Archive for Thermoforming Material

Thermoforming Material Selection: 5 Ways Thermoplastic Materials Can Influence Product Appearance

The facade or exterior enclosure is often the first impression a customer or operator has of your product. This is also your first chance to impact how your product is perceived. While this is certainly not a new concept, it is a worthy reminder that look, style, and appearance are important. Selecting a thermoforming material with the right properties can provide shape, finish, and cosmetic capabilities that are unique to the thermoforming process and customizable to your company’s brand and product design needs.

5 ways plastic thermoforming affects product apperance

Here are 5 ways thermoplastic material can influence the exterior look of your next project.

1. Geometry – 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 economically with the same elegant geometry, continuity of parts, and seamless assembly.

Producing this design physically will, to a certain degree, be subject to the manufacturing process selected, but will also be heavily dependent on the capabilities of the material selected. Thermoplastic materials require relatively lower heat and pressure to shape resulting in lower tooling and capital equipment costs than competing process materials.

For more information on how part geometry with thermoforming can shape your product and brand, check out this previous Productive Ideas blog post: Geometry and Mating Points.

2. Color – With many other materials, the only way to achieve a desired color finish, is to paint the material post production. Yes, this is also an option for most thermoplastic. However, many thermoplastic providers also produce integral colored plastic material (plastic with coloration). These materials can eliminate the extra time and cost associated with the additional process of painting your components as well as avoid the inherent maintenance issues with paint such as chipping. Many suppliers also have material products with integral patterns such as wood grain, carbon fiber, and metallic replications. See some integral color plastic and pattern examples here from one of our partnered suppliers. Silk screening and distortion printing overlays are also options with most thermoplastic material for more complex branding and surface designs. Molded-in color can provide product branding, safety awareness, color fast durability, color coordination and more.

The Perception of Color

While color match to a provided sample color chip is available for thermoforming materials there are many variables that come into play during application that may affect the perception of match. Reflection and absorption of light will be different on metals, composites, wood, plastic and other materials. Varying lighting conditions will change appearance of a color. Other physical characteristics of the objects such as surface finish, part geometry, and angle of view as well as the manufacturing process affect the color range of the sample and the finished product. This can result in a visual color difference to the observer and must be taken into consideration for design and color match considerations.

3. Gloss – High gloss finishes present a very high quality visual perception and are often desirable in markets such as medical device, recreation, food service and many other OEM markets. This look is easily achievable on most thermoplastic material by either the addition of a high gloss color film capped material or by applying a high gloss paint which is then buffed to the desired level of gloss. High gloss metal flake or pearlescent capped materials are also available as additional high gloss visual options.

4. Texture – The addition of surface texture on a thermoformed part can be accomplished via two methods.

In the first method, in-mold texturing, the texture is produced by casting, peening, or etching the texture designs directly into the tooling used in the part’s production. This method is more reliant on the design, mold construction, and forming process than it is on the thermoforming material. In mold texturing enables the manufacturer to form areas with and without texture in the component design for achieving a non-slip surface or contrasting finishes.

The second method utilizes pre-textured plastic sheet material (some examples from a sheet supplier) to produce thermoformed parts with a textured finish. To avoid “texture wash”, this method is compatible for designs with relatively low depth of draw features

Additional features and benefits of textured surfaces using the thermoforming process.

5. Weatherability – Most materials have a tendency to eventually fade when exposed to prolonged UV radiation from sunlight. While thermoplastic is no exception, there are many formulations of plastic available that have either an inherent or designed high resistance to fading or discoloration from UV radiation.

Accelerated Weathering (Ref Q-Lab) is a standardized industry test used to evaluate the color fade of a material in relation to time and UV exposure. Reference the chart below for a comparison of the accelerated weathering performance of common thermoplastic materials.

Weatherability Performance of Thermoforming Materials

Thermoplastic MaterialIndustry AbbreviationUV Resistance
Polyether-Block-Amide(PEBA)Excellent
Thermoplastic Polyimide(TPI)
Polyphenylene Sulfide(PPS)
Polyether-Ester Block Copolymer(TEEE)
Acrylic(PMMA)
Polyetheretherketone(PEEK)
Polyetherketone(PEK)
Perfluoroalkoxy(PFA)
Ethylene Tetrafluoroethylene(ETFE)
Polyvinylidene Fluoride(PVDF)
Liquid Crystal Polymer(LCP)
Polyetherketoneetherketoneketone(PEKEKK)
Polyetherketoneketone(PEKK)
Polypropylene(PP)Fair/Good
Nylon 6(PA 6)
Nylon 6/10(PA 6/10)
Nylon 11(PA 11)
Nylon 6/12(PA 6/12)
Amorphous Nylon(PA)
Nylon 12(PA 12)
Impact-Modified Nylon 6/6(PA 6/6)
Polycarbonate(PC)
Low Density Polyethylene(LDPE)
Polysulfone(PSU)
Polybutylene Terephthalate(PBT)
Polyethylene Terephthalate(PET)
Polyethersulfone(PES)
Modified Polyphenylene Oxide(PPO)
Polycarbonate/Acrylic Alloy(PC/PMMA)
Polyetherimide(PEI)
Polycarbonate/ABS Alloy(PC/ABS)
Thermoplastic Vulcanizate(TPV)
Polymethylpentene(PMP)
Polyphthalamide(PPA)
Polysulfone/Polycarbonate Alloy(PSU/PC)
High Temperature Nylon(HTN)
Syndiotactic Polystyrene(SPS)
Polytrimethylene Terephthalate(PTT)
Nylon 6/6(PA 6/6)Poor
Polystyrene(PS)
Styrene Acrylonitrile(SAN)
Acrylonitrile Butadiene Styrene(ABS)
High Density Polyethylene(HDPE)
Acetal(POM)
Ester-based Thermoplastic(TPUR)
Ether-based Thermoplastic(TPUR)
Rigid Thermoplastic Polyurethane(RTPU)
Styreflex™ Styrenic Block Copolymer Thermoplastic Elastomer(SBC)
Fluorinated Ethylene Propylene(FEP)

View the full list of plastic abbreviations and acronyms.

