POM White or Black Plastic Sheets

3 week ago

1 0 

5 year

Product details

POM bar, or polyacetal bar, is a kind of engineering plastic bar with excellent performance. Because of its high hardness, high strength, wear resistance and good self-lubrication, it is widely used in many fields. In order to meet the different needs of use, POM rods have a variety of common processing methods.

1. Cutting Processing

Cutting is one of the most basic operations in the processing of POM rods. Common cutting methods include sawing and laser cutting.

Sawing: Sawing is a processing method that uses a saw blade to cut off a POM bar. According to the type of saw blade and power source, can be divided into manual sawing and mechanical sawing. Manual sawing is suitable for the precision requirements are not high, the number of cuts is relatively small, the operation is relatively simple, but the labour intensity is greater, and the cutting accuracy is limited. For example, in some small workshops, when a small amount of cutting POM rods, manual sawing may be used. Mechanical sawing is done with the help of professional sawing machines, such as band sawing machines and circular sawing machines. The band sawing machine cuts through a continuous rotation of the saw blade, and can cut larger diameter POM rods, with high cutting efficiency and relatively flat cuts. The saw blade of the circular sawing machine rotates at high speed, cutting speed is fast, and the precision is also higher, commonly used in mass production of POM bar cutting. However, the sawing process generates a certain amount of cutting heat, which may affect the surface quality of POM rods, so it is necessary to control the cutting speed and feed, and the appropriate use of cutting fluid for cooling.

Laser cutting: laser cutting is the use of high energy density laser beam irradiation POM bar, so that the material instantly melted or vaporised, so as to achieve the purpose of cutting. Laser cutting has the advantages of high cutting precision, narrow kerf and small heat-affected zone. It can cut a variety of complex shapes of POM rods, for some of the very high requirements for precision, complex shape parts processing, laser cutting is a good choice. For example, in the processing of electronic equipment parts, POM rods need to be cut into fine shapes, laser cutting can well meet the demand. But the laser cutting equipment cost is high, the running cost is relatively high, so in some cost-sensitive large-scale production application will be subject to certain restrictions.

2. Turning

Turning is a method of processing POM bars on a lathe, which is mainly used to change the outer diameter size of POM bars and process external threads.

Rough turning: the purpose of rough turning is to quickly remove most of the residual, so that the size of the POM bar close to the final requirements. During rough turning, a larger depth of cut and feed are usually used to improve machining efficiency. However, the large cutting force may lead to some deformation of the POM bar, so it is necessary to reasonably select the tool and cutting parameters. For example, it is necessary to choose suitable carbide tools, which have high hardness and wear resistance and can withstand large cutting forces. At the same time, according to the material and diameter size of the POM bar, the spindle speed, depth of cut and feed should be reasonably adjusted to ensure the stability of processing.

Precision turning: precision turning is based on rough turning to further improve the dimensional accuracy and surface quality of the POM bar. When fine turning, the depth of cut and feed are smaller, and the spindle speed is relatively high. By accurately controlling the movement trajectory of the tool and cutting parameters, it is possible to achieve a high level of dimensional accuracy of the POM bar, and the surface roughness can also meet the design requirements. For example, in the manufacture of precision mechanical parts, the requirements for the external dimensional accuracy of the POM bar may be within a few filaments or even less, which needs to be realised by fine turning. In the process of fine turning, the sharpening quality of the tool has a great impact on the machining quality, and it is necessary to use sharp tools and pay attention to the wear of the tool, and replace or regrind it in time.

3. Milling

Milling can be performed on POM rods for a variety of operations such as flat surface milling, grooving, gearing and so on.

Surface milling: Surface milling is the use of a milling cutter to mill the end face or cylindrical surface of a POM bar to obtain a flat surface. According to the type of milling cutter and milling method, it can be divided into circumferential milling and end milling. Circumferential milling uses the circumferential edge of the milling cutter for milling, and is suitable for milling narrow and long flat surfaces. End milling is to use the end face of the milling cutter for milling, high milling efficiency, good surface quality, commonly used in milling larger planes. In the plane milling process, we should pay attention to the speed of the milling cutter and the matching of the feed, as well as the control of the milling depth, to avoid improper milling parameters lead to the surface of the POM bar ripples or other defects.

