1, plastic parts stripping slope:
The size of the draft angle is not a certain criteria, most are based on experience and in accordance with the depth of the product to decide In addition, the molding method, wall thickness and plastic options are also considered.
In general, any side of the molded product, there must be a certain amount of stripping slope, so that the smooth release of the product from the mold.Demolition slope of the size of the general 0.5 ° ~ 1 ° majority.
Specific choice stripping slope pay attention to the following points:
Plastic surface is smooth, high dimensional accuracy, shrinkage is small, should use a smaller stripping slope, such as 0.5 °.
Higher, larger size, according to the actual calculation to take a smaller stripping slope.
Plastic parts of the shrinkage, should choose a larger value of the slope.
Plastic thick wall thickness, will increase the molding shrinkage, mold release slope should be larger values.
Under normal circumstances, PS material stripping slope should be not less than 2.5 ° ~ 3 °, ABS and PC material stripping slope should not be less than 1.5 ° ~ 2 °.
With the appearance of skin, sandblasting and other plastic parts should be based on the specific circumstances take 2 ° ~ 5 ° demoulding slope, depending on the depth of the dermatoglyphics specific dermatoglyphic depth, stripping slope should be The bigger
Structural design into the pair, the insertion plane slope is generally 1 ° ~ 3 °.
Take the direction of the slope, the general hole to the small end shall prevail, in line with the pattern, the gradient obtained by the expansion of the shape of the big end prevail, in line with the pattern, the gradient obtained by reducing the direction.
Under normal circumstances, the stripping slope is not included in the plastic parts tolerances.
Shell surface demoulding slope greater than or equal to 3. Outside the shell surface, the rest of the shell demoulding slope of the characteristics of 1 ° as the standard demoulding slope, in particular, can also be taken according to the following principles: less than 3mm high Of the stiffener stripping slope taken 0.5 °, 3 ~ 5mm take 1 °, the rest take 1.5 °; less than 3mm high cavity demoulding slope of 0.5 °, 3 ~ 5mm take 1 °, the rest to 1.5 °.
2, plastic wall thickness to determine and wall thickness
Reasonable to determine the thickness of plastic parts is very important. Plastic parts of the wall thickness depends first and foremost on the use of plastic parts requirements: including parts strength, quality cost, electrical performance, dimensional stability and assembly requirements, the general wall Thick have experience, reference can be determined.
Note the following points:
Plastic wall thickness should be as uniform as possible to avoid too thin, too thick and sudden changes in wall thickness, if the plastic parts must have wall thickness changes, should use a gradual transition or arc transition, otherwise it will cause shrinkage caused by uneven plastic parts, the impact Plastic parts strength, injection molding fluidity and other molding process problems.Difference in thickness as much as possible control in 25% of the basic wall thickness, the minimum thickness of the entire part of not less than 0.4mm, and the back of the Department is not A-level appearance and requirements The area can not be more than 100mm².
Plastic wall thickness is generally in the range of 1 ~ 5mm, while the most commonly used value is 2 ~ 3mm.
Try not to stiffener and screw column design is too thick, it is generally recommended to take the body half the thickness of the insurance, otherwise easily lead to appearance problems such as miniature.
Try not to design the part as a separate plate, the size of the other, otherwise the deformation caused by uneven parts.
The minimum wall thickness of plastic products and common wall thickness recommended values in the table below:
