2. Recycling of water inlet

It is suggested that the addition ratio should not exceed 25%. Using too much recycled material will reduce the mechanical strength and heat resistance due to the cutting of glass fiber, and the color will also change to a certain extent.

3. Injection molding equipment

Due to the high forming temperature of th830, in order to obtain excellent products, try to choose a machine with stable mechanical performance, and the motor is the best. As with general materials, the amount of injection molding at one time should generally not exceed 75% of the injection molding capacity of the machine. The injection capacity should not be too much greater than the weight of the injected product, otherwise it will cause the molten material to stay in the tube for too long, the molecular chain will become shorter, and even cracking will occur, resulting in the reduction of mechanical properties and the production of cracking gas, causing foaming. The length diameter ratio of the screw is controlled at 20:1; The compression ratio is about 4 to 1. Since most of the fillers are glass fiber and other substances that wear the screw, the double alloy screw with good quality should be selected (replaced regularly according to the actual use situation), so as to avoid the insufficient compactness of the molten material caused by the wear of the screw, the gas cannot be discharged, and the production of biological degradation, foaming and other defects.

4. Save

Please put it on a wooden frame or board in a cool, ventilated and dry place. In the process of loading and unloading, pay attention not to damage and dirty the packaging bag. Unused raw materials should be sealed as soon as possible to prevent impurities from mixing.

5. Cleaning of material pipe

No matter what kind of plastic is used, the material pipe should be cleaned before forming. Because the plastic stays in the tube for a long time, it is easy to age, crack, and even carbonize. For th830, if the molding temperature is different from that of the previously used resin, and it is not stable within its molding temperature range, first raise the temperature to the molding temperature of the previously used resin, appropriately increase it by about 10 degrees, and then clean it with a resin (such as PP, high-density PE or PC) with the same molding temperature as the residual resin and good thermal stability (it is necessary to select the washing material according to the actual molding temperature of the residual resin). Then raise it to the forming temperature and clean it with HPPA. If only the same series of materials are switched, they can be cleaned directly. Because the forming temperature of different specifications is different, we must pay attention to their temperature range. During shutdown, if it can be predicted that the same resin will be used next time, inject the remaining material from the feed pipe and turn off the power. If not, it can be cleaned with PP or high-density PE. When the machine is shut down for a short time (generally within 30 minutes), it is not necessary to reduce the temperature, but it is also necessary to inject the remaining material from the feed pipe. It is OK to clean it properly when the machine is turned on.

6. Crushing processing

In order to better recycle, we must pay attention to the following points:

(1) The crusher should be dedicated, and should be kept away from the crusher crushing other plastics as far as possible, so as to avoid mixing materials and mixing other plastic powder, resulting in defects such as reflow soldering blistering.

(2) The crushing room should be kept clean and cleaned regularly. When the crusher is not in use, sealing measures should be taken.

(3) Try to crush it after molding to produce less powder. At the same time, ensure that the nozzle is clean. The decomposed nozzle and the injected rubber head must be separated from the normal nozzle, otherwise it will also lead to foaming and other adverse phenomena.

(4) Use the cutting method to produce less powder. The crusher should be maintained regularly and the blade should be kept sharp.

(5) Choose the crusher with the smallest blade clearance. The speed is controlled at about 300rpm. Rotating too fast is easy to produce too much powder.

(6) The nozzle should also be dried before use under the same conditions as the raw materials.

II mould design 

1. Steel: it is recommended to use SKD-11, DC53, etc

2. Runner: for materials without additives, the runner diameter should be about 3mm due to low viscosity. For reinforced materials, a large runner diameter of 5-8mm is required, and the shape is recommended to be circular.

3. Gate: the injection gate shall be as short as possible, and various forms of gates can be used. Do not use a small gate for large plastic parts. This is to avoid excessive pressure or excessive shrinkage on plastic parts. The thickness of the gate directly feeding the glue should be the same as that of the plastic part. If the submerged gate is used, the minimum diameter is recommended to be 0.7-0.8mm. The temperature of the hot runner mold needs to be controlled accurately to prevent the material from leaking or solidifying at the nozzle. The gate size should be smaller than the cold runner. Pay attention to setting the cold charging well at the end of the main runner.

4. Draft angle: at least 1/2-1 º is recommended

5. Exhaust port: the exhaust port of the mold should be designed reasonably with a depth of 0.01mm-0.03mm.