Groove milling: groove milling is a variety of shapes of grooves on the POM bar, such as rectangular grooves, dovetail grooves, T-shaped grooves and so on. Groove milling needs to choose the appropriate milling cutter according to the shape and size of the groove, such as end milling cutter, keyway milling cutter and so on. During processing, the feed direction and depth of the milling cutter should be strictly controlled to ensure the dimensional accuracy and shape accuracy of the groove. For example, when manufacturing moulds, it is often necessary to process precise dovetail grooves on POM rods for mounting other parts, which requires precise control of the milling parameters to ensure that the angle and size of the dovetail grooves are in accordance with the design requirements.

Gear milling: Gear milling is a method of processing POM bar gears. Through a specific gear milling cutter, according to the modulus of the gear, the number of teeth and other parameters of the milling process, can produce different specifications of the gear. Gear milling on the processing of high precision requirements, the need for strict control of the milling cutter's trajectory and cutting parameters to ensure that the gear tooth precision and tooth side clearance meet the requirements

4. Drilling process

The drilling process involves drilling holes of various diameters in POM rods.

Ordinary drilling: Ordinary drilling involves drilling holes in POM rods using standard drills such as twist drills. During the drilling process, attention should be paid to the selection of the rotational speed and feed of the drill. Too high a rotational speed may cause the drill bit to overheat and wear out, or even break; too large a feed may cause the accuracy of the holes to drop, with problems such as enlarged hole diameters and unsmooth hole walls. In order to ensure the quality of drilling, it is usually necessary to use cutting fluid for cooling and lubrication to reduce the friction and heat generation between the drill bit and the POM rod. For example, in the manufacture of mechanical equipment components, often need to drill mounting holes in the POM rod, then you need to be based on the diameter and depth of the hole, a reasonable choice of drill bit and drilling parameters to ensure the accuracy and quality of the hole.

Deep hole drilling: When deeper holes need to be drilled in the POM rod, ordinary drilling methods may not be able to meet the requirements, which requires the use of deep hole drilling technology. Deep hole drilling usually uses specialised deep hole drills, such as gun drills and BTA drills. These deep hole drills have a special structure and cooling system, which can effectively discharge chips and cool the drill bit while ensuring drilling accuracy. The deep hole drilling process requires higher requirements for drill guiding and feed control, and requires the use of high-precision machining equipment and advanced control technology to ensure the straightness and hole diameter accuracy of deep holes.

5. Grinding

The grinding process is mainly used to improve the surface quality and dimensional accuracy of POM rods, especially for some occasions that require very high surface roughness and dimensional accuracy.

Cylindrical grinding: Cylindrical grinding is the use of grinding wheels to grind the cylindrical surface of POM rods, which can obtain very high dimensional accuracy and surface finish. In the grinding process, the selection of the grinding wheel is very important, according to the material of the POM bar and the processing requirements to choose the appropriate grinding wheel size, hardness and bond. At the same time, grinding parameters such as wheel speed, feed and grinding depth also need to be precisely controlled. By grinding several times and gradually reducing the grinding allowance, the cylindrical dimensional accuracy of the POM rods can be made to reach the micron level, and the surface roughness can reach the level of Ra0.1 or even lower.

Bore grinding: Bore grinding is to further grind the processed holes on the POM rods in order to improve the accuracy and surface quality of the holes. Internal hole grinding requires the use of specialised internal grinding tools, such as internal grinding wheels. Due to the limited space for internal hole grinding, it is relatively difficult to dissipate heat and chip removal during the grinding process, so it is necessary to control the grinding parameters and machining process more finely. For example, in the manufacture of high-precision bushing parts, the dimensional accuracy and surface roughness of the inner hole of POM rods are very high, and internal grinding can meet these requirements to ensure the assembly accuracy and performance of the parts.

In summary, the common processing methods of POM rods have their own characteristics, in the actual processing, according to the material of POM rods, size, machining accuracy requirements and production batch and other factors, a reasonable choice of processing methods and machining processes, in order to achieve the best processing results.