Generic selectors
Exact matches only
Search in title
Search in content
Search in posts
Search in pages

Heavy vs thin gauge plastic thermoforming – what’s the difference?

The dimensional difference between heavy gauge thermoforming (sometimes referred to as thick gauge or sheet fed thermoforming ) and thin gauge (also referred to as roll fed) thermoforming may only start as a few tenths of an inch in part thickness, but the manufacturing techniques, machinery required, and scope of applications that the two are best suited for are quite distinct from one another.

Additionally, because the machinery required is unique for each process category, most plastic thermoforming manufacturers specialize in only one or the other. For instance, Productive Plastics is a custom heavy gauge plastic thermoforming manufacturer. So, you can save some time when searching for a processor if you know which category of thermoforming is the right solution for your application.

Here are the essential differences between heavy and thin gauge plastic thermoforming:

Plastic Thermoforming Heavy Gauge Thin Gauge
Manufactured Part Thickness (approximate) .060 -.375″ 1.5 – 9.5 mm < .125” < 3mm
Machinery Type Sheet Fed Roll Fed
Thermoplastic Materials Used (Most Common) ABS
Polycarbonate
HDPE
Polypropylene (many material variants available)
PETG
PET
Clear PVC
Styrene
Polypropylene  
Annual Volume Low – Mid Volume < 10,000 High Volume > 10,000
Typical Applications -Medical device enclosures
-Transportation interior parts (window masks, wall and ceiling panels, seating, luggage racks)
-Kiosk enclosures
-Industrial equipment covers
-Electronic equipment enclosures
-Clamshell packaging
-Food service packaging
-Disposable cups, plates, and trays
-Food containers
-Small medical device packaging

Does your application favor heavy gauge thermoforming? If so, contact us or download our Heavy Gauge Plastic Thermoforming Design Guide for more detailed  information on the features and benefits of plastic thermoforming and to explore how Productive Plastics can provide manufacturing solutions for your product.

Please contact Productive Plastics for more information on the thermoforming process
Please download the heavy gauge thermoforming design guide from Productive Plastics

Plastic Thermoforming, Pressure Forming, and Vacuum Forming – What’s the Difference?

The terms “plastic thermoforming”, “pressure  forming”, and “vacuum forming” are all used to describe plastic forming processes. While similar, there are subtle and important differences in these terms and processes that may not be well known outside of the plastic manufacturing industry.

Here is a brief breakdown to get you talking thermoforming like a pro in less than a minute:

Plastic Thermoforming is the generic broad label given to the plastic manufacturing process that heats thermoplastic sheet material (thermo) and then applies pressure or vacuum to form into a 3-dimensional shape (forming).

Pressure and Vacuum Forming are the 2 most common plastic thermoforming manufacturing techniques, under the umbrella of plastic thermoforming. They differ primarily in the method of applying pressure/vacuum to transform the heated plastic sheet into the desired 3-dimensional shape.

Pressure Forming Process

Pressure Forming Process

Vacuum Forming Process

Vacuum Forming Process
 

Plastic Thermoforming


 

Pressure Forming

Vacuum Forming

 Pressure Forming IllustrationVacuum forming Illustration
Process DescriptionSheet thermoplastic material is heated until pliable. Positive pressure is then applied above the heated sheet, pressing the material into the surface of a mold to create the desired 3-dimensional part shape.

 

Full Disclosure – The air under the sheet is also evacuated to assist in stretching the material over the mold, but the positive pressure applied is up to 5x greater.

Sheet thermoplastic material is heated until pliable and placed over a mold. The air is then evacuated between the heated sheet and mold creating a vacuum that pulls the material onto the surface of the mold to create the desired 3-dimensional part shape.

 

 

Watch a 1-minute video of a part being vacuum formed.