Productive Plastics is a 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

Is Your Material Tougher than Thermoplastic?

Whether it’s luggage or shopping cart impact, physical stress caused by operator or passenger mishandling, or the wear and tear of constant load bearing, it can be a rough world out there for the components of your product or application. Want to know which thermoplastic material can handle the abuse? Take a look at the following considerations and mechanical properties of today’s common thermoforming plastic materials.

Is your material tougher than thermoplastic

How do thermoplastic mechanical properties factor into the material selection process?

The plastic materials used in thermoforming undergo extensive testing to determine their performance capabilities. See Thermoforming Material Selection (Material Testing and Datasheets Decoded) for more information on industry testing standards, their definitions, and practical uses for each test in regards to material selection. Material manufacturers generally provide the results of these industry tests in data sheets online.

When determining if a plastic material has the mechanical strength performance and toughness for the structural needs of your product or application, there is no one test that gives a definitive answer. Instead to determine the general impact strength and damage resistance of a plastic material, take a combined look at the results of these common material tests:

  • Stiffness (Flexural Modulus) – Provides design criteria to determine the necessary thickness required for a given load and a measure of stiffness
  • Tensile strength – Tells how much a material stretches before failure; force necessary to pull the specimen apart
  • Hardness – Material resistance to abrasion, chipping, and cracking
  • Notched Izod impact strength – Pendulum style impact test on a notched sample that’s good for comparison of similar materials

The relationship between strength and weight is also important in industries where the reduction of weight is desirable so the following should also be considered:

  • Density – how much a given volume of the material weighs
  • Specific gravityindication of material density. Like density, it provides a quick reference to the relative weights of different objects that have the same volume

Mechanical property advantages of thermoformed parts with thermoplastic materials:

Lightweight – In most cases, thermoplastic offers material options that are substantially lighter than comparable optional materials

Resistance to impact damage – Due to the flexible nature of thermoplastic it is less likely to dent like metal or crack like FRP

Strength to weight ratio – (also known as specific strength) Short fiber reinforced thermoplastics can often have equal to or greater strength characteristics than metals like aluminum and steel at a fraction of the weight

Corrosion resistance – Thermoplastics do not oxidize or rust like aluminum and steel therefore providing an environmentally stable material

Recyclability – Fiberglass is not recyclable while thermoplastics are

Reduced maintenance and replacement costs – Thermoplastic as a whole is more durable than materials such as metal or fiberglass, requiring less maintenance with a longer service life

Available thermoplastic options regarding impact resistance and toughness

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 mechanical properties 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 specialty thremoplastic products, visit our material supplier datasheet page.

Thermoforming Material Impact Resistance and Mechanical Property Comparison Chart (Sorted by Tensile Strength)

 

Thermoplastic MaterialTensile Strength (psi)Flexural Modulus (psi)HardnessIZOD Notched Impact (ft-lbs/in)Specific Gravity
Continuous Glass Thermoplastics (C-glass) 60/4036,9001,500,000~1.48
Continuous Glass Thermoplastics (C-glass) 70/3035,1001,395,00015.7~1.48
PPS17,0001,000,000M95, R125, Shore D 855.21.35
PEEK14,000590,000M105, R126, Shore D 851.61.32
Nylon12,400410,000M85, R121, Shore D 801.21.14
PSU10,200390,000M75, R125, Shore D 801.31.24
PPSU10,100350,000M80, R120, Shore D 80131.4
Acetal10,000420,000M89, R121, Shore D 831.51.42
Acrylic10,000480,000M95, R900.41.19
Polycarbonate9,500375,000M70, R118, Shore D 80161.2
NORYL (PPO, PPE, & Polystyrene blend)9,200370,0003.51.08
PBT8,690330,000M721.51.3
TPO (22% strand glass fiber filled)8,500600,0005.21.03
ECTFE (film 5-20 mil thick)8,300261,000Shore D 73 R93No break1.68
PVC8,000400,000Shore D 802.51.4
PETG7,700310,000R1151.71.27
PVDF3,500 – 7,200170,000 – 1,200,000M75, R100, Shore D 772.51.78
TPE1,000 – 7,0005,000 – 800,000Up to 85 Shore D2.5 -No break0.95
CAB7,000230,000R1054.41.2
ETFE (film 5-20 mil thick)6,100145,000Shore D 67 R85No break1.7
ABS6,000320,000R1027.71.04
PCTFE (film)5,710243,000Shore D 903.52.11
Polypropylene5,400225,000Shore D 75, R921.90.91
TPO4,400170,000Shore D 7460.9
FEP (Teflon film)4,35095,000Shore D 55No break2.12
HDPE4,000200,000Shore D 69No break0.96

 

View the full list of plastic abbreviations and acronyms.

 

Productive Plastics is a 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

Thermal Performance and Considerations in Plastic Thermoforming Material SelectionWhy is temperature an important consideration in 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.

Thermoforming Material Selection Material Testing and Datasheets Decoded

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