How do hdpe and ldpe differ

Polyethylene is a polyolefin. Polyolefins are high molecular weight hydrocarbons. Polyolefins include linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene copolymer, polypropylene, and polymethyl pentene. These are the only plastics that have a lower specific gravity than water. This means that they weigh less than water. These materials can become brittle from oxidation and are damaged by exposure to UV light.

When ethylene is polymerized the result is relatively straight polymer chains. From the main chain they can branch out. We get different kinds of Polyethylenes from the varying degree of branching in their molecular structure.

What is HDPE? What is LDPE? It actually has a higher strength to density ratio when compared to LDPE. This is due to its structural composition. HDPE has a rigid structure with very less branching. This gives it more tensile strength and has stronger intermolecular forces.

These forces are mainly the dipole-induced-dipole interactions. Blow Molding :. This processing method is utilized to manufacture hollow-shaped plastic components.

Rather than injecting the molten plastic, blow molding uses compressed air to blow the material into the mold. Extrusion :. Like injection molding, this method also uses heat to melt the plastic granules. However, the difference is seen in the final part of the machine, where instead of going through the mold, the melted plastic goes through a pre-designed opening and is then cooled down to solidify.

Although it heavily depends on the product, recycling LDPE can be challenging due to softness; it is very likely to get stuck in the machinery. On the side, HDPE is easier to recycle and transport thanks to its hardness. Engaging Read — Plastics Vs. Polymers What are the Differences? Fascinating Read — What is a Plastic Pallet? The Definitive Guide. However, the price difference between both is not very substantial. The most useful solvents for dissolving HDPE are trichlorobenzene, trichloroethylene, tetralin, Benzene, toluene.

But if you want to go for less hazardous options than toluene, xylene, and trichloroethylene are good choices. HDPE is called the best food-safe plastic. Some of the industries that commonly use both materials include:. This difference in polymer organization leads to distinct characteristics in each material. Compared to HDPE, it is more likely to crack under stress.

HDPE is rigid and durable and offers greater chemical resistance. Its more crystalline structure also results in greater strength and opacity of the material. Depending on the product, LDPE can also be more difficult to recycle as it is softer and can get caught in recycling machinery.