Requirements of the hottest glass fiber plastic ma

2022-10-01
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Requirements of glass fiber plastic materials for molds and injection molding equipment

Molds - in order to ensure a good appearance, there must be a mold temperature machine (the mold surface temperature must reach above ℃); In order to reduce the stress of the gate, choose the type of gate (generally speaking, compared with the point gate, the side gate or tunnel gate will be better); In addition, because the fluidity of pc/gf is relatively poor, the number of gates also hopes to increase accordingly

injection molding method - screw retention time and minimize screw residue (cushion) (to prevent material decomposition and poor appearance caused by gas); In addition, when passing through the gate, the injection speed is minimized (in order to reduce the stress phenomenon of the gate)

injection molding machine - it is hoped to use a high-speed injection molding machine

the mold temperature of glass fiber plastic material is on the high side, reaching 110 ℃ or higher. The mold temperature of general pc+abs is 90 ℃. Is there any impact on mass production and special requirements for the machine

answer: temperature - we know that the fluidity of glass fiber material is worse than that of ordinary materials, so it is easy to produce surface floating fiber and other phenomena. Increasing the mold temperature is one of the ways to improve these problems. However, high temperature does make the processing cycle longer, so when raising the temperature, appropriate adjustments should be made within the acceptable range of surface floating fibers according to the characteristics of the material

injection molding machine - the processing temperature is higher than pc/abs (290c-320c); In addition, if glass fiber materials are used for a long time, the wear of barrel and screw of the injection molding machine will be greater than that of non glass fiber materials

how about the service life of the mold

answer: when using glass fiber materials, the service life of the mold will vary according to the different types and contents of glass fiber and the structure of the mold; The average is between 200000 and 300000

when using PC pendulum to quickly fall back and pc/abs to process the shell, gradually restrict and stop the use of this kind of flame retardant. Normal materials have good toughness, but also 4. What factors are mainly related to the embrittlement of electrical installation

answer: normal pc/abs has good toughness, and PC toughness is excellent, but embrittlement can also occur, which is mainly related to the following factors: (1) unreasonable structure, such as too thin wall thickness, too sharp corner, too small sprue, etc; (2) Unreasonable processing conditions, such as insufficient drying of materials, high processing temperature, low mold temperature, excessive forming pressure, etc; (3) Improper post-treatment, such as the mismatch between paint and rubber, unreasonable spraying process, unreasonable assembly process such as hot melt or ultrasonic, etc

about the thickness of stiffeners: in order to ensure no shrinkage, pc+abs generally takes 0.7 of the maximum wall thickness. Is there any design suggestion for adding glass fiber plastic

answer: the shrinkage of glass fiber material is smaller than that of PC, so the sink phenomenon caused by shrinkage is not obvious. Generally speaking, it is OK to design according to the same level of PC material; However, if it is due to strength problems, the maximum wall thickness can be taken as 0.8 times

glass fiber plastic materials need special treatment on the surface of the mold cavity. What are the general treatment methods

answer: there are many methods for the treatment of mold surface. In order to reduce the wear caused by fiber reinforced materials on the mold, it is generally recommended to use high hardness materials to coat the mold surface. However, because the mold will often be modified, and it will be difficult to modify after hard coating. In addition, the cost of processing will also rise, so it should be considered according to the actual situation

what is the minimum demoulding slope of glass fiber material

answer: because the shrinkage of glass fiber materials is relatively small, it is generally recommended that the demoulding slope be larger than that of non reinforced materials; However, because the shell is generally thin, the larger the angle, the better

in the design of Samsung Electronics, the average value is generally about 1 degree

if there is rib (stiffener), the angle will be smaller because the wall is very thin, starting from 0.5 degrees at least

in addition, if the surface needs to be Matt treated (corroded), an angle of more than 3 degrees will be selected

does glass fiber material have special requirements for paint? Is there any special treatment for plastic parts before painting

answer: because the glass fiber part on the surface of plastic parts will reduce the adhesion of paint, it is generally necessary to use a special primer to treat the surface before spraying color paint (three layers: primer + color painting + hard coating)

in addition, for PPA materials, because they are crystalline nylon materials, they need to be specially treated with solvents during painting. If necessary, we can invite relevant spraying enterprises to give you technical support

on the premise of ensuring the strength, what is the minimum wall thickness (pc+gf)? What is the average wall thickness? What is the minimum wall thickness of Samsung ultra thin machine

answer: because the thickness varies greatly according to different shapes and positions. In some extreme small parts, 0.4mm is OK, but generally not less than 0 6m whether the machine often uses m or not. The average wall thickness is about 0.8 to 1.0 (ultra thin is mainly due to the thin internal structure, not the thin shell. Because the impact strength of pc+gf is lower than that of ordinary PC, and the fluidity is poor, in order to ensure the impact resistance and processing performance, it is necessary to increase the wall thickness appropriately)

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