Plastic mold injection molding defects and solutions

Plastic mold injection molding defects and solutions


plastic mould injection molding product refers to the plastic mold injection molding machine heat plastics plasticized melt, and then injected into the forming die cavity in forming, after cooling, the melt solidification after stripping injection molding products. Plastic mould injection molding defects reasons: injection of discontent, sag, the fusion seam, material flow lines, the luster is bad, porosity, black spots, overflow, warping deformation, silver, demoulding is bad, the clouds, punching rough, horseshoe, center small hole, hole big, the substrate is too thick, the substrate is too thin, birefringence, low birefringence, substrate fracture, fracture flow, the radial streaks, record grooves, halo, pitting gas and burnt, cold material uneven, jetting, silver lines, embossing, scratches, flash, markings, surface stripping, bubble, discoloration, hollow, corrugated, crack, sprue cutting die scale, wire drawing, bad, bad measurement, injection quantity is unstable, the mainstream way sticky mold, salivate, streamline, mold temperature, punching knife, flow temperature, injection speed, injection pressure, time, pressure, pressure point, clamping force, cooling time, gun barrel temperature, plasticizing time, plasticizing rate, back pressure, etc. Products defects and reasons. Plastic mold injection molding defects solution: 1, in the case of the screw rotation speed must, increasing back pressure pressure make the liquid inside the cylinder temperature, shear effect are improved. 2, modify mould, special gating system, such as the gate is too wide, melt materials through the turbulence effect is poor, temperature increase is not high, hence uneven, ribbon cavity, should be change to narrow. 3, improve the feed temperature, feed back end temperature, in particular, make its temperature close to or slightly higher than the melting temperature, molten masterbatch into the period when the melt as soon as possible, promote and dilution mixing, increase the chance of liquid mixture.


eliminate the crack injection mold products is


in injection mold injection molding, plastic products occur crack is a common problem, so, how can we do to eliminate crack injection mold products? One, the causes of cracks in the plastic products to produce 1, residual stress caused by molding set conditions ( Too full mold) ; 2, parting when residual stress; 3, the shape of products caused by stress concentration; 4, with the edge of the error due to thermal expansion; 5, the material degradation. 2, 1, metal associated knowledge set piece of preheat, could be formed when the residual stress relaxation, the same principle, instead of panel board with formed after annealing heat is also a kind of method; 2, in the condition of forming, with injection pressure decline in this measure is the most effective; 3, if the ejection pin is balanced, respectively is combined with bigger force in the stripper. 3, eliminate injection mold products crack solution 1, instant: improve the temperature of the material, reduce the injection pressure, reduce the ejection speed; 2, short-term: to improve the smoothness of the mold cavity, 3, long-term: draft should be enough, the ejection pin to distribution balance, don't design products on acute Angle, and try to avoid products thickness difference. Four, the differences between the material 1, because of polycarbonate ( PC) Materials such as PVC is easy to stick in the mold of the chromium plating layer, special be inverted cone in the corner, so to give attention to; 2, polycarbonate, PC) Easy to produce cracks in the mould set piece, like this is the best in the material added to improve glass fiber as well.


double color mould injection molding processing safety knowledge


double color mould two-color injection molding process in addition to outside the double color injection molding machine to make corresponding changes, the technique of double color mould design is the soul of the technology. Double color mould two-color injection through rotating shift, to achieve the effect of double color injection different materials. Double color mould two-color injection is usually divided into two categories: the first category, there are two cavity, using the rotation mode transfer half forming module 180 degrees to another within the cavity, its advantage is to make the first and second process can be synchronized. The second type is single cavity, semi-finished products, together with the mould rotate 180 degrees, design is simpler, but production efficiency to reduce accordingly. Warm prompt: due to the double color mould or semi-finished products need to rotate, so double color mould two-color injection molding machine and the design requirements of more precise. Double color mould two-color injection of variability is very high, if you want to achieve smooth production, in line with expectations ideal, all of the double color mould design must consider, with product design and market popular double-color mould double color injection molding machine specifications are not unified, lead to double color mould design when considering problems more, add less commonality, double color mould two-color injection manufacturer must redouble their attention. Double color mould two-color injection products generally with the TPE with ABS, PC and other hard plastic soft plastic is given priority to, suitable for manufacturing tableware, tool handles, watchcase, telephone shell and buttons and other products. Double color mould two-color injection production enterprises in technology must pay attention to the following three points: 1, the fusion of two types of materials; 2, the complexity of the product; 3, double color injection molding machine set-up. Because of the cost or application, for example, using materials may not have the good adhesiveness, double color mould two-color injection are usually more debugging work in this aspect.