Everything You Should Know About ABS Injection Molding

ABS Injection Molding

ABS is a common plastic injection molding material that contains three main ingredients. ABS’s “A”, acrylonitrile, confers hardness, heat, and chemical resistance. The “B”, which is butadiene, gives toughness and resistance to impact. The “S” stands for styrene and offers gloss, strength and processability.

ABS plastic is inexpensive and easy to insulate mold. ABS plastic is used in electronic components and consumer goods, but it’s not the best material for outdoor applications because of its weak resistance to weather and sunlight. ABS can be used to increase its resistance against ultraviolet (UV) light. For added strength, Injection-molded ABS can be filled with filler materials. You can use glass as filler material, or nylon, acrylic, or stainless steel fibers.

Processing parameters can be affected by additives and fillers. Different grades of ABS might contain different combinations of butadiene and acrylonitrile. It is important to work with an ABS injection moulder who knows more than just the benefits and uses of this popular plastic. Your project’s success will depend on the material properties and how it is processed.

Material Processing Concerns

ABS is known to absorb moisture, as shown in the table. It must be dry before it can be processed. This adds to time and costs. However, if the moisture is not removed, molds may develop cloudiness, bubbles or lines. You may need to dry your parts for a highly reflective, high-gloss surface. This can take up to nine hours.


Because of the relationship between melting temperature and viscosity (a measure of fluid’s resistance, flow), another important consideration is melt temperature. When ABS pellets melt beyond their plasticizing temperatures, the material’s viscosity will increase and it will be more difficult to mold. This is unlike other amorphous materials, which have viscosity that decreases with increasing temperature.

Temperature Control

Overheated ABS is subject to thermal degradation, which is the heat-induced destruction of chemical bonds. The presence of brown granules in injected-molded parts indicates that the molding took place at high temperatures. This is often due to old equipment and poor temperature control. Injection molded ABS parts with a higher gloss must be kept at a higher temperature to prevent damage. ABS is more stable than other materials and the temperature of the mold is higher.

Injection Pressure

ABS’s viscosity means that higher injection pressures are required than for other materials. However, lower pressures might still be appropriate for smaller, simpler or thicker products. Keep in mind that too much pressure can cause parts to stick to the mold, making it more difficult to remove and increase production costs. Mold shrinkage can increase and result in parts that are not acceptable for end-use.

Injection Speed

Injection molding speed are other important considerations. The speed of ABS plastic can burn or decompose if it is not fast enough. These defects can include weld lines and poor glossiness. Insufficient filling may occur if the injection molding speed is too slow. ABS requires a smaller shot than other plastics to achieve better dimensional stability. While this reduces material consumption, it still requires proper processing techniques.


ABS is an injection molding plastic that is widely used. However, this doesn’t mean any manufacturer partner can make the parts you require. While many injection molders are able to describe ABS’s advantages and uses, they don’t know much about ABS’s material properties or processing considerations. You don’t want the extra processing costs, risks, and part defects that can come with improper drying or other incorrect processing methods. Want.Net is a professional manufacturer of injection molding. We have serve our customers for more than a decade. Get an online quote of injection molding to start your project today.

Learn more:
Want.Net Technical Team

Want.Net Technical Team

The Want.Net Technical Team has diverse members with extensive education and training in CNC machining. They prioritize precision, efficiency, and innovation to provide high-quality manufacturing solutions globally.

Push Your Order into Production Today!

Table of Contents


You’re one step from the  factory-direct price of part manufacturing services.