POM (Polyoxymethylene) rods, as a high-performance engineering plastic, offer advantages over metals in many applications due to their high wear resistance, self-lubricating properties, low coefficient of friction, lightweight nature, and resistance to chemical corrosion. Let's take a look at which scenarios were POM more outstanding.
1. Mechanical Transmission and Sliding Components
POM's wear resistance and self-lubricating properties (requiring no additional lubrication) make it outstanding in oil-free/low-oil environments, especially suitable for components with frequent relative movement:
Gears and Bearings: POM gears can replace metal gears in low-speed, medium-load applications (such as instruments and small machinery). Its low coefficient of friction (approximately 0.1-0.3, lower than steel) reduces energy loss, and its operating noise is significantly lower than that of metals.
Pulleys and Slider: In conveyor lines and automated equipment guideways, POM sliders have a wear life 2-3 times that of metals (especially in dusty or dry environments), and will not be scratched by direct metal-to-metal contact.
2. Automotive Interior and Functional Components
The automotive industry's demand for lightweight, low-noise, and maintenance-free components makes POM superior to metal in the following parts:
Seat Adjustment Mechanisms: Using POM in seat tracks and gear sets reduces weight and provides self-lubrication, reducing noise (metal requires regular grease application to prevent jamming).
Windshield Wiper Systems: Using POM in wiper motor gears and linkage joints offers superior weather resistance (-40℃~100℃) and impact resistance compared to metal, and it is less prone to rusting under prolonged sun and rain.
Door Locks and Hinges: Using POM in door lock latches and interior panel hinges prevents metal from jamming due to moisture and rust, and provides a smoother feel.
3. Electronics and Precision Equipment
POM's electrical insulation, dimensional stability (low coefficient of thermal expansion), and wear resistance make it suitable for precision applications:
Printers/Copiers: Using POM in paper feed rollers, drive gears, and toner cartridge drive components prevents paper jams caused by static electricity attracting dust from metal gears, and the gear teeth maintain their shape better over long-term operation.
4. Cameras/Optical Instruments:
POM is used in lens focusing gears and shutter components. Its low friction ensures precise focusing and prevents lens contamination from wear and tear, unlike metal.
5. Medical Equipment and Food Machinery:
Biocompatibility and chemical resistance expand the application scope of POM: Surgical instrument guides: such as sliding grooves in orthopedic traction devices and adjustment knobs in dental equipment. POM is wear-resistant and poses no risk of metal ion leaching (metals may cause allergies or tissue reactions).
Food Packaging Machinery: POM (compliant with FDA standards) is used in conveyor belt rollers and valve seals in filling machines. It is resistant to grease and detergent corrosion, preventing metal rust from contaminating food.
6. Outdoor and Corrosive Environments:
In humid, salt spray, or chemically corrosive environments, metal rust accelerates wear, while POM offers more stable overall performance: Garden Tools: POM is used in lawnmower blade guides and trimmer gears. It is resistant to acidic and alkaline components in soil (such as fertilizer residue) and does not rust over long-term use. Chemical pipeline fittings: POM (resistant to organic solvents) is used for valve gaskets and pump body bushings to prevent leakage and accelerated wear caused by metal corrosion.
While POM rods do not outperform metals in all applications (such as high-load, high-temperature environments where metals are still necessary), their comprehensive performance (wear resistance + self-lubrication + corrosion resistance + insulation) makes them a superior choice in applications requiring lightweight construction, poor lubrication, low noise/corrosion resistance, precision transmission, or outdoor/humid environments. Typical applications include mechanical transmission components, automotive parts, precision components for electronic devices, and medical/food machinery.
The production of POM Rod (Polyoxymethylene Rod) use extrusion molding as the core process, combined with raw material pretreatment, cooling and shaping, traction cutting, and heat treatment. The key is controlling temperature, pressure, and cooling rate to avoid degradation and internal defects. AHD, with its professional technology and rich experience, strictly controls production to provide the market with high-quality POM rods!
1. Raw Material Preparation and Mixing: Select POM resin (homogeneous or copolymer) as the main raw material, add color masterbatch as needed (if colored products are required), pour into a mixer and mix evenly to ensure that no impurities are mixed into the raw materials and color masterbatch.
2. Drying Treatment: POM is highly hygroscopic and needs to be dried with 80°C circulating hot air to reduce the moisture content to below 0.03% (to prevent moisture evaporation during extrusion, which can lead to porosity).
3. Extrusion Molding: The dried raw material is fed into a single-screw extruder. It is melted and plasticized by electromagnetic induction or resistance heating (the barrel has three temperature control zones: Zone 1 165-175°C, Zone 2 170-180°C, and Zone 3 170-180°C). The molten material is then extruded into a rod-shaped preform through the die (coaxial with the extruder head) under the screw's thrust.
4. Cooling and Shaping: The extruded rod needs rapid cooling to fix its shape. Key improvement: A direct-immersion cooling and shaping sleeve (combining indirect cooling and direct immersion) is used. The surface of the rod is first indirectly cooled through the cooling water chamber of the shaping die. After the surface solidifies, cooling water from the immersion cooling chamber enters the gap between the rod and the die, directly immersing the core and preventing the formation of a "white core" (micropores in the core). The cooling water temperature is controlled at room temperature or lower to ensure cooling efficiency.
5. Traction and Cutting: After cooling, the rods are traction-driven at a uniform speed (matching the extrusion speed) to maintain dimensional stability. They are then cut to the required length using a cutter and stacked on a dedicated rack.
6. Heat Treatment (Optional): To eliminate residual stress within the rods (preventing subsequent bending deformation), segmented heat treatment is required (e.g., 40°C heating → 70°C constant temperature → 100°C constant temperature → 120°C constant temperature → gradual cooling) to ensure the rods meet straightness requirements.
POM Rod also called Polyacetal Rod
Precautions:
Temperature Control: POM is a heat-sensitive plastic (easily degraded above 240°C). The extrusion temperature must be strictly limited to 170-200°C to avoid prolonged heating.
Pressure Control: Adjust the extrusion pressure using the traction machine or braking device to ensure a compact rod structure, free from delamination or air bubbles.
Cooling Rate: Direct immersion cooling requires balancing the cooling rates of the surface and core to prevent dimensional deviations or internal defects caused by uneven cooling.
The above process ensures that the POM rod has high crystallinity, high strength and dimensional stability, meeting the requirements for wear resistance, self-lubrication and other properties in industrial applications.
AHD has gone through the test of time and the market and has become a high-quality supplier. Choose AHD, Choose reliable POM rods.
