Der Unterschied zwischen Schleifen und Sandstrahlen

24. September 2024

What are grinding materials?

Definition: Grinding material is a material that changes the surface topography of the workpiece through friction, cutting, or grinding. Grinding materials can be used for surface roughness adjustment, oxide layer removal, and pre-processing for precision machining.

Function: Grinding is mainly used to pretreat workpieces to remove large pieces of dirt, scale, surface defects, and irregularities. This process is often used for surface modification, weld processing, and large-area grinding to make the material surface smoother and provide a good foundation for subsequent processing such as sandblasting and painting. Grinding can also effectively extend the service life of the workpiece and improve the finish and overall performance of the product.

Grinding history

Grinding is an ancient processing technology that has existed thousands of years ago. Its origins can be traced back to the Stone Age when humans used natural stones to grind and process rough surfaces to make tools and weapons. Over time, the grinding process evolved, and its range of applications expanded.

In ancient times, grinding mainly relied on manual techniques. Craftsmen used natural materials such as sand and gravel and rough plant fibers to polish metal and wood. The grinding process at this stage is relatively simple, mainly relies on human strength and experience, and is less efficient.

Entering the period of the Industrial Revolution, especially in the late 19th century, the rise of mechanized production led to the rapid development of grinding technology. With the popularity of steam engines and electric machines, grinding machines came into being. In particular, the invention of the “grinding wheel” marked the grinding process entering a new era. Grinding wheels are made from a variety of grinding materials, allowing for more refined and efficient grinding.

In the 20th century, with the continuous development of new materials and the continuous advancement of grinding technology, grinding technology has been widely used in many fields. Modern grinding is not limited to metals but has also expanded to the processing of a variety of materials such as ceramics, plastics, glass, etc. Any material with a certain strength and toughness, naturally produced or artificially manufactured, can be used, so even walnut shells are a good grinding medium.

In recent years, the concept of intelligent manufacturing has emerged, and grinding technology has gradually developed towards automation and digitalization. The emergence of high-precision CNC grinding machines, robots, and other equipment has unprecedentedly improved the efficiency and precision of the grinding process. At the same time, the increasing awareness of environmental protection has also promoted the green development of grinding materials and processes, promoting the sustainable development of the industry.

Techniques used in the grinding process

1. Dry grinding: No coolant is added during the grinding process, and grinding is achieved by controlling the contact time and pressure between the grinding and the workpiece. This method is suitable for materials that are not easily deformed.
2. Wet grinding: Add coolant during the grinding process to reduce the heat generated by friction and improve grinding efficiency. It is suitable for processing high-hardness materials.
3. Precision grinding: Micron-level surface finish is achieved through high-precision equipment and process parameter control. It is often used in the processing of optical components and high-precision parts.
4. Ultra-precision grinding: Combined with ultrasonic technology or laser technology to achieve nanometer-level surface precision, it is mainly used in high-tech fields such as semiconductors and optical devices.
5. CNC (computer numerical control) grinding: The computer controls the movement of the grinding machine to achieve efficient and precise processing, and can handle complex-shaped workpieces.
6. Laser grinding: The laser beam is used to heat the surface of the material and soften it to achieve the grinding effect. It is suitable for fine processing of high-hardness materials.

Classification of grinding materials

1. Plastics and Polymers

– Polymethyl methacrylate (PMMA): has good transparency and is often used in optical components.

– Polycarbonate (PC): Impact-resistant, suitable for protective gear and electronic housings.

– Nylon (PA): It has strong wear resistance and is widely used in mechanical parts.

2. Metal

– Aluminum: lightweight material widely used in the aerospace and automotive industries.

– Stainless steel: highly corrosion-resistant, suitable for medical devices and the food industry.

– Copper: has excellent electrical conductivity and is often used in electronic components.

– Titanium alloy: high strength and lightweight, widely used in aerospace.

3. Zusammengesetzte Materialien

– Carbon fiber composite materials: lightweight and high-strength, widely used in the aerospace and automotive industries.

– Fiberglass composites: corrosion-resistant, often used in construction and shipbuilding.

4. Ceramics

– Alumina ceramics: High hardness and wear resistance, often used in knives and grinding tools.

– Silicon carbide ceramics: high thermal conductivity and strength, suitable for cutting tools and refractory materials.

