Plastic additives are substances that must be added to polymers (synthetic resins) to enhance their processing performance or to enhance the performance of the resin itself. For instance, a plasticizer is added to polyvinyl chloride resin to reduce the molding temperature and soften the finished product. Another illustration is the use of a blowing agent to create foamed polymers that are light, vibration-resistant, heat-insulating, and sound-insulating. Some polymers cannot be molded without the use of a heat stabilizer because their thermal breakdown temperature is so near to their processing temperature during molding. As a result, plastic additives  play a crucial role in the production of plastic molding.

A vast group of additives, such as plasticizers, heat stabilizers, antioxidants, light stabilizers, flame retardants, foaming agents, antistatic agents, antifungal agents, colorants, and enhancers, are utilized in plastic molding goods. Whitening, filling, coupling, lubricating, and releasing agents, among other things. Among them, colorants, brighteners, and fillers are general-purpose compounding ingredients rather than compounds designed specifically for plastics.

Although the plastic formula design appears straightforward at first glance, it really has several internal connections. When choosing additives, a number of criteria need to be taken into account in order to build a formula with good performance, simple processing, and cheap cost. Depending on the goal to be attained, choose the best option. The kind of additives, the added additives should be capable of achieving the required indications and having the full impact of their anticipated effects. The following is the precise selection range for additives:

Range of auxiliary selection

Pick stiff toughening materials, thermoplastic elastomers, and elastomers for toughening.

Pick glass fiber, carbon fiber, whisker, or organic fiber for reinforcement;

hydrated metal hydroxides, antimony trioxide, nitrogen/phosphorus composite intumescent flame retardants, phosphorus, and bromine (common bromine and environmental bromine) are all examples of flame retardants;

Various types of antistatic agents;

Conductive materials include metal oxide, metal fiber and powder, carbon (including carbon nanotubes, carbon nanotube black), and graphite.

Samarium cobalt (SmCo5 or Sm2Co17), neodymium iron boron (NdFeB), samarium iron nitrogen (SmFeN), and aluminum nickel are examples of rare earth magnetic materials.

Metal fibers, metal powders, metal oxides, nitrides, and carbides all have high thermal conductivity, as do carbon-based materials like carbon black, carbon fiber, graphite, and carbon nanotubes, as well as semiconductor materials like silicon and boron.

Glass fibers, inorganic fillers, heat-resistant substances such substituted maleimides, and crystal nucleating agents are examples of materials that resist heat;

The finest transparent nucleating agent for polypropylene is from the sorbitol class of crystal nucleating agents;

Graphite, molybdenum disulfide, copper powder, and other cobalt-based magnetic powder are three groups of materials that are wear-resistant;Calcined kaolin insulation;Barrier: quartz, mica, montmorillonite, etc.

Matching additives for plastics

Nylon (PA), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT) are all resistant to flame when treated with red phosphorus;

Flame retardants made of nitrogen are efficient for oxygen-containing compounds as PA, PBT, PET, etc.;

Polypropylene (PP) that has been copolymerized responds favorably to the nucleating chemical;

Glass fiber with a heat-resistant modification performs better with crystalline polymers than amorphous plastics;

conductive plastic that is loaded with carbon black and works well with crystalline resins;

Different types of the same composition’s additives have a significant impact on the modification.

Additive form

The aspect ratio of the additives may be used to describe the degree of fibrosis; the higher the aspect ratio, the stronger the reinforcing effect; for this reason, glass fiber should be injected through the vent hole ;than retain the aspect ratio and lower the likelihood of fiber, the molten state is preferable than the powder state.

A excellent toughening effect and great brightness are possessed by spherical additions.

High-gloss PP is filled with barium sulfate since it is a typical spherical addition and does not significantly affect stiffness and toughness.

Size of additives’ particles

Mechanical characteristics are impacted by additive particle size in one way.

The filler material’s tensile strength and impact strength benefit more from smaller particle sizes;

Effect of additive particle size on the effectiveness of flame retardants

The effectiveness of a flame  retardant increases with decreasing flame retardant particle size. For instance, less hydrated metal oxide and antimony trioxide must be used to have the same flame retardant effect as smaller particle sizes;

The impact of additive particle size on color matching

The tinting intensity, concealing power, and color uniformity of a colorant all increase with decreasing particle size;

The impact of additive particle size on electrical conductivity

Using carbon black as an example, the easier it is to create a network conductive channel, the less carbon black has to be added to have the same conductive effect. However, just like a colorant, a particle size has a limit value. If a particle size is too tiny, it is simple to collect and challenging to disperse, which has a negative effect.

Additional surface preparation

The modifying impact will be enhanced following the treatment of the surfaces of all inorganic additives. The most visible ones are fillers, but there are also glass fibers and inorganic flame retardants.

Agents de couplage and compatibilizers are the principal ingredients used in surface treatment. The coupling agents are specifically silanes, titanates, and aluminates. The resin’s matching maleic anhydride-grafted polymers serve as the compatibilizers.