Both PP plastic sheets
and PET plastic sheets
can be used to make disposable plastic water cups by thermoforming and blistering process. So what is the difference in the performance of these two plastic sheets, and what is the difference in the use of the disposable plastic water cups they make?
PP plastic sheet
Polypropylene (PP) is one of the most commonly used thermoplastics in the world and is odorless, tasteless and nontoxic. PP plastic sheet is the lightest of all sheets. PP plastic sheet
is a material with tensile strength, high temperature resistance and high corrosion resistance. The plastic cup produced from PP plastic sheet has good heat resistance, and the continuous use temperature can reach 110-120 ℃.
PET plastic sheet
Polyethylene terephthalate (PET) is a tough synthetic material belonging to the thermoplastic family. It is suitable for a range of beverages including carbonated, still and dilutable beverages, juices and bottled water. PET plastic is 100% recyclable.
The molecular structure of PET plastic sheet
is highly symmetrical and has a certain ability of crystal orientation, so it has high film-forming and forming properties. PET has good optical properties and weather resistance, and amorphous PET has good optical transparency.Advantages of PET plastic sheet as packaging material:
1. It has good mechanical properties, the impact strength is 3 to 5 times that of other films, and the folding resistance is good.
2. Oil resistance, fat resistance, dilute acid, dilute alkali, and most solvents.
3. Low gas and water vapor permeability, with excellent gas barrier, water, oil and odor properties.
4. High transparency, can block ultraviolet rays, and have good gloss.
5. Non-toxic and tasteless, good hygiene and safety, can be directly used in food packaging.
How to distinguish whether the plastic cup is PP or PET?
The bottom or lid of the disposable plastic cup has a triangle with an arrow. There are different Arabic numerals inside, representing different plastic materials.
The number "1" at the bottom of the disposable plastic cup means that the material of the plastic is PET, that is, polyethylene terephthalate.
Common mineral water bottles, carbonated beverage bottles, etc. It is heat-resistant to 70°C and easily deformed, and there are substances that are harmful to the human body melted out.
PET plastic cups used for a long time may release harmful DEHP. Can not be placed in the car in the sun, do not pack alcohol, oil and other substances.
The number "5" at the bottom of the disposable plastic cup means that the material of the plastic is PP, that is, polypropylene.
Common ones are soy milk cups, yogurt cups, juice drink bottles, microwave lunch boxes, etc. The PP plastic sheet has a melting point of up to 167°C and is the only plastic box that can be put in a microwave oven and can be reused after careful cleaning.
The plastic cup produced from PP sheet can hold both cold and hot drinks. The plastic cups produced from PET sheets can only be used for cold drinks. Compared with PET, PP plastic cups are more popular, both hot and cold, and it is also the only plastic container material that can be put into a microwave oven.