Archive for Converting to Thermoforming
Download the New Plastic Thermoforming vs Injection Molding Manufacturing Process Comparison and Selection Guide
Both injection molding and plastic thermoforming have widespread uses in a long list of industries. Each process has some unique features and benefits that are often advantageous for a specific application. In these instances, the choice to manufacture with plastic thermoforming or injection molding may be very obvious. This is most apparent in production volume. Low to mid volume tends to favor thermoforming, while high volume is usually more cost effective with injection molding.
However, a product’s needs and the capabilities of these two processes sometimes overlap. A part’s geometry may seem better suited for injection molding, but in a limited production run, but it may be drastically more cost effective to manufacture it with plastic thermoforming. This is just one example of an application where deciding between injection molding and plastic thermoforming may not be a clear choice. Selecting the right method in these situations requires a deeper appraisal of the features, benefits, and costs associated with each process.
The Clear Choice
As mentioned above, there are some instances when the type and specifications of an application drastically favor one or the other plastic manufacturing process when the choice is between injection molding or plastic thermoforming.
Injection molding offers the key benefit of cost effectiveness at the mass production scale. When an application requires the production of more than 3,000-5,000 Estimated Annual Usage (EAU) identical parts with uniform wall thicknesses, injection molding often is the clear choice. This can be attributed to a high upfront tooling investment that is gradually offset by a generally low per unit manufacturing cost. The volume range of 3,000 – 5,000 is due to a variation on part cost in respect to part size. Smaller parts are generally cheaper to manufacture than larger.
- Part production volumes > 3,000- 5,000
- Uniform part wall thickness required
Plastic thermoforming, on the other hand, has a substantially lower tooling investment and a slightly higher per unit manufacturing cost. This equates to a much lower total part cost at low to moderate part volumes. Plastic thermoforming becomes the clear choice when the volume of manufacturing is less than 3,000 – 5,000 parts per estimated annual usage. This process also has the capability to produce single parts with very large dimensions, whereas the injection molding process is limited to single part sizes of about 4 feet x 4 feet.
- Single part dimensions > 4’x4’
- Part production volumes < 3,000 – 5,000 EAU
Considerations When the Process Choice Is Not Clear
If your part or project doesn’t require a uniform wall thickness, large single part dimension, or has a volume requirement that is in the mid thousands, then you have landed in an area where the capabilities of plastic thermoforming and injection molding may overlap, and your process choice is not so obvious.
The good news is that you are now no longer handcuffed to a process that, while cost or size necessary, may not have the most comprehensive scope of benefits that would contribute the greatest to the success of your project.
Here are some points to consider for each process that can be taken advantage of or avoided now that you are free to choose a manufacturing method better suited to your project’s needs.
- Large single part capability (maximum dimensions approximately 10’ x 18’)
- Short lead time ( 6-12 weeks )
- Able to reproduce injection molded level detail
- Smaller investment in tooling
- Lower equipment capital investment leads to lower set up and machine time costs
- Can produce thinner wall parts than injection molding, resulting in weight savings
- Greater options for part surface finishing (textures, patterns, distortion printing, painting, etc.) that can be accomplished in the mold.
- Multi material structures for cosmetic and engineering structure options (e.g. Acrylic/ABS)
- Variable part wall thickness depending on depth of draw
- Improved cost effectiveness at lower to mid volumes (< 3,000-5,000)
- Lighter part weight compared to injection molding for most applications
- Less molded in stress than injection molding
- Twin sheet capability for hollow parts and added structure
- Longer lead time (22-24 weeks)
- Large investment in tooling
- Cost effective at high volumes ( > 3,000 – 5,000)
- Efficient material use
- High level of precise part detail
- Limited single part size capability (maximum dimensions approximately 4’ x 4’)
- Finished parts often require post processing painting or finishing
- Greater design freedom on single wall parts
Want More Information?
What you see above is just the tip of the iceberg when it comes to comparing these manufacturing processes. For more information and for assistance in choosing the right process for your project, please contact Productive Plastics and connect with our industry experts and engineers to see how we can put over 62 years of manufacturing experience to work contributing to your project’s success.
