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What Is the Recycling Code for LDPE
What Is the Recycling Code for LDPE?
CSR Plastic recycles LDPE (low-density polyethylene) plastic, which is identified by the recycling code 4. Harmless LDPE is used in various products such as garbage bags, dry cleaning bags, and food storage containers. Due to its low density, LDPE is both flexible and lightweight. Known as a thermoplastic polymer, LDPE has a semi-transparent appearance.
LDPE, marked with code 4 in nature, is highly resistant to electricity, chemicals, and moisture. Therefore, it has a wide range of applications. LDPE consists of low-density molecules that play a role in the production of thin resin. Among plastics, LDPE has the simplest structure, making its production very easy.
Crystal Properties of LDPE Plastic
LDPE plastic, recycled by CSR Plastic's expert team, has low crystallinity and branched polymer characteristics. Due to its high branching, it has lower density, melting temperature, and hardness compared to other polyethylene types. Because of its low crystallinity, it is also known as an amorphous polymer. LDPE does not have a regular crystalline structure; it is a type of plastic made up of amorphous, non-crystalline, and irregular polymer chains.
Due to its low crystalline nature, LDPE has gained flexibility. LDPE crystallinity is measured with a Differential Scanning Calorimeter (DSC), which measures the amount of heat absorbed or released by the material during controlled temperature changes. DSC also determines the softening and melting points of LDPE crystallinity and plays an active role in the investigation of phase transitions in LDPE crystallinity. Unlike highly crystalline polymers, LDPE plastic melts at very low temperatures, making it suitable for injection molding and similar processes.
What Is the Melting Point of LDPE Plastic?
The melting point of LDPE plastic ranges between 105 and 115 degrees Celsius. Therefore, LDPE consists of both high flexibility and density. The melting temperature of LDPE is measured with DSC. LDPE plastic is a flexible product with flow properties. These features have made it widely used in:
- Shrink films
- Shopping bags
- Plastic films
LDPE plastic is generally heated to a temperature of 110 degrees Celsius. This allows materials to be easily stretched and then molded. Films are shaped according to the users' preferences and then quickly cooled to stabilize the structure. LDPE shrink films shrink when exposed to heat, such as from a heat gun. They begin to shrink at temperatures between 90-110 degrees Celsius. This shrinkage provides a secure packaging feature for products.
Thermal Stability of LDPE Plastic
The thermal stability of LDPE plastic ranges between -50 and 85 degrees Celsius. In the absence of oxygen, LDPE plastic has thermal stability at 290 degrees Celsius. At temperatures above 350 degrees Celsius, this plastic type produces gaseous products. LDPE thermal stability is measured with DSC or STA PT 1000.
LDPE's thermal stability is highly resistant to a wide temperature range without decomposition. Therefore, it can be used for many purposes, such as the production of stretch films to protect food. The most important feature of LDPE stretch films is that they protect food from both moisture and air, extending its shelf life. Due to its thermal properties, LDPE films can be used safely if not exposed to extreme heat. They do not melt in a microwave, for example. LDPE plastic acts as a barrier against external factors, thereby preserving the flavor of food.
The glass transition temperature (Tg) of LDPE plastic is determined to be approximately -100 degrees Celsius. Below this temperature, LDPE plastic is both solid and hard. Thanks to its glass transition temperature, LDPE can be processed and has mechanical properties. You can contact CSR Plastic for more detailed information about the recycling code of LDPE.
