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Comparing Polyethylene (PE) Bags with Polypropylene (PP) Bags
2025-02-26
Ⅰ.What exactly is a polypropylene(pp) bag?
PP bag is a bag made of polypropylene material. Polypropylene is a common plastic, so PP bags are essentially plastic bags. It's a bit stiff to the touch and has a certain crispness that allows the bag to hold its shape. It's just plain transparent, not super transparent. PP bag is also relatively heat-resistant, not easy to be burned deformation. In life, we can see it used to hold rice, fertilizer, feed and other things, because it can keep these items flat. And some products that need to be stored or transported in a high temperature environment can play a good protective role.
Ⅱ.What exactly is a Polyethylene (PE) Bags？
PE bag is a bag made of polyethylene, a particularly common plastic bag in life. It feels soft and slippery, just like plastic wrap used at home, but it is much stronger than plastic wrap, very resilient, and not easy to tear. Its transparency is particularly high. Because it is soft and transparent, it is easy to use, can wrap things well, and let us see what is inside at a glance.
Ⅲ.What is the difference between PE bag and PP bag?
A.Material properties
● Temperature tolerance
PE: Excellent low temperature resistance (-50℃ to 80℃), easy to soften at high temperature;
PP: High temperature resistance is stronger (can withstand 100-120℃), low temperature embrittlement (below 0℃ performance).
Mechanical property
PE: good flexibility, strong impact resistance, but low tensile strength;
PP: High hardness, excellent tensile and wear resistance, and stronger rigidity.
Chemical resistance
PE: resistant to acid, alkali and salt solutions, but sensitive to fats and organic solvents;
PP: More comprehensive chemical resistance (including acid, alkali, grease), but easily corroded by strong oxidants.
Moisture proof and breathable
PE: Excellent moisture resistance, low permeability, suitable for sealed packaging;
PP: moisture resistance is good, but the air permeability is slightly higher than PE.
Ultraviolet (UV) resistance
PE: easy to age when untreated, need to add UV stabilizer;
PP: UV resistance is weaker, long-term outdoor need special coating or modification.
B.Processing and production costsSling material
Production technology
PE: easy to blow film, injection molding, low processing temperature (130-160℃);
PP: requires a higher processing temperature (160-200 ° C), poor ductility, but can produce thinner and stronger films.
Production cost
PE: the raw material price is usually lower than PP, and the economy is better;
PP: Lower cost per unit strength (reduced material usage due to high strength).
C.Application scenario difference
Typical use of PE bag
Food packaging (e.g. plastic wrap, shopping bags);
Moisture-proof packaging (medicine, chemical lining bag);
Agricultural covering film (dependent on flexibility and low temperature resistance).
Typical use of PP bag
High strength packaging (industrial parts, building materials);
High temperature sterilization environment (medical equipment bags, hot filling products);
Packaging that requires printing (PP surface is easier to print and has strong adhesion).
Ⅳ.Conclusion
Summary of advantages and disadvantages
PE bag advantage
Low cost, high flexibility, low temperature resistance, moisture resistance;
Disadvantages: high temperature deformation, low tensile strength, easy to be penetrated by grease.
PP bag advantage
High strength, high temperature resistance, chemical corrosion resistance, good printing performance;
Disadvantages: low temperature brittleness, poor UV resistance, slightly higher raw material cost.