Key Benefits
  • Aesthetic surface finishes (texture, branding, in mold design)
  • Often eliminates need for post-production painting
  • High level of detail (rivals injection molding)
  • Tighter radius formation
  • Greater undercut depth and definition
  • In mold vents, louver, and attachment point geometry
  • Larger part capability
  • Faster cycle times
  • Lower tooling costs
ToolingNegative  toolingPositive  tooling (typically)
 

 

Primary Part Surface (Dimensional & Aesthetic)

 

 

 

Outside (part surface contacting the tool)

 

 

Inside (part surface contacting the tool)

Application Examples
  • Device Enclosures (medical, dental, kiosk, electrical, etc.)
  • Transportation (air, mass transit, rail) interior components (seating, window masks, wall and ceiling paneling, etc)
  • Material handling equipment interior components
  • Recreation and utility vehicle components
  • Food service components
  • Handling trays and dunnage
  • Pick up truck bedliners
  • Waste water management components
  • Portable toilet components
  • Large equipment enclosures
  • Agricultural related equipment and components

In addition to pressure forming and vacuum forming, there are other methods, such as twin sheet thermoforming (to be covered in a future post), that give plastic thermoforming a vast portfolio of manufacturing capabilities that offer product solutions to a wide range of industries and applications. Plastic thermoforming often outperforms other processes and materials such as fiberglass (FRP) , metal, or injection molding.

Want to learn more about which plastic thermoforming process is the right solution for your project?

Please contact us.

Please contact Productive Plastics for more information on the thermoforming process

5 Questions to discover if your manufacturer can produce high quality parts, time and time again?

The heavy gauge plastic thermoforming process can produce a very versatile range of highly detailed, durable, and tight tolerance parts with almost limitless design possibilities. The process is fast, cost effective, and ideally suited for a large list of markets and applications. However, like all manufacturing processes, plastic thermoforming requires technical expertise, detailed operating procedures, engineered tooling design and construction, and a comprehensive quality management system to ensure the consistent production of the most cost-effective solutions at the desired level of quality.

As such, not every plastic thermoforming processor is equally capable. Contract manufacturers with poor tooling, processing and quality controls can end up delaying your project or OEM product and increase costs.  Productive Plastics recommends asking the following questions to gauge if a custom plastic manufacturer will be able to consistently produce parts at your required level of quality and dimension tolerances.

1. Does the manufacturer have an accredited quality control program?

ISO9001-2015-Certification-Productive Plastics

Ensuring that your manufacturer has adopted an accredited quality control program, such as ISO 9001, will indicate that the company has an active quality control process in place that has been evaluated and certified by an industry recognized third party. The accreditation documentation, often available on the manufacturer’s website, will give you detailed information on what aspects of the company have been certified and supporting quality documentation can often be requested from the processor.

2. Is the manufacturer’s facility organized and clean?

This may seem like a trivial point, but it can be a key indicator to a company’s commitment to quality. A company with a well-organized manufacturing floor is much more likely to take quality, efficiency, process improvement, and safety seriously. If you are not offered a tour of the facility, ask for ne and witness firsthand the quality control measures in action. Cleanliness and organization are vital since thermoforming is an “open mold process” meaning airborne dirt could end up as an inclusion in the finished part and become a cosmetic flaw.

3. Does the contract manufacturer utilize efficient manufacturing methodologies and conduct process improvement events, such as Lean Manufacturing and Kaizen events?

Lean Manufacturing practices are focused on the removal of inefficient practices in manufacturing, management, and administration operations and part of the methodology is the regular evaluation of current processes with emphasis on continual improvement. Companies that are committed to following Lean Manufacturing techniques often have a very efficient manufacturing operation, state of the art equipment, and produce quality parts with a low rejection rate.

4. Does the thermoforming processor have dedicated engineering experts on staff (in-house) to provide tooling design and construction project management?

Properly designed and constructed tooling is the foundation of plastic thermoforming and is essential to producing a high quality consistent product. Poorly engineered tooling can result in part dimension variations, surface abnormalities, and other defects. See 6 Common Thermoforming Quality Issues Actually Caused by Improper Tooling.

5. Does the processor conduct a “Define and Discover” Innovation Engineering approach to seek avenues for collaborative project development and management?

This collaboration innovation technique sets the stage for a smooth product development which is more likely to meet performance and delivery expectations.

Ultimately, each project is unique. A commodity type part will likely not require the same level of quality in detail and precision as a multi-part medical device assembly. However, finding a reliable custom manufacturer that can produce your parts consistently, efficiently, and to your specification is a paramount factor to the success of any product.

At Productive Plastics, we go to great lengths to ensure quality

Have more questions about the role of quality manufacturing for your parts and components? Interested in exploring plastic thermoforming solutions for your OEM product?

Please contact us.

Please contact Productive Plastics for more information on the thermoforming process

How far does your manufactured part travel to get painted?

