During the processing of ordinary glass in a tempering furnace, numerous parameters are involved. These parameters, if not carefully controlled, can affect the quality of the tempered glass. Today, we'll simplify the application of various parameters in a tempering furnace for a better understanding.

　　Small bending sections use a counter-pressure molding method to meet production needs. Its advantages include a wide range of applications and the ability to produce glass with R450 and various curvatures. However, some units are not yet proficient in adjusting the upper pressure roller and applying various parameters. The adjustment method of the upper pressure roller in the small bending section and the application of related parameters are listed below for user reference:

　　1. Adjustment method of the upper pressure roller: Use two long strips of glass with the same thickness as the required production glass. Place them at both ends of the small bending section. Lower the superior grid to flatten it. Check the air pressure of the upper pressure roller and adjust it to 0.5 kg of pressure. Then, adjust each pressure roller's conical wheel one by one until the pressure roller can be rotated by hand but feels relatively heavy. Each roller should have this feel. Do not adjust only one roller and then measure the length of the threaded rod outside the conical wheel and uniformly adjust the length of the threaded rod. This is a misconception because the threaded rod is not a reference point. Adjusting the pressure roller is a meticulous task that requires careful attention.

　　2. Application of upper pressure roller pressure: If the glass curvature R is below 1000 or the glass is relatively thick, pressure can be applied, generally around 2 kg. Excessive pressure is unnecessary and can affect the optical properties of the tempered glass surface. The key to eliminating straight edges does not solely depend on the pressure size. If the R is above 1000 mm, pressure is unnecessary; the weight of the pressure roller is sufficient.

　　3. Selection of locators: The role of the locator is to prevent long and narrow glass from deviating and forming warped corners during long-term operation. If the arc length of the glass is less than 600 mm, the 3rd one can be used. If the arc length of the glass is more than 600 mm, it is better to use the 1st air knife as a locator, so that the glass has sufficient reciprocating intervals in the air grid. If the gap of the upper pressure roller is adjusted well, the longer the reciprocating interval, the better the curvature of the glass, and the straight edges will be correspondingly reduced or eliminated. The operating time of the locator can be set. The principle is that when the glass leaves the furnace and reaches the locator and moves in the opposite direction, it can fall to correct the glass.

　　4. Confirmation of the entry quench distance: After using the locator, the entry quench distance is a crucial parameter and needs to be adjusted so that the glass moves in the opposite direction immediately after reaching the locator. Do not allow the glass to move forward after contacting the locator; this will not only bend the locator but also cause the straight edge of the glass to protrude forward, which can reach 4-5 mm in severe cases. The gap of the pressure roller above the locator should be adjusted accordingly to prevent it from bending the locator forward during rotation. A parameter closely related to the entry quench distance is the effective quench length, which determines the reciprocating interval of the glass in the air grid. The length of the air grid should be fully utilized, but if the quenching reciprocating speed is too fast, the glass may swing out of the air grid, requiring adjustment of the effective quench length to control the reciprocating position of the glass.

　　5. Setting of the blow postpone time: This is a crucial parameter for producing bent glass. It is closely related to the grain size of the glass because the glass is not blown immediately after leaving the furnace; it needs to be blown after the glass is formed. However, the temperature of the glass will drop rapidly at a rate of about 20-30 degrees per second. If the blow postpone time is too long, the glass will break during blowing, especially 3.2, 3.5, and 4 mm glass. To achieve good curvature requirements without affecting the grain size requirements, the blow postpone time should be set so that when the glass reaches the locator and moves backward, it is blown when it moves forward again.

　　To meet the grain size requirements, the quench oscillating speed can be increased. If R is small, the ARC-forming speed should also be increased. We should understand that when the glass is in a soft state, the longer it reciprocates in the air grid, the better the curvature. The shape of the glass cannot be changed after blowing (if the quench reciprocating speed is increased, the glass may swing out of the air grid with the same effective quench length, requiring appropriate adjustment). Of course, if the glass thickness is more than 6 mm, the blow postpone time can be appropriately extended. Since the thickness, shape, size, and other parameters used by different units vary, we cannot confirm the specific time in seconds here. Each unit needs to explore and establish process parameters.

