How is LDPE Made?

If you are seeking low density polyethylene (LDPE) for your business, you may ask, “How is LDPE made?” Perhaps you would like to know more about its manufacturing process. Polyethylene is one of the most extensively used thermoplastics worldwide. Polyethylene is found in almost everything from plastic bottles, packaging, shrink wrap, bakery bags, to grocery bags. Plastics are utilized by a variety of businesses for many different reasons, making it one of the most popular materials in the world. Plastic is one of the most reliable materials. Its highly durable characteristics ensures it will last a long time without puncturing or breaking easily. Plastic is manufactured to withstand rough and challenging situations. Two of the most common types of polyethylene are low density polyethylene (LDPE) and high density polyethylene (HDPE). 

LDPE is valued more than any kind of plastic. LDPE is defined as a clear or translucent plastic which is durable, chemically resistant, and displays waterproofing capabilities. It is present in cling films often used in households. LDPE is used to manufacture a wide variety of products, such as plastic bags and stretch wrap. LDPE material is clear, strong, and flexible and frequently used in stretch wrap applications. LDPE is used to create bottles and lids and cables and wires, all of which are flexible.

How is LDPE Made and What are its Characteristics?

LDPE is made through a process known as polymerization, where the polyethylene monomer is derived. Polyethylene monomers are compressed in an autoclave or tubular reactor to enable polymerization. LDPE is produced by compressing monomer ethylene gas in a reactor to begin the process of polymerization. Polymerization is defined as the linking of monomers into polymer chains. Small molecules known as fractions are removed and certain fractions transform into the desired thermoplastic result. Under high temperatures and high pressure, the LDPE plastic is then extracted from the ethylene gas along with catalyst oxide initiators. The LDPE manufacturing process forms a polymer structure with both longer and shorter branches of LDPE. There are two methods commonly used for LDPE production: tubular routes and stirred autoclave. Tubular routes are currently gaining traction due to their high conversion ratio of ethylene.

While it is important to ask, how is LDPE made, it is equally important to be familiar with its characteristics. LDPE shares many similarities with high density polyethylene (HDPE), such as having similar applications. Their internal compositions, however, result in many distinct differences. The polymer chains in both materials are branched in LDPE whereas with HDPE, polymers have a crystalline structure. These differences in the way polymers are organized result in distinguishing characteristics in both LDPE and HDPE materials.

LDPE and HDPE share differences in their physical composition and recyclability. The fundamentally contrasting physical compositions of both materials result in many of their differences. The polymer chains of the LDPE and HDPE are branched in the LDPE material. The polymers possess a more crystalline arrangement in the HDPE material. The contrasts which are present in the organization of polymers in both materials result in different characteristics in each material.

LDPE material is softer and more flexible than HDPE material. The melting point of LDPE is much lower at 115 degrees Celsius. This results in LDPE material being more transparent than HDPE material. LDPE film is more likely to crack when it is put under stressful conditions. HDPE is more of a rigid material that offers more chemical resistance. Because it is melted at higher temperatures, it can withstand greater temperatures. LDPE and HDPE are both recyclable materials but must be recycled separately as each material is classified at different recycling levels. For LDPE, it is recycling number 4 and for HDPE, it is recycling number 2. Products containing LDPE can also be more complicated to recycle, as the LDPE material is softer and can get caught in the recycling machinery. HDPE is generally much easier to transport and put through recycling machines.

LDPE has a large range of properties. Though LDPE and HDPE have distinctive differences, they share many similar applications. Some industries that use both LPDE and HDPE materials in their applications are packaging, automotive, pipe and piping, hydraulics and pneumatics, and electrical industries.

LDPE displays optimal resistance to acids and alcohols, as well as excellent electrical insulation characteristics. The high chemical resistance and low solubility of LDPE makes it a distinctly useful material for a variety of applications. LDPE has a high impact strength at low temperatures and can effectively withstand the elements. Being less expensive to produce than HDPE, LDPE is a preferred material for manufacturing plastic bags and stretch wrap. HDPE is often utilized for more durable products, as it is a stronger film than LDPE.

At Danshar Polybag and Resin and Toronto Stretch Wrap, we are here to answer all your questions, such as how is LDPE made. Our many years of experience in the plastics industry speak for themselves. Our manufacturers use high quality resins to produce the finest LDPE materials. Whether you are seeking plastic bags or stretch wrap, you and your customers are certain to be satisfied with our expertise and recommendations. Contact us today for a custom quote.    

Please contact us for quotes

2899 Steeles Ave. W.,
Units 9 & 10,
North York, Ontario
M3J 3A1


Fax: 1-855-669-6184

For skid quantities of stretch wrap, resin, or plastic bags only, please call

By appointment.