The manufacturing supply chain can be long and complex. Managing independent suppliers for design, tooling construction, assembly, part painting, and more can be challenging, and each has an influence on the quality, timing, and cost of the finished product.

For custom plastic thermoforming, post-production part painting is a key link in this supply chain. That is why Productive Plastics decided to bring our own painting operation under the same roof as our manufacturing facility.

Our cutting edge painting and finishing facility is solely dedicated to meeting the surface finishing needs of custom heavy gauge thermoformed parts manufactured by Productive Plastics.

What are the Benefits to Our Customers?

Reduced Risk

If a supply chain is only as strong as its weakest link, then strengthening or removing that link reduces the risk of a break. Consolidating the painting and manufacturing operation at Productive Plastics means that there is one fewer supplier to manage and monitor.

Reduced Cost

In-house facilities and complete control over the painting process reduces or eliminates the logistical and quality control costs associated with an off-site supplier.

Reduced Lead Time

The painting facility is located a mere 100 feet from the manufacturing floor which means that parts can be painted, cured, and ready for shipping or assembly in the same day that they are manufactured.

Increased Process and Quality Control

Incorporating a painting facility into the operation at Productive Plastics allowed us direct control of the painting process and quality management.  We implemented the same lean manufacturing techniques, proven processes, and quality controls that we have been evolving on the manufacturing floor for over 6 decades.

Strategically consolidating the manufacturing supply chain is just one of the ways Productive Plastics is constantly improving our ability to contribute to your product’s success. Contact us and give us the opportunity to show you how we can provide much more than a high quality plastic part.

Please contact Productive Plastics for more information on the thermoforming process

Part Size Has a Big Impact When Choosing Between Injection Molding and Plastic Thermoforming

When comparing a part manufactured with the heavy gauge plastic thermoforming process and the injection molding process, next to production volume, the largest factor that can impact the cost and even process feasibility is the size of the part.

Essentially, the larger the part is, the more expensive it becomes to produce with injection molding. Comparatively, part size has a very minimal cost effect on plastic thermoformed parts. The breakeven point on cost between the two manufacturing processes, with respect to annual production volume (Deciding Between Plastic Thermoforming and Injection Molding – The Choice is Not Always Obvious), increases as part size increases to approximately 5,000 parts or higher depending greatly on how large the part is.

Why Does Part Size Affect Cost and Manufacturing Process Selection?

The injection molding process requires a very large initial capital investment in the tooling and equipment needed to produce a part. This is because the nature of the process involves a very highly engineered 2-sided mold to create a part by feeding thermoplastic resin into a heated barrel with a rotating screw. The screw delivers the raw material forward collecting under pressure the amount required to fill the mold cavity and then injecting into the mold at high pressure and velocity. This action requires highly structured molds and equipment capable of withstanding very high clamping pressure.

As part size and dimensions increase, the complexity of design, engineering, and calibration required to construct, install, and process this 2-sided mold results in a significant increase in the cost of equipment, tooling and setup. The per-part production cost and lead time may also see an appreciable increase as the part size increases requiring much more robust molds and equipment. These increased capital expenditures will result in greater investment and overhead costs calculated in the piece price. Injection molding machines have a limited total mold size capability but can often accommodate multiple parts within the construction of a mold. Smaller part sizes equate to a higher number of parts manufactured per mold and machinery cycle. Larger part sizes decrease the number of parts that can be manufactured per mold and cycle.

Think of a muffin tray with 3-inch diameter muffin molds. Now take that same size tray but with 6 or even 10-inch diameter muffin molds and you imagine the impact on production and cost. In fact, most standard injection molding machines can only accommodate a maximum part size of 4’ x 4’. Larger machinery is available but is also drastically more expensive.

The heavy gauge plastic thermoforming process, on the other hand, involves considerably less pressure and most applications only require a single one-sided tool to produce a part. Additionally, only one part is formed per cycle in heavy gauge thermoforming applications. Consequently, the initial tooling investment is drastically reduced. While an increase in part size will still increase the tooling investment, the impact on cost is substantially less when compared to injection molding. Heavy gauge thermoforming equipment has oven zoning and variable sheet size capabilities which allow for a wide range of part sizes to be efficiently formed from the same equipment investment. The nature of the thermoforming process and flexible capacity capabilities makes scaling production for larger part sizes a relatively easy process. Since most heavy gauge thermoforming operations utilize cell-based manufacturing and CNC part trimming, a larger part can be produced with little impact, other than increased material, on per part cost, cycle time, and lead time. Thermoforming machinery can also manufacture part sizes as large as 10’ x 18’ providing a much larger part size capacity than injection molding.

