Table of Contents
Reviewed and updated by ICD - Week 46/2026
Choose PP when you need stiffness and more heat resistance, and PE when you need flexibility and toughness: PP melts at about 160-165 °C, while PE melts at only about 105-135 °C depending on type. PP plastic and PE (polyethylene) are the two most common plastics in packaging, crates, pallets and stretch film. This article compares them with sourced figures, then shows which ICD Vietnam products use which type.
Summary of the main points
PP is stiffer, more heat-resistant than PE and can take a living hinge; PE is more flexible, tough at low temperature, and makes good film and bags. For crates, baskets and pallets, both are used; pallet stretch film specifically is made from PE, while food reheating tubs are mostly PP.
What is PP plastic?
PP (polypropylene) is a thermoplastic in the polyolefin group, made by polymerising propylene, with resin code number 5. It melts at about 160-165 °C and has a density of 0.90-0.91 g/cm³ according to resin makers’ data sheets.
Properties of PP plastic
- Stiff, more heat-resistant than PE: the EPA summarises PP as having a higher working temperature and more stiffness than PE; heat deflection temperature at light load is about 95-102 °C, Vicat about 85-92 °C.
- Chemical resistance: inert to most acids, alkalis and alcohols at room temperature; according to INEOS, PP is not affected by slow environmental stress cracking.
- Light and hinge-capable: suits flip-top lids and folding crates.
- Weak points: homopolymer turns brittle around 0 °C and needs UV additives outdoors.
How to identify PP plastic
Read the code on the underside: PP carries number 5. For PE, HDPE carries number 2 and LDPE number 4 (code system per ASTM D7611). PP is stiffer than PE when squeezed or bent; flame tests and burning-smell tests have no standard reference and should not be used to draw conclusions, so ask the supplier for the resin grade.
What is PE plastic?
PE plastic (polyethylene) is a thermoplastic made by polymerising ethylene, and is the most-produced plastic in the world according to Wikipedia. There are three main groups: LDPE (density about 0.92 g/cm³, highly branched), LLDPE (about 0.92, with short branches) and HDPE (about 0.96, unbranched). PE is used mainly for packaging: bags, film, bottles, containers.
Properties of PE plastic
- Flexible, tough: LDPE is softer and clearer than HDPE; LLDPE is used mainly for film because it is tough, flexible and fairly clear.
- Lower heat resistance than PP: HDPE and MDPE typically melt at 120-130 °C, commercial LDPE at 105-115 °C.
- Tough in the cold: polyethylene turns brittle below about -73 °C (Polymers 2021 study), so HDPE can be used in cold rooms.
- Electrical insulation: PE is used as cable sheathing, including high-frequency cable (Wikipedia).
How to identify PE plastic
HDPE is number 2, LDPE number 4; it feels softer and stretches more than PP. Pallet stretch film, bags and cling film are PE.
What PP and PE have in common
Both are thermoplastics in the polyolefin group: lighter than water, inert to most common chemicals, easy to injection-mould, extrude and blow-mould, and they absorb no water. Both carry identification codes for recycling collection, but collection depends on the place; a plastic code does not prove a product is recyclable. Containers and film made from food-grade resin are used for food under rules such as the FDA, EU 10/2011 and QCVN 12-1:2011/BYT (PE and PP share a dry residue limit of 30 µg/ml).
How PP and PE differ
| Criterion | PP plastic | PE plastic |
|---|---|---|
| Melting point | about 160-165 °C | LDPE 105-115 °C; HDPE 120-130 °C |
| Density | about 0.90-0.91 g/cm³ | about 0.92 (LDPE, LLDPE) to 0.96 g/cm³ (HDPE) |
| Stiffness | Stiffer | Softer, more flexible |
| In the cold | Homopolymer turns brittle around 0 °C | Tough down to about -73 °C |
| Common forms | Crates, boxes, lids, pallets, fibre, car parts | Film, bags, bottles, jerrycans, pipes, crates, pallets |
In short: PP wins when you need stiffness and heat; PE wins when you need flexibility and cold. HDPE sits in the middle: stiffer than LDPE but tougher in the cold than PP.
How PP and PE differ from PVC, PC and PET
PET (code 1) melts at about 250-260 °C, is transparent and is widely used for water bottles; see the comparison of PET and PP plastic. PVC (code 3) is used for pipes, wrap and window frames according to the EPA’s plastic code list; polycarbonate falls under code 7 with other plastics. I do not give figures for PVC and PC because I could not verify them against a source; if you need to choose between PP, PE and these plastics for a specific application, take the data sheet of the exact resin grade.
Conclusion: should you choose PP or PE?
Choose PP when you need stiffness, heat resistance, reheating tubs or hinged parts; choose PE when you need flexibility, film, or a cold environment. At ICD Vietnam, plastic crates and plastic pallets come in PP and HDPE lines depending on the product; check the specification of each line for the resin grade. PE is the raw material of stretch film used on pallet wrapping machines.
See also: PP versus HDPE comparison.
Frequently asked questions
Should I choose PP or PE plastic?
If you need stiff, heat-resistant plastic, choose PP; if you need flexible plastic that is tough at low temperature or makes film, choose PE.
How much heat can PP withstand?
It melts at about 160-165 °C, but products under load soften from about 85-102 °C; PE melts lower, about 105-135 °C depending on type.
What are PP’s standout properties compared with PE?
Stiffer, more heat-resistant and lighter; in exchange homopolymer is more brittle in the cold and less flexible.
Contact ICD Vietnam for bin and plastic pallet advice
ICD Vietnam Industrial Manufacturing Co., Ltd.
North: 3rd Floor, Thang Long A1 Building, Bau Hamlet, Thien Loc Commune, Hanoi, 0983 797 186 / 090 345 9186 / 090 5859 186
South: 551/212 Le Van Khuong Street, Tan Thoi Hiep Ward, District 12, Ho Chi Minh City, 098 6784 186
Email: sales@icdvietnam.com.vn
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References
- Wikipedia, Polyethylene and Polypropylene (melting point, density, applications) - en.wikipedia.org
- US FDA, 21 CFR 177.1520 Olefin polymers - law.cornell.edu
- QCVN 12-1:2011/BYT, National technical regulation on safety and hygiene for synthetic plastic packaging and utensils in direct contact with food - nafiqad5.gov.vn
- Smith R.L., Takkellapati S., US EPA, Recycling Plastics in the U.S.: Polypropylene Flows and Recycling Processes (AIChE 2023; plastic code catalogue, PP properties) - cfpub.epa.gov
- Basell, Moplen HP500N datasheet (HDT, Vicat, density) - pimd.vn
- Ducor Petrochemicals, DuPure G 72 TF datasheet (haze, density, temperature) - ducorchem.com
- Poly Processing, Polyolefins technical data (PP brittle at 0 °C, UV, autoclaving) - tanks.polyprocessing.com
- INEOS, Environmental Stress Crack Resistance of Polyethylene - ineos.com
- Salakhov et al., Low-Temperature Mechanical Properties of High-Density and Low-Density Polyethylene, Polymers 2021 (HDPE brittle below about -73 °C) - pmc.ncbi.nlm.nih.gov
- Wikipedia, Resin identification code (codes per ASTM D7611)
