Plastic material: Thermoset plastic

author: Universe plastic

2024-09-29

Thermoset plastics are a type of plastic material that is chemically cross-linked after heating or chemical treatment, and has the property of irreversible curing. When cured, thermoset plastics form a three-dimensional network structure, which makes them highly rigid, heat-resistant, chemically stable and insulating.

Unlike thermoplastics, thermoset plastics cannot be melted or reprocessed by heating after solidification. Universe Plastics Engineers will take you to learn more about thermoset plastics.

Characteristics of thermosetting plastics

1. Irreversible solidification

Once heated or chemically solidified, the chemical bonds formed between the plastic's molecular chains cannot be broken, so they cannot be melted or reshaped again.

2. Excellent heat resistance

Cured thermosetting plastics have high heat resistance and can withstand high temperature environments without deformation.

3. High hardness and strength

Due to the cross-linked structure between molecules, this type of plastic usually has high mechanical strength, hardness and creep resistance.

4. Good electrical insulation

Many thermoset plastics have excellent electrical insulation properties and are widely used in the electronics and electrical industries.

5. Chemical corrosion resistance

Thermoset plastics are generally resistant to chemical corrosion and are suitable for use in chemical containers, coatings, etc.

Key points of thermosetting plastic injection molding

1. Curing process

Thermoset plastics are cured by heating or chemical initiators during the injection molding process to form an irreversible cross-linked structure.

2. Low injection molding temperature

Compared to thermoplastics, thermosets are typically injection molded at lower temperatures (between 100-200°C) but are able to withstand high temperatures after curing.

3. Mold requirements

Since it cannot be reshaped after curing, the mold design requires more precision and the mold temperature must be kept uniform to ensure that the material is fully cured.

4. Short injection molding cycle

Compared with thermoplastics, the injection molding cycle of thermoset plastics is shorter, but the subsequent curing time is longer.

Common thermoset plastics

1. Phenolic resin

Features: Good heat resistance, excellent mechanical properties, good insulation and chemical resistance.

Applications: Electrical equipment, automotive parts, kitchen appliance handles, etc.

2. Epoxy resin

Features: Strong adhesion, heat resistance and chemical corrosion resistance after curing, and good mechanical strength.

Applications: Adhesives, coatings, composite materials, electronic component packaging, etc.

3. Unsaturated polyester resin

Features: It can be cured by heating or adding an initiator. After curing, it has good strength and corrosion resistance.

Applications: FRP products, ship hulls, auto parts, pipes, etc.

4. Amino resin

Common types: urea-formaldehyde resin (UF resin), melamine-formaldehyde resin (MF resin).

Features: high hardness, wear resistance, smooth surface, often used to prepare high-gloss products.

Application: furniture surface coating, decorative materials, daily necessities (such as tableware, buttons, etc.).

5. Polyurethane resin

Features: It can be cured by chemical reaction and has good elasticity, wear resistance, oil resistance and chemical corrosion resistance.

Applications: Sealants, elastomers, insulation materials, foam materials, etc.

6. Silicone resin

Features: Excellent high temperature resistance, weather resistance, high chemical stability, good electrical insulation.

Applications: high-temperature coatings, potting materials for electronic equipment, sealing materials, etc.

Disadvantages of thermoset plastics

1. Non-recyclability

Since cured thermoset plastics cannot be remelted, they are difficult to recycle.

2. Relatively brittle

Although high in strength, some thermosets can exhibit brittle characteristics under impact.

3. Difficulty in processing

Once cured, thermoset plastics cannot be heat processed or thermoformed, limiting their processing flexibility.

Thermoset plastic application areas

1. Electronics and electrical fields: such as electrical insulation materials and packaging materials for electronic components.

2. Construction and decoration materials: used to make corrosion-resistant and high-temperature-resistant coatings and composite materials, such as floors and tactile floor tiles.

3. Automobile and aviation industry: As a high-strength, high-temperature-resistant component material, especially in the application of composite materials.

4. Daily necessities: manufacturing of furniture, kitchen utensils, lamps, plastic jewelry and other products.

Summarize

Thermoset plastics are widely used in many industrial fields, especially in products that require high strength and high heat resistance. Their superior performance makes them irreplaceable in many critical industrial applications.

Dongguan Universe Plastic Factory has more than 15 years of experience in plastic injection molding manufacturing. It has a professional team and advanced processing equipment, and can provide injection molding manufacturing of various plastics with cost-effectiveness.

If you are choosing a professional plastic injection molding company, please contact us to get the latest service information.

Injection Molded Manufacturing Products: Plastic Caps

Post-processing of plastics: annealing treatment