May 11, 2024

Plastic Melting Point Guide: Understanding Temperature Ranges

melting point of plastic

Plastic materials are widespread in our lives, from packaging to construction, cars, and electronics. A significant factor which should be taken into account when dealing with plastics is the temperature at which they would start to melt. This melting point is the transition from a solid plastic to a liquid one. It is a crucial element in the process of choosing the plastic to be used for different purposes.

Manufacturers and processors should be aware of melting point because it is very important. It allows them to decide which of these techniques, such as injection molding, extrusion or blow molding, is the most suitable for shaping the plastic. When the plastic has reached its melting point or higher, it becomes soft and can be shaped according to the desired form. Temperature control is also essential for the quality and efficiency of the plastics. In case the temperature goes too high, the plastic can decompose or lose its desirable features. If it is too low, the plastic might not flow well for molding.

In the following article, ACO Mold will discuss the melting temperature ranges of some of the most commonly used plastic materials in different industries.

What is the Melting Point of Plastic?

Plastic doesn’t have a fixed melting point; it changes according to the type. It is the reason why it is possible to mold and work with the material. Knowing these temperature ranges is a must for manufacturers to produce without any interruptions.

Every kind of plastic has its own melting point, which decides the way it is used and processed.

Thermoplastics such as polyethylene and polypropylene are the ones that melt at lower temperatures. Thus, they are very simple to mold using techniques such as injection molding and extrusion.

Plastics like polycarbonate and nylon melt at higher temperatures during the recycling process. They can withstand heat well and are used in applications that require heat resistance.

Knowing the melting points helps manufacturers to choose the most appropriate materials for their products. It makes production more efficient and improves the products’ performance. Moreover, it also helps in making decisions about recycling as different melting points may need different recycling techniques. Taking melting points into account, enables manufacturers to improve the production process and the quality of the final product.

Plastic Material Melt and Mold Temperatures Table

Below is a comprehensive chart to the melting and molding temperatures of various plastic materials:

MaterialAlso CalledMelt Temperature Range (°C)Mold Temperature Range (°C)Material Characteristics
ABSAcrylonitrile Butadiene Styrene190 – 27040 – 80Strong impact resistance, excellent insulation
ABS/PC AlloyABS/Polycarbonate Alloy245 – 26540 – 80High mechanical strength, good impact resistance
AcetalPolyoxymethylene (POM)180 – 21050 – 120High strength, good dimensional stability, low friction
AcrylicPolymethyl Methacrylate (PMMA)220 – 25050 – 180Excellent optical clarity, high impact resistance
CABCellulose Acetate Butyrate170 – 24040 – 50Good weather resistance, lower moisture absorption
HDPEHigh-Density Polyethylene210 – 27020 – 60Rigid, strong, good chemical resistance
LDPELow-Density Polyethylene180 – 24020 – 60Flexible, lightweight, good impact resistance
Nylon 6Polyamide 6230 – 29040 – 90Tough, durable, good wear resistance
Nylon 6 (30% GF)Nylon 6 with 30% Glass Fiber250 – 29050 – 90Increased stiffness and strength with glass fiber
Nylon 6/6Polyamide 6/6270 – 30040 – 90Excellent mechanical properties, good heat resistance
Nylon 6/6 (33% GF)Nylon 6/6 with 33% Glass Fiber280 – 30040 – 90Extremely high strength and rigidity
Nylon 11Polyamide 11220 – 25040 – 110Good impact resistance, low water absorption
Nylon 12Polyamide 12190 – 20040 – 110Flexible, good chemical resistance
PEEKPolyether Ether Ketone350 – 390120 – 160Outstanding thermal and chemical resistance
PolycarbonatePC280 – 32085 – 120High impact resistance, good optical clarity
Polyester PBTPolybutylene Terephthalate240 – 27560 – 90Excellent mechanical properties, good chemical resistance
PET (Semi Crystalline)Polyethylene Terephthalate260 – 28020 – 30High strength, good dimensional stability
PET (Amorphous)Polyethylene Terephthalate260 – 28020 – 30Transparent, good chemical resistance
Polypropylene (Copolymer)PP Copolymer200 – 28030 – 80Good impact resistance, excellent heat resistance
Polypropylene (Homopolymer)PP Homopolymer200 – 28030 – 80Rigid, high tensile strength, good chemical resistance
Polypropylene (30% Talc Filled)PP with 30% Talc Filler240 – 29030 – 50Increased stiffness and dimensional stability
Polypropylene (30% GF)PP with 30% Glass Fiber250 – 29040 – 80Improved strength and rigidity with glass fiber
PolystyrenePS170 – 28030 – 60Rigid, transparent, low cost
Polystyrene (30% GF)PS with 30% Glass Fiber250 – 29040 – 80Enhanced strength and stiffness
PVC PPlasticized Polyvinyl Chloride170 – 19020 – 40Flexible, good chemical resistance
PVC UUnplasticized Polyvinyl Chloride160 – 21020 – 60Rigid, good electrical insulation properties
SANStyrene Acrylonitrile200 – 26050 – 85Transparent, good chemical resistance
SAN (30% GF)SAN with 30% Glass Fiber250 – 27050 – 70Increased strength and stiffness
TPEThermoplastic Elastomer260 – 32040 – 70Flexible, rubbery, good impact resistance

Detailed Temperature Ranges for Common Plastics

melting point of plastic


Numerous industries use polyethylene, particularly HDPE and LDPE, for a variety of purposes. HDPE is the best material for uses like industrial containers, fuel tanks, and water pipelines because of its superior chemical resistance and higher melting point. However, LDPE works well for packaging films, plastic bags, and squeeze bottles because to its lower melting point and flexibility. Additionally, because of its resilience to weather and durability, both HDPE and LDPE are frequently used in playground equipment, agricultural films, and geomembranes.