– Zirconia ceramics: excellent toughness and crack resistance, used in medical devices and dental materials.

5. Glass

– Ordinary glass: used for windows and containers.

– Optical glass: used in lenses and optical instruments, requiring high transparency and low impurities.

6. Wood products

– Solid wood: such as oak, and pine, suitable for furniture and decoration.

– Composite wood: such as plywood, is commonly used in construction and interior decoration.

7. Semiconductors

– Silicon wafers: used to manufacture electronic components, which require extremely high flatness and smoothness.

– Gallium arsenide: used in optoelectronic and high-frequency applications and has excellent electronic properties.

8. Eraser

– Natural rubber: has good elasticity and is used to make various seals and shock-absorbing materials.

– Synthetic rubber: wear-resistant and oil-resistant, used in tires and industrial products.

– Foam rubber: lightweight and good at soundproofing, often used in packaging and car interiors.

– Barite: used as filling material and barrier material, widely used in oil drilling.

9. Stonemasonry

– Granite: High strength and wear-resistant, often used in construction and decorative materials.

– Marble: beautiful and suitable for indoor and outdoor decoration, but soft and easy to wear.

– Ceramic tiles: hard and wear-resistant, widely used in floor and wall decoration.

10. Biomaterials

– Polylactic acid (PLA): biodegradable plastic used in medical devices and packaging materials.

– Polyhydroxyalkanoate (PHA): highly biocompatible and suitable for biomedical applications.

– Natural cellulose: used in pharmaceutical and food packaging, with good biocompatibility.

11. Mineral ores

– Quartz: High hardness, often used in glass manufacturing and electronics industries.

– Feldspar: used in the ceramic and glass industries as an important raw material.

Material characteristics and selection methods

Features

• Hardness: The hardness of different grinding materials determines their applicability. Generally, the higher the hardness, the wider the range of applicable materials.
• Wear Resistance: Premium grinding materials maintain the shape and performance of the grinding over extended periods of use.
• Particle shape: The shape and distribution of particles affect the grinding effect. Regularly shaped abrasives can improve grinding uniformity.
• Particle size: The finer the particle size, the finer the grinding effect, and is usually used for precision machining.
• Adaptability: The adaptability of different materials makes them more outstanding in specific industries, such as the application of stone and masonry materials in the construction industry.
• Environmental protection: With the focus on sustainable development, biomaterials and degradable materials are becoming popular choices for grinding.

Select method

• Selection based on processing materials: First consider the type and characteristics of the material to be processed, and select grinding materials suitable for its hardness and toughness.
• Consider processing requirements: Select the corresponding particle size and shape according to the required surface finish and precision requirements.
• Evaluate the cost: Combine the performance and cost of the material to select cost-effective grinding materials.
• Trial and feedback: Conduct a small-scale trial before formal production, and make adjustments based on actual results.
• According to industry applications: Different industries have different requirements for grinding materials. For example, the construction industry tends to use highly wear-resistant stone, while the biomedical field pays more attention to the biocompatibility of materials.
• Consider environmental impact: When selecting grinding materials, you should consider their environmental protection and recyclability, and choose environmentally friendly materials.

Type of machine used for grinding

The grinding machine is the main equipment to realize the grinding process. There are many types and are suitable for different materials and process requirements. When choosing a grinding machine, you need to decide based on your specific processing needs. Factors considered include the workpiece material, shape, dimensional requirements, and the accuracy and finish of the surface treatment. Here are some common types of grinding machines:

• Surface grinder

The surface grinder is used to process the flat surface of metal or other materials. It achieves surface grinding and smoothing through friction between the grinding disc and the workpiece. Surface grinders usually have high-precision control systems and are suitable for high-demand precision machining.

• Cylindrical grinding machine

A cylindrical grinding machine is used to process the outer and inner surfaces of cylindrical workpieces. It contacts the workpiece through the rotating grinding wheel to achieve uniform grinding of the workpiece. Cylindrical grinding machines are widely used in the processing of mechanical parts.

• Belt grinder

The belt grinder uses a continuous grinding belt as a grinding tool and is suitable for processing large areas of flat and curved surfaces. Belt grinders are easy to operate and efficient, and are often used for surface treatment of wood, plastic, and metal.

• Vertical grinder

A vertical grinder fixes the grinding in the vertical direction and grinds the workpiece by moving it. This equipment is suitable for complex-shaped workpieces and difficult-to-machine surfaces, and can effectively improve processing accuracy.

