Dec12
Why Re-grind Resin in Plastic Injection Molding Causes Degradation and Weakens Strength

post on December 12, 2024

The use of re-grind resin and recycled material in plastic injection molding is a persistent challenge for engineers. The more re-grind resin or recycled material is added, the more severe the degradation of the plastic becomes. This degradation weakens the material’s structural strength and increases the risk of brittle fractures, especially in stress-bearing areas such as hooks and screw holes.

However, incorporating re-grind and recycled materials in plastic parts is also an environmental issue. To support sustainability and reduce waste, adding an appropriate amount of re-grind or recycled material during the injection molding process can help balance material performance and environmental protection.

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Plastic, Quality, Reliability     WorkingBear    Views (1,634)     comment (0)

Dec05
7 Common Reasons for Elevated MFI (Melt Flow Index) in Plastic Resin Testing

post on December 5, 2024

Plastic resin

Workingbear’s company recently encountered a quality issue with a plastic product. The problem was, “Why is it that products made from the same type of plastic resin sometimes show normal MFI (Melt Flow Index) values, while others have unusually high values? When we asked the plastic injection supplier, they insisted they hadn’t added any regrind material.”

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Plastic, Quality     WorkingBear    Views (1,849)     comment (0)

Nov28
Understanding Melt Flow Index (MFI) for Quality Control in Plastic Injection Molding

post on November 28, 2024

MFI/MI/MFR tester

The “Melt Flow Index” (MFI) of plastic refers to the weight (in grams) of molten plastic that flows through a standardized tube with a specific diameter under a defined load (in kilograms) and temperature (in °C) within a set period of time (typically 10 minutes). A higher MI value indicates better plastic flowability, while a lower MI value suggests poorer flowability. This concept is similar to comparing clear broth and thick soup in the same type of container: when you open the valve, the amount of liquid flowing out within the same period will differ, as clear broth flows more easily than thick soup. Essentially, the thicker the liquid, the less it will flow out.

MFI: Melt Flow Index
MI: Melt Index
MFR: Melt Flow Rate

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Plastic     WorkingBear    Views (2,899)     comment (0)

Nov21
What Are PCB Cross-out Boards (X-out Boards)?

post on November 21, 2024

What Are PCB Cross-out Boards (X-out Boards)? | Definition and Explanation of Defective PCBs

In the PCB industry, there is a specific term called “Cross-out boards” or “X-out boards” to indicate that a panel of PCBs contains defective boards. The term “Cross” refers to marking these defective boards with an “X” symbol.

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PCB/FPC/PTF     WorkingBear    Views (1,550)     comment (0)
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Nov07
The Benefits of Using “Mirrored Panelization” for PCBs

post on November 7, 2024

The Benefits of Using

In the electronics assembly manufacturing industry, what we commonly refer to as a “Mirrored Panel Board” or “Flipped Panel Board” actually comes in two types. The first type is a different-side mirrored panel board, where one board’s top side and another board’s bottom side appear on the same panel. The second type is a same-side mirrored panel board, where all boards are oriented on the same side but are mirrored left to right, such as in a “pdpd” layout pattern.

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PCB/FPC/PTF, Process, SMT     WorkingBear    Views (1,061)     comment (0)