At what temperature does pet plastic melt?
Plastic welding is a process for joining parts made of thermoplastic materials. Welding takes place by the softening of the areas to be joined. The polymer molecules acquire certain mobility by the action of an external agent (heat, vibration, friction, solvent, etc.).
When both parts are joined and pressure is applied to them, the molecules of both parts to be joined interact and intertwine. Once the action of the external agent has ceased, the movement of the molecules decreases and an interlocked structure of the molecules is formed, forming the union of both plastic parts.
Welding can be used to produce joints with mechanical properties approaching those of the parent material. Plastic welding is limited to thermoplastic polymers, because these materials can be softened and melted by heat.
Thermoset polymers once hardened cannot be softened again by heating. The heat required for welding thermoplastic polymers is less than that required for metals.
Thermofusion of plastics
Monomers are the building blocks of the structure of plastics (e.g. ethylene). They are simple molecules (carbon and hydrogen). The union of many monomers constitutes a polymer (e.g. polyethylene).
It is produced through terephthalic acid and ethylene glycol by polycondensation. There are two types: textile grade and bottle grade, for bottle grade it must be post condensed, and there are different colors for these uses.
It is a thermoplastic manufactured from ethylene (made from ethane, one of the components of natural gas). It is very versatile and can be transformed in different ways: injection, blow molding, extrusion or rotational molding.
It is produced from natural gas. Like HDPE, it is highly versatile and can be processed in different ways: injection, extrusion, blow molding and rotational molding. Its transparency, flexibility and economy make it present in a variety of containers, alone or in conjunction with other materials and in a variety of applications. Advantages
Automotive plastic welding
Due to PE, most industries have benefited greatly. An example of this is in the food industry, where the shelf life has been extended economically, safely and with a wider market reach.
It is obtained from the polymerization of ethylene (chemical formula CH2=CH2 and called ethene by the IUPAC), from which it derives its name, consisting of a pair of methylene groups (CH2) connected by a double bond.
Polyethylene PE is a thermoplastic polymerization based on long hydrocarbon chains. Depending on the crystallinity and its molecules, the melting and transition points may or may not be observable. The average melting point of commercial low density polyethylene is in the range of 105 to 115°C (221 to 239°F).
It has outstanding chemical resistance and low wear. Its characteristics make it a reliable material for the manufacture of machine handling parts, moving parts of sewing machines, bearings, articulated parts for human implants, gears or even artificial joints.
Classification of plastics according to their origin
HDPE is obtained by a Ziegler-Natta polymerization process, which is a catalytic polymerization process (Ziegler-Natta catalyst). There are three major commercial processes used in the polymerization of HDPE: solution, suspension and gas-phase processes. The catalysts used in the manufacture of HDPE are generally either of the transition metal oxide or Ziegler-Natta type. In this process, a solvent is used which dissolves the monomer, the polymer and the polymerization initiator. By diluting the monomer with the solvent, the polymerization rate is reduced and the heat released by the polymerization reaction is absorbed by the solvent. Benzene or chlorobenzene can generally be used as solvents. In bulk polymerization only the monomer is polymerized, usually in a gas or liquid phase, although some solid state polymerizations are also carried out. This is a direct polymerization of monomers into a polymer, in a reaction in which the polymer remains soluble in its own monomer. Additionally, with Phillips catalysts (chromium trioxide), HDPE with very high density and straight chains is produced.