As we all know, film coating technology has been widely used in confectionery in recent years. Through film coating, it can avoid light, moisture, and air isolation to increase the products' stability and make them look more bright and more beautiful.
The quality of film coating mainly depends on the composition and quality of the gum, the coating solution's prescription, the coating's operating conditions, packaging and storage conditions, etc. The composition and quality of the gum are mainly reflected in the active components, appearance, hardness, fragility, chip type, and so on. The prescription of coating solution usually contains polymer, elasticized, dye, solvent, etc. And the operating conditions of coating are the dynamic balance of spray and drying and coating equipment.
Here share some common problems and solutions in the film coating process with you briefly based on our more than 15 years of experience.
First: wearing, cracking, and peeling on the surface
There are three main reasons, first is the chewing gum itself; second is because fast drying speed leads to slow film formation; third is due to the low viscosity of the coating solution. To solve these issues, we need to reduce the coating pan speed and increase the flow of the coating solution. On the other hand, we need to adjust the formula of the coating solution. Anyway, adjusting the chewing gum recipe and manufacturing technique is also important.
Second: adhesion and blistering
It is because of the dry speed and spray speed. The other reason is the large viscosity of the coating solution. To solve this issue, adjusting the formula of the coating solution is also a good idea. Besides, increase the volume and temperature in the air inlet, increase the speed of the coating pan and control the humidity in the workshop.
Thirdly: rough and wrinkled on the surface
Sometimes, it is because of the gum itself; the other is caused by rapid evaporation and coating process. It makes the coating paste spread badly. According to this issue, first should improve the quality of gums. In the premise of good gums, they should increase the coating pan's speed and reduce the air inlet's temperature and volume. Also, adjusting the distance between the spray and gum or selecting a suitable spray and nozzle can also solve this issue.
Fourth: marks on the surface
This situation always occurs on the surface of pieces, mainly for tablets, as the film's mechanical parameters are not so reasonable, such as a high elastic coefficient, poor membrane strength, and bad adhesion. Sometimes during the drying process of the film, there will be some high back tension which will pull the film surface from the marks. Thus, the film shrinks, and the marks disappear or become unclear. First, adjust the coating solution formula to solve this issue, which can also decrease the mist spray speed and increase the inlet air temperature. On the other hand, when designing of marked mold, pay attention to the width of the cutting angle and other subtle points to prevent the occurrence of this situation as far as possible.
Finally: color difference for film coating
There are four reasons: 1, the speed of the coating pan is too slow or mixing efficiency is too poor; 2, the gum is irregular, such as rectangular or capsule, which cannot roll in a circle; 3, excessive coloring matter concentration or solid content in coating solution; 4, excessively high temperature leads to poor coating spread and adhesion. To solve this issue, we can increase the rotation speed of the coating pan. Then adjust the baffle so that the gum can roll evenly in the coating pan. Besides, adjusting the coating solution formula and decreasing the air inlet's temperature and volume is also helpful.
In the process of film coating, there are often various problems, but no matter what kind of problems, there are so many factors. They can all be solved by improving the quality of the chewing gum and adjusting the coating formula and operation process. We can achieve flexible applications by dialectical operation. With the mastery of coating technology, the development and application of new coating machinery, and film coating materials, coating technology will be greatly improved; film coating will also produce solid preparations for rapid development.
If you have concluded other problems and solutions, welcome to leave messages to us. We will replenish it later accordingly. If you have other doubts about chewing gum, bubble gum, or gum base, you are also welcome to call or email us. We are professional in the gum base, and chewing gum and all colleagues at Wuxi Gum Base will try our best to answer your questions and solve your worries.
Author: Wuxi Gum Base
Publication Date: 10/13/2022
