Thermoplastics are one of the most commonly used materials for manufacturing everyday parts. These materials offer several benefits, such as higher tensile strength and durability. The ABS material is the most commonly used thermoplastic. As a result, ABS injection molding is one of the most commonly used injection molding processes today.
In this process, the liquefaction temperature is 221° F. After cooling, the ABS plastic is reheated. Because thermoplastics such as ABS can withstand temperature changes without damage, they are used in a wide variety of manufacturing applications. For this reason, they are used in a wide variety of manufacturing processes. This ABS Materials Guide will introduce you to all of its properties and applications.
Table of Contents
What is ABS plastic?
So, what is ABS material?ABS stands for Acrylonitrile Butadiene Styrene. It is an opaque, impact-resistant, amorphous thermoplastic. As such, it is one of the most commonly used injection molding materials. As the name suggests, it is a polymer composed of three monomers. Since it is an amorphous material, it does not have a proper melting point.
Styrene gives the plastic a shiny, impermeable surface. Conversely, the polybutadiene component provides excellent durability over a wide range of temperatures. In addition, the chemical structure of ABS can be altered, which can improve various properties of the plastic for certain applications.
Because ABS plastic is a thermoplastic. As such, it can be used in a variety of industries that require the production of strong, impact-resistant materials. As a thermoplastic, ABS does not burn when heated. Instead, it becomes liquid during the ABS molding process, making it easy to mold and recycle.
Some of the most typical applications for ABS plastic include computer keyboard keys, plastic protective coatings, power tool housings, Legos, and more.
Characteristics of ABS Plastic
The common characteristics of ABS plastic are listed below:
- Its chemical formula is (C8H8) x-(C4H6) y-(C3H3N) z)
- Excellent heat and chemical resistance
- Good resistance to impact, abrasion and staining
- Normal temperature is 204 – 238 °C
- The liquefaction temperature of ABS is 105 °C
- Tensile strength equal to 46 MPa (6600 PSI)
- Specific gravity equal to 1.06
- Shrinkage = 0.5-0.7%
ABS Injection Molding Technology
Depending on the product you are trying to make using this method, the procedure will vary. Here are a few examples:
- Thin-walled: Due to the high viscosity of the melted ABS material. Therefore, the pressure must be increased for thin-walled products, and the mold must be able to withstand the extra pressure.
- Large and Hollow: Making huge, thin, or hollow items is often challenging. But water- or gas-assisted injection molding can help. This technique forces the molten plastic against the sides of the mold to achieve uniform thickness and smoothness.
- Thick Walls: Standard techniques can leave dents in thick-walled parts. One solution is compression injection molding. This method involves injecting a certain amount of molten plastic into the mold to form the finished product. This method also reduces internal stresses. On the other hand, using a thinner mold wall or increasing the heat capacity of the mold can also reduce sink marks.
- Multiple Materials: If a part consisting of multiple materials is required. Then techniques such as insert molding or overmolding can be considered. For example, the ABS handle of a cordless drill can be over-molded to improve the grip.
ABS Injection Molding Advantages
Because ABS injection molding has many advantages. Therefore, it is widely used in various industries. This material has the following advantages:
Energy Efficiency
Machines used for ABS injection molding offer excellent results in thermoplastic processing. Their power and strength enable consistent and reproducible production results. In addition, energy-saving devices help you reduce energy consumption and shorten the entire production cycle.
Wide Range of Applications
ABS injection molding is also extremely versatile. Designed for use with different diameters of ABS resin, this technology has a high degree of integration capability. This adaptability therefore makes it possible to manufacture components for a wide range of industries.
Accurate Reproducibility
The ABS injection molding process can produce complex parts for difficult applications. This is often limited to different injection molding methods. The ability to combine complementary technologies with regulated injection molding ensures consistent shape and quality of molded parts. In addition, the material maintains its properties and performance at extreme temperatures.
Other Advantages
Other important advantages of ABS injection molding include:
- Load stabilization
- High impact strength and dimensional stability
- High tensile strength
- Recyclability
Disadvantages of ABS Injection Molding
Although ABS plastic has many advantages. However, just like any other material, it has some disadvantages. Some of the disadvantages of this material include:
Poor UV Resistance
ABS plastic does not perform well when exposed to sunlight. It degrades if exposed to the sun’s UV rays for a long time. Therefore, it is usually necessary to coat it with a UV-resistant substance to provide proper protection.
High Smoke Generation
Although the substance is considered non-toxic to humans, fumes are generated during the manufacturing process. This can be hazardous to operators and technicians. Therefore, the shop where ABS injection molding and CNC machining are performed needs to be well-ventilated.
Poor Fatigue Resistance
Due to the weak fatigue resistance of ABS plastic. Therefore, it may not be the ideal material for high-stress applications. When ABS plastic is subjected to sustained stress or strain, it may disintegrate quickly.
Precautions for ABS Plastic Injection Molding Process
Prior to injection molding ABS plastic, some preparations must be made. The following guidelines will ensure successful molding and desired results:
Consider ABS Plastic Part Design
Plastic parts must be designed with uniform wall thicknesses, with a 25% variation between part wall thicknesses. When wall thicknesses are uniform, large stresses can be avoided. In addition, additional ribs or radii may be required to improve strength and bite.
