How to ensure the thickness uniformity and surface smoothness of Clear Acrylic Sheet during the production process?

Update:10-03-2025

In the process of producing clear acrylic sheets, ensuring thickness uniformity and surface smoothness are key quality control goals. These two characteristics directly affect the optical properties, mechanical properties and final application effects of acrylic sheets. The following are specific production technologies and quality control measures:

Control of thickness uniformity
Selection and proportion of raw materials
Use high-quality methyl methacrylate (MMA) monomer as raw material to ensure the consistency and stability of the polymerization reaction.
Add appropriate amounts of cross-linking agents, initiators and other additives to optimize the fluidity and curing properties of the material.
Choice of production process
Casting method
Casting method can better control thickness uniformity by injecting liquid monomer into the mold for polymerization.
The design and manufacturing accuracy of the mold are crucial, and the mold gap needs to be strictly controlled to ensure consistent sheet thickness.
During the polymerization process, a constant temperature heating system (such as a water bath or hot air circulation) is used to ensure uniform temperature distribution to avoid thickness deviation caused by local overheating or uneven cooling.
Extrusion method
Extrusion method is suitable for large-scale production by extruding molten acrylic material through a screw.
Use high-precision die head design and control system to ensure stable flow rate and pressure of molten material.
Install online thickness detection equipment (such as laser thickness gauge) to monitor the sheet thickness in real time and make automatic adjustments.
Cooling and solidification process
Cooling rate has an important influence on thickness uniformity. Uneven cooling may lead to uneven distribution of internal stress, which may cause thickness variation.
In the casting method, a slow and uniform cooling process (such as segmented cooling) can reduce internal stress.
In the extrusion method, use cooling rollers or cooling water tanks and ensure that the temperature and flow rate of the cooling medium are consistent.
Online monitoring and feedback control
Install high-precision thickness measuring instruments (such as ultrasonic thickness gauges or infrared thickness gauges) to monitor the sheet thickness in real time during the production process.

Various Sizes Of Acrylic Sheets
Feedback the measurement data to the control system to automatically adjust the die gap or extrusion parameters to ensure that the thickness deviation is within the allowable range (usually ±0.1mm or less).
Surface smoothness control
Precision of molds and equipment
Casting method
The mold surface must be polished with high precision to achieve a mirror effect (Ra value is usually less than 0.05μm). Use high-quality mold materials (such as stainless steel or chrome-plated molds) to prevent surface wear or corrosion.
Extrusion method
The outlet surface of the extrusion die head needs to be highly polished to ensure that the molten material flows out without scratches or textures.
The surface of the cooling roller also needs to be precisely polished and cleaned regularly to prevent impurities from adhering.
Fluidity of molten material
Ensure that the molten acrylic material has good fluidity to avoid surface roughness due to excessive viscosity.
In the extrusion method, optimize the screw design and heating temperature to fully plasticize and evenly distribute the material.
Cooling and molding process
The cooling process is critical to surface smoothness. If the cooling speed is too fast, it may cause ripples or stress marks on the surface.
In the extrusion method, use a multi-stage cooling system (such as air cooling + water cooling) to gradually reduce the temperature to avoid surface defects caused by rapid cooling.
In the casting method, ensure the uniformity of the mold surface in contact with the material to avoid bubbles or impurities affecting the surface quality.
Post-processing process
Polish the finished acrylic sheet (such as flame polishing or mechanical polishing) to further improve the surface smoothness.
Use antistatic coating or anti-scratch coating to reduce surface damage during transportation and use.
Quality control measures
Raw material testing
Conduct comprehensive testing of raw materials before production, including purity, viscosity and molecular weight distribution, to ensure stable material performance.
Process parameter optimization
Develop a detailed process parameter table, including temperature, pressure, cooling rate, etc., and strictly implement it.
Regularly calibrate production equipment (such as molds, extruders, cooling systems) to ensure their operating accuracy.
Finished product testing
Use high-precision measuring equipment (such as three-coordinate measuring machines, surface roughness meters) to sample and test finished products.
Check whether optical properties (such as transmittance and haze) meet the standards and ensure that the surface smoothness meets the requirements.
By adopting advanced production technologies (such as casting or extrusion), high-precision molds and equipment, and strict online monitoring and post-processing processes, the quality and consistency of products can be effectively improved. These measures can not only meet the needs of high-end application scenarios, but also improve production efficiency and customer satisfaction.