• Polyethylene (High Density) HDPE

    Polyethylene (Polythene) is one of the world’s most popular plastics. It is an enormously versatile polymer which is suited to a wide range of applications from heavy-duty damp proof membrane for new buildings to light, flexible bags and films.

    Two major types of PE are in use in the films and flexible packaging sector – LDPE (Low Density) used generally for trays and heavier duty film such as long-life bags and sacks, poly tunnels, protective sheeting, food bags etc and HDPE (High Density) which is used for most thin gauge carrier bags, fresh produce bags and some bottles and caps.

    There are other variants on these two main types and PAFA members can recommend the best material for your application. All offer an excellent vapour or moisture barrier qualities and are chemically inert.

    By altering the formulation and gauge of polyethylene, the producer/converter can adjust impact and tear resistance; transparency and tactility; flexibility, formability and coating/laminating/printing capability. PE can be recycled and many bin bags, agricultural films and long-life products such as park benches, bollards and waste bins use recycled polyethylene. Due to its high calorific value, PE offers excellent energy recovery through clean incineration.

    APPLICATIONS
    Chemical drums, jerricans, carboys, toys, picnic ware, household and kitchenware, cable insulation, carrier bags, food wrapping material.
     
    PROPERTIES
    Flexible, translucent/waxy, weatherproof, good low temperature toughness (to -60'C), easy to process by most methods, low cost, good chemical resistance.

    PHYSICAL PROPERTIES
    Tensile Strength 0.20 - 0.40 N/mm²
    Notched Impact Strength no break Kj/m²
    Thermal Coefficient of expansion 100 - 220 x 10-6
    Max Cont Use Temp 65 oC
    Density 0.944 - 0.965 g/cm3

    RESISTANCE TO CHEMICALS
    Dilute Acid ****
    Dilute Alkalis ****
    Oils and Greases ** variable
    Aliphatic Hydrocarbons *
    Aromatic Hydrocarbons *
    Halogenated Hydrocarbons *
    Alcohols ****

    KEY * poor ** moderate *** good **** very good
     
    CURRENT CASE STUDIES
     
    Garden containers made from high density polyethylene. Low cost, high rigidity and ease of blow moulding has made the material a natural choice in gardening furnishings.