Properties of HDPE, LDPE and PET Bottles
Do you struggle to work out which kind of plastic bottle to use for your products? Here are a few pointers, but don’t hesitate to contact us if you are in any doubt. We can advise you.
High Density Polyethylene (HDPE) is the most widely used resin for plastic bottles. This material is economical, impact resistant, and provides a good moisture barrier. HDPE is compatible with a wide range of products including acids and caustics but is not compatible with solvents. It is supplied in FDA approved food grade. HDPE is naturally translucent and flexible. The addition of colour will make HDPE opaque although not glossy. HDPE lends itself readily to silk screen decoration. While HDPE provides good protection at below freezing temperatures, it cannot be used with products filled at over 160 °F (71 °C) or products requiring a hermetic (vacuum) seal.
Low Density Polyethylene (LDPE) is similar to HDPE in composition. It is less rigid and generally less chemically resistant than HDPE, but is more translucent. LDPE is used primarily for squeeze applications. LDPE is significantly more expensive than HDPE.
Polyethylene Terephthalate (PET, PETE or polyester) is commonly used for carbonated beverage, water bottles and many food products. PET provides very good alcohol and essential oil barrier properties, generally good chemical resistance (although acetones and ketones will attack PET) and a high degree of impact resistance and tensile strength. The orienting process serves to improve gas and moisture barrier properties and impact strength. This material does not provide resistance to very high temperature applications—max. temp. 200 °F (93 °C).