Large part size infographic

Deciding Between Plastic Thermoforming and Injection Molding – The Choice is Not Always Obvious

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

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

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.

Plastic Thermoforming:

  • 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

Injection Molding:

  • 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.

Please contact Productive Plastics for more information on the thermoforming process
Please download our complimentary thermoforming design guide for more information on the thermoforming process

5 Key Points in the Process of Upgrading Parts from Fiberglass to Plastic Thermoforming

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.

  1. Choosing the right plastic thermoforming manufacturer and process
    1. 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.
    2. Select a thermoforming contract manufacturer experienced in processing a wide variety of material options with a strong understanding of those material properties.
    3. 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.
    4. 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.
    5. Select a manufacturer that is up to date with best practice methodology such as ISO, Lean Manufacturing, Six Sigma, etc.
  2. Adapting your existing product design to the plastic thermoforming process
    1. 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.
    2. 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).
      1. Tighter part tolerances
      2. Reduction in part wall thickness
      3. Complex or aesthetic design enhancements unachievable or not cost effective with fiberglass
      4. Textured surface finish
      5. Lighter weight than FRP
      6. Consistent surface gloss
  1. Material selection
    1. 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.
  2. Tooling
    1. 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.
    2. Choose a thermoforming contract manufacturer experienced with tooling materials options and processes to assure the right tool choice for your application and product life.
  3. Prototype testing
    1. 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.

Please contact Productive Plastics for more information on the thermoforming process
Please download our complimentary thermoforming design guide for more information on the thermoforming process

Temperature Considerations in Plastic Thermoforming Material Selection

If you’ve ever microwaved last night’s leftovers in the typical plastic to go container, you’ve witnessed the effect that high heat can have on thermoplastic. The plastic begins to soften and lose its stiffness as the material temperature increases and if you heat it long enough or exceed the limit of its operational temperature range, it will begin to distort. Worst case scenario, when you open the microwave door to enjoy your meal, you are presented with something that can be quite unrecognizable from what you put in.

While this example may not be relevant in all cases, it does demonstrate the importance of selecting a plastic thermoforming material with the appropriate temperature properties for your application’s operating environment. Imagine a similar scenario on an essential safety, structural, or functional component for a medical, transportation, or industrial application. Loss of stiffness (flexural modulus) and material distortion (heat deflection) are just a few of the factors to account for when addressing the temperature requirements of a project.

Material considerations for prolonged exposure to excessive temperatures

Most of the effects of temperature to thermoplastic occur at high heat levels, although excessively low temperatures can have an impact as well. Mechanical properties, chemical resistance, electrical conductivity, material fatigue, and many other attributes can be affected by increased temperatures. Below is a list of the most common considerations.

Note: The exact temperature thresholds and performance will vary for each different plastic material. In addition, factors like part geometry and material thickness will also affect material properties under extreme temperatures both high and low. The considerations below are just a general behavior characteristic of plastic in relation to temperature. (reference our article on material testing and data sheets for more information on standard testing of a material’s temperature performance)

Distortion

  1. Exceeding a material’s approximate heat deflection temperature can cause the material to distort.
  2. Prolonged exposure to heat while subjected to a load or force can also cause plastic to deform or “creep” over time.
  3. Most thermoplastic materials have a heat distortion temperature (HDT) of less than 500 degrees F
  4. HDT is a good comparative specification of how different materials respond to the HDT test conditions but provides little information regarding the long term effects of continuous high temperature exposure on their physical, mechanical, thermal, and electrical properties.

Softening

  1. As temperature increases, material stiffness (flexural modulus) will decrease.

Expansion

  1. As with most materials, plastic expands as temperature increases (coefficient of thermal expansion – CTE). This can be a consideration when the plastic is mated with another material, such as metal, that may have conflicting thermal expansion rates.
  2. If the dimensional change is obstructed, stresses can be induced in the plastic part due to excessive tensile, shear, or compressive stress loads that could result in unexpected failure.

