Box type Zirconia Sintering Furnace for Sinter Zirconia Dental Crowns

The zirconia sintering furnace is specially used for sintering zirconia ceramic materials. The design of this furnace takes into account the high-temperature stability of zirconia materials and the specific requirements of the sintering process, and can provide uniform heating and temperature control at high temperatures (usually between 1400°C and 1600°C). The zirconia sintering furnace has a wide range of applications, including in the fields of manufacturing structural ceramics, dental materials, biomedical ceramics, etc. 

Product Overview:

The zirconia sintering furnace is mainly used in dental prosthesis processing factories to complete the crystallization sintering of zirconia dental crowns. This zirconia sintering furnace uses 1800-degree pure heating rods, which will not cause secondary pollution to the dental crowns; the furnace chamber adopts four-sided heating, and the temperature field is more uniform than that of traditional muffle furnaces and crystallization furnaces, and the permeability and consistency of the sintered dental crowns are better. The intelligent temperature control can store multiple heating curves, with accurate temperature control. The lifting furnace chamber is convenient for you to load raw materials and take down finished products, and all operations can be completed on the touch screen, greatly improving your production efficiency. The technology of this box-type furnace is mature and the quality is stable. It is one of the box-type furnaces with the highest cost performance. 

Product Features:

High-temperature control: Equipped with an accurate temperature control system to ensure the temperature stability during the sintering process.
Atmosphere control: It can operate in a vacuum or a specific atmosphere (such as inert gas, oxygen, etc.) to prevent the influence of oxidation or other atmospheres on sintering.
Multi-stage heating: It has a multi-stage heating system to ensure the uniformity and controllability of the temperature gradient to achieve the best sintering effect.
Insulation performance: High-quality insulation materials are used to reduce heat loss and improve the uniformity of the temperature in the furnace.

 Purchase Information:

If you are interested in our zirconia sintering furnace, please feel free to contact us for more information and a quotation.
Contact number: +86 18516380382
Email: Jimmy@cysitech.com
Contact person: Jimmy Hao
WeChat: +86 18516380382 

Technical Parameters:

Main Components:

 Application Fields:

Structural ceramics: Such as ceramic knives, ceramic bearings and other high-strength, wear-resistant materials.
Dental materials: Used for manufacturing dental crowns and dental bridges and other high-wear-resistant and corrosion-resistant materials.
Bioceramics: Zirconia ceramics have good biocompatibility and are suitable for the biomedical field, such as joint implants 

Application Case: Using Zirconia Sintering Furnace to Sinter Zirconia Dental Crowns

1. Prepare Zirconia Green Body
Design and Forming: Design a suitable zirconia dental crown shape according to the patient's tooth model and use the CAD/CAM system for numerical control processing to prepare the zirconia green body.
Cleaning: Use an ultrasonic cleaner to clean the zirconia green body to ensure that the surface is dust-free and impurity-free. After cleaning, dry it. 

2. Pre-sintering Treatment (Optional)
Sometimes a pre-sintering step is carried out, and the green body is sintered at a low temperature for a short time in the range of 900°C to 1100°C. This can increase the hardness of the green body and make it less likely to deform and be damaged in subsequent operations.
After pre-sintering, the green body can still be subjected to some fine manual trimming. 

3. Load into the Sintering Furnace
Placement: Place the zirconia dental crown green body into the sintering tray and ensure that there is sufficient space between the green bodies to avoid mutual contact during the sintering process.
Fixing: To prevent the green body from sliding or deforming at high temperatures, use a suitable support material (such as an alumina bracket) to fix the position of the dental crown. 

4. Set Sintering Parameters
Heating Phase: According to the sintering process, gradually heat up to the target sintering temperature, usually 1450°C to 1550°C. The heating rate needs to be controlled within 5 - 10°C/min to avoid cracks in the green body due to rapid expansion.
Insulation Phase: Insulate for 1 to 2 hours at the target temperature to ensure that the zirconia is fully densified. The length of the insulation time will affect the final strength and density of the dental crown.
Cooling Phase: Slowly cool down to room temperature, and the cooling rate should be controlled within 5 - 10°C/min to avoid cracks or deformation due to uneven shrinkage of the green body due to rapid cooling. 

