Two of the most prevalent plastics used in the food packaging sector are polyethylene and polypropylene. They appear to be extremely similar on the surface, but they each have distinct traits and functions.
Which is superior, polypropylene or polyethylene, is a timely debate. It’s not a question of which is superior; rather, what is your application?
What exactly are you attempting to accomplish with each type of plastic?
Polypropylene and polyethylene are both types of polymer, which is a type of plastic. With carbon and hydrogen molecules, their molecular structure appears to be similar—but that’s where the similarities end.
Let’s compare some of their mechanical characteristics.
Polypropylene (PP) has a density of between 0.895 and 0.92 g.cm. The density of polyethylene can range from 0.857 g/cm3 to 0.0975 gm/cm3. PP has the lowest density, as you can see. Polyethylene is further divided into weights or densities so that it can be used for a more precise purpose.
THE DIFFERENCES BETWEEN POLYETHYLENE AND POLYPROPYLENE
1. CHEMICAL AND HEAT RESISTANCE
- High temperatures: Polypropylene is better than polyethylene in withstanding high temperatures. While the first remains in fine condition between 140oC and 170oC, the latter can only resist temperatures of 105oC and 115oC.
- Low temperatures: Polyethylene is more resistant to low temperatures in this scenario, keeping its properties as low as -80oC. Only above 0 C does polypropylene retain its characteristics.
- Although polyethylene has a higher resistance to wear and tear, polypropylene stands out for its great resistance to abrasive acids, which is one of the primary differences between the two plastics.
Polyethylene is a relatively pliable material that stretches quickly, making it ideal for food packaging. Polypropylene is less flexible than polyethylene, but it is also more difficult to break. Depending on the orientation of the plastic, i.e. based on the systemic placing of polymeric chains within– it will have a different elasticity.
3. THE ABILITY OF RECYCLING
Because both polypropylene and polyethylene are thermoplastics, they are easy to recycle. This means they can be moulded repeatedly and melt when subjected to heat processes. These two polymers, in particular, can be given a new life after recycling. Polyethylene is the more widely recycled of the two.
4. USES IN FOOD PACKAGING
The distinct features of both plastics mean their uses as food packaging are often very different. Let’s look at some examples:
- Because of the differences in the properties of these polymers, their applications as food packaging are frequently very different. Consider the following examples:
- Microwaveable packaging: Polypropylene is ideal for microwaveable packaging due to its excellent temperature resistance.
- High hot-tack: Food packaging with a high hot-tack, or heat-sealing resistance, is ideal for storing nuts, grains, and sauces. It’s made primarily of biaxially oriented polypropylene.
- Polypropylene is an excellent material for heat treatments like sterilisation and pasteurization, since it can tolerate both. Polyethylene can only tolerate pasteurisation.
Read more:- Price Rise in Seasonal Agri-Commodities
Other than food packaging, polyethylene and polypropylene can be used for:
- Insulation: PP FLOC, a unique polypropylene film, is mostly used for automotive interior parts, as well as doors and windows.
- Plastic bags: Polyethylene is one of the most regularly used plastic bag materials. These could be shopping bags, rubbish bags, or other types of bags.
- Most sticky tapes are constructed of polypropylene, which is a strong material.
- Toys: high-density polyethylene is frequently used in the manufacture of children’s toys.
- Polypropylene, a durable and abrasion-resistant material, is commonly used to make stackable plastic storage boxes.
- Greenhouses and geothermal blankets are examples of agricultural use.
- In the construction business, pipes in the form of electrical conduits, rain water & sewage pipes are built using polypropylene. PVC Insulation on cables, Insulation Tapes, flooring tiles & rolls are other applications of this type of plastic.
For all your polymer associated worries, OfBusiness stands out with its product range. To know more, please click here:- www.ofbusiness.com