{"id":5299,"date":"2026-08-25T09:39:19","date_gmt":"2026-08-25T07:39:19","guid":{"rendered":"https:\/\/schoutengroup.com\/thermoforming-choosing-sheetmaterial\/"},"modified":"2026-08-25T10:19:09","modified_gmt":"2026-08-25T08:19:09","slug":"thermoforming-choosing-sheetmaterial","status":"publish","type":"post","link":"https:\/\/schoutengroup.com\/en\/thermoforming-choosing-sheetmaterial\/","title":{"rendered":"Themoforming: which sheetmaterial do you choose?"},"content":{"rendered":"\t\t
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Which sheetmateriaal is suitable?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Vacuum forming, also called thermoforming, appears straightforward at first glance: a plastic sheet is heated, drawn over a mold, and held in place by vacuum pressure. In practice, however, the choice of sheet material largely determines whether that process runs stable and reproducibly.<\/p>\n

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PETG, PET, PC, ABS and HIPS each have distinct properties and behave differently during heating and forming. That choice ripples through production affecting cycle time, material flow, and ultimately the strength, wall thickness, dimensional stability, chemical resistance, appearance and service life of the finished part. A successful vacuum-formed product, then, doesn’t start with the machine alone; it starts with the interplay of sheet thickness, product geometry and process settings.<\/p>\n

From Material Specification to End Product<\/span><\/h3>\n

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A material can look excellent on paper yet prove unsuitable for a specific application.<\/p>\n

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Polycarbonaat (PC) staat bijvoorbeeld bekend om zijn hoge slagvastheid, wat het aantrekkelijk maakt voor beschermkappen en machineafschermingen. Tegelijk vraagt PC om een nauwkeuriger thermoformproces en moet het materiaal zorgvuldig worden gedroogd voordat het de verwarming in gaat. PETG<\/a> is simpler to form and offers a wider practical processing window; for a transparent protective cap, that’s often exactly what’s needed. If the same cap must withstand heavy impact, PC may still be the better choice..<\/p>\n

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The best material choice therefore does not come from looking at a single material property, but from assessing the entire product and manufacturing process.<\/p>\n

The Most Important Materials for Thermoforming<\/span><\/h3>\n

<\/p>\n\n\n\n\n\n\n\n\n\n\n
Material<\/th>\nStructure<\/th>\nTg approx.<\/th>\nTm approx.<\/th>\nPractical thermoforming range*<\/th>\nKey property<\/th>\n<\/tr>\n<\/thead>\n
PETG<\/td>\nAmorphous<\/td>\n~80 \u00b0C<\/td>\n\u2014<\/td>\n~130\u2013160 \u00b0C<\/td>\nVery easy to form<\/td>\n<\/tr>\n
PET<\/td>\nSemi-crystalline \/ amorphous<\/td>\n~75 \u00b0C<\/td>\n~245\u2013250 \u00b0C<\/td>\n~125\u2013165 \u00b0C<\/td>\nStrong and efficient<\/td>\n<\/tr>\n
PC<\/td>\nAmorphous<\/td>\n~145 \u00b0C<\/td>\n\u2014<\/td>\n~177\u2013185 \u00b0C**<\/td>\nExtremely impact-resistant<\/td>\n<\/tr>\n
PP<\/td>\nSemi-crystalline<\/td>\n~\u221210 \u00b0C<\/td>\n~160\u2013170 \u00b0C<\/td>\n~140\u2013165 \u00b0C<\/td>\nLightweight and chemically resistant<\/td>\n<\/tr>\n
ABS<\/td>\nAmorphous<\/td>\n~105\u2013110 \u00b0C<\/td>\n\u2014<\/td>\n~150\u2013180 \u00b0C<\/td>\nTechnical all-rounder<\/td>\n<\/tr>\n
HIPS<\/td>\nAmorphous<\/td>\n~95\u2013100 \u00b0C<\/td>\n\u2014<\/td>\n~150\u2013175 \u00b0C<\/td>\nInexpensive and easy to form<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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*Indicative sheet temperature ranges. The exact temperature depends on factors such as the grade, sheet thickness, machine, and product geometry.
**For PC, the general literature range is broader. The practical processing window of a specific sheet can be considerably narrower.<\/p>\n

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For simple, easy-to-form products and model making, HIPS<\/a> is often the economical choice, while ABS<\/a> offers greater technical stiffness.<\/p>\n

Tg, Tm, and Thermoforming Temperature Are Not the Same<\/span><\/h3>\n

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An important distinction: Tg indicates when an amorphous plastic begins to lose its glass-like characteristics. Tm is the melting point of a semi-crystalline material. The thermoforming temperature is the practical temperature range in which the sheet becomes sufficiently pliable to form without sagging excessively or degrading. Confusing these three values can quickly result in setting the heating temperature too high or too low. Further definitions can be found in our glossary of moulding materials and systems<\/a>.<\/p>\n

Sheet Thickness Is Just as Important as Material<\/span><\/h3>\n

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Choosing PETG, PC, or ABS is only the beginning. A 1 mm sheet behaves differently during heating than a 3 mm sheet, and with thicker sheets there is also a greater temperature difference between the surface and the core. This difference affects how evenly the material can be drawn.<\/p>\n

