Pet Tracker Manufacturer
This plastic product of pet tracker is our representative masterpiece for DOCOMO. As usual, the whole plastic part manufacturing includes process injection molding, spray coating, surface treatment, screen printing, metal parts, screw, nut and so on. After our clients decide to start the custom parts manufacturing, we have cooperated with them to debug the many times. Of course, it includes thermoforming mold adjustment, test, and sample assembly. Our injection molding engineer provide die mold adjusting solution according to the customer’s requirements for the final performance plastics products. And we took the lead in the plastic production debugging and mass production of all the hardware of this plastic product. What’s more, there are some structure feasibility defects of customer’s parts design. After finding that, we have put forward some suggestions and improvements, which are almost adopted by the client.
1. Plastic structure
As plastic parts suppliers all know, injection molding process technician will find many problems during the commission period of consumer plastic products. And these issues need to be solved by constantly debugging and modification. Generally speaking, there are these problems we should fix.
1.1 Plastic parts shrinkage problems and solutions
1.1.1 Plastic injection molding machine
On the one hand, when the injection nozzle of injection molding machine is too large, it will cause the melt to flow back and injection molding parts will shrink. On the other hand, when the injection nozzle of small injection molding machine is too small, other problems arise. There is high resistance and no enough materials for injection molding, and molding plastic parts will also shrink. Also, it also shrinks when the mould clamping force is not enough and the flash appears. Under this circumstance, we should check if there is something wrong with the clamping system during the plastic injection molding machine process. Last but not least, when the amount of plasticization is not enough, we should choose a injection mold machine with more plasticization capacity. And we also need to check whether the screw and barrel of injection molding machines are worn.
1.1.2 Injection molds
Firstly, plastic moulded products manufacturers should make the wall thickness be uniform when it comes to the injection mold design engineering. Its aim is to ensure the consistent shrinkage.
Secondly, plastic products manufacturer need to guarantee the consistent temperature of all parts of plastic product. It’s not only for the heating system, but also during the process of custom injection molds cooling.
Thirdly, automotive plastic parts manufacturers should guarantee the runner system to be fluent, and the resistance can’t be too large. And when it comes to injection molding design, the dimension of sprue, runner, and gate should be proper. What’s more, there should be enough smooth finish, and an arc to transit in the transition zone.
Fourthly, with regard to thin injection molded parts, the injection molding operator should raise the temperature to ensure the smooth flow. Certainly, as for thick molded plastic parts, the injection molding machine operator should reduce the injection molding temperature.
Last but not least, plastic parts manufacturer should open the gate symmetrically, and try to open it in the thick wall of manufacturing plastic parts. Also, we should increase the volume of quench well.
1.1.3 Raw material for plastic injection molding
The shrinkage of crystalline thermoplastic is bigger than that of amorphous thermoplastic. During the scientific molding process, plastic components manufacturers will increase the using amount of injection molded plastic materials. Or they add an agent into injection molding plastic materials to speed up the crystallization process and decrease the shrink and deboss.
1.1.4 Plastic injection molding process
Generally speaking, the temperature of cylinder is pretty high, and its volume change is big. Especially for the front furnace, we should appropriately increase the injection molding temperature to ensure the smooth going of plastic product manufacturing process. Of course, it’s under the circumstance of using thermoforming mold material with poor fluidity.
Also, there are other two main causes of shrinkage. The first is that the density or vacuum forming materials used is not enough. And it’s because the injection pressure, speed or back pressure is too low and the time during injection mold process is short. The other is when the flashing occurs during the pressure forming process. And it’s because the injection pressure, speed or back pressure is too high or the time is too long. When the added amount of mold materials for injection molding is too much, it will consume injection pressure. On the other hand, when the added amount of injection molding material is too little, the injection mold will also shrink due to the insufficient capacity.
1.2 Sticky injection molds and solutions
There may be sticky injection mold China because of overfilled filler, too high injection pressure, too much glue, too long shot time or too high injection mold materials temperature. In these cases, China plastic products manufacturers will reduce the injection pressure, reduce the amount of injection, reduce the injection time or reduce thermoforming materials temperature. The injection molding operator can use these methods to debug the appropriate threshold.
When the thermoforming process of adding plastic injection molding materials is not uniform, it causes some areas to be too full. Under this circumstance, injection molding machine operator needs to change the size or position of the nozzle. And when the temperature of mold injection is too high or too low, the thermoforming mold could also be sticky. At this time, injection molding engineer will adjust the custom injection molds temperature and the relative temperatures on both sides.
