Understanding the Process
Thermoforming involves heating a plastic sheet until it becomes pliable, then stretching it onto a mold, where it cools and becomes the desired shape. This process utilizes single-sided molds and is best suited for larger parts that require complex shapes, high cosmetics, and lower tooling costs. The finishing process includes trimming and secondary operations like bonding of blocks or the installation of attachment hardware, ensuring a high-quality aesthetic appeal.
Injection molding requires melting plastic pellets and injecting the molten plastic into a two-sided mold. It’s ideal for smaller parts that need to be produced at a very high volume. After cooling, the parts may require minimal finishing.
Evaluating the Costs
When it comes to tooling costs, pressure forming is significantly less expensive than injection molding, making it a cost-effective option for projects involving larger parts or multiple components.
While per-piece production costs for pressure forming are generally higher, these become extremely competitive as the part size increases. For example, consider a 48” x 60” part in the low- to mid-volume range. Not only does pressure forming offer lower mold costs, but it also reduces lead times to market. These factors combined can lead to substantial total cost savings, making the overall cost of a pressure forming project potentially lower than that of injection molding, despite the higher price per part. This total cost benefit is critical for companies looking to maximize their budget while achieving quality, efficiency and repeatability.
Lead Time Considerations
Lead time is a critical factor in manufacturing. Pressure forming offers a quicker turnaround – typically between 8 – 12 weeks for both tooling and initial production – compared to injection molding, which can take up to 20 weeks or more.
Other Key Factors to Consider
The size of the part can be a deciding factor, as well as total production requirements for a project. Pressure forming shines with the capability of producing parts as large as 6′ x 10′, which helps in part consolidation, while injection molding is usually limited and known for its smaller part sizes that require more parts and more tooling per project. The aesthetic quality is exceptional in pressure forming, which allows for fine details and textures on the surface of molded parts. The cosmetic surfaces are practically identical in both processes.
What Each Method is Best For
Pressure forming is ideal for:
· Large part sizes, offering a greater surface area than most injection-molded parts.
· Projects that have multiple parts coming together to create a device, medical cart, etc.
· Projects with a smaller run size, being cost-efficient for production volumes from launch volumes to thousands of production parts.
· Aesthetics, as it provides enhanced cosmetics and detail that are created in the tool.
Injection molding is suited for:
· Manufacturing smaller parts that require intricate designs and tight tolerances.
· Larger run sizes, as the per-unit cost can decrease significantly with higher volume orders.
· Products with design stability, ensuring uniformity in mass production.
Still undecided about which manufacturing process to use for your next project? Ray Products is here to help. Our expert team can guide you through the advantages of each method to find the perfect fit for your manufacturing needs – contact us today!