Here are a few questions that we hear regularly at Productive Plastics regarding fiberglass and plastic thermoforming.
What is the difference between the fiberglass and plastic thermoforming manufacturing process?
How do plastic thermoformed parts compare to fiberglass molded parts?
What are the benefits and process of converting my part from fiberglass to thermoforming?
To answer these common questions and help you determine which process best meets the needs of your project, the team at Productive Plastics has put together a comparison and conversion guide for fiberglass vs plastic thermoforming. The guide is full of useful information from basic process overviews to technical comparison data on material and processing.
What you will find inside the guide:
- Fiberglass and Plastic Thermoforming Process Overviews
- Tooling and Process Comparisons
- Weight Considerations
- Cost, Material Properties, and other Considerations
- Upgrading your Application to Plastic Thermoforming
Follow the link below to instantly download a PDF copy of the Fiberglass vs Plastic Thermoforming – Comparison and Conversion Guide.
Transitioning your product manufacturing process from fiberglass to plastic thermoforming can allow you to capitalize on some major upgrades, benefits, and cost savings for your project. (See some of the advantages of plastic thermoforming vs. fiberglass in a previous post).
However, the process of transitioning from one manufacturing material and process to another, and doing it correctly, may be more complex than simply handing over the existing design and tooling. Below are the basic steps and considerations for the transition process that Productive Plastics has found to help ensure you get the best results from the conversion.
- Choosing the right plastic thermoforming manufacturer and process
- Plastic thermoforming encompasses a number of sub processes such as vacuum and pressure forming. Consult with your thermoformer to aid in selecting the ideal process for your application. Visit our thermoforming process pages for more information on each process.
- Select a thermoforming contract manufacturer experienced in processing a wide variety of material options with a strong understanding of those material properties.
- Choose a manufacturer with experience in converting applications from fiberglass to plastic thermoforming to avoid common pitfalls that can delay or increase the cost of the transition.
- Strong consideration should be given to a manufacturer with in house design engineers. The onsite expertise will help to ensure a smooth technical transition from fiberglass to plastic thermoforming.
- Select a manufacturer that is up to date with best practice methodology such as ISO, Lean Manufacturing, Six Sigma, etc.
- Adapting your existing product design to the plastic thermoforming process
- Manufacturing techniques, process capabilities, and material properties differ from fiberglass to plastic thermoforming. This is a good thing. The differences are what motivated you to consider converting your product in the first place. These differences will, more than likely, necessitate modifications to your existing design and tooling to meet your product’s needs and to maximize the advantages available with the thermoforming process.
- A design engineer, with plastic thermoforming experience, can adapt your product’s design to harness the benefits of the thermoforming process. (Productive Plastics utilizes our experienced in-house design engineers to help our customers with process conversions).
- Tighter part tolerances
- Reduction in part wall thickness
- Complex or aesthetic design enhancements unachievable or not cost effective with fiberglass
- Textured surface finish
- Lighter weight than FRP
- Consistent surface gloss
- Material selection
- An important consideration when manufacturing a thermoformed plastic part is the selection of appropriate material. There are a multitude of different types of plastic materials, each with their own specific characteristics, properties, strengths, and weaknesses. Communicating your product’s requirements and industry material standards early in the conversion process will allow your thermoformer to assist in selecting the ideal material for the application. Learn more about thermoforming material considerations and options.
- Properly designed and constructed tooling sets the foundation for tight tolerances and a high quality part. This becomes increasingly more important for complex and multi-part designs. Having your existing tooling evaluated by your thermoforming contract manufacturer as early in the transition process as possible can have a large impact on the lead time of your first part run.
- Choose a thermoforming contract manufacturer experienced with tooling materials options and processes to assure the right tool choice for your application and product life.
- Prototype testing
- Prototype development should be considered with a testing plan that includes dimensional as well as properties evaluation. Engaging in early involvement, support, and collaboration with a thermoforming manufacturer, like Productive Plastics, can aid in creating a successful verification plan.
Productive Plastics is top contract manufacturer for heavy gauge thermoforming, including vacuum forming and pressure forming. Contact us or request our complimentary thermoforming design guide for more information.