stresses which can degrade it faster than a shorter production run.
Low Maintenance
Injection molds are durable and relatively low-maintenance compared to other types of manufacturing tools. This low maintenance requirement results in fewer production interruptions and increased productivity for the manufacturer. Injection molding is also eco-friendly and produces minimal scrap plastic that can be re-used for other applications.
Proper maintenance protocols can extend the lifespan of injection molds by reducing the frequency of repair and replacement. These protocols can include a cleaning schedule, proper lubrication, and regular inspections. Adding surface treatments, such as anti-corrosion coatings or protective waxes, to the injection mold can also help reduce wear and tear.
Other measures that can improve injection mold durability include slower cycle times, appropriate clamp force, and accurate temperature control during the process. These measures can prevent the plastic injection molds for sale occurrence of common problems that decrease mold longevity, including flash marks, sink marks, and warping. They can also prevent the accumulation of debris and contaminants in the injection mold cavity and core.
Aesthetics
Injection molding clients have many goals and priorities when developing a new plastic component – reducing time to production, ensuring functionality, minimising unit cost, enhancing reliability and delivering high quality aesthetics. Achieving these is largely dependent on the quality of the injection mold used to manufacture the product.
The beauty of a finished plastic part can be improved through a variety of techniques, including the use of high temperatures and pressures to achieve a gloss finish, or by adding texture to a molded component. Textured parts are often used in the automotive and consumer electronics industries, for example.
Flow lines are discolored lines and streaks that appear on the surface of a molded part, near the gate area where the molten plastic is injected. These blemishes don’t affect the function of the plastic part but may have a negative impact on its appearance. Knit lines are another common cosmetic issue, resulting in a lighter textured area on the surface of a part. This is due to inadequate bonding between two or more melt fronts during the solidification process.
Customization
Plastic injection molding offers extensive customization capabilities for producing unique products. For example, the ability to incorporate multiple colors and material combinations. This allows for a wide range of aesthetics to match existing branding and marketing materials. Injection molding also allows for the addition of fillers to improve strength, sun resistance or another product characteristic. This is possible due to the efficiencies of injection molding, which only requires minimal human supervision. Loading and unloading the machines is automated, which allows for precise control.
Choosing the right material for your custom injection molded product is critical. The design of the part will dictate what kind of plastic is required to achieve its functional and aesthetic goals. For example, a design with bendable sections or “living hinges” will need a flexible plastic like polypropylene. Structures that require durability, heat resistance or chemical resistance will need a harder plastic like PEEK or Nylon.