9 Most Commonly Used Plastic Additives

Plastic additives are compounds added to plastic materials to enhance their properties, improve their performance, and make them easier to process. There are various types of plastic additives, 9 most commonly used plastic additives include plastic fillers, plasticizers, stabilizers, lubricants, coloring agents, flame retardants, blowing agents, anti-static agents, and diluents.

1. Fillers

Plastic fillers are added to plastic materials to improve their mechanical properties and expand the range of plastic applications. It can reduce the amount of resin used, lower the cost, and increase the volume.

① Classified by shape:

• Powder: wood powder, paper pulp, talcum powder, mica powder, asbestos powder, etc.
• Fiber: cotton, flax, glass fiber, carbon fiber, etc.
• Layer (sheet): paper, cotton, linen, glass cloth, etc.

② Classified by chemical properties: organic, inorganic

E.g. Phenolic compression powder without fillers is neither molding nor practical; PE, PVC + CaCo3 = cheap calcium plastics with sufficient rigidity and heat resistance; glass fiber improves mechanical properties of plastics; asbestos improves heat resistance;

2. Plasticisers

Plasticizers are added to plastic materials to make them softer, more flexible, and easier to mold. They are typically used in applications where the plastic needs to be flexible and durable, such as in automotive interiors, medical tubing, and toys.

Role:

• Increases plasticity, fluidity, and flexibility;
• Reduces rigidity and brittleness;
• Improve the process performance and use performance of plastics.

E.g.: Nitrocellulose without plasticizer, can neither molding process nor practical value; nitrocellulose, acetate fiber, PVC, etc. must be added to the plasticizer.

3. Stabilizers

Any substance that retards the deterioration of a material is called a stabilizer.

They can be classified into the following three types:

• Heat stabilizer: Its main function is to inhibit or prevent the degradation of the resin by heat during processing or use.
• Light stabilizer: its main role is to prevent resin degradation under the effect of light (plastic discoloration, loss of mechanical properties, etc.).
• Antioxidant: It slows down or inhibits the oxidation of plastics.

Stabilizers are added to plastic materials to prevent them from degrading due to heat, light, and other environmental factors. They are mainly used in applications where the plastic needs to have a long service life, such as in outdoor products, electrical and electronic devices, and construction materials.

4. Lubricants

Adding lubricants to plastic materials prevents the plastic from sticking to the mold during the molding process and reduces the friction of the plastic against the mold. Improve the fluidity of plastic and increase the surface gloss of plastic parts.

5. Colouring agents

Coloring agents are added to plastic materials to enhance their appearance and make them more visually appealing. They can be used to match specific color standards or create custom colors. Commonly used coloring agents include pigments and dyes.

The coloring agent used in the plastic industry is mainly pigment, which can be divided into two kinds: inorganic and organic:

• Inorganic pigment: poor in coloring ability, transparency, and vividness, but better in light resistance, heat resistance, and chemical stability, and not easy to fade.
• The characteristics of organic pigments are between inorganic pigments and dyes.
• Dyes: bright and complete colors, good coloring ability, and transparency. However, their heat resistance, light resistance, and solvent resistance are generally poor, and they are easy to bleed out or migrate from plastics, so the water-soluble dyes used in the printing and dyeing industry are generally not applicable to the plastics industry.

6. Flame retardants

Flame retardants are added to plastic materials to reduce their flammability and improve their fire resistance. They are typically used in applications where the plastic needs to meet strict fire safety regulations, such as in electrical and electronic devices, building materials, and transportation.

7. Blowing agents

Blowing agents are added to plastic materials to create foam structures. They can reduce the density of the plastic and improve its thermal and acoustic insulation properties. Commonly used blowing agents include chemical gases and physical foams.

8. Anti-static agents

Anti-static agents are added to plastic materials to reduce or eliminate static electricity. They can prevent dust and dirt from being attracted to plastic surfaces and improve the plastic's electrical properties. Commonly used anti-static agents include quaternary ammonium salts, amines, and phosphonium compounds.

9. Diluents

Diluents are added to plastic materials to modify their physical properties, such as viscosity and flexibility. They can also improve the plastic's processing characteristics and reduce its cost. Commonly used diluents include solvents, plasticizers, and low-molecular-weight polymers.

In conclusion, plastic additives provide a variety of advantages to plastic materials, including improved performance, enhanced appearance, and increased functionality. By selecting the right type and amount of plastic additives, manufacturers can tailor plastic materials to meet specific design requirements and optimize their product quality and efficiency.

“Qingdao Victory Plastics Co., Ltd. specializes in white goods plastic parts injection molding. We select the most cost-effective and suitable material types and additives according to customer needs, product usage scenarios, and material features, to meet the diverse customized needs of our customers.”