Key Takeaways
- Thermoforming uses hot plastic sheets to create shapes by draping them over molds, providing an economical option for producing large and simple components.
- Injection mold technology uses heated liquid plastic that is forced into molds under pressure and cooled to create complex, high-precision parts in large quantities.
- All types of thermiformed parts are best produced in low-to-moderate volumes; injection molded parts are best produced in larger volumes and with complicated shapes.
- The criteria for the right process are: the materials used, design complexity, and production volume.
Thermoforming: Process and Applications
Thermoforming is an easy-to-understand and very flexible method of manufacturing. During this method, a plastic sheet is heated until it becomes soft and flexible. The heated plastic is then pulled over a mold (custom-made) and either vacuum-sealed or pressure-sealed until it fits the mold. After the plastic has cooled off, it will be cut to meet the exact requirements.
Thermoforming offers a cost-effective method for producing large amounts of small, lightweight objects with low tooling costs. Several industries – both traditional and emerging sectors–are already using thermoforming in conjunction with a thermoforming company (e.g., food and beverage packaging, medical, etc.) to create products such as trays, panels, single-use containers, and enclosures for medical devices. The versatility of thermoforming allows manufacturers to produce products in many different thicknesses and with a wide variety of part geometries.
Injection Molding: Process and Applications
Injection molding is a type of manufacturing process used in plastic. With injection molding, manufacturers can create large quantities of plastic components or products with excellent dimensional stability in an efficient and fast manner. Injection molding is commonly used for creating automotive dashboards, electronic components, and medical devices.
Many injection molding companies are leveraging the technology for many applications (electronic, automotive, and consumer products). It has many advantages over traditional manufacturing processes, including maintaining product quality, reducing production costs, and increasing manufacturing speed/efficiency.
Comparing Costs and Production Volumes
The costs and competitiveness for production volume differ between thermoforming and injection molding. Thermoforming offers better economic benefits than injection molded parts because it has lower tooling costs, a lower initial investment and provides fast-turn prototypes. As a result, businesses can significantly reduce their financial exposure by introducing a new part or fulfilling a specially requested order.
Through injection moulding, companies pay more for mould design at the beginning; however, due to the potential for high levels of repeat production, companies benefit from decreased costs per-unit pricing as production increases.
Furthermore, the speed and efficiency of the production value of injection molded parts provide a significant amount of savings as production increases; as a result, large global brands typically use injection molds for high-volume production of globally distributed products.
Material Considerations and Design Complexity
The selection of material will have the largest effect on the outcome of a manufacturing process as well as the method of manufacturing itself. Thermoforming is the most suitable method for many different kinds of thermoplastics, depending on their intended usage and their physical characteristics. Most thermoplastics are produced as either thin-walled or flat form parts.
Similarly, injection molding gives designers the most freedom in the manufacturing of complex and highly durable products made from engineered plastic. Designers should consider the intended use of the part, the environmental impact, and any applicable regulations when selecting a manufacturing method for a specific part.
In addition to allowing for designs that are exceptionally engineered, injection molding offers the greatest degree of precision in producing very complex features, including small ribs, screw bosses, and snap fit configurations. Therefore, injection molding is used extensively by industries that require precise tolerances.
Advancements in Manufacturing Technologies
Automation, intelligent sensor systems, and real-time process control have increased repeatability of these processes and decreased waste in both thermoforming and injection molding. The digitization of processes has enabled companies to respond more quickly to market changes and their customers’ evolving needs.
Recycling and energy-efficient machinery have been the driving forces behind sustainable manufacturing practices for both thermoforming and injection molding. Furthermore, businesses are now focusing on creating closed-loop systems, where surplus materials can be reprocessed, as a method of achieving both cost reductions and environmentally sound practices.
Choosing the Right Process for Your Project
There are many factors to consider when determining which manufacturing process is the best for your project: up-front versus ongoing expenses, the complexity of the geometry of the parts to be produced, the quantity of parts that will be manufactured in a production run, how quickly you intend to deliver those parts, and the physical characteristics of the raw materials being used.
For parts with complex geometries that are to be manufactured in high volumes, injection molding offers significant efficiency through the use of automated mass production techniques.
If, on the other hand, your project involves fairly straightforward processes for producing the parts, and you will also be able to make design modifications if necessary, then thermoforming should be a primary consideration.
In order for your company to effectively explore all technical trade-offs between processes for engineering excellence, it is essential to partner with reliable experts who specialize in either thermoforming or injection molding.
Conclusion
The manufacturing industry is continually changing and developing as new production techniques are created, making informed decisions on which technique(s) will give your company the greatest long-term competitive advantage even more critical than before. The thermoforming and injection moulding processes together form the foundation of the plastics industry.
Each process has its own advantages relative to specific uses; therefore, by being aware of and taking advantage of technological advancements and aligning product requirements with process capabilities, manufacturers can be more efficient, cost-effective and develop their market share in this rapidly changing environment.
