Whether in China or in foreign countries, the binder formulas of different carton factories are different, and the formulations are usually adjusted according to the specific requirements of the equipment and the principles of starch adhesives. Therefore, in some low-tech factories, special training must be given to the rubberizing operators so that they can understand the principles of starch adhesives.
The glue maker can dilute or thicken the adhesive's viscosity according to the needs of the production; the gel point can also be adjusted according to whether the degree of gelation is too high or not, and the solid content, etc. This kind of training is very important for the production of corrugated boxes. It can enable operators to deal with some issues that may arise in production in a timely manner.
The technicians in the factory must check the standard device of the mixing cylinder. The measurement rods of many manufacturers are incorrect. Technical management personnel must adjust the volume measuring rod to the top of the barrel to the liquid level, so that it is not necessary to measure the measuring rod in the barrel each time, and then scrub the measuring rod. In these areas, the glue maker must pay attention.
Also, don't rely solely on water meters to measure volume, because it will sooner or later exceed the standard range. If you use an automated device to measure water and slurry, ensure that the probe and screw valve are clean to prevent the foam on the liquid surface from introducing errors into the measurement.
When you start mixing, the chemicals used to weigh and measure all are on hand, which reduces operational errors. When taking the material, separate the hopper for each chemical. Weighing means that for all solid chemicals, the measurement refers only to the liquid.
Keep the viscosity cup clean, preferably in a bucket filled with water. Dry starches or damage to the lower lip of the cup will affect the accuracy of the measurement. Before starting a batch, the stopwatch should be proofread.
Beware of the use of steam. Be quick when you start blowing. As soon as signs of viscosity increase appear, the amount of air blowing is immediately reduced. If the heat is too high, the viscosity increases too quickly during preparation and it is difficult to control, resulting in excessive viscosity and waste. If you do not add boric acid due to loss of viscosity control during careless heating, add some alum, resorcinol, tannin, or acidic chemicals as quickly as possible. Then open the water valve and pour enough water into the bucket to keep the stirrer turning. If the viscosity is slightly higher than you require, you can add the same ratio of starch and water, about a bag of starch and 15-20 gallons of water. Finally, the technical indicators of the rubber were measured.
All adhesive storage buckets should be equipped with agitators. The low-power stirrer can run continuously at low speed, while the high-power stirrer is used for intermittent operation. Intermittent stirrer timing controllers are inexpensive and suitable for any corrugating mill. The starch in the storage tank is suitable for storage at a controlled temperature or at least temperature conditions.
The starch binders all show a decrease in temperature and become sticky and increase in temperature and thinning. The adhesive should be continuously stirred during night or weekend shutdowns. If the starch stops stirring or there is no insulation, the glue becomes sticky and cannot flow in the pipe. Single-sided machines and double-sided machines should use storage barrels and circulation systems, respectively.
The circulatory system has three basic forms.
First, the gravity feed pump returns to the system. In the past, this system had the most problems. The bucket must be placed in a high place above the machine. The system is very sensitive to changes in starch viscosity. This problem often arises. After parking on the weekend, it is difficult to make the adhesive flow through the gravity feed system on Mondays. Due to the high position of the barrels, it is also a common problem that it is difficult to keep them because the barrel must be climbed to a very high position.
Second, pumped feed. The tank is below the horizontal plane of the corrugator machine base, and it flows into the tank by its own gravity. This system has many advantages, but the structure of the plant should be suitable for the installation of the equipment. If the bucket is semi-underground, the adhesive can be held at a stable temperature without the use of a tank level controller and a return pump. The precondition for this kind of low-level liquid storage tank is that the discharge pump is installed at the same level of the liquid level or lower than the bottom of the storage tank, and the bottom of the storage tank is discharged when cleaning.
Third, the most commonly used storage and recycling systems for modern corrugating machines are pump-in feed/feedback systems. Through an annular tube, the excess returns to the drum. The single-sided machine is best not to use a line that feeds the pressure pump, because it will cause pressure fluctuations in the pipe, resulting in a phenomenon that the single-sided bonding and feeding are unstable. The single-sided bonding back to the feed separately eliminates fluctuations. High-power PVC pipes are used for starch, easy to install, pressure fluctuations can be minimized and easy to clean, but need to be fixed bracket, away from heat, such as steam.
(to be continued)