Security
Food-grade PET is widely used in food and beverage packaging and is highly recognized for its safety and stability. It does not release harmful substances and complies with international food safety standards, which allows consumers to rest assured during use. However, one thing needs special attention: PET may release some harmful substances, such as DEHP+, under high temperature conditions. Therefore, when using PET containers, be sure to avoid high temperatures to prevent the release of harmful substances.
Food-grade PP is everywhere in our daily lives, such as the fresh-keeping boxes in supermarkets and microwave lunch boxes, many of which are made of PP. Why is it so popular? First of all, this material is non-toxic, tasteless and odorless, making it extremely safe to use. Besides, it has excellent heat resistance and can be put into the microwave to heat food without any problem. It will not deform when heated like some plastics and may also release harmful substances. At present, its chemical stability is also excellent. Under normal use, it is not easy to react with other substances.
More importantly, PP material does not require the addition of any harmful substances during the production process. Under high temperature conditions, it will not decompose bisphenol A*, a chemical that is harmful to the human body. This means that tableware or packaging made of PP material is safer and especially suitable for storing food. Therefore, when choosing food packaging or tableware, PP material can be given priority. After all, safety comes first.
Transparency
The food-grade PET material has a very high transparency, allowing you to see the food inside at a glance, and the appearance and quality are clearly displayed. Therefore, it is particularly suitable for use in packaging that needs to display food, such as the beverage bottles we often drink, and food cans for biscuits and candies. Most of these packages are made of PET. Why use it? It's because merchants want to show the best side of their products to consumers and attract them to buy. Moreover, this type of packaging not only looks fresh and clean, but also protects food to a certain extent, preventing it from getting damp and deforming, ensuring that the food reaches the hands of consumers intact and in good condition.
Food-grade PP has a low level of transparency, typically being translucent. Although it has poor light transmittance, it has a wide range of applications. Take the yogurt box for example. The translucent PP material allows people to vaguely see the thick texture of the yogurt, while also leaving a sense of mystery for the product. There are also trays commonly seen in supermarkets. Fresh meat trays are a typical example. Pallets made of PP material are shatter-resistant and practical, and their translucent texture looks clean and hygienic. Using PP material to make food boxes and trays can not only meet the needs but also ensure food safety.
Heat resistance
Heat resistance is a major feature of food-grade PET. Although it is heat-resistant, it cannot withstand high temperatures. When the temperature reaches 70-80°C, the surface of the PET packaging will deform and lose its original shape. Therefore, food-grade PET is not suitable for use in situations where high-temperature sterilization or heating is required. For example, in the food production process, it is useless in some links that require high-temperature packaging and sterilization. If PET packaging is used to hold hot water, it will easily deform, resulting in damage or even unusability. Therefore, when selecting packaging materials, it is important to fully consider the temperature requirements of food processing to avoid problems caused by the packaging material's lack of heat resistance.
Food-grade PP has excellent heat resistance, typically tolerating temperatures between 110°C and 120°C. It is also the only plastic that can be heated directly in a microwave, which is very practical. If food requires high-temperature sterilization or heating before packaging, PP packaging is ideal. Many of the food storage containers we often use for meals, as well as those heat-and-eat lunch boxes sold in supermarkets, are made of PP. Using it to hold food and heat it in the microwave is convenient and safe. There is no need to worry about it melting or releasing harmful substances. This is very convenient in daily life.
Chemical resistance
Food-grade PET has good tolerance to acids and alkalis and can cope with the acidic and alkaline environments in daily food. But if you encounter strong oxidizing agents or organic solvents, that won't work. For example, strong oxidizers such as bleach and disinfectant, as well as things like paint thinner, may corrode PET after contact, making it brittle, deformed, or even damaged. Therefore, when packaging food, it's best to keep it away from these substances to ensure the integrity of the packaging and the safety of the food.
Food-grade PP offers excellent chemical stability and is unreactive to most chemicals, with the exception of strong oxidants. This material is popular in both the food and industrial sectors. For example, food containers and microwave lunch boxes are ideal for storing food, ensuring they are protected from chemical attack. There are also some industrial chemical packaging that can be made of PP material if the acidity or alkalinity is not too strong. It even finds use in the packaging of cosmetics and cleaning products, preventing the chemical components within from reacting with the packaging material and ensuring consistent product quality. In short, as long as it does not encounter strong oxidants, PP material can hold firmly and is a good choice for packaging that resists chemical erosion.
