Wuhan Handern Impregnation Machine
日期：2020/9/11 8:59:29 / 阅读： / 来源：本站
Wuhan Handern Impregnation Machine
In the industrial manufacturing of plastic laminates, the paper web is saturated with the soak in a machine called a soaking machine or soaking device. It includes a paper roll unwinding device, a resin tank, a facility to remove excess resin, and a A drying chamber that evaporates most of the volatiles, a device for cooling the paper sheets, and a reel or paper cutting and stacking machine. www.handern.com Breathable membrane equipment
1. Paper ejection device
The unloading device usually includes a storage device or a mobile splicer, so that the roll change does not need to stop the paper web. New machines tend to use mobile splicers. www.handern.com Breathable membrane equipment
2. Resin tank
The specifications and structure of resin tanks or soaking pans vary greatly. A large plate with a few soaking rollers can perform multiple controls when the paper web is in contact with excess resin, thereby controlling the amount of resin absorbed. www.handern.com The air-permeable membrane equipment can generally handle even paper that is difficult to soak. On the other hand, the large amount of resin contained in the pan makes it not sensitive to temperature or resin solid content. Because the cost of resin is usually higher than that of paper, it is always desirable to minimize the amount of resin absorbed. But when using a large dish soaking, this usually causes at least a part of the dish to be bypassed. Therefore, a compromise must be found. The new machines all use medium-sized resin tanks with a relatively short soaking time. The adjustment of the soaking roller is often automatic, so as to use the inertia from the online test system to maintain a stable resin absorption.
Maynard proposed a new control system for the resin tank of the soaking machine. He suggested using a deeper slot between trees. The resin solution is added to the tank with an adjustable-speed quantitative pump. The speed of the pump is coordinated with the speed of the paper web, so that the amount of resin added to the tray is exactly the amount of paper carried away. If the paper web absorbs the required amount of resin, the liquid level in the pan will remain stable. If the paper web suction is less than the required amount, the pan liquid level will rise, increasing the contact time between the paper and the resin, thereby increasing the resin absorption the amount. If the paper web absorbs too much resin, the resin level will drop, thereby reducing the soaking time. Whether this method has been tried in a commercial immersion machine is not known. With the advancement of online testing devices with feedback control, the Maynard control system still has advantages, but the necessity is not great. www.handern.com Breathable membrane equipment
3. Removal of excess resin
There are two main methods for removing excess resin from the surface of the paper web: a doctor blade and a squeeze roller. The secondary knife can be as simple as a pair of angle irons arranged in contact with the paper web. Usually they are mounted on a common rotatable support to control the pressure of the sharp knife against the paper sheet, because the pressure of the secondary knife against the paper web determines the initial properties of removing excess resin, and the uniformity of the tension on the paper web. very sensitive. The horizontal distribution of the resin absorbed by the paper web where the stripes are mostly slack is not good.
The squeeze roll is just a pair of steel rolls. After the paper web leaves the resin tank, it passes through the nip of the roll, and the excess resin removed from the nip flows to the resin tank. Most squeeze rolls cannot exert sufficient compressive force on the paper web to remove much of the resin in the microporous structure of the paper web. In an attempt to reduce the amount of resin absorption by increasing the nip pressure, it often happens that the roller is bent to form a downward depression. www.handern.com The breathable film equipment clearly shows that the resin content in the middle part of the paper web is high, and the resin content in the two sides is low. The supplementary measure is to use a stiffer (large diameter) newspaper to break on the existing roll. More mid-to-high. Changing the paper sheet to reduce its saturation and lowering the resin absorption at the lower nip pressure may be the best solution to this problem. www.handern.com Breathable membrane equipment
In a few special cases, a completely different concept is used to control the amount of resin absorbed. This is to use a reverse wiper to apply the required amount of resin to the paper. At this time, rely on the pressure between two steel rollers. The zone adds the resin quantitatively to the top coat. The direction of rotation of the upper coating roller is opposite to the running direction of the paper sheet, which creates a wipe action to ensure 100% resin transfer. www.handern.com Breathable Film Equipment This provides a means to control the amount of resin applied without involving any paper capillary properties. However, since all resin must be applied to a certain side of the paper, its advantages are weakened. In recent years, there has been a trend to adopt thick basis weight paper so that a small amount of paper can be used to make laminates. This makes the shortcomings of single-sided coating increasingly obvious. The coating device of the coating machine is more precise and more expensive than the soaking and scraping or squeezing roller device. Putting the resin on the other side of the paper web with a second coater was considered economically infeasible.
Another report of applying resin to the paper web with a coating machine appeared in the United Kingdom during World War II. At that time, the resin was applied on the paper machine using a Massey-type in-machine coater that applied pigment coating. The dryer section of the paper machine is used to remove volatiles and cool the paper. The finished product is used as a substitute for the aluminum plate of the aircraft shell.