Service Life

  1. Thermal Degradation – Plastic materials subjected to prolonged exposure to high temperatures will lose strength and toughness, becoming more prone to cracking, chipping, and breaking, at a rate in proportion to the temperature and time of exposure. Materials exposed to higher heat for longer duration will wear substantially faster than those exposed to more moderate temperatures and exposure times.
  2. The Continuous Use Temperature Rating is based on a thermal aging test that predicts the temperature at which a 50% loss of the original mechanical properties will occur after 100,000 hours of continuous exposure at that temperature. (see table below)Continuous Use Temperature Thermoplatic Chart

Thermal Conductivity

  1. The quantity of heat that passes through a cube of the material in a certain period of time when the difference in temperature between the two surfaces becomes one degree.
  2. Plastic materials generally have a much lower Thermal Conductivity than metals. This makes them excellent replacement materials when thermal insulation is important.

Some questions to consider to determine your application’s temperature profile and ideal material candidates

During the product development process, Productive Plastics uses the following questions to zero in on the plastic material options that will be temperature compatible for a customer’s application:

  1. What environmental temperature range (high and low) will the part be exposed to operationally?
  2. What dimensional and stiffness (flexural modulus) tolerances are required of the part at the high, mid, and low points of its expected temperature range?
  3. What loads or forces are expected on the part at the high end of its temperature range?
  4. What is the time/temperature relationship? A low temperature for a long time can result in comparable properties damage as a high temperature for a short time.
  5. What is the projected service life of the application?
  6. Will the plastic part be mated to any other material types, such as metal, as part of the application design?
  7. What are the specified (FST) flame, smoke & toxicity requirements?

Available thermoplastic options and temperature performance

As discussed in previous posts on material selection, when it comes to plastic material options, there are many choices and each has different thermal and mechanical performance properties. The information below will give you a general understanding of the operating thermal ranges of the common plastic material options available.

Note: The options listed are generic plastic material formulations. Many plastic material companies have specific plastic material products formulated and designed to meet the demands of a wide range of industry requirements. For information on the thermal performance of these products, visit our material supplier datasheet page or our thermofoming materials page.

Thermoplastic Material Heat Performance

Click here for a full list of plastic abbreviations and acronyms.

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.

Please contact Productive Plastics for more information on the thermoforming process
Please download our complimentary thermoforming design guide for more information on the thermoforming process

Thermoforming Material Selection (Material Testing and Datasheets Decoded)

When it comes to plastic thermoforming materials, one of the greatest advantages is that they can be manipulated and alloyed at the polymer level as well as being co-extruded to produce a multitude of variations. The result is a large list of available and even customizable plastic material products, each with its own unique properties and often formulated to meet the requirements of a particular industry.

The task of comparing and selecting the appropriate thermoforming material can therefore be daunting. To make the selection process easier, plastic material manufacturers have their material products independently tested to provide potential users with general characteristic and performance data, which is then presented via material product datasheets. These data sheets are excellent for material property comparisons but not always a exact indicator of field performance due to test sample preparation.

See some examples of thermoforming material datasheets here.

This data can give the end user an indication on how that material will behave once thermoformed into a finished component and if it is compatible with their application.

Measuring Plastic Thermoforming Material Properties:

Below is a list of the common tests that are performed on each plastic thermoforming material product, a description of what is measured, and how it should be used to assist in material selection.

Note – The data from raw material testing may not be exactly representative of how a material will perform on your finished product and in the field. Testing performed on material samples is done in a very controlled environment, at a uniform thickness, and as a flat extruded sheet of plastic or often injection molded. Your component, once thermoformed and assembled into a finished product, will likely have complex geometry, varying part thickness, and environmental factors such as temperature that are unique to your application and unaccounted for in standard material testing. For example, a raw material test may indicate a heat deflection (material distortion) of 200 degrees. However, once that same material is thermoformed and assembled on your finished product, it may have a heat deflection of only 190 degrees. So, ultimately, while testing will give you a ballpark indication on how your product will perform, keep in mind that results may vary. For more accurate data, conduct product testing on a finished and fully assembled prototype.

Physical Property Testing

Notched Izod Impact Strength (Ref ASTM D256)

Test definition: Pendulum style impact test of a notched sample subjected to a shock force. Typically used on more notch sensitive materials such as HIPS and ABS. The force absorbed by the notchedsample is measured and the type of failure is described

Material selection application:

  • Good comparison test between similar materials
  • Not a direct indicator of field performance

Specific Gravity (Ref ASTM D792)


Test definition: The ratio of the density of any substance to the density of an equal volume of water. Because Specific Gravity is a ratio it is a unitless quantity.