Then when the surface of custom injection molds is not smooth enough, our injection molding machine operator will polish the mold. And if there is a vacuum forming environment because of mold releasing, it can also be sticky die mould. In this case, the thermoforming process steps of thermoforming molds opening will slow down.
Another cause is that the injection mold manufacturing cycle time is too short. Therefore, the injection molding operator need to increase the cooling time. Last but not least, when there is no enough release agent, it can also cause sticky thermoforming mould. And the solution can be slightly increasing the release agent for plastic moulding products.
1.3 The strength assurance of BOSS column
BOSS column, as an important part of strong plastic products, plastic products suppliers should guarantee its strength. And the engineer mainly achieve it by changing the plastic part design for injection molding. At the same time, it’s necessary to ensure that there is no problem on the BOSS column and its surrounding areas during the plastic part manufacturing process.
1.4 Injection molding problems of trimming
The trimming phenomenon mainly happens on the thermoforming mould parting surface, insert surface or ejection part and insert core surface. And there are main three causes of trimming during the injection molding manufacturing process. Firstly, the precision of companies manufacturing plastic products is poor. Secondly, it’s because of plastic parts deformation. Thirdly, the clamping force of plastic injection molding machine is not enough. There are many reasons in different aspects. For example, small injection molding machine problem, thermoforming mold material problem, vacuum mold problem, and thermoforming process problem.
1.5 Difference between upper plastic case and lower plastic case
The injection molding engineer should make the design of plastic parts be reasonable. Then, it can avoid the problem of shrinkage and deformation. What’s more, thermoforming plastic suppliers should have good and stable injection molding process control to guarantee the precision of advantage plastic products.
1.6 Injection molding problems of flange
Flange means that there are excess plastic injection molding materials on the injection molding parts. They usually appear on the dividing line of plastic molded parts or on a slot or hole in a die mould. There are some causes and corresponding suggestions.
1.6.1 Injection molding machine
Firstly, the pressure of plastics injection molding is too big. We can solve this problem by reducing the thermal injection molding pressure to transform the injection molding pressure into pressure protection. And plastic parts suppliers can reduce the screw forward time. Secondly, the thermoforming mold material which is injected into injection molding die is too much. Under this circumstance, plastic products suppliers will reduce the speed and capacity of injection molding. Thirdly, the temperature of injection mold plastics is too high. And manufacturers of plastic products will reduce the melt temperature, total cycle time and injection speed. Last but not least, the production of plastic runs intermittently. When the plastic production stops, the injection molding engineer should check the plastic injection molding service, especially the melt temperature.
1.6.2 Injection molding molds
Firstly, the injection molders pressure is not evenly distributed in the injection mold China. Injection molded plastic parts manufacturers should balance the injection molding die cavity layout and check whether the wall thickness of thermoforming parts is average.
Secondly, the foreign body becomes a prominent part on the joint surface. If the flange occurs on the side of painting plastic parts, injection molding engineer should check whether the compound die is balanced. And the injection molding machine operator should check the joint area of the plastic moulding products, and clean up where they need it. Finally, the injection molding operator check the balance again with blue ink.
Thirdly, there is no outfit of injection molding molds or the plastic part on the surface of custom soft plastic molds. Then manufacturers of plastic products will disassemble the mold and examine it carefully. Its aim is to obtain a balanced fill pattern by repairing and correcting the uncorrected position of injection molds.
Fourthly, the projected area is too large. The whole projected area of mold injection is too large for the mould clamping force.
At last, the improper venting make the injection molding material out of production plastic model. The solution is that injection mold manufacturers examine and clean the vent hole. What’s more, they expand the vent hole of die and mould until the mold can be filled correctly.
2. LDS treatment
The most basic function of pet tracker we have to guarantee is the antenna performance. As plastic products manufacturers all know, the height difference between LDS embossing area and PC plat area should not be too large. Otherwise, the large height difference will have a bad effect on surface treatment in the later stage. And at the same time, it will affect the touch feeling of the pet tracker. Also, uniform distribution of LDS material is also an important influencing factor. Generally speaking, the more uniform the material distribution is, the better the touch feeling will be. On the contrary, the more uneven the material distribution is, the worse the touch feeling will be.
