Surface lapping machines

Types of surface lapping machines

Surface lapping machines are finishing machines for achieving a specific surface texture or roughness on materials like metals and ceramics. They are an integral part of manufacturing pipelines, valves, fittings, and other things used in the oil-and-gas, plumbing, and other industries. Companies that specialize in manufacturing these materials may want to invest in a lapping machine that fits their needs.

• An electronic lapping machine operates using electrical energy. It may be a benchtop or standalone model, and its features can vary widely, depending on the make and manufacturer. Some allow for the customization of the lapping plate speed and pressure, while others have automated control systems that monitor the entire process.
• A manual lapping machine requires the operator to take manual control of the machine and lap the workpiece. These are usually low-tech machines with few electronic components. They are significantly less expensive than their automated counterparts, but they do require a high degree of operator skill or training. Plus, they are limited in how much consistency and precision they can deliver. Some hand lapping machines have a rotating plate driven by the workpiece's weight on the plate, while others use the workpiece's hand movement to control the plate's motion.
• An automated lapping machine is more precise and consistent than manual machines. It uses a computer or some other external controls to manage the lapping speed, pressure, and duration to lap many workpieces uniformly and reliably. The automation can also monitor and adjust various parameters in real time to improve efficiency and productivity. While such a machine may be quite costly at first glance, it can provide significant long-term savings through reduced labor costs per workpiece and precise, reproducible results.
• An oscillating lapping machine takes the workpiece and subjects it to oscillations on the lapping plate. This kind of repeated motion distributes pressure evenly across the entire surface to be flat, which makes wear on the lapping plate and workpiece uniform. In this way, uneven wear, round corners, and other problems can be avoided.

Other types of lapping machines include vibration lapping machines, which use vibration to lap the surface of a workpiece; wet lapping machines, which use a wet medium to assist with the lapping process; and dry lapping machines, which use no wet medium, to name a few. Ultrasonic lapping machines use ultrasound in addition to or instead of a vibrating element.

Specification and Maintenance of Surface Lapping Machines

Specification

• Surface area: The table surface area of a lapping machine indicates the maximum size of materials to be processed. It usually measures a surface area around 18-120cm. Larger surface areas allow for handling more significant workpieces, though control and precision on the edges may be less. An adequate surface area for the job is essential for achieving high productivity and excellent surface finish quality.
• Rotation speed: The lap table's rotational laps speed is another critical machine parameter. Lapping machine speeds usually range from 40-1000 rpm. Higher speeds shorten processing time, but workpieces must be sufficiently robust. Controlled laps speed is crucial for evenly distributing the lapping liquid over the whole surface area to achieve uniform abrasion.
• Power: Lapping machines' motor power typically ranges from 0.5-2 kW. Higher motor power levels are required for quicker table lap surface rotating speeds as well as larger machine sizes. Motor power greatly influences the machine's stability, processing timeframes, and finished workpiece quality.
• Pneumatic cylinder: The clamping force on workpieces during lapping is controlled by pneumatic cylinders. Their clamping force usually ranges from 500-5000 N. Higher clamping forces enable better precision, higher productivity, and improved surface polishing quality, but workpieces may incur damage if the force is too high. Proper selection of clamping force is vital for achieving the right balance between workpiece protection and lapping effectiveness.

Maintenance tips

• Regular lubrication: Components such as ball screws and linear guides should be kept adequately lubricated according to the laps machine manufacturer's requirements to ensure smooth movement and minimize wear.
• Lubricant selection: Choose high-quality lubricants that meet product specifications to enhance machine life and performance.
• Clean the machine: Remove lapping powder debris, coolant residue, and dirt from the machine's surface and parts with proper cleaning tools and equipment for hygiene and optimal operation.
• Replace the lap disc: Examine the lap disc's wear condition regularly and clean it back to its uniformity and efficiency. Replace it immediately if it's uneven and can't be restored to its original status.
• Quality control: Maintain the machine's processing quality by repeatedly inspecting the accuracy of lapping surfaces and lapping the machine's parts.
• Training personnel: People operating lapping machines should be well trained to ensure safe, standardized operation and proper maintenance practices.

Scenarios of surface lapping machines

Lapping applies to a wide range of industries and materials. Here are some common examples of what kinds of things are lapped with lapping machines.

Optical glass surfaces such as lenses, mirrors, and prisms are lapped to achieve a high level of flatness and surface roughness essential for proper light transmission and imaging.

