What are the materials used in plastic bags?
Initially, polyethylene is produced by tapping natural gas or oil to extract ethylene. It is then specially treated to become polyethylene. Polyethylene is modified to suit the different types of bags it will be used for. This material is made from Rutan Poly, which is easy to make out of monomers. A polymer is a chain of carbon atoms that is mixed and bonded together with hydrogen atoms. A polymer is a low-density material that can be molded into different shapes and densities.
Materials for plastic bags
- High-Density Polyethylene (HDPE): As a result of its linear structure, HDPE is very durable and resistant to ordinary solvents and temperatures as high as 120° C in Rutan Poly. It can withstand temperatures as low as -28° F and is also resistant to various acids.
- Low-Density Polyethylene (LDPE): Bags made of LDPE are thick, flexible, and resistant to punctures and tears. These bags are measured in mils or one-millionth of an inch. These bags differ from kitchen bags with 0.9 mils to contractor bags with 6.0 mil thickness.
- Linear Low-Density Polyethylene (LLDPE): A light-gauged gusseted bag can be made from LLDPE bags, which are less costly than LDPE bags and more environmentally friendly. They have better strength and puncture resistance than LDPE bags. To produce them, ethylene is copolymerized with butene, hexene, and octene.
- Medium Density Polyethylene (MDPE): The density of MDPE makes it shock and drop-resistant as well as stress-crack resistant. MDPE is stronger, harder, and still flexible enough to be used for handle and loop bags despite being much thicker than PE.
- Metallocene (mPE): There are particles of metal ions coupled with carbon atoms within metallocene, which are not monomers like ethylene, propylene, or vinyl acetate. It has the same density standards as polyethylene with lower densities being softer, while higher densities are more durable. The downside of metallocene is its expense, which is caused by its being mixed with polyethylene. Its manufacturing process involves blending it with LDPE and LLDPE to create enhanced poly films that seal rapidly and better.
- Vinyl: The process for making vinyl is to combine chlorine and ethylene to produce ethylene dichloride. Vinyl EDC is made by polymerizing vinyl chloride monomer (VCM), resulting in PVC resin powder. Modifiers and additives alter the material’s physical properties. With its positive properties, vinyl is ideal for storing and preserving precious items. It is flexible, waterproof, durable, flame retardant, and wear and tear.
- Polypropylene: With its flexibility and strength, polypropylene is resistant to fatigue and does not sustain damage from repeated use, thanks to its long chains of propylene molecules. As a lightweight material, polypropylene bags are like any other plastic bag but have a high strength-to-weight ratio. They’re most used for totes and shopping bags.