CNC Machining | Introduction to the Characteristics and Applications of Plastic Materials

Plastic is a common non-metallic material with excellent insulation properties and low cost advantages. Plastics are commonly used in the manufacture of electronics, electrical appliances, and automotive parts. When selecting a plastic material, consider factors such as its physical properties, mechanical properties, temperature resistance, and processability.

We have selected and launched a variety of plastic materials suitable for CNC machining. This article will focus on the plastic materials shown above for your reference.

1. ABS (Acrylonitrile-Butadiene-Styrene)

ABS is a terpolymer of acrylonitrile, butadiene, and styrene. It is the most widely used polymer. It organically combines the properties of PS, SAN, and BS, offering excellent mechanical properties with a balanced balance of toughness, hardness, and rigidity.

Colors:
White, black, beige

Features:
ABS shares the common properties of its three components:

A makes it chemically resistant, heat-resistant, and has a certain surface hardness. It is unaffected by water, inorganic acids, and food acids and alkalis, and can be used in temperatures ranging from -50 to +70°C. It exhibits excellent impact resistance at low temperatures and good shape and dimensional stability at warm temperatures.

B imparts high elasticity and toughness. It also boasts high mechanical strength and rigidity, resists scratching, and exhibits high tensile strength, chemical resistance, and surface strength.

S imparts thermoplastic processing and molding characteristics while improving electrical properties. It is easily colorable, easy to process, and can be electroplated, possessing excellent chemical and electrical insulation properties.

Disadvantages:
It is not weather-resistant and is susceptible to weathering conditions; it has limited acid and corrosion resistance, is soluble in ketones, and softens in chlorinated hydrocarbons, fats, aromatic compounds, and aldehydes.

Applications:
Model materials, such as architectural models, action figures, food industry parts, electronic components for the imaging industry, and the refrigeration industry. In the electronics and electrical industry, ABS can be used to manufacture components such as antenna sockets, coil bobbins, terminal blocks, converters, speakers, and connectors.

2. POM (Polyoxymethylene/Polyoxymethylene)

POM is a thermoplastic engineering plastic with a high melting point and high crystallinity. It is the hardest among thermoplastics and one of the plastic materials with mechanical properties closest to metal, commonly known as polyoxymethylene.

Colors:
Black, White

Features:
Resistant to organic solvents, insoluble at room temperature, with excellent low-temperature properties. Its heat deflection temperature is similar to that of PC/PTFE nylon and higher than PVC/PS/PE. It has high compressive strength, second only to fiberglass. It offers excellent wear resistance and creep deformation resistance, high rigidity, mechanical strength, and hardness, high dimensional and shape stability, and maintains toughness even at -400°C. It also has good sliding properties, is non-absorbent, and exhibits excellent wear, chemical, and hydrolysis resistance. It is naturally inert, suitable for food contact, and has excellent machinability.

Disadvantages:
It is not acid-resistant, especially mineral acid-resistant, is not UV-resistant, is not self-extinguishing, cannot be used near fire, and is not impact-resistant.

Uses:
Suitable for manufacturing sliding parts, precision mechanical components, water-resistant parts, dimensionally stable precision parts, and a wide range of components used in mechanical equipment. Examples include bearings, gears, impellers, cams, washers, bushings, guide rails, handles, and other fixture materials. Applications extend across the automotive, electronics, medical, and food processing industries.

3. Bakelite

Bakelite, also known as bakelite or phenolic laminated paperboard, is made by hot-pressing bleached wood pulp impregnated with phenolic resin.

Colors:
Orange, Black

Features:
Excellent electrical properties at room temperature and good machinability. With a specific gravity of 1.45 and a warpage of ≤3‰, it offers excellent electrical, mechanical, and processing properties. It also possesses intermediate electrical insulation properties, is non-hygroscopic, non-conductive, and anti-static, and is wear-resistant and high-temperature resistant.

Disadvantages:
Because bakelite products require heating during molding, processing time is longer than with ordinary plastics, molds are subject to greater wear, and require higher steel quality.

Uses:
Suitable for use as insulating components in motors and electrical equipment requiring high mechanical performance, and can be used in transformer oil. It is also suitable for PCB drilling, silicone rubber molds, jigs, switchboards, electrical appliances, mechanical parts, communications equipment, and electrical insulation accessories.

Economic Benefits:
The raw material price of Bakelite is approximately 50% that of ABS. Although Bakelite requires heating during molding, processing time is longer than that of ordinary plastics, mold wear is greater, and steel requirements are higher, its competitive raw material price makes it a preferred alternative for many plastic parts.

IV. PMMA (Plexiglas/Acrylic)

PMMA (Plexiglas), also known as acrylic sheet, is an important, early-developed plastic polymer material.

Color:
Colorless and transparent

Features:
High gloss, suitable for surface polishing, with a transmittance of 92% and a refractive index of 149, comparable to the best optical glass. It is thermally stable and suitable for temperatures ranging from -40°C to 90°C. It is UV-resistant, weather-resistant, resistant to inorganic acids and alkalis, lipid hydrocarbons, and detergents, and has superior tear resistance compared to other plastics. It also has good electrical and dielectric properties and excellent mechanical strength.

Disadvantages:
It is easily damaged by stress cuts, has poor chemical and impact resistance, is brittle, and has short-term mechanical properties. Long-term use requires a tensile strength below 1500 psi to prevent brittle cracking. It has low impact resistance, and its toughness decreases with temperature. It is easily corroded by chlorinated hydrocarbons, aromatics, esters, and ketones.

Applications:
Machine covers and accessories, clock and watch dials, electric fan blades, relay covers, windshields, electrical and medical equipment, transparent models, specimens, decorative items, dentures, advertising nameplates, etc.