• CNC grinding machine

CNC grinding machine is a representative of modern grinding technology. It controls the grinding process through a computer program to achieve high-precision and high-efficiency processing. CNC grinding machines can handle complex workpiece shapes and are widely used in high-tech industries such as aerospace, automotive, and mold manufacturing.

• Optical grinding machine

Optical grinding machine is mainly used to manufacture optical components and lenses, which require extremely high surface finish and precision. The equipment uses special abrasives and processes to ensure the quality of optical products.

• Wet and dry grinders

According to different processing requirements, grinders are also divided into wet and dry grinders. Wet grinding machines add coolant during processing, which can effectively reduce the temperature of the grinding and workpiece and improve the processing effect. Dry grinders are usually used to process materials in dry environments.

What is sandblasting material?

Definition: Sandblasting materials refer to materials that act on the surface of the workpiece through high-speed spraying to achieve cleaning, removal of burrs, or change of surface roughness. Common sandblasting materials include glass beads, quartz sand, metal particles, etc.

Function: The sandblasting process is used to clean, deburr, roughen, or finely polish the surface of the workpiece. It can remove the oxide layer, dirt, or surface residues, and can also form a specific texture or roughness on the surface to improve the adhesion of the material. Properties, such as surface preparation before coating or plating.

Examples of sandblasting materials:

• Quarzsand: Quartz sand is one of the most commonly used materials in sandblasting. It is cheap, has uniform particles, and is suitable for surface cleaning of most metal and non-metal materials.
• Glasperlen: Glass bead blasting is usually used for fine polishing and is suitable for finishing aluminum, stainless steel, etc., making the surface of the workpiece appear smooth and matte.
• Steel shot and steel grit: Steel shot and steel grit are often used in heavy-duty sandblasting processes. They can effectively remove rust, oxide scale, or large areas of dirt, and are suitable for metal components that require high-intensity surface treatment.
• Plastik: such as plastic media, nylon sand, frozen sand, etc., which are especially good at deburring high-precision and complex-shaped parts, and are suitable for soft workpieces.

The selection of sandblasting materials is usually determined based on the material of the workpiece, the desired surface effect, and process requirements. Harder steel grit is suitable for processing hard metals, while glass beads and ceramic particles are suitable for fine processing.

Similarities and Difference

Connection: Grinding and sandblasting both use grinding materials to provide surface treatment to workpieces, so there is arguably some overlap in their uses. Both can be used for surface cleaning, polishing, and roughening. Certain grinding materials (such as aluminum oxide, and silicon carbide) can also be used as sandblasting materials, so there is overlap in material selection between the two processes. Sandblasting materials can be considered as part of grinding materials, but not all grinding materials are sandblasting materials.

Difference: The main difference is reflected in the process sequence and application scenarios. Typically, grinding is a pre-treatment step before sandblasting, especially when large areas of defects, uneven surfaces, or large amounts of dirt need to be removed. Grinding pays more attention to large-area surface modification and basic sanding while sandblasting pays more attention to the refinement of details.

• Grinding materials are generally rough and are mostly used for large-area processing in the early stage. Their function is to remove large particles of impurities, scale, oil stains, etc. It is usually a preliminary step before machining to prepare a good surface for the sandblasting or painting process.
• Sandblasting materials are more refined and are used to remove small particles of burrs, and tiny imperfections, and give the surface the desired texture or roughness. Sandblasting can handle surface adjustments down to the micron level and is particularly suitable for use in the final surface treatment stage.

For example, in the automobile manufacturing process, after welding or mold manufacturing is completed, the body may need to be initially cleaned with coarser grinding materials and then sandblasted to achieve finer surface treatment requirements, such as polishing or subsequent preparation.

Grinding and sandblasting each have their unique roles and functions, but the two are often complementary in surface treatment processes. By rationally selecting and combining these two processes, the surface quality and performance of the product can be greatly improved.

Grinding and blasting materials play a vital role in modern manufacturing and surface treatment processes. Grinding materials are used to roughen and prepare the surface, providing a good foundation, while sandblasting materials further enhance the detail and quality of the surface. By understanding the material properties, application scenarios and process characteristics of the two, customers can better choose a treatment solution that suits their needs and ensure that the final quality of the product meets expectations.