Because of its high melting point and resilience to chemicals, polypropylene is used extensively in automobile applications, such as battery casings, interior trim pieces, and bumpers. It is also a favored material for furniture, home appliances, and food containers due to its rigidity and dimensional stability.


In packaging applications including foam cups, food containers, and protective packaging materials, polystyrene is widely used, despite its comparatively low heat resistance. Its cost-effectiveness, insulating qualities, and lightweight design make it a desirable option for CD cases, insulation boards, and throwaway cutlery. Extended polystyrene (EPS) is also widely used in construction as void fillers, lightweight concrete additives, and insulating panels.


Polyamide, commonly known as nylon, is valued for its exceptional strength, toughness, and abrasion resistance, making it ideal for engineering applications. Nylon’s high melting point and chemical resistance make it suitable for automotive components such as gears, bearings, and bushings. Its self-lubricating properties also find application in conveyor belts, textile machinery components, and industrial seals.

Polyvinyl Chloride (PVC)

PVC’s versatility, durability, and flame-retardant properties make it a preferred choice for various construction materials, including pipes, fittings, window profiles, and flooring. Its excellent chemical resistance also finds application in chemical processing equipment, water treatment systems, and corrosion-resistant coatings.

melting point of plastic

The Importance of Understanding Plastic Melting Point

Understanding the melting point of plastic is crucial for making high-quality plastic products. Knowing when plastics melt helps in molding and prevents defects. Different plastics have different melting points, which affect their properties and final forms after molding.

Manufacturers need to know the melting temperatures for each plastic type they use to ensure quality and durability. Not following these temperatures can lead to issues like poor rigidity or insulation in the final products. Therefore, understanding plastic melting points is vital for successful molding.

By monitoring and controlling melting temperatures during production, manufacturers can improve product quality and consistency while reducing defects and meeting industry standards.

Factors Influencing Plastic Melting Points

Molecular weight, polymer chain length, additives, and ambient conditions all have an impact on plastic’s melting point. Understanding these aspects is critical for optimizing processing settings and producing the desired product attributes. Let’s take a closer look at a few critical factors:

Molecular Weight and Polymer Chain Length

The length of polymer chains and the molecular weight of plastic polymers are important factors in regulating how the material melts. Because of the enhanced intermolecular interactions and improved heat stability, longer polymer chains and higher molecular weights generally result in heightened melting temperatures. On the other hand, shorter chains and lower molecular weight may reduce the melting point, making manufacturing simpler but perhaps sacrificing mechanical characteristics.

Additives and Their Impact on Melting Temperatures

The addition of plasticizers, fillers, and stabilizers can drastically affect the melting behavior of plastics. Plasticizers, for example, are often used to improve the flexibility and lower the melting point of hard polymers such as PVC. Fillers, such as glass fibers or minerals, may improve mechanical qualities while increasing the material’s melting temperature. The kind and concentration of additives must be carefully considered in order to obtain the necessary balance of attributes while retaining processability.

melting point of plastic

Practical Applications of Plastic Melting Points

Injection Molding Process and Optimal Temperature Settings

Injection molding is a widely used method for making precise plastic parts with intricate shapes. It works by injecting melted plastic into a mold under high pressure, then cooling it to form the final product.

Having the right temperatures is crucial in injection molding to make top-quality plastic parts. The melt temperature, mold temperature, and barrel temperature all matter for getting the best results.

The melt temperature affects how easily the plastic flows into the mold and copies fine details. Mold temperature controls how the plastic cools and solidifies, which affects the final product’s size, surface, and strength. The barrel temperature keeps the melted plastic consistent during injection.

By carefully adjusting these temperatures, manufacturers can make high-quality plastic parts with fewer flaws, consistent size, and the right physical properties.

3D Printing

Knowing plastic melting points is essential for 3D printing. Each type of plastic needs a specific melting temperature to turn from solid to liquid properly. Following these temperature ranges ensures good quality prints. In 3D printing, getting the melting temperature right is key to success. Wrong temperatures can lead to problems like poor layer bonding or weak structures. So, understanding plastic melting points is crucial for successful 3D printing.

Different plastics behave differently when melting. Some have a narrow melting range, while others are more forgiving with temperature changes. It’s important for 3D printing enthusiasts to grasp these differences to improve their printing and get consistent high-quality prints.

Aside from melting points, factors like cooling speed after melting, consistent filament diameter, and bed adhesion also affect 3D printing success. Mastering these factors helps improve 3D printing skills and create precise designs reliably.

Final Words

In summary, the melting point of plastic is a crucial factor that significantly affects its performance, processability, and end-use applications. A thorough grasp of the temperature ranges and variables affecting plastic melting points allows producers to improve product quality, optimize production parameters, and open up new avenues for innovation. The dynamic world of modern production makes understanding and mastering plastic melting points vital, especially as the need for lightweight, strong, and sustainable materials grows.

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