So you have a fantastic idea for a plastic part, but how do you bring it to life?

Embarking on a new project can be daunting. You have to be precise when considering each factor in the process: design, materials, manufacturing, and costs. Project managers plan for an end product that is high quality while also staying within a predetermined budget.

Luckily, existing popular methods of manufacturing can help achieve the end goal. Thermoforming, injection molding, and 3D printing are three very popular manufacturing methods, each with advantages and disadvantages over one another. Each method holds its unique advantages and limitations, influencing the overall success of your project.
So, which manufacturing method is right for your project?
Let’s dive into the pros and cons of each of these manufacturing processes:

3D Printing

In 1984, the invention of 3D printing marked the emergence of the youngest among the three popular production methods. This process has revolutionized rapid prototyping and the creation of one-of-a-kind designs. It works with a wide range of materials and can create detailed prototypes quickly, making it an appealing choice.

3D printing processes require digitally created designs using popular software like AutoDesk or Blender. Next, the printer replicates these models by slicing them into thin digital layers. Upon uploading the design file, the printer heats up a thin spool of plastic thread and starts creating the object layer by layer. Once the printer finishes printing all the layers, the 3D object is complete!

Depending on the shape of the printed object, it may require additional post-print support removal or CNC. So what does a 3D printer do best?

Pros:

• Customization: 3D printing is perfect for one-of-a-kind designs and intricate prototypes
• Material Diversity: 3D printed objects can be made from a wide variety of materials including plastics, metals, and even some biocompatible materials
• Rapid Prototyping: Printing a model means you can have a physical 3D object within hours
• Complex Geometries: If you can think it, you can print it – 3D printing leaves a lot of room for creativity

What are some weaknesses?

Cons:

• Limited production: 3D printing is not suitable for mass manufacturing
• Cost per part: Can be expensive, especially for larger objects
• Strength limitations: 3D printed parts may not be as strong as traditionally manufactured ones
• Surface finish: The surface of the object may be rough or have obvious layers, which may require post-processing

Injection Molding

On the other end of the spectrum lies injection molding, renowned as the king of mass production. This method excels at creating millions of identical parts with consistent quality. It’s particularly beneficial for projects demanding high volume, complex details, and tight tolerances.

This production process starts with creating two halves of a metal mold in the desired shape of the final part. Next, the machine pours tiny plastic pellets into an adjoining chamber and melts them to a thick liquid consistency.

Once the plastic reaches the correct viscosity, a powerful screw forces it through a tube into the mold. The high pressure of the screw ensures thorough filling of every nook and cranny of the mold. The mold promptly ejects the finished part after cooling, either by water or another method.

This high-precision process is highly effective for various product development.

Pros:

• High-volume production: Injection machines can create millions of identical parts with consistent quality
• Wide material range: Materials vary from common plastics to engineering resins
• Tight tolerances and complex details: Useful for intricate gears or medical devices
• Durable parts: Molded parts can withstand high stress and harsh environments

However, injection molding comes with some challenges.

Cons:

• High tooling costs: Steel molds can be expensive, especially for complex parts
• Long lead times: Months may pass from design to production
• Minimum order quantities: High volume production means not ideal for small-scale projects

Thermoforming

Let’s dive into our core expertise! Plastic thermoforming traces back to the 19th century, coinciding with the creation of celluloid, an early form of plastic.. The process involves heating a plastic sheet until it’s pliable, then molding it over a shape to make the desired form.

Various industries widely utilized the thermoforming process today. They employ it in packaging for items such as clamshells and blister packs. This technique also plays a role in manufacturing automotive parts such as interior trims and dashboards. In addition, thermoforming is essential in the manufacturing of medical devices, including trays and blisters.

Its scale, speed, and cost-effectiveness make it a popular choice for a wide range of applications. This versatile technique excels at many things including the following.

Pros:

Large, complex shapes: Think bathtubs, kayaks, car dashboards, and airplane panels
Low-to-medium volume production: Ideal for batches between 50 – 10,000 units
Quick turnaround: Go from concept to part in weeks rather than months
Cost-effective tooling: Aluminum molds are cheaper than their injection molding counterparts

However, thermoforming has limitations.

Cons:

• Limited material selection: Mostly thermoplastics like ABS, acrylic, and polycarbonate
• Potential for surface imperfections: A flawless surface requires careful control of the heating process

So, which one is right for your project?

It depends! Here’s a quick synopsis of each manufacturing type:

• Moderate volume, large parts, fast turnaround? Thermoforming should be a perfect fit.
• High volume, complex details, tight tolerances? Explore injection molding for this project.
• Unique designs, rapid prototyping, diverse materials? 3D printing will be a quick solution.

When planning your project, don’t forget to consider factors like budget, material needs, desired strength, and production volume. Each of these elements plays a significant role in determining the overall success and feasibility of your project. If you are unsure of the best solution, feel free to consult manufacturing professionals for expert guidance. They can provide valuable insights and recommendations.

Our team at ThermoPro offers a combined 40 years of manufacturing expertise. Contact our engineers to help you through early product design stages, molds and tooling. They excel at post-production trimming and assembly as well.

Think thermoforming is right for your project? Send us a message for a free consultation.