Granite slabs, with their excellent hardness, low thermal expansion coefficient, and superior stability, play a key role in precision measurement and machining. To ensure long-term accuracy and stability, shaping treatment and subsequent maintenance are crucial. This article will explain the principles and processes of shaping treatment, as well as key points in subsequent treatment and maintenance.
1. Shaping Treatment: The Cornerstone of Long-Term Precision
The core of shaping treatment for granite slabs is to remove internal stresses and stabilize the microstructure, laying the foundation for subsequent processing and use.
Natural Aging Treatment
Granite slabs are sourced from rock formations deep underground. Complex internal stresses have accumulated over time through geological processes. Natural aging involves exposing the mined material to the elements, subjecting it to years of wind, sun, and rain. During this process, cyclical temperature fluctuations, humidity fluctuations, and wind forces gradually release internal stresses in the rock. For example, the rock expands during high summer temperatures and contracts during low winter temperatures. This repeated deformation gradually disperses and dissipates stresses. After natural aging, granite’s internal structure becomes more uniform, making it less susceptible to deformation due to stress release during subsequent machining, thus ensuring the initial accuracy of the slab.
Artificial Aging
For granite slabs requiring high precision, natural aging alone often fails to achieve the desired result. Artificial aging is therefore necessary. The slab is typically placed in a specially designed constant-temperature furnace, slowly heated to a specific temperature range, and held there for an extended period. The high temperature enhances the activity of the mineral particles within the rock, further releasing stress. Subsequently, the temperature is slowly lowered, allowing the rock structure to solidify during the cooling process and preventing new stresses from being generated by rapid cooling. Artificial aging allows for more precise control of treatment conditions, shortens the processing cycle, and further improves the stability of the slab.
Roughing and Semi-finishing
After aging, the granite slab undergoes roughing and semi-finishing. During the roughing stage, a large milling machine or grinder is used to remove excess surface area, initially bringing the slab within the specified dimensional range. During this process, the cutting volume and cutting speed must be strictly controlled to avoid redistributing stress within the slab due to excessive cutting or uneven cutting forces. Semi-finishing, based on roughing, further improves the surface flatness and dimensional accuracy of the slab. Through repeated, meticulous grinding, the slab’s surface is gradually smoothed, while further removing the micro-stresses generated during machining, preparing it for subsequent finishing.
II. Post-Processing and Maintenance: Maintaining the Slab’s Excellent Precision
Granite slabs are subject to various influences during use, including environmental factors and usage, and therefore require proper post-processing and maintenance.
Daily Cleaning and Maintenance
During daily use, granite slabs easily accumulate impurities such as dust and oil on their surfaces. Use a clean, soft cloth or feather duster to gently remove dust. Avoid using rough cloths or hard-bristled brushes, as these can scratch the surface. For stubborn stains such as oil, use a neutral detergent. Gently wipe the affected area with a soft cloth dampened with clean water. Rinse thoroughly with clean water and wipe dry with a dry cloth to prevent residual moisture and water stains. Regular cleaning maintains the surface cleanliness of the slab and prevents impurities from interfering with measurement accuracy.
Environmental Control
Granite slabs are sensitive to ambient temperature and humidity. They should be kept indoors in a stable, moderately humid environment, away from direct sunlight and high temperatures. Rapid temperature fluctuations can cause the slab to expand and contract, affecting its dimensional accuracy. Excessive humidity can cause moisture to absorb onto the surface, leading to localized swelling. Also, keep the slab away from sources of vibration and corrosive gases, as vibration can affect the stability of the slab, while corrosive gases can corrode the surface and shorten its service life.
Regular Calibration and Repair
Granite slabs may gradually lose accuracy over time. Therefore, regular calibration is necessary. Use accurate measuring instruments to check the slab’s flatness, perpendicularity, and other parameters, and make appropriate repairs based on the results. Minor wear or scratches can be repaired by hand grinding. Use a fine-grained abrasive paste and an oilstone, applying the appropriate grinding direction and pressure to gradually restore the slab’s surface accuracy. Severe wear requires reprocessing by a skilled fabricator.
Post time: Sep-09-2025