Bottles made of HDPE, PE-HD (high-density polyethylene)

Polyethylene is the most commonly used thermoplastic worldwide and is primarily used in the packaging industry, but also in technical applications. Depending on the degree and type of branching of the polymer chains, a distinction is made between three main types: HDPE (high-density polyethylene), LLDPE (linear low-density polyethylene), and LDPE (low-density polyethylene).

HDPE has very low chain branching, resulting in high crystallinity (60–80%) and thus high density (0.94–0.97 g/cm³). This structure gives the material high rigidity, tensile strength, and chemical resistance. Compared to LDPE, HDPE is more dimensionally stable, has lower gas and water vapor permeability, and is also more temperature-resistant.

Typical applications range from blow-molded articles such as canisters, bottles, and tanks to injection-molded parts such as closures, housings, and technical components to films, pipes, and cable sheathing. Thanks to its good recyclability, HDPE also plays an important role in sustainable packaging concepts.

HDPE is often used for chemical bottles because it combines several properties that are particularly important for this application:

High chemical resistance: HDPE is resistant to many acids, alkalis, alcohols, and numerous solvents. This means that the material is not easily attacked or becomes brittle.

Low permeability: It has relatively low permeability to water, water vapor, and many chemicals—important to prevent liquids from evaporating or penetrating from the outside.

High dimensional stability: Due to its density and crystallinity, HDPE remains stable even at higher filling weights and hardly warps.

Break resistance: Compared to glass, HDPE bottles are lighter, shock-resistant, and significantly less prone to breakage.

Processability: HDPE can be easily processed into hollow bodies such as bottles and canisters using blow molding.

Recyclability: Chemical bottles made of HDPE can be easily recycled after appropriate cleaning.

In short: HDPE combines chemical resistance, stability, and safety, which is why it is the standard plastic for many laboratory and industrial bottles.