3. Surface treatment
3.1 Adhesive dispensing
We mainly pay attention to three holes of plastic parts which need the glue in place to plug the hole completely. If the glue is not in place, there may be uneven phenomenon in the new plastic products vacancy area after the oil injection.
3.2 Base coating
We use Musashi paint which serial number is SP12-W20607 for the pet tracker. Then add hardner of 8954NZS, and add thinner of 2854, the ratio is 10:1:8~10.
This plastic production process is very crucial. Plastic parts manufacturers try to polish it a little bit deeper in the case of not leaking the substrate. And we polish 2000C small sand paper after soaking it, which make plastic products polish smoothly.
3.4 Spray coating
Supreme plastic products use Musashi paint which number is SP12-W20226. We plastic product manufacturer add the hardner of 8954NZS, and the thinner of 2854. The ratio of these three materials is 10:1:8~10. After spraying this layer, we won’t see the trace of antenna.
3.5 Polishing again
The aim of this polishing process is to see if the antenna trace can be seen after the first polishing. And custom plastic parts manufacturers need to confirm that there is no bad points from the appearance of the per tracker. If there is any badness on the surface of thermosetting plastics products, we need to polish it again. Of course, if there is no any badness after the plastic production, then there is no need to polish. In addition, this polishing process needs to be light.
3.6 Spray coating again
During this plastic formation process, we use Musashi paint which number is P79-C13-39378LE. And we add the hardner of H-300-50, add the thinner of 27993. It’s very important of this plastic parts manufacturing process since this layer is the final product color paint. Before using it, we plastic injection molding manufacturer mix evenly, and make the ratio of proportion be 4:1:2~4. With regard to best plastic products, we can’t see the trace of adhesive deposite and the antenna.
3.7 UV treatment
The serial number of Musashi paint is UV95025, and the thinner we use is P315. In this case, the using ratio of these two material is 100:60~80. Before spraying this layer, we plastic products supplier needs to confirm that the three coats of primer are dry. Because the base coat of custom plastic parts has three layers, and each layer is thick, which results that it’s difficult to be dry completely. And when these layers don’t dry completely, there will be bubbling. The injection molding technician should pay much attention on this point. In conclusion, it’s normal when the total thickness of oil painting is 110~130μ.
4. Metal parts
4.1 Screw Production Flow
Casting metal parts in the pet tracker are mainly screw and nut. Generally speaking, we make the head die mold according to customer’s screw specifications. Then we extrude the shape of the screw heads and studs through the injection molding die, and make plastic extruded products. Next, QC measures the size of the screw head and stud of the first screw based on the screw specification.
According to customer’s screw specifications, we make the thread rolling die mold. And we plastic product manufacturer rolls the grain of the stud through the thread rolling die mould. Then, QC measures the thread of the first screw according to screw specification.
The inspection standards are as follows.
Screw hardness: 400~480HV
Destructive torque: 1.4kgf.cm max.
Toughness: Screw inclination 15 degrees, no rupture.
We test the surface coating and adhesion of each batch of thermoforming material, and do 48 hours salt spray test.
4.2 Screw Heat Treatment Process
Then we plastic products supplier cleans the screws with detergent, and heats the screw to harden it.
Quenching temperature: 860 °C
Quenching time: 45~50mins
Methanol flow: 8~10ml/min
Toluene flow: 2~3ml/min
Firstly, we plastic products manufacturer uses oil to cool the screws. Secondly, the injection molding process technician uses a centrifuge to remove oil. Thirdly, they heat the screw to make it toughened, and increase the screw toughness. And the tempering temperature ranges from 410°C to 420°C. The inspection standards are as follows.
Screw hardness: 400~480HV
Destructive torque: 1.4kgf.cm max.
Toughness: Screw inclination 15 degrees, no rupture.
4.3 Screw Plating Process
At first, injection molding technician washes three processes with clean water. Then we plastic product manufacturer makes surface treatment with concentrated hydrochloric acid. The total time of this process injection molding is about 30 minutes.
After that, the injection molding process technician washes three processes with clean water again. And then, plastic products supplier uses dilute hydrochloric acid to activate. In general, the total time of this plastic formation process is 15 minutes.
Then injection molding process engineer uses pure water to clean it one time, and roll nickel on the surface of screw for 60-90 minutes. Finally, injection molding technician washes three processes with clean water and use the oven to dry for 10-20 minutes.