Centric and eccentric discs are lapping machines accessories used to enhance the quality of lapping and polishing operations. Lapping and polishing discs for the surface plate are usually made of high-quality leather, which is then cemented to a sturdy wooden base. The leathers are then sometimes used to lap and polish metallic and non-metallic items, including discs, cylinders, squares, and asymmetric forms, that need to be treated to achieve a mirror or, at the very least, a shiny finish. The process of lapping and polishing is an essential and necessary step before any object is put through the test to see how hard it is, particularly in geology. The object is usually polished to see through the translucent parts. When it comes to hardness tests for geological specimens, these may include rocks, minerals, and concrete, among others.

Powder metallurgy is an emerging industry that manufactures metal parts with high strength, excellent corrosion resistance, and stability. Parts made with powder metallurgy may include anything from 50% to 75%, depending on the chemical constitution and physical structure. Metal parts include filters, bearings, bushings, sprockets, gears, flywheels, helical gears, friction plates, and rotary brakes. Not all powder metallic parts are lapped; those that are usually include precision holes and require excellent surface finish and dimensional accuracy.

Semiconductor devices, such as silicon wafers, are lapped to achieve precise thickness control and uniformity across the wafer, ensuring consistent performance in electronic and photovoltaic applications.

Medical devices like stents, implants, and surgical instruments often undergo lapping to attain smooth edges and precise dimensions, promoting functionality and biocompatibility.

Mechanical components like valves, seals, bearings, and guideways may be lapped to enhance surface quality, reduce friction, and improve the reliability of the assemblies and parts.

How to choose surface lapping machines

The following tips will help business buyers to select the right lapping machine for their purposes:

• Workpiece materials and compatibility

  Confirm that the lapping machine can process the materials used to manufacture workpieces. Different machines work with specific materials, so choose one that matches the material used to make workpieces. For example, some lapping machines handle only metal and ceramic workpieces. It's also important to verify the machine's compatibility with workpieces in terms of size and geometric complexity.

• Surface finish requirements

  Select a lapping machine that achieves the desired surface quality. Lapping machines have various designs, operations, and abrasives. The process may not yield the same surface finish when an unsuitable machine is used for a particular workpiece material.

• Production volume and efficiency

  The type of lapping machine chosen will depend on the number of workpieces that need to be processed during routine operations. Automated lapping machines are preferred when high production volumes must be sustained, as they offer greater efficiency. Manual machines are sufficient for low-volume production with periodic processing.

• Process control and automation

  Choose a lapping machine with the required level of automation and process control features. Some machines have digital controls and automatic feeding systems for precise control. Others have manual setup with basic control features. Select the machine that provides the desired process control and automation.

• Available floor space

  Business buyers with limited floor space should consider the machine's dimensions and its space requirement. Be sure the machine will fit in the work area after leaving the required space for maintenance and operation.

• Cost and budget considerations

  Balance the factors discussed previously with the total cost of the lapping machine. It's important to consider the initial purchase price and operating costs over the machine's lifespan. This includes maintenance cost, energy consumption, and spare parts cost.

• Supplier reputation and support

  Select a machine from a surface lapping machine supplier with a good reputation in the industry. The supplier should offer good customer support, including spare parts availability and technical support. A dependable supplier makes it easy to source machine parts and receive prompt support whenever needed.

FAQ

Q1: Is lapping better than polishing?

A1: While polishing can deliver excellent flatness and the desired finish, it probably won't achieve the same degree of flatness as lapping. Moreover, lapping is more efficient than polishing when working with many pieces or large ones. This is because, in the latter situation, the cost of labor becomes prohibitive.

Q2: What are the facets of lapping machines?

A2: Lapping machines have numerous facets, such as working plates, fixed abrasive plates, and thin-film plates. The latter typically uses diamond as an abrasive, which offers the least material removal rate but the finest possible level of control and flatness. Water or oil can act as a carrier for the diamond to help control the amount of material removed.

Q3: What are the configurations of lapping machines?

A3: According to the way the workpiece and abrasive interact, lapping machines' configurations include the fixation of the workpiece, the motion of abrasive particles, and the motion of the machine itself. Different configurations lead to various types of surface lapping machines.

Q4: Can people perform lapping at home?

A4: People can do lapping at home, provided they have the proper equipment and experience. It is, however, not advisable because improper lapping can damage the surface of the workpiece. Industrial lapping machines are more effective than home-made models.