Material selection application:

  • The Specific Gravity of plastic materials are an indication of their density
  • Higher Specific Gravity will result in heavier material so caution must be taken when estimating and comparing part weights with varied materials

Chemical Resistance (Ref ASTM D543)


Test definition: Evaluation of plastic materials for resistance to chemical reagents (ex. lubricants, cleaning agents, inks, foods) The test includes provisions for reporting changes in weight, dimensions, appearance and strength properties.

Material selection application:

  • The published chemical resistance properties are a good guideline for material selection. However since variable factors can affect chemical resistance one should always test under their own conditions
  • Chemicals can affect strength, flexibility, color, surface appearance, and dimensions of plastics.
  • Plastics often fail even under very low stress when in contact with some chemical agents. This is called environmental stress cracking and is of great importance in material selection

Stiffness (Flexural Modulus) (Ref ASTM D790)


Test definition: Rigidity of material / a measure of stiffness

Material selection application:

  • Provides design criteria to determine the necessary thickness required for a given load
  • Good for comparison of different materials

Hardness (Ref ASTM D2240)

Test definition: A measure of how resistant a material is to various kinds of permanent shape change when a compressive force from a harder body is applied

Material selection application:

  • This is a good measure of resistance to wear by friction or erosion
  • Material resistance to abrasion, chipping, and cracking

Tensile strength (Ref ASTM D638)

Test definition: Resistance to being pulled apart

Material selection application:

  • Tells how material stretches before breaking
  • Provides an indication of overall toughness
  • The most important indication of strength of the material

Dielectric Strength

Test definition: Electrical insulation- the maximum voltage that can be applied to a material without it breaking down

Material selection application:

  • Plastics are generally considered insulators but they can transmit some electrical energy at high frequency
  • Many variables such as material fillers and additives, part thickness, and environmental conditions will affect the plastic’s dielectric constant

Thermal Property Testing

Thermal Conductivity (Ref ASTM E1530)

Test definition: A measure of the ability of a material to transfer heat.

Material selection application:

  • Most plastics are insulators and not good conductors of heat

Coefficient of Thermal Expansion (CTE) (Ref ASTM E831, ASTM D696, and ISO11359)


Test definition: Amount of expansion and contraction at a given temperature

Material selection application:

  • Impact relating to very narrow dimensional tolerances
  • Potential interference and fitment issues when plastic components are combined in assembly with dissimilar material components
  • Tooling and process design considerations are affected by CTE
  • Strict control of temperature during forming, post forming, trimming, and QC processes must be understood and maintained

Heat Deflection (Ref ASTM D648)

Test definition: The temperature at which the material will distort

Material selection application:

  • Usually listed at 2 loading values (264 psi and 66 psi)
  • Lower heat distortion materials will require a greater processing time
  • The temperature up to which rigidity for mechanical loads is retained

Flammability

Test definition: Extent to which a material will support combustion

Material selection application:

  • Plastics made up of organic chemical materials can have violent oxidation reactions in the presence of air at elevated temperatures like any other organic materials such as wood, paper and textiles.
  • Many plastics are now available compounded with flame, smoke and toxicity suppressant ingredients
  • In many applications, government mandated standards will dictate the required testing (See FST testing)

Fire, Smoke, and Toxicity (FST) Property Testing

In industries such as aviation and mass/rail transit, there are very strict regulations on the fire, smoke, and toxicity properties of utilized materials. Many thermoplastic suppliers produce material variations that are specifically designed to meet U.S. and international regulatory requirements. These very industry specific thermoforming material products will typically list the particular industry regulation directly on the material’s data sheet.