5. Cooling and Removal
After the sintering furnace has cooled to a safe temperature (usually below 200°C), open the furnace door and remove the sintered zirconia dental crown. Avoid taking it out directly at high temperatures to prevent damage due to thermal stress.
Carefully remove the dental crown from the tray and conduct a preliminary inspection to ensure that there are no cracks, pores, or other defects. 

6. Subsequent Processing
Polishing: Use a dedicated tool to polish the dental crown to make its surface smooth and present a luster similar to that of natural teeth.
Coloring: If necessary, glaze or color the dental crown at this stage to achieve an appearance that matches the patient's teeth.
Try-on: Send the zirconia dental crown back to the dentist for a try-on and make fine adjustments and bonding as needed. 

7. Quality Check
Check the size, shape and surface quality of the dental crown to ensure that it meets the design requirements and the patient's needs.
It is also necessary to detect the density and strength of the dental crown to ensure that it has good wear resistance and service life in the use process.
By strictly controlling the parameters and operating conditions of each step, a zirconia dental crown with uniform density, high strength and smooth surface can be obtained. 

Common Problems and Solutions When Using a Zirconia Sintering Furnace: 

Uneven Sintering:
Problem Description: After sintering, there are differences in density or hardness in different parts of the zirconia ceramic.
Possible Reasons:
The temperature distribution in the furnace is uneven.
Too many samples are loaded or arranged unreasonably, affecting the uniformity of air flow and temperature.
Solutions:
Check and correct the thermal field in the furnace to ensure that the heating elements are intact.
Try to adjust the placement of samples to ensure that there is sufficient space between samples to promote uniform heating.
Reduce the number of samples sintered at a single time to avoid overloading. 

Cracks or Deformations on the Sample Surface
Problem Description: After sintering, cracks or deformations appear on the surface of the zirconia ceramic.
Possible Reasons:
The heating or cooling rate is too fast, resulting in excessive thermal stress.
The sample is unevenly stressed in the furnace or placed unstably.
Solutions:
Adjust the heating and cooling rates and use a slow heating and cooling program, especially in the high-temperature stage.
Ensure that the sample is placed stably and try to avoid contacting the furnace wall or other samples.
If the problem persists, consider reducing the final sintering temperature or extending the insulation time to gradually optimize the sintering process. 

Impurities or Color Changes on the Surface
Problem Description: After sintering, unexpected colors or impurities appear on the surface of the zirconia.
Possible Reasons:
There are residual impurities or pollutants in the furnace.
The atmosphere control during the sintering process is improper, resulting in oxidation or other chemical reactions.
Solutions:
Regularly clean the furnace, especially after sintering different materials each time, to avoid pollutant residues.
Check the atmosphere control system to ensure the appropriate gas purity and flow rate and avoid the entry of external polluting gases into the furnace.
If it is necessary to sinter in a specific atmosphere (such as inert gas or vacuum), ensure good sealing to avoid oxygen infiltration. 

The Sintering Temperature Does Not Reach the Set Value
Problem Description: After setting a high temperature, the sintering furnace cannot reach the target temperature.
Possible Reasons:
The heating element is damaged or aged, resulting in a reduction in heating efficiency.
The power supply voltage is unstable, affecting the operation of the heating system.
Solutions:
Check and replace the damaged or aged heating element.
Ensure that the power supply voltage is stable and avoid operating the sintering furnace during periods of large power fluctuations.
Regularly maintain the equipment and check whether the electrical system has losses. 

Abnormal Temperature Control System Display
Problem Description: During the sintering process, the temperature display is unstable or abnormally fluctuates.
Possible Reasons:
The temperature sensor is faulty or calibrated inaccurately.
The control system software or hardware is faulty.
Solutions:
Check whether the temperature sensor is damaged, regularly calibrate or replace the sensor to ensure the accuracy of temperature measurement.
If the temperature control system fails frequently, contact the manufacturer's technical support for maintenance or software upgrade.

