What is PP plastic?
PP plastic or polypropylene is the world's second most commonly used thermoplastic and is gradually conquering further application fields and domains. PP plastic is very soft and extremely stretchable and is therefore suitable in combination with a very high maximum use temperature of 100°C for a wide variety of blisters, thermoformed parts, and packaging areas.
Processing and thermoformability of PP
Thermoforming PP is usually more challenging than with comparable plastics. Thermoformed parts made from PP plastic require longer heating and cooling cycles, which reduces the processing speed.
Material options for PP plastic
Weldable
PrintableWeaknesses and strengths of PP at a glance
Price
Colors
Features
- Food-safe (also as an A-PET alternative)
- Very good heat resistance, sterilizable up to 125°C
- Resistant to: chemicals, alcohol
- Low density: light weight
- Stable prices due to versatile industry use
Weaknesses
- Strong tendency to deformation
- No oxidizing agents
- No alcohols
- Assembly: bonding not possible
- Inferior optics: not suitable as visible part
- Complex tool required
Challenges in processing PP
Tool requirements
Thermoforming tools are made of aluminum and are usually cost-intensive because they require optimal continuous temperature control. This is achieved through cooling with deep-hole drilling, which requires that the thermoforming tool be built in one piece. Therefore, no base tools with various multi-part inserts can be used for PP plastic.
Sampling
Likewise, the creation of a 3D-printed or Ureol sample tool is not possible for PP plastic thermoformed parts due to the lack of temperature control options. The sampling of the thermoformed articles must be done from the production tool under optimal production conditions.
Post-processing
With PP plastic, it should be noted that the thermoplastic does not allow bonding processes in the post-processing of blisters. However, welding is possible and is the preferred joining method for PP plastic.
Facts and figures about PP
| Group | Standard Thermoplastics |
| Structure | Semi-Crystalline |
| Density | 0.91 |
| Continuous Use Temperature Max. (in °C) | 100 |
| Thermal Expansion Transverse/Longitudinal to Flow Direction (10^-6 *K) | 100 - 200 |
| Melting Temperature (°C) | 163 |
| Max. Temp. Short-Term (°C) | 140 |
| Max. Temp. Long-Term (°C) | 100 |
| Impact Strength (KJ/m^2) | 50 |
| Abrasion Resistance | ++ |
| Yield Stress (N/mm²) | 33 |
| Tensile Strength (N/mm²) | 30 |
| Tensile Modulus of Elasticity (N/mm²) | 1200 |
| Elongation at Break (%) | 700 |
| Ball Indentation Hardness (N/mm²) | 72 |
| Dielectric Strength (kV/mm) | 50 |
| Volume Resistivity (Ω · m) | >1E14 |
| Surface Resistivity (Ω) | 1E13 |
| Tracking Resistance CTI | 600 |
Applications of PP plastic
Food
- Cups for dairy products (yogurt, quark)
- Microwave-safe containers
- Food packaging
- Frozen food packaging
- Margarine cups
- Meal trays
- Salad bowls
Automotive
- Sunroof frames
- Door inner frames
- Battery covers for forklift trucks
- Splash protection for batteries
- Underbody panels
- Cable ducts
Medical Technology
- Medical packaging (sterilizable)
- Medical housings
- Lids for pharmaceutical shipping containers
- Petri dishes
- Laboratory trays
- Disposable medical products
Consumer Goods
- Product packaging
- Clamshell packaging
- Household containers
- Storage boxes
Industrial Solutions
- Washing carrier basket inserts
- Cleaning trays
- Automation container inlays
- Covers
- Disposable trays
- Plastic trays
- Bottom trays
- Transport trays for steel components
- Box inserts
- Inlays for stainless steel components
- Drip trays
- Back walls
Agriculture & Horticulture
- Plant pots
- Planting trays
- Seed transport containers
- Fertilizer containers (chemical-resistant)
- Irrigation system components
Robotics
- Chemical-resistant trays for cleaning stations
- Lightweight transport trays for automation
- Protective covers in chemical environments
Electronics
- Housings for temperature-resistant applications
- Battery covers
- Insulating parts
More Information about Materials
Frequently asked questions about PP plastic
What is PP plastic?
PP plastic, also known as polypropylene, is the second most commonly used thermoplastic worldwide after PET. Its high elasticity, low density and good heat resistance make it ideal for thermoformed parts, packaging, blister packs and technical applications in industries such as automotive, medical technology and food packaging.
Further Information That Might Interest You
Thermoformed Parts in Practice
What is Recyclate? Options in Plastic Recycling and Distinction from Virgin Material
In an increasingly sustainability-oriented world, recycling and the reuse of materials play a key role. Plastic recyclates offer a sustainable alternative to virgin materials. But what exactly does the term mean, and how can recyclates be distinguished from virgin materials? Read more now.
Thermoformed Parts in Practice
Plastic Extrusion: How Plastic Film is Made
Plastic extrusion is a highly efficient manufacturing process that transforms plastic granules into continuous film. This versatile material is used across various industries, tailored to specific applications and performance requirements.
Thermoformed Parts in Practice
Design Guidelines for Plastic Thermoformed Parts – Top 13 Tips for Plastic-Optimized Construction
Plastic thermoforming is shaped by factors like material quality, temperature, pressure, speed, and tool geometry. With the right design principles, you can prevent errors in CAD and production. formary has gathered key tips to help you optimize your thermoformed parts.