Some common industry regulations:

FAR25.853a

FAR25.853d iv & v

ADB-0031

D6-51377

DIN 5510

ASTM E662 & E162

Look & Appearance Property Testing

Accelerated Weathering (Ref Q-Lab)

Test definition: Provides a simulated exposure sequence to ultra violet radiation that allows weatherability to be categorized

Material selection application:

  • The advantage of thermoforming and the use of coextruded material stands out here with the ability to form parts subject to ultraviolet radiation on the outside with a coextruded material that has high weatherability coextruded with a lower cost rigid substrate material
  • Evaluation of color fade relating to time and UV exposure

Scratch & Mar (Ref Taber Method)

Test definition: Provides a measurement of the scratch or mar resistance of plastic sheet

Material selection application:

  • The visual appearance of a scratch or mar normally involves changes in surface topography, color or brightness
  • Some plastic materials have elastic recovery properties that occur after removal of the applied stress

References:

Click here for more detailed information on the testing of thermoplastic properties. (Society of Plastics Engineers – Thermoforming Quarterly 2015 Q1)

For additional information on ASTM standards of material testing, visit the official ASTM website.

You can also visit our Plastic Thermoforming Materials page for more in depth information.

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.

Please contact Productive Plastics for more information on the thermoforming process
Please download our complimentary thermoforming design guide for more information on the thermoforming process

Thermoforming Can Help Shape Your Product & Brand – Geometry and Mating Points

Product designs come in all shapes and sizes as savvy and experienced executives, engineers, and designers strive to differentiate their product or part. If you are one of these individuals, you know that whether your target audience is a consumer, a passenger, a patient, or an operator, that the look and feel of your product or part shapes the perception and experience of the end user.

Why is Part Geometry and Mating So Important to a Design?

A study done by the Chalmers University of Technology and published in the International Journal of Design in 2013 showed that:

Roughly 2 out of 3 people will select a product with good geometry over a product with geometric deviations, such as gaps between assembled parts.

The study also stated that people may associate products with geometric deviations, such as gaps in a product’s design, with poor quality, durability, reliability, and performance. (Click to read the full study for more details.)

Geometric design flexibility with plastic thermoforming
Precision mating points on multiple part assembly with complex geometry using plastic thermoforming

Creating a product design with excellent and highly appealing part geometry may only be limited by creativity and inspiration. However, it is one thing to render an image of a flawlessly designed part or product, it can be quite another to manufacture such a design with the same elegant geometry, continuity of parts, and seamless assembly.

Producing this design physically will be dependent on the capabilities of the medium and manufacturing process selected. This is especially true of projects comprised of multiple parts requiring assembly, as achieving a seamless mating of parts with geometry can be difficult if not impossible with some manufacturing processes. Material characteristics, manufacturing tolerances, mold and processor capabilities, and many other variables will ultimately influence the ability turn your ideal design into an achievable finished product.

Part Geometry and Mating Points with the Heavy Gauge Thermoforming Process

complex part geometryand mating points with plastic thermoforming
Complex part geometry, undercuts, and mating points with plastic thermoforming

If aesthetic design, high quality part geometry, or brand differentiation are important to your project, you should consider the benefits of the heavy gauge thermoforming process. The thermoforming process has a number of advantages in achieving high quality finished parts with unique styling and design more economically than other processes.

Consider some of the advantages:

  • Complex geometry achieved economically
    • extensive styling can be achieved with much lower tooling costs than matched mold processes in either metal, composites or other plastic molding methods
    • includes very large parts
  • Styling and design geometry flexibility
    • design can include aerodynamics, a rugged look, logo and other features
    • parts are not limited to a boxy look or enclosure as with certain processes such as sheet metal
    • make a product recognizable from a distance no matter the color
  • Part design continuity, tight tolerance capability, and mating points
    • can provide design continuity over multiple part assemblies, even with complex design geometry
    • creation of “lap joints” for mating parts is much easier with thermoforming and can be more stylish than with metal
    • one advantage of this type of assembly mating is to avoid gaps created by varying materials expansion/contraction allowance
    • thermoforming design flexibility allows for more stylish mating edges and surfaces
    • a “returned edge” on a thermoformed part can provide a clean sharp edge and will provide greater part rigidity
  • Tactile geometry
    • soft touch and feel thermoformed plastic materials can convey features of safety or add to styling by varying surface look and feel throughout the geometry of the component
    • thermoforming assemblies can include varying geometry parts with surface decoration to simulate the look of carbon fiber, camouflage, brushed metal, and many more

Looking for more information on how the heavy gauge thermoforming process can help shape your product or brand? Please explore our website or contact us.

Looking for more technical information?

Download the Thermoforming Design Guide, Process Comparisons, Conversion Guides, and other useful thermoforming information from our technical resource library.

Contact Us

Ready to explore how Productive Plastics can add to the success of your project?