Views: 34 Author: Site Editor Publish Time: 2025-03-17 Origin: Site
For beauty and personal care products, packaging materials need to combine portability with structural integrity. Lightweight yet sturdy plastics like HDPE (High-Density Polyethylene) excel in safely containing liquids, gels, and creams while ensuring easy handling for daily use. Beyond its durability and low weight, HDPE stands out as a budget-friendly solution, making it accessible for brands across price ranges to deliver reliable packaging performance. MGG Group is a leading custom plastic container manufacturer, providing a wide range of custom services. Let's take a look at the characteristics of HDEP plastic.
The molecular structure of HDPE (high-density polyethylene) consists of highly crystalline linear chains, which gives it excellent chemical resistance. Common active ingredients in cosmetics (such as retinol, fruit acid), solvents (alcohol) and emulsifiers are not easy to react with HDPE, thereby avoiding deterioration of contents or degradation of containers. For example, the packaging of strong acid exfoliating products (pH value below 3) usually adopts HDPE because its stability is significantly better than ordinary PET or PP materials.
The density of HDPE is only 0.94-0.97 g/cm³, which is more than 80% lighter than glass. At the same time, the impact strength can reach 20 kJ/m² (ASTM D256 standard), which is suitable for the bumpy environment in long-distance transportation. Taking the international brand shampoo bottle as an example, the thickness of the HDPE bottle wall can be designed to be 0.8-1.2mm, which can reduce the consumption of raw materials while ensuring the anti-drop performance, and meet the needs of low-carbon logistics.
HDPE belongs to No. 2 plastic, and the recycling rate is as high as more than 30% (data from the US Environmental Protection Agency). Leading companies in the cosmetics industry such as L'Oreal and Unilever have promised to achieve 100% recyclable packaging by 2030. HDPE has become the first choice because of its easy sorting and melt-recyclable characteristics. Some brands have even launched a "bottle-to-bottle" closed-loop recycling program to reduce carbon footprint by adding 30% recycled HDPE (PCR-HDPE).
Lotion bottles and shower gel bottles: Through multi-layer co-extrusion technology, the HDPE bottle body can be compounded with an EVOH oxygen barrier layer to extend the shelf life of products containing antioxidant ingredients (such as vitamin C).
Child-safe bottle cap: The HDPE bottle mouth is combined with the PP cap body, designed as a press-and-turn opening structure to prevent children from accidentally ingesting it, and meets FDA safety standards.
For high-priced essences, HDPE pump bottles achieve dosage control (such as 0.1ml/time) through precision injection molding. The moisturizing essence pump head of the Korean brand "Sulwhasoo" adopts HDPE+spring stainless steel structure to ensure that it will not deform after long-term pressing. The extrusion tube uses a threaded design at the mouth of the tube (such as a spiral check valve) to avoid reflux contamination of the contents.
Paste products (such as mud masks and hair wax) require low adsorption of the inner wall of the container. After fluorination treatment, the friction coefficient of HDPE surface can be reduced to 0.1, ensuring that the paste is taken without residue. The bamboo charcoal mask jar of Estee Lauder's brand "Origins" is made of matte HDPE material, with metal texture labeling, taking into account functionality and high-end visual presentation.
The price of HDPE raw materials is about US$1.2-1.5/kg (market price), which is only 1/3 of glass. Taking a 200ml lotion bottle as an example, the comprehensive cost of HDPE bottle (including mold and production) is about US$0.15/piece, while the cost of the same glass bottle is more than US$0.4. For fast-moving consumer brands (such as Dove and Vaseline), HDPE can reduce the total packaging cost by 15%-20%.
1) Blow molding: suitable for hollow bottles, the wall thickness uniformity error can be controlled within ±5%;
2) Injection molding: used for precision parts (such as bottle caps, pump heads), the minimum wall thickness can reach 0.5mm;
3) Thermoforming: produce thin-walled trays, support customized embossed textures (such as imitation leather, wood grain).
The interference fit design between the HDPE bottle mouth and the PP/PE cover can achieve a water vapor transmission rate (WVTR) of less than 0.5 g/m²·day (40℃/90%RH) and an oxygen transmission rate (OTR) of less than 50 cm³/m²·day·atm, effectively blocking external pollutants. Shiseido's research shows that the shelf life of moisturizing cream packaged in HDPE can reach 36 months at 25℃, which is the same as glass packaging.
HDPE has a crystallinity of up to 80%-90%, resulting in severe light scattering, and the transmittance is usually less than 30%. To meet the needs of high-end brands, the industry has made improvements through the following solutions:
Adding transparent nucleating agents (such as sorbitol derivatives) to increase the transmittance to 75%;
Double-layer structure design: the outer layer of HDPE ensures strength, and the inner layer of co-extruded transparent PETG makes the contents visible;
Surface coating process: UV-cured matte coating is used to cover the internal turbidity.
HDPE has a heat deformation temperature of about 75℃ (0.45MPa load) and cannot withstand high-temperature filling (>80℃) or steam sterilization. Solutions include:
Low-temperature aseptic filling technology: filling at 25-30℃ in a clean room environment, combined with gamma ray irradiation sterilization;
Blending modification: adding 10%-15% polypropylene (PP) to increase heat resistance to 100℃;
Metalization treatment: the vacuum aluminum layer reflects heat to prevent the bottle from deforming (common in sunscreen product packaging).
HDPE has become the cornerstone material for cosmetic packaging due to its cost-effectiveness, plasticity and environmental protection properties. Despite its shortcomings in transparency and temperature resistance, its application scenarios continue to expand through material modification, process innovation and recycling technology. In the future, with the integration of bio-based materials and smart packaging, HDPE may be upgraded from a "functional carrier" to a strategic symbol of brand sustainable value.