The melting temperature of Recycled PE particles is a key physical property that is affected by a combination of factors.
First, the source of Recycled PE particles has a significant impact on their melting temperature. If it is recycled from high-density polyethylene (HDPE) material, its melting temperature is usually around 130 - 135°C. Because HDPE itself has a high degree of crystallinity and the molecular chains are arranged more closely, it requires higher energy to make its molecular chains overcome the interaction force and melt. If the pellets are recycled from low-density polyethylene (LDPE), the melting temperature is relatively low, about 110 - 120°C. The molecular chain of LDPE contains more branches, and the arrangement between the molecular chains is relatively loose, so it can be melted at a lower temperature.
Secondly, the processing technology during regeneration can also change the melting temperature. During the regeneration process, if it has been heated, cooled and mechanically processed multiple times, the molecular chains of the PE particles may be degraded or cross-linked to a certain extent. For example, excessive thermal processing may cause molecular chains to break, reducing the molecular weight of Recycled PE particles, thereby lowering the melting temperature. On the contrary, if some cross-linking agents are added during the regeneration process to form more cross-linked structures between molecular chains, then a higher temperature is required to melt the particles.
The impurity content in Recycled PE particles also has an important impact on the melting temperature. The presence of impurities will interfere with the regular arrangement and interaction of PE molecular chains. If the impurities are small molecular organic compounds, they may lower the melting temperature of the particles and act like plasticizers. However, if the impurities are refractory substances such as some inorganic minerals, the apparent value of the melting temperature may be increased to a certain extent, because these impurities need to absorb more heat to reach the same temperature state as the PE particles.
Understanding the melting temperature of Recycled PE particles is critical for their processing applications. During the plastic processing process, such as injection molding, extrusion and other processes, the processing temperature needs to be set appropriately according to its melting temperature to ensure that the Recycled PE particles can be melted and formed smoothly, thereby producing plastic products with qualified quality.