On the other hand, the radius of the part will be determined by the wall thickness. Therefore, you must make sure that the ratio of radius to wall thickness is at least 0.3. The larger the radius, the lower the stress. However, you must be careful when using a large radius because too large a radius can cause shrinkage. Therefore, the possibility of shrinkage must be considered during the ABS injection molding process.
Drying the ABS Material Before Processing
ABS plastic absorbs moisture from the material to be processed. It is therefore important to ensure that the material is thoroughly dried before processing. the moisture absorption capacity of ABS plastic can lead to a number of problems. The main problems are increased operating costs and longer processing times. Similarly, failure to remove moisture can lead to fogging of molded parts.
However, heat-resistant ABS resin absorbs moisture from the air when it is stored and transported. Moisture absorption rates range from 0.2% to 0.4%. However, prior to processing ABS plastic for molding, the moisture content must be significantly reduced to 0.05% or less. This will help prevent molding problems during processing. Typically, drying temperatures of 80-95°C will take 3-4 hours to complete.
Injection Temperature Control
Temperature control is also an important factor in ABS injection molding. This is because overheating of ABS plastic can lead to thermal decomposition. When a manufacturer heats the material too much, the chemical connections break. As a result, brown particles appear on the injection molded part. Temperature control problems are almost always unavoidable when using old equipment with weak temperature regulation.
However, when injection molding ABS parts with high gloss, the molding temperature must be higher. This prevents damage to the material throughout the process. Therefore, when ABS plastic is used in combination with a mold, the temperature will be higher than for other processed materials. The optimum temperature range is 180-230 degrees Celsius. Again, the higher the temperature, the shorter the time the plastic should be exposed to the temperature to avoid degradation.
Injection Pressure
Due to the high viscosity of ABS plastics, higher injection pressures are required than for normal injection molding materials. This may not apply to simple, minor, or bulky products. However, large increases in injection pressure may cause molded parts to stick together due to increased friction.
In addition, separating molded parts can increase production costs. On the other hand, too low a pressure can lead to increased mold shrinkage. This can lead to the creation of unserviceable, inferior parts.
Injection Speed
Injection speed is also critical to ensure a high-quality end product. Too fast an injection speed can lead to burning or thermal degradation of the plastic substance. In addition, too fast a speed can lead to poor gloss, fusion marks, and color fading.
If the speed is too slow, it can lead to the underfilling of the mold. Therefore, the dynamics must be balanced to ensure proper material processing. In addition, the injection size of ABS plastics is smaller than required for dimensional stability compared to other polymers. In addition, less material is required for processing, while remaining consistent with the method.
If you are unsure where to begin processing plastic parts. You should contact Yonglihao Machinery first and we can provide you with the help you need to get going.
ABS Injection Molding Applications
Every day, we use materials made of ABS plastic in our daily activities. ABS polymer can withstand a variety of physical and chemical changes. This makes it very useful in both industrial and commercial applications.
It is also one of the most commonly used materials in modern molding due to its low melting point and ease of machine handling. Similarly, the cost of ABS plastic is low. Therefore, it is widely used in the injection molding industry.
ABS plastic is used in various areas of life, including:
- Automotive: In the automotive industry, ABS plastic is particularly suitable for products that must be lightweight and can replace metal. Materials include door restrictors, instrument panels, dashboard components, pillar trim, handles, and seat belt components.
- Commercial Applications: This method is very useful in the commercial industry, especially for household products. Refrigerator liners, vacuum cleaners, control panels, and food processors are some examples of such products.
- Electrical Industry: ABS also has applications in the electrical industry, such as electronic housings and computer keyboards.
- Construction Industry: ABS materials are particularly suitable for pipes and fittings. This is because ABS plastic is highly impact-resistant and can withstand chemical and physical changes.
- Other Applications: ABS material can also be used for musical instruments and sports facilities. In addition, it can be used in the manufacture of medical devices such as compressors and nebulizers.
Conclusion
ABS material is one of the most commonly used plastics for injection molding. It is a heat-resistant thermoplastic that is durable and suitable for a wide range of applications. Let’s say you are looking for a lower-cost alternative to injection molding. In this case, try ABS injection molding. When you can’t decide which plastic is best for injection molding, ask Yonglihao Machinery for expert advice.
FAQ
Is ABS toxic?
ABS plastic is safe and non-toxic. This is one of the reasons why many experts recommend the use of this material in various applications. Exposure to this material is not a health hazard. On the other hand, some polymers are carcinogenic. When heated, they release toxic gases that have a negative impact on health. However, it is important to remember that ABS plastic is not recommended for medical implants.
Does ABS Plastic Break Easily?
One of the characteristics of ABS plastic is its ability to withstand high temperatures while being insensitive to humidity fluctuations. Molding ABS plastic at high temperatures increases its heat resistance. Molding at lower temperatures increases the strength of the plastic. For this reason, ABS polymer is an ideal material for the production of rugged, impact-resistant products.
How Do I Calculate the Cost of ABS Injection Molding?
To calculate the cost, add up the cost of all materials and tools. Then, divide the sum by the number of parts. Then, add the answer to the cost per hour. Finally, divide the answer by the manufacturing time. This will yield the cost of ABS injection molding.