plasticengineeringdiary.blogspot.com
teknologi plastik: Knit lines
http://plasticengineeringdiary.blogspot.com/2009/10/knit-lines.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as the inability of two or more flow fronts to ` knit' together, or "weld", during the molding process. This normally occurs around holes or obstructions and causes locally weak areas in the molded part. 11; LOW BARREL TEMPERATURE. 11; . INADEQUATE BACK PRESSURE . INJECTION PRESSURE 0R SPEED TOO LOW. 11; . MOLD . 11; . 11; . 11; .
plasticengineeringdiary.blogspot.com
teknologi plastik: 2009-10-04
http://plasticengineeringdiary.blogspot.com/2009_10_04_archive.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Wednesday, October 7, 2009. During the final stage of cooling, mould temperature directly affects product dimensions and stability. Therefore, moulds must have an even distribution of water lines to accurately control the process and part-to-part uniformity. A hot mould will. 183; Produce parts with less stress and higher gloss. 183; Usually requires less clamp tonnage to mould the part.
plasticengineeringdiary.blogspot.com
teknologi plastik: Bubbles
http://plasticengineeringdiary.blogspot.com/2009/10/bubbles.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as a voided area trapped within a molded plastic part. It differs from a blister in that there is no surface protrusion with a bubble. Bubbles are usually caused by trapped gases or air pockets, but can also be caused by differential shrinking. MACHINE . LOW INJECTION PRESSURE OR HOLD TIME. 11; . 11; . IMPROPER INJECTION TEMPERATURE PROFILE.
plasticengineeringdiary.blogspot.com
teknologi plastik: 2009-10-11
http://plasticengineeringdiary.blogspot.com/2009_10_11_archive.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Saturday, October 17, 2009. Can be defined as linear grooving, or circular ripples, on the surface of a molded part that indicate the direction of material flow within the cavity of the mold. MACHINE INADEQUATE INJECTION PRESSURE . 11; . MOLD . 11; . 11; . SMALL GATES AND/OR RUNNERS . 11; IMPROPER FLOW RATE. INADEQUATE MOLDING LUBRICANT . OPERATOR . 11; . Flash -...
plasticengineeringdiary.blogspot.com
teknologi plastik: Sink Mark
http://plasticengineeringdiary.blogspot.com/2009/10/sink-mark.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as a depression, resembling a dimple or groove, caused by excessive localized shrinking of the material after the part has cooled. MACHINE . BARREL TEMPERATURE TOO HIGH. INSUFFICIENT INJECTION PRESSURE OR TIME. 11; . 11; . INSUFFICIENT CUSHION AND/OR HOLD TIME. 11; . EXCESSIVE NON-RETURN VALVE CLEARANCE. 11; . SMALL GATES AND/OR RUNNERS.
plasticengineeringdiary.blogspot.com
teknologi plastik: Non-fill (shorts)
http://plasticengineeringdiary.blogspot.com/2009/10/non-fill-shorts.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as an incomplete molded part caused by insufficient material injected into the mold. Non-fill can be an extension of a flow line or knit line condition. 11; INSUFFICIENT MATERIAL IN HOPPER. 11; . 11; . 11; . INJECTION PRESSURE OR SPEED TOO LOW. 11; . EXCESSIVE NON-RETURN VALVE CLEARANCE. 11; . BRIDGING IN FEED THROAT. 11; .
plasticengineeringdiary.blogspot.com
teknologi plastik: Contamination
http://plasticengineeringdiary.blogspot.com/2009/10/contamination.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as an imperfection in a molded part caused by the presence of a foreign object or material that is not part of the original molding compound. MACHINE . OIL LEAKS AND GREASE DRIPS. 11; . 11; . MOLD . 11; . 11; CONTAMINATED RAW MATERIAL. 11; . 11; . 11; . Posted by yus's choices. 169;2009 teknologi plastik.
plasticengineeringdiary.blogspot.com
teknologi plastik: Blush
http://plasticengineeringdiary.blogspot.com/2009/10/blush.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as a clouded discoloration normally found at gate locations, but they can be found anywhere on the part surface. These visually defective areas have very weak physical properties due to loose molecular structure. EXCESSIVE INJECTION FILL SPEED . MELT TEMPERATURE TOO HIGH OR TOO LOW. NOZZLE DIAMETER TOO SMALL. 11; . 11; LOW MOLD TEMPERATURE.
plasticengineeringdiary.blogspot.com
teknologi plastik: Burn marks
http://plasticengineeringdiary.blogspot.com/2009/10/burn-marks.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as small dark brown or black discolorations on the surface of a molded part, usually found at the end of the material flow path or in blind pockets. MACHINE . EXCESSIVE INJECTION SPEED OR PRESSURE. 11; . 11; . HIGH SCREW ROTATION SPEED. 11; . IMPROPER COMPRESSION RATIO OF SCREW. FAULTY TEMPERATURE CONTROLLERS AND HEATER BANDS. 11; .
plasticengineeringdiary.blogspot.com
teknologi plastik: Cracking and/or Crazing
http://plasticengineeringdiary.blogspot.com/2009/10/cracking-andor-crazing.html
In injection moulding, we can describe the following three phases of operation:· Plastication· Injection· Cooling. Sunday, October 18, 2009. Can be defined as a fracture or surface breakage in the material of a molded part, usually found in weld line areas, but also on the surface in general. MACHINE . 11; . COOLING TIME TOO SHORT. 11; . MOLD . UNDERCUTS OR PARTING LINE BURRS. 11; . 11; . USE OF MOLD RELEASE. 11; . 11; . 11; . EXCESSIVE MOISTURE . 11; . Posted by yus's choices.