 Gas Leakage:

Problem Description: During the atmosphere sintering process, gas leakage occurs in the furnace.
Possible Reasons:
The airtightness is insufficient, the seals are aged or damaged.
The gas pipe connections are not secure and there are loose connections.
Solutions:
Regularly check the seals and pipe connections, and replace the seals or tighten the pipes if necessary.
Before each use, conduct an airtightness test to ensure that the atmosphere system works normally.

 Equipment Alarm

Problem Description: The sintering furnace triggers an alarm during operation.
Possible Reasons:
The internal temperature of the equipment is too high, the gas pressure is abnormal, etc., triggering a safety alarm.
The sensor gives a false alarm, or the alarm system is set too sensitively.
Solutions:
Stop the operation, check the alarm reason, confirm whether the conditions in the furnace meet the operation norms.
Check the sensor and alarm system settings, if false alarms are frequent, contact the manufacturer to adjust the alarm parameters or conduct system repair.

 High Power Consumption

Problem Description: The power consumption of the equipment increases significantly during operation.
Possible Reasons:
The heating element is aged, resulting in a reduction in the conversion efficiency of electrical energy.
The furnace insulation material is damaged, resulting in an increase in heat loss.
Solutions:
Check and replace the heating element and insulation material to keep the equipment in the best state.
After closing the equipment, regularly check the internal structure to ensure that the adiab0Layer is complete and reduce heat loss.

 Precautions for Using a Zirconia Sintering Furnace:

 Temperature Control

Ensure that the set temperature meets the sintering requirements of zirconia materials. Zirconia is usually sintered at a high temperature between 1400°C and 1600°C. A temperature too low will lead to incomplete sintering of the material, while a temperature too high may cause grain coarsening or material damage.
Before use, ensure that the temperature control system's sensor is accurate to avoid temperature deviation affecting the sintering effect.

 Atmosphere Control

According to the sintering requirements, adjust the atmosphere in the zirconia sintering炉内. Some sintering processes may need a specific atmosphere (such as inert gas atmosphere or vacuum) to prevent oxidation or reduce the introduction of impurities.
Ensure that the atmosphere control device works normally to avoid oxygen or other gases leaking and prevent adverse reactions during the sintering process.

 Heating and Cooling Rates

The heating and cooling rates have a large impact on the sintering effect of zirconia. Usually, slow heating and cooling rates can reduce thermal stress and help avoid cracks or warping.
Follow the sintering process requirements and try to avoid rapid heating and cooling, unless special process requirements exist, otherwise use a program-controlled step-by-step heating and cooling setting.

 Uniform Thermal Field

The uniformity of the temperature in the furnace is crucial for ensuring the consistency of the sintered product. Regularly check and correct the temperature field in the furnace to avoid differences in the sintering effect of different regions of the product due to an uneven thermal field.
Check the state of the heating element to ensure that it is intact or not aged, and replace it if necessary.

Maintenance and Cleaning
Regularly clean the inside of the sintering炉, especially the furnace chamber, to avoid the residue of zirconia powder or other impurities, which may affect the purity of the next sintering.
Regularly maintain and check the heating element, sensor, electrical connection and airtightness of components to ensure that the furnace operates in a safe and reliable state.

 Safety Operation

Wear appropriate protective equipment when operating, such as high-temperature gloves and goggles, to prevent high-temperature and possible thermal radiation damage.
The operating environment of the sintering炉 should have good ventilation conditions, especially when conducting atmosphere sintering, it is necessary to ensure that the waste gas can be discharged in a timely manner and avoid accumulation in the working area.

 Loading and Unloading

When loading and unloading materials, operate carefully to avoid direct contact with the high-temperature part. Especially when in a high-temperature state, wait until the furnace temperature drops to a safe temperature before carrying out the removal operation.
When loading, ensure that the samples are placed evenly and not overly crowded to ensure the uniform distribution of air flow and temperature in the furnace chamber.

 Power Management

Before use, ensure that the power supply and voltage are stable to avoid affecting the sintering process or damaging the equipment due to power fluctuations.
After use, cut off the power to avoid the aging of the heating element and control system due to long-term power-on.