Processing performance
Food-grade PET is a bit troublesome to process. It needs to be thoroughly dried before it can be molded. If it is not completely dry, defects may easily occur during the processing, such as bubbles or impurities on the surface of the product. In addition, PET is relatively difficult to process, and the equipment and process requirements during the production process are more stringent. This directly leads to its manufacturing cost being higher than some other plastic materials. Therefore, PET products are usually more expensive. Despite this, it is still widely used in packaging such as beverage bottles and food storage boxes, mainly because of its good performance, high transparency, ability to display food, and ensure safety.
Food-grade PP has excellent processing performance and can easily adapt to various complex processing technologies, such as injection molding, extrusion, and blow molding, which it can complete excellently. During the manufacturing process, PP does not require the same stringent equipment and process requirements as some other plastics, and is also easier to mold, resulting in a relatively low manufacturing cost. As a result, food-grade PP is particularly popular in the packaging industry. For example, many of our daily food containers and yogurt cups are made of PP. With low cost, good quality and the ability to meet market demand, it is no wonder that it has a place in the food packaging field.
Applicable Scenarios
Food-grade PET is actually more suitable for packaging that needs to show the appearance of food but does not need to withstand high temperatures. It has high transparency and can clearly show the appearance and quality of food. It is very suitable for packaging such as beverage bottles and transparent food cans that require consumers to directly see the contents. However, its performance at high temperatures is not ideal, and its surface usually deforms at 70-80°C, so it is not suitable for packaging hot beverages and hot foods. If high-temperature sterilization or heating is required, PET is not suitable.
Food grade PP is a very practical material, especially suitable for packaging that needs to resist chemical attack and for frozen foods. For example, many of our common food boxes, trays, and microwave heating containers are made of PP. PP has excellent chemical stability and does not react with most chemicals except strong oxidants, making it extremely safe for packaging food. PP is also resistant to low temperatures, so frozen foods can be placed in it without becoming brittle or deforming like some other materials. If you want to heat it, the PP container can be put directly into the microwave, which is convenient and quick. In short, PP is a true "all-rounder" in the field of food packaging and is particularly suitable for these scenarios.
Environmental protection
Although food-grade PET has good environmental performance, some additives such as catalysts and antioxidants may be added during the processing. These additives may migrate and seep out during long-term use, thus affecting food safety. For example, the catalysts used in the polycondensation reaction of PET (such as antimony trioxide +) and the by-products produced by the reaction (such as acetaldehyde) are all toxic and have migration risks. Therefore, when choosing PET as a food packaging material, the amount of additives used and their migration limits must be strictly controlled to ensure compliance with food safety standards.
Food-grade PP offers excellent environmental performance, releases no harmful gases during use, and poses minimal impact on human health. It is a relatively safe plastic material and is particularly suitable for food packaging. For example, many of our commonly used food containers and microwave lunch boxes are made of PP. When you use it to store food, whether you are refrigerating or heating it, you don't have to worry about releasing harmful substances. Moreover, PP materials are relatively easy to handle after being discarded and will not cause a heavy burden on the environment like some plastics. Therefore, PP is widely used in food packaging and daily necessities, and everyone feels at ease with it.
Conclusion
If you want to show the appearance and quality of food and need to withstand high temperature conditions, food-grade PET material may not be suitable because PET is easy to deform at high temperatures. It is recommended to choose other materials that are more suitable for high temperatures. However, PET has high transparency and is very effective for display.
If you need to resist chemical erosion and package frozen food at the same time, food-grade PP material is a good choice. PP has good chemical stability and is resistant to low temperatures. It can also be used for microwave heating, which is very practical.
Food-grade PET and PP each have their own characteristics: PET has high transparency but limited heat resistance; PP has good heat resistance and chemical stability, but slightly poor transparency, so when choosing, you must decide based on the specific application scenarios and needs, so that you can choose the most suitable material.
