PC board processing cost analysis and raw material loss rate
When direct gate or edge gate is used for processing, the extrusion speed and firing rate have a lot to do with gate design. In order to prevent sun shining and wave flow marks, a slower rate of fire is applied. In addition, if the thickness of the finished product is above 5mm, in order to prevent bubbles or dents, slow injection will help. Generally speaking, the principle of the rate of fire is that the thinner is fast, and the thicker is slow. What causes the loss of plastic parts? Need to consider first. The material used for mold washing is attrition, and when the mold is changed production. If the waste caused by insufficient heat is a loss, then it is the nozzle produced in the middle.
has higher requirements for color and appearance. The mixing amount of the nozzle is smaller, and the mixing nozzle of the inner view piece is more. Generally speaking, if one ton of data is input, only 0.7-0.8 ton of products will be produced if qualified products occur. In this way, a loss rate of about 20%~30% can be defined, and the remaining nozzles need to be considered for the next batch or how to dispose of them. Quotation of plastic parts u003d weight of plastic parts * 1.03 * unit price of plastic parts + processing fee + post-processing fee (oil injection, other interest calculations are similar. Electroplating, etc.) + packaging fee + transportation fee + company management fee + profit PC type plastic even if encountered Very low moisture will also cause hydrolysis and bond breakage, decrease in molecular weight and decrease in physical strength.
The moisture content of polycarbonate should be strictly controlled below 0.02%, so before molding. In order to prevent the mechanical strength of the molded product from being reduced or the appearance of bubbles, silver streaks and other abnormal appearances. In order to prevent abnormalities caused by moisture, the polycarbonate should be dried by a hot air dryer for more than 3-5 hours before processing, and the temperature should be set to 120℃, or the moisture can be treated by a de-temperature dryer, but the dehumidified air is in the funnel. There should be a dew point of 30°C at the entrance.
Extrusion molding polycarbonate has different melt index specifications. Usually the melt index is between 5-25g/lOmin, which can be applied to extrusion molding. However, its best processing conditions are different depending on the type of extruder, the shape of the molded product, and the specifications of polycarbonate, so as to meet the needs of various extrusion molding processes. However, there are considerable differences and should be adjusted according to the actual situation. Extruder selection points. The clamping pressure is 0.47-0.78t per square centimeter or 3-5t per square inch by the projected area of u200bu200bthe waste product.
usually needs to be reduced by 10%. The general waste weight of the processing machine is about 40%-60% of the capacity of the extruder. For example, when the capacity of the machine is expressed by polystyrene. The L/D is 201** and the compression ratio should be (1.5:1-301). The stop valve at the front end of the screw should adopt a sliding ring type. 3. The length of the screw should be at least 15 diameters. The resin can flow through the gap* If the diameter is less than 3.2mm, the nozzle diameter should be 9.50mm or more. In addition, 4. The nozzle tip opening should have a diameter of 4.5mm or more.) If the waste mass is more than 5.5kg. The tip opening needs to be 0.5-10mm smaller than the gate diameter and the shorter the segment, the better, about 5mm.
PC sheets processing and molding conditions such as extruder size, screw configuration, mold and molded product design And molding cycle time. Melting temperature and mold temperature** Molding temperature setting is related to many factors. In order to gradually melt the plastic, generally speaking. Set a lower temperature in the back section/feeding zone of the material pipe, and set a higher temperature in the front section of the material pipe. However, if the screw design is improper or the L/D value is too small, the reverse temperature setting is also possible. Warm mold can provide better appearance and mold temperature. The residual stress will also be smaller, and it will be easier to fill up thinner or longer molded products. To a lower temperature can shorten the molding cycle. The rotation speed of the screw is generally recommended to be 40-70r/min, but it needs to be adjusted by the design of the machine and screw. The larger the extrusion pressure, the better, generally about 850-1400kg/cm2. The extrusion pressure is to fill the mold as quickly as possible. It can reach 2400kg/cm2lkg/cm2u003d0.098MPa, but for uniform feeding, the back pressure is generally set as low as possible. It is recommended to use 3-14kg/cm2
At the same time, as the recent research of UNQ shows, the benefits of improved productivity and firm performance can make implementing basic management practices worth it.
Hebei Unique Plastics Manufacturer Co., Ltd intends to make enough profit to generate a fair return for our investors and to finance continued growth and development in custom polycarbonate sheet.
Hebei Unique Plastics Manufacturer Co., Ltd knows how important it is to offer optional extras, such as custom polycarbonate sheetcustom plastic sheets to provide quality products for customers.