Thermosetting plastic, with thermosetting resin as the main component. It is a plastic that forms a product through a process of cross-linking and curing with various necessary additives. It remains liquid during the early stages of the manufacturing or molding process. Insoluble after curing. In other words, it can no longer melt or soften.
What is the difference between thermosets and thermoplastics?
Thermosets can soften and flow when first heated to a certain temperature. A chemical reaction (crosslinking reaction) then occurs, leading to curing and hardening. This change is irreversible!
The resin molecular chains in thermoplastic polymers are straight or branched. It softens and flows when heated, whereas the process of cooling and hardening is a physical change, which means it is reversible.
What are the main types of thermoset plastics?
Phenolic resin (PF); it has the advantages of easy molding, good dimensional stability, especially good electrical insulation. It also has good heat resistance. Primary applications are electrical sockets and coatings and adhesives.
Animal plastic (AF); has the advantages of rigid plastic, scratch resistance, colorless and translucent. Mainly used in industrial parts, medical equipment, decorative materials and thermal insulation materials.
Urea-formaldehyde resin (UF); colorless, easy to transport, good heat resistance. Coupled with high hardness and good mechanical properties, it has great advantages in applications such as tableware and furniture.
Melamine formaldehyde resin (MF); has the advantages of high hardness, wear resistance, flame retardant and so on. Ideal for use as coatings, trim panels, molding materials and adhesives.
Epoxy resin (EP); excellent adhesion, electrical insulation and chemical resistance. With these advantages, the main applications are eg adhesives and coatings.
Silicone resin; has the advantages of electrical insulation, heat resistance and water resistance. Therefore, there is great interest in electrically insulating materials.
Unsaturated polyester resin; advantages of low pressure molding and glass fiber reinforced. Primary applications are fiberglass reinforced plastic (FRP) manufacturing and potting materials.
Polyurethane; this is a lightweight foaming and easy-to-process process. Therefore, the main applications are furniture, packaging and coatings.
How to Improve Durability and Color Stability of Thermosets
Although most thermosetting plastics have the advantages of heat resistance and good electrical insulation, with the development of industrial technology, more and more fields have put forward higher requirements for color retention and durability.
The first important improvement was the use of UV absorbers. We will focus on our two main UV absorbers for thermoset polymers:
Omnistab UV 1 is mainly for UV B band protection. If you are working with cost-effective thermosets, the Omnistab UV 1 is the product you need. Like polyurethane, adhesives, foams and other thermoset molding materials.
Omnistab UV 1577 is ideal for systems with high demands on product clarity and color stability. Such as high-end furniture decorative panels, automotive decorative materials and artificial jewelry.
Second, the right antioxidants can greatly extend service life and durability. Especially when you combine them with UV absorbers.
The best way is to add hindered phenolic antioxidant Omnistab AN 1076, together with macromolecular auxiliary antioxidant Omnistab AN 626, not only play a protective role in the process, but also play a lasting role in the use stage. It will mitigate photo-oxidative aging degradation of the material.
If you would like to know more about this topic, or if you have specific inquiries related to your production process, please contact us!
