Forming slot bit: In plastic processing, sometimes large quantities of commodities are relatively small, and then the precision of directly formed holes is relatively low. It is difficult to realize the application standard. Drilling is often used to process holes after injection molding. Many factories drill common plastic spring steel twist drill, insert welding carbide tool twist drill, the overall carbide tool drill. In which the spring steel drill is mainly used for milling thermosetting plastic plastic, carbide tool drill bit is used for milling thermosetting plastic plastic.

Selection criteria for basic parameters of twist drills

Spiral angle to expand the spiral angle will also reduce the compressive strength of the cutting edge, but can reduce the cutting speed, so that the success of the cutting flow, drilling is very easy to carry out. When processing plastic parts, the lower the helix angle of the forming groove drill bit, the less likely it is to guide chips, and the more likely it is to produce deadlock or burn. Therefore, the helix angle of the twist drill used for milling plastic can be selected to be larger, but it is not suitable for large, so as to prevent the drill bit from breaking due to insufficient compressive strength.

Forming groove drill bit: the size of the rear angle of the front angle harms the friction between the rear face and the processing surface layer, especially when the front angle at the core is relatively large, the drilling standard of the chisel edge needs to be improved to significantly reduce the axial force, but the front angle near the edge will make the compressive strength of the drill bit weak. Therefore, when grinding the back face of the twist drill, the back angle should be ground to a small edge, and the closer to the core, the more.

The reduction of the front angle can improve the sharp angle at the edge corner, improve the heat discharge standard of the numerical control blade, improve the durability of the tool, and at the same time soften the cutting and reduce the axial force. But too short a front angle will expand the torque. When processing plastic parts,Forming slot bitThe more the front angle, the easier it is to crack the hole edge of the plastic part, so the front angle of the twist drill for drilling plastic parts is generally smaller. The drill can also be sharpened into a two-way front angle, so that the cutting near the hole edge is thinner than hammering, preventing or alleviating the hole edge cracking.

Some Precautions in Plastic Punch Processing

During the operation, the forming groove drill bit should not rotate at a high speed in the drilling hole, so as not to cause part of the over-temperature, which will cause the plastic to fade, melt and ignite.

The drill bit should be withdrawn frequently to facilitate cooling.

Because the plasticity of plastic is relatively large, the linear expansion coefficient is large, after processing, because the elastic recovery and thermal deformation of the close, will reduce the diameter, so it is appropriate to choose a bit slightly larger than the outer diameter (generally 0.05~0.25mm).

　　Forming slot bit: Air-cooled is the best choice for refrigeration. Air compression or emulsified oil with 5% water can also be used for cleaning, milling, refrigeration and moistening. The application of frozen liquid refrigeration, should be selected according to the type of plastic, can not be applied will also cause plastic moldy deterioration of frozen liquid. For example, the freezing liquid perforated by plexiglass plate cannot be used with automobile engine oil (automobile engine oil will make plexiglass plate yellow and brittle), polyester is easy to absorb moisture, oil-soluble freezing liquid, polyethylene or polycarbonate should be used, and freezing liquid containing chlorinated hydrocarbon or p-xylene should not be used to prevent stress cracking and melting.