EPC is divided into white area, yellow area and black area, and each part is closely linked and highly related. No problem is allowed in each part, otherwise qualified products cannot be cast.
The white area is part of the foam model. Only qualified models can be produced without defects. There are two ways to make white mold, i.e. manual cutting mold and forming machine mold.
The first step to make the white mold is to determine the amount of shrinkage. It is found that the non shrinkage of the anode steel claw is 0.02.
Manual cutting die needs to be equipped with cutting platform, voltage regulator, resistance wire, PS board, wallpaper knife, sandpaper, nails, paper tape and other items.
The first point of the manual cutting die is to make the template, which is engraved according to the size of the part plus the reduction. The anode steel claw is divided into various parts and the template is made respectively. It can be divided into four parts: shoulder, riser, claw, welding guide rod platform. Then according to the size of each part of the blanking, fixed template production white mold.
It should be noted that the size of the manual cutting die must be correct, the surface must be smooth and clean, no grooves are allowed, and the amount of glue used at the bonding part is less, otherwise, the air volume will be large, and it is easy to reverse spray when casting, so as to ensure that the four claws are in the same straight line.
The forming mechanism die is divided into two parts: pre forming and forming.
The electric pre engine is used in the pre engine process. Compared with the steam pre engine, the water content of the pre engine beads is low and the pre engine beads are full.
The pre density is set as 23g / L, which is easy to form when the pre density is large, but it is difficult to form when the pre density is small due to the large gas volume and carbon increase during casting. The more important parameters in the pre delivery process are pre delivery temperature and pre delivery time. If the pre delivery temperature is too high, it will cause bead agglomeration, and if the time is too long, it will also cause agglomeration. Adjust the time appropriately according to the temperature. Before the pre delivery, preheat the pre delivery machine first, and then start feeding the pre delivery after reaching the pre delivery temperature.
At the site of hollingoler, the pre delivery temperature is set at 111-112 degrees, and the pre delivery time is about 320s, which is adjusted appropriately according to the situation. For the first three times of pre delivery, the beads after pre delivery shall be weighed to check whether they meet the density requirements, and then the parameters shall be adjusted appropriately according to the results. When the pre delivery density meets the requirements and is stable, the continuous automatic pre delivery can be carried out. After the pre delivery is completed, the discharging time should be adjusted appropriately. If the discharging is not complete, the remaining materials will be caked. Therefore, after discharging, check whether there is no remaining material in the barrel through the observation window.
After the pre release, the beads arrive at the ripening bin, and the beads can be used only after two hours of ripening. The bead should not be placed for more than 48 hours, otherwise the pentane gas in the bead will be emitted, which will cause certain difficulties in the molding process.
It is emphasized here that the seriousness of bead caking. If the caking is serious, it is necessary to dismantle the side plate of the pre hair machine to clean the pre hair machine, which is time-consuming and labor-consuming and delays production. If several beads are caked into one small piece, it will cause the tedious feeding of the late molding machine, because the small bead caking will block the muzzle of the material gun.
After the completion of the ripening, the ripened beads shall pass through the automatic feeding system to the bin of the molding machine. The automatic feeding system consists of feeding fan, feeding pipe and ball valve. In the process of automatic feeding, it should be noted that the first step is to turn on the fan first, and then slowly open the ball valve at the lower part of the curing bin. If the feed is too much, the fan will be blocked, resulting in motor overload, resulting in motor burnout. There are three molding machines on site, and the ball valve after each molding machine is used to supplement materials for each molding machine reasonably.
There is a vent valve on the feeding pipe. When feeding, add air to relieve the pressure of the fan and avoid blocking.
After the matured beads arrive at the bin of the molding machine, they enter the mold through the feeding pipe. Compared with manual cutting, the white mold is easy to form, easy to operate, efficient and clean in the factory.
The process of forming mechanism die mainly lies in the grasp of parameters. There are three main parameters: pressure, heating and cooling.
In general, the minimum pressure of secondary ripening is set at 0.6 to 0.7, and the upper limit is about 1.2. Otherwise, the bead will not expand and ripen. In addition, the general pressure during the commissioning of the molding machine is a fixed value, which can not be adjusted at will. If there is a problem in the white mold forming process, the heating and cooling parameters can be adjusted.
In the molding process, the heating mode can be divided into two ways: time control and pressure control. The pressure penetration mode is not intuitive, so the pressure control mode is adopted in hollingerler’s field to heat the molding. The heating mode here is that when the solid mold and the moving mold are heated respectively, the main heating control mode is the time control set by the program. After the heating mode is determined, the control amount of pressure heating can be set, i.e. the number of steam penetration. Here, the number of penetration, i.e. the number of times that the pressure passes through the lower limit of the electric contact pressure gauge. The number of penetration is adjusted according to the model of the forming mechanism. If the white mold is not ripe (unfamiliar, that is, foam beads are not bonded together, the beads touch automatically), the surface of the mold is not ripe or the mold surface is not familiar when checking, and then the main heating time or pressure penetration times are adjusted according to the situation. If overburning occurs (i.e. wrinkles or crusts appear on the surface of the white mold), the main heating time can be shortened or the penetration times can be reduced.
Water cooling is required after the white mold is matured. Because the white mold after forming has not been fixed, the whole is softened. If the water cooling time is not enough, the most serious will cause the bending deformation of the white mold, and the lighter surface will have small bumps like goosebumps, resulting in poor surface quality. Water cooling has a great influence on mold lifting. If the water cooling time is not enough, the white mold will stick on the mold surface and it is not easy to lift the mold. The time setting of water cooling should be adjusted by the mold temperature and water temperature after mold lifting. Water and mold are hot but also cold, the most suitable mold.
The forming mechanism makes half of the anode steel claw, and the coating can only be brushed after two butt joints are bonded. During the bonding process, it should be noted that the two white molds should be perfectly aligned, and the butt joint should be sealed with paper tape, otherwise, paint will leak into the white mold.