5. PP (Polypropylene)

PP, also known as PP, is a polymer formed by the addition polymerization of propylene. It is a white, waxy material with a transparent and lightweight appearance.

Color:
White

Features:
High stiffness, hardness, and surface strength, but average notched impact toughness. PP material can withstand tensile stress and is easily welded. Heat-resistant, operating temperature ranges from +5°C to +100°C without deformation, good chemical stability, and excellent electrical properties.

Disadvantages:
Average oxidation resistance, average wear resistance, brittleness at low temperatures, average notched impact toughness. PP material can withstand tensile stress, but cannot be welded at high frequencies. Adhesion to paint is average, and it is susceptible to weathering conditions.

Applications:
Pump and valve components, drinking water and sewage pipes, seals, spray carriers, electroplating processes, toy parts, dental catheters, etc.

FR-4 (Epoxy Sheet)

FR-4 is a flame-retardant material grade designation, meaning that the resin must be able to self-extinguish after combustion.

FR4 epoxy sheet is a high-performance, multifunctional insulation material composed of a high-temperature-resistant composite material and glass fiber.

Colors:
Green, Yellow, Black

Features:
Stable electrical insulation performance, excellent flatness, a smooth surface without pits, and standard thickness tolerances. It offers high dielectric strength, heat resistance, and moisture resistance, as well as excellent machinability and structural stability. Its most notable feature is its high flame retardancy.

Applications:
Used in products requiring high-performance electronic insulation and as insulating components in motors and electrical equipment, such as FPC reinforcement plates, PCB drilling pads, insulation plates for electrical (applied) equipment, and insulation plates for electronic switches.

VII. PA6 (Polyamide Resin/Nylon)

PA6, also known as nylon 6 or polyamide 6, is a high-performance compound. It possesses superior overall properties, including mechanical strength, toughness, mechanical shock absorption, and wear resistance, and is commonly used in the manufacture of mechanical structural components and maintainable parts.

Colors:
Black, White

Features:
Hard, low friction coefficient, wear-resistant and pressure-resistant; dimensionally stable when not absorbing water, but increases ductility and toughness after absorbing water; heat-resistant, with excellent thermal stability; high toughness, maintaining strength even below zero, with high tensile strength and elastic modulus; excellent sliding and energy-absorbing properties, and excellent chemical resistance to many oils, fats, and mineral oils; good dielectric properties, easy processing, gluing, and welding, and insulating.

Disadvantages:
Rapid water absorption; tensile strength and rigidity decrease with increasing temperature and humidity.

Applications:
Widely used in chemical machinery, gears and component blanks for corrosion-resistant equipment, wear-resistant parts, transmission components, household appliance parts, automotive parts, screw-type machinery parts, chemical machinery parts, and chemical equipment.

VIII. PC (Polycarbonate)

PC is an amorphous, odorless, non-toxic, highly transparent, five-color or slightly yellowish thermoplastic engineering material, known as transparent metal.

Color:
Colorless and transparent

Features:
High-molecular-weight, low-crystalline plastic with excellent impact resistance, toughness, creep resistance, mechanical strength, and dimensional stability over a wide temperature range. It also offers transparency and ductility, weather and high-temperature resistance, and is suitable for temperatures between -150°C and +120°C. It is flame-resistant and radiation-resistant, with excellent insulation properties. It is strong and strong, and possesses good electrical insulation.

Disadvantages:
It is sensitive to dents and prone to cracking due to stress notches. It reacts to hydrolysis and has poor chemical resistance. It scratches easily, is difficult to polish, and is not arc-resistant. It can become brittle when immersed in water for a long time, dissolve in hydrogen peroxide, and crack due to corrosion from aromatics, copper, and acids.

Applications:
It is widely used in high-tech fields such as insurance glass, slide projection equipment components, machinery and electronics, automobiles, construction, household goods, and prototype materials. It is currently used in aviation, electronics, and machinery for windshields, bulletproof glass, instrument viewing windows, terminal blocks, jigs, and models.

With the growing demand for precision engineered plastic products, the importance of reliable and experienced CNC machining services is self-evident. With over 25 years of industry experience, Huateng Metal Products (Dongguan) Co., Ltd. has become a leading provider of high-quality CNC machining services for plastic products.

At Huateng Metal Products, we understand the unique challenges and requirements of CNC machining plastic materials. Our experienced team of engineers and technicians has honed their skills over the past 25 years, mastering the processing of a wide variety of plastics and striving to deliver superior results.

One of the key advantages of our extensive experience is our ability to optimize the CNC machining process for plastic products. We have developed specialized techniques and best practices to achieve precise and consistent results, even when dealing with complex geometries and tight tolerances.

In addition, our state-of-the-art facilities are equipped with advanced CNC machining equipment, ensuring that we can efficiently and accurately meet the diverse needs of our customers. Whether it is prototyping, small batch production or large-scale manufacturing, we are capable of providing high-quality plastic parts that meet the highest industry standards.

Beyond our technical expertise, our commitment to quality and customer satisfaction sets us apart in the CNC machining industry. We work closely with our customers to understand their specific needs and provide customized solutions that meet their expectations. Our commitment to continuous improvement and innovation keeps us at the forefront of CNC machining technology, providing our customers with the most advanced and cost-effective solutions.

In summary, with over 25 years of experience in CNC machining plastic products, Huateng Metal Products (Dongguan) Co., Ltd. is a trusted partner for companies seeking reliable, high-quality plastic parts. Our expertise, combined with our unwavering commitment to excellence, makes us the preferred choice for companies looking to bring their plastic product designs to life with precision and reliability.