-
Injection Molding Defects and Solutions -- Surface Flow Marks
2025-10-17
Surface Flow Marks (Flow Lines / Flow Ripples): This defect appears as streaked patterns radiating from the gate on the surface of the molded part. It occurs when the molten resin does not flow smoothly along the cavity surface but moves in a semi-wavy manner. During flow, stagnant zones form, and the resin that initially enters the cavity cools too quickly, creating a boundary with the subsequent...
view more
-
Injection Molding Defects and Solutions -- Bending
2025-10-17
Bending: For narrow and long parts, one end deforms upward or downward, forming a shape similar to a bow. 10.1 Causes 10.2 Solutions 10.1.1 Poor part structure or low processability. 10.2.1 Modify the part structure. 10.1.2 Improper gate location. 10.2.2 Place the gate at one end of the part, not in the middle, or reshape the part after demolding. 10.1.3 Improper mold temperature (moving or fixed ...
view more
-
Injection Molding Defects and Solutions -- Warping and Twisting Deformation
2025-10-17
Warping and Twisting Deformation: During molding, various internal stresses cause uneven shrinkage in different directions of the part. Poor demolding, insufficient cooling, or other factors can lead to abnormal shapes, uneven warping, or uneven wall thickness around holes. If the deformation occurs along edges in a parallel direction, it is called warping; if it occurs along diagonal directions, ...
view more
-
Injection Molding Defects and Solutions -- Bubbles
2025-10-17
Bubbles: Bubbles and voids are cavities formed inside molded products. There are two types of bubbles: one occurs when the product cools and shrinks — as the surface hardens, the thicker areas inside form hollow voids known as vacuum bubbles; the other type occurs when moisture, volatile substances, or air trapped in the resin enter the cavity with the melt during molding and become enclosed insid...
view more
-
Injection Molding Defects and Solutions -- Dimensional Instability
2025-10-17
Dimensional Instability: This occurs when the molded part exhibits inconsistent shrinkage due to poor mold manufacturing accuracy, unstable injection molding process conditions, or improper post-processing of the product. 7.1 Causes 7.2 Solutions 7.1.1 Unstable electrical or hydraulic system of the machine. 7.2.1 Check for faults in electrical components or hydraulic systems; regularly clean elect...
view more
-
Injection Molding Defects and Solutions -- Weld Line
2025-10-17
Weld Line: When two or more streams of molten resin meet and the temperature drops during flow, the resin at the junction fails to fully fuse or bond. This results in a fine line formed along the surface or inside the molded part at the point of convergence. 6.1 Causes 6.2 Solutions 6.1.1 Low nozzle temperature or low mold temperature. 6.2.1 Increase melt and mold temperatures to improve resin flo...
view more
-
Injection Molding Defects and Solutions -- Delamination or Peeling
2025-10-17
Delamination or Peeling: This defect occurs when foreign materials are mixed into the raw material, the mold temperature is too low, or the material compatibility is poor. Excessive shear stress during melt flow along the mold surface causes the material to separate into thin layers, resulting in peeling or delamination. 5.1 Causes 5.2 Solutions 5.1.1 Material not properly dried. 5.2.1 Dry the mat...
view more
-
Injection Molding Defects and Solutions -- Flash and Burrs
2025-10-17
Flash and Burrs: When the molten material enters the gaps between the mold parting surfaces or the joints between the mold and the slider, excess thin fins or burrs appear on the molded part. 4.1 Causes 4.2 Solutions 4.1.1 Poor closing or misalignment at the parting surface. 4.2.1 Increase clamping force; repair the mold parting surface to ensure tight fitting. 4.1.2 Excessive clearance between th...
view more
-
Injection Molding Defects and Solutions -- Silver Streaks
2025-10-17
Silver Streaks: Shiny, silvery lines appearing on the surface of the molded product or near the gate along the flow direction. These are caused by excessive moisture or volatile substances in the material, poor adhesion between the melt and the mold, or rapid cooling after the melt has been subjected to excessive shear stress—resulting in needle-like or mica-like streaks. In addition, if the silve...
view more
e-mail
English
français
Deutsch
русский
italiano
español
português
العربية
日本語
한국의
中文