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Sheet thickness also has a direct influence on the final wall thickness of the formed product. In deep shapes, the material is stretched, meaning that considerably less material may remain in some areas than was present in the original flat sheet. The required sheet thickness therefore depends not only on the starting material, but on the product geometry and draw ratio, the desired final wall thickness, mechanical loads, tolerances, and the behaviour of the material as a whole.<\/p>\n

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A thicker sheet is therefore not automatically the better solution: having too much material available during the draw can actually be a common cause of wrinkling or webbing<\/a>.<\/p>\n

Material, Geometry, and Process Must Work Together<\/span><\/h3>\n

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A successful vacuum-forming application results from the interaction of several factors that all influence one another. The material must meet the mechanical, chemical, and optical requirements, while the sheet thickness must be selected so that sufficient wall thickness remains after forming.<\/p>\n

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The product geometry then determines how demanding the draw will be: draw depth, sharp corners, and undercuts each require their own approach.<\/p>\n

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The mould design determines how the material is distributed across the shape, and the choice between a positive or negative mould<\/a> changes where the material becomes thinnest. The heating system must bring the sheet to temperature quickly but evenly, the vacuum must be applied at the right moment and at the appropriate rate, and cooling determines when the product has become dimensionally stable enough to be removed from the mould. For those who want to go through the process step by step, it is briefly explained in thermoforming in a nutshell<\/a>.<\/p>\n

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The mould itself also deserves attention. Models can be made from materials such as epoxy<\/a>, plaster, or 3D-printed tooling<\/a>, each with its own temperature resistance, service life, and level of detail.<\/p>\n

From Prototype to Series Production<\/span><\/h3>\n

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Production volume also plays a role. For a prototype, a material may be selected primarily because it is quick and easy to process. In series production, the focus shifts towards cycle time, material consumption, mould costs, energy consumption, scrap rate, repeatability, post-processing, and material cost. A material that appears to be the best choice for a single prototype is therefore not automatically the most economical solution for thousands of products.<\/p>\n

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The same applies to the machine: a benchtop machine<\/a> may be sufficient for prototypes and small production runs, while larger products and higher volumes require a large-format or automated system<\/a>.<\/p>\n

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By considering material selection, sheet thickness, product design, and the production process together from the outset, problems later in the process can be avoided. In series production, this can save far more than a low sheet price could ever compensate for.<\/p>\n

Need Advice on Material, Sheet Thickness, and Process?<\/span><\/h3>\n

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The material choice does not necessarily have to be fixed in advance. When developing a new vacuum-formed product, it is usually better to first consider the complete application: the required mechanical properties, temperature and chemical exposure, UV and weather resistance, desired appearance and transparency, geometry and required wall thickness, tolerances, production volumes, and repeatability.<\/p>\n

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From this overall assessment, the appropriate material and sheet thickness can be determined, along with the mould and process settings that go with them.<\/p>\n

Or would you prefer to outsource the thermoforming process? Take a look at our thermoforming service<\/a>.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Frequently Asked Questions<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhich Sheet Material Is Best for Thermoforming?<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

There is no single material that is always the best choice. PETG and HIPS are the most forgiving during the forming process, ABS offers greater technical stiffness, and PC is the preferred choice when impact resistance is the decisive factor. The application, draw depth, and production volume determine which of these materials is the right fit.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat Temperature Should a Sheet Be Heated To?<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

The thermoforming temperature is clearly above the Tg of an amorphous material and below the melting range of a semi-crystalline material. For PETG, the practical range is around 130\u2013160 \u00b0C, while for ABS it is around 150\u2013180 \u00b0C. The exact setting depends on the grade, sheet thickness, machine, and geometry, so testing is still necessary.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tHow Thick Should the Sheet Be?<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

This depends on the desired final wall thickness and the draw ratio. Because the material is stretched during deep forming, the wall thickness in the product can be significantly lower than the original sheet thickness in the areas subject to the greatest draw. A thicker sheet does not always solve the problem, as excess material can contribute to wrinkling and webbing.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat Is the Difference Between PET and PETG?<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

PETG is PET modified with glycol. This modification suppresses crystallization, giving PETG a wider and more manageable thermoforming window. PET is stronger and more material-efficient, but it places greater demands on temperature control.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tDoes Plastic Need to Be Dried Before Forming?<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

PETG is PET modified with glycol. This modification suppresses crystallization, giving PETG a wider and more manageable thermoforming window. PET is stronger and more material-efficient, but it places greater demands on temperature control.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tAdvice for Your Application<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t

If you are unsure between two materials, or an existing vacuum-formed product is experiencing wall-thickness or dimensional-stability issues, discuss your application with us. Our specialists can advise you on the material, sheet thickness, mould, and process settings, and supply the sheets and systems you need. Call +31 (0)186 600 880<\/a> or visit the thermoforming information centre<\/a>.<\/p>\n

Or, if you prefer to outsource the process, take a look at our thermoforming service<\/a>.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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