　　6. Setting of the quench upper roller ACT time: This is a parameter that needs to be set after the pressure roller applies pressure. If your product can only produce one piece per furnace, the principle is that the pressure roller can be released a few seconds after the quenching wind blows. If the product is a row that can hold multiple pieces, the down-pressure time should be set longer to prevent the glass from colliding with each other due to high wind pressure.

　　7. Setting of the ARC-forming speed: This parameter needs to be set before adjusting the arc. The principle is that the smaller the R, the faster the speed, but generally not exceeding 400; the larger the R, the slower the speed. If the arc forming speed is set after adjusting the arc, the curvature of the glass may not be consistent with the curvature of the air grid.

　　8. Relationship between temperature and curvature: Some units have reported that the curvature and straight edges of the glass are good when the arc is initially adjusted, but the curvature becomes shallower and straight edges appear after a period of time. In fact, the temperature in the furnace is higher at the beginning, and the glass is softer. After a period of time, the temperature in the furnace is relatively lower, and the glass changes. If higher requirements are placed on the curvature and straight edges, the heating time can be appropriately increased, or the curvature can be adjusted slightly smaller.

　　9. Enter Interval (F) is a parameter that needs to be set when multiple workstations are used. Its calculation method is: quenching time multiplied by n, the heating time minus their sum, minus the reversal time of two ceramic rollers (about 20 seconds), divided by n is the entry interval time (for example: the heating time for 4 mm glass is 220 seconds, the quenching time is 30 seconds, multiplied by 3 (workstations) equals 90 seconds, 220-90 equals 110, minus 20 seconds equals 90, divided by 3 equals 30 seconds, so it can be set to 25 seconds. It should be understood that the more uniform the output time of each furnace of glass, the better the consistency.

　　10. Several points to note about the requirements: If the curvature of the glass is found to be irregular, it should be noted whether the gap of the pressing roller is too small or the pressure is too high; if the front end (the end that exits the furnace first) of the tempered glass in the tempering furnace has good curvature, but the rear end has a straight edge and is relatively long, it should be noted whether the reciprocating interval is too short, the delay time is too short, or the gap of the pressing roller is too large; if the front end (straight edge) of the glass protrudes forward, it should be noted whether the exit interval is too long or the positioning device acts for too long (often a few more millimeters will cause the straight edge to protrude forward, especially for narrow and long glass of shower rooms). If the straight edge is too long and needs to be adjusted, it should be understood which two pressing rollers need to be adjusted. Some units only adjust the pressing rollers near the positioning device, but the effect is not obvious. You should pay attention to the position of the glass when it is reciprocating and blowing in the wind baffle. This is the pressing roller that needs to be adjusted. If a positioning device is used and the glass still has a warped corner, pay attention to whether the in-gate interval is too short and the positioning device is not working. In addition, if the upper pressing roller does not apply pressure, when the wind baffle is opened, the position of the glass should be in the center of the wind baffle to avoid slight scratches on the two straight edges of the glass. If it is not in the center, the rapid cooling time can be shortened or lengthened by 1-2 seconds.

　　11. If it is troublesome to readjust the gap of the pressing roller when the thickness of the tempered glass in the tempering furnace changes, it is recommended that you make some special shims with a diameter of 30 mm, an inner hole of 12 mm, and a slot with the same width as the inner hole, and a thickness of 2 mm; when you want to change from 4 mm to 5 mm, you can push the conical wheel inward and insert the shim into the screw rod. One 2 mm shim can raise the pressing roller by about 1 mm. To make a 6 mm one, just insert another one. This method can greatly improve efficiency.

　　The above is a detailed introduction to the various parameters of the tempering furnace compiled by the editor. If you want to learn more about the operation of the tempering furnace, please continue to follow us.