GD-10 plasma cleaning machine is with 10 L plasma chamber and 40 kHz IF power supply. The inside chamber has three trays which size is 175 x 185 cm. Three trays can achieve high efficiency treatment. At the same time , it can all-round treatment the irregular products with different size.
Secondary injection molding is a special plastic molding process, also known as beer or plastic packaging. It is similar to the two-color forming process, but there is a big difference with the two-color forming process. This is a kind of plastic raw materials in a plastic mold molding, and then take out the molding parts into the secondary molding mold again injected into the same or another plastic material molding process. Generally speaking, the first injection material is called the substrate or substrate material, and the second injection material is called the cover material.
In the whole production process, the most important thing for the second injection molding is whether the surface of the two products is firmly bonded during the second injection molding. Because the secondary injection molding is to make a color plastic part on a monochrome injection molding machine, and then manually put the product into a mold for molding, because it is difficult to place the product accurately, so the product will have surface quality problems such as edge, pull, break and so on after coming out, it is more difficult to bond closely with the product.
To enhance adhesion, the best condition is that the melting temperature of the covering material resin should be the same as that of the substrate. If the melting temperature of the covering material is too low, the substrate surface will not melt, and the bond between the two will not be strong enough. But if the melting temperature is too high, the substrate will soften and deform. In severe cases, the covering material will penetrate the substrate, resulting in component processing failure.
Therefore, the choice of matching materials to ensure good adhesion. In general, matching materials should have similar chemical properties or contain matching composite components.
But sometimes the multi-material injection molding can not achieve the base material and cover material exactly the same, to achieve the best adhesion effect we must use other technological means. This problem has been solved under the current technological development. Now, a better way to deal with the injection bonding fusion is to use plasma to treat the substrate surface, so that the secondary injection can bond firmly.
Compared with the traditional process, plasma cleaning technology has an innate advantage, that is, it can safely and effectively improve the adhesion of the material surface without damaging the basic energy of the material itself, and it can also do the whole process of pollution-free treatment. The reason why plasma can clean so efficiently is that in low-temperature plasma under non-thermodynamic equilibrium, the electrons have high energy, which can break the chemical bonds of the molecules on the surface of the material and improve the chemical reactivity of the particles (greater than that of hot plasma), while the temperature of neutral particles is close to room temperature. These advantages provide suitable conditions for surface modification of heat-sensitive polymer.
Through low temperature plasma surface treatment, a variety of physical and chemical changes occur on the surface of the material, or produce etching and rough, or form a dense cross-linking layer, or introduce polar groups containing oxygen, so that the hydrophilicity, cohesiveness, dye ability, biological compatibility and electrical properties are improved.
Plasma surface treatment equipment has two types: atmospheric plasma treatment machine and vacuum plasma cleaning machine. The plasma treatment of PC tube before the secondary injection process, because the product surface is irregular shape, we choose to use vacuum equipment for processing. The reason for choosing the vacuum type is that the advantage of the vacuum type equipment is that it can cover the plasma evenly without any difference, and it is suitable for a variety of plastic material products. It is simple to operate and can handle multiple products at one time.
After plasma processing, we used a Dyne pen for hydrophilic testing. The results show that the surface hydrophilicity of PC tube after plasma treatment can reach 60 dyne value, and the ink can be continuously discharged without shrinking. The test results show that plasma cleaning can effectively improve the surface adhesion and hydrophilicity of PC tube.
After sending the finished product to the customer, we got the customer’s feedback two days later. The customer said that the plasma-treated product had a stronger bonding effect when compared with the untreated product.
