Common defects of disposable medical device injection moulding


We all know that some defects often occur in Disposable […]

We all know that some defects often occur in Disposable medical device mould after moulding. This time seriously affects the normal use of workpieces, and even makes the manufactured workpieces unusable. This will seriously affect the cost and efficiency of manufacturing workpieces. Therefore, we must make the relevant preparations before forming the mould, and find out the specific causes of these defects.

1. Lack of glue

(1) If there is a lack of glue in the multi-cavity cavity, it may be because the water inlet point is different in size, or the flow path length of each cavity is different.

(2) Poor exhaust of the mould can also cause lack of glue, but it is often accompanied by scorching.

2. Shrinkage

(1) Shrinkage caused by uneven product wall thickness.

(2) Shrinkage caused by uniform product wall thickness.

Phenomenon: There is a wave phenomenon on the surface of the product. Reason: (1) The CUSHIONVOLUME of the injection moulding machine may be missing or insufficient. (2) The reverse flow may prevent the valve from operating smoothly.

3. Scorch

Suggestion: Grind the exhaust on the mould, or change the water level to facilitate the exhaust.

4. Black bars

Phenomenon: The product extends from the black position from the water entry position.

5. The surface gloss of the product is bad, and it is cloudy.

6. Silver stripes: One-color lines appear in the direction of rubber flow.

7. Flow mark: A wave shape is formed around the water inlet of the product.

8. Welding marks:

A fusion line created at the cavity of the product.

(1) It is very difficult to completely eliminate weld marks.

(2) The number of water entry points also affects the number of weld marks.

(3) Other ways to consider improvement:

a: Change the water inlet method.

b: Add exhaust equipment.

c: Add bone at the place where the weld line appears.

9. Jet flow: forming an earthworm-like line in the water inlet part.

(1) Other improvement methods:

It is possible to add a blocking needle at the place where the water-injecting rubber flows.

10. Impurities: impurities in the product

Other reasons: COLDSLUGWELL is not saving light. Debris is generated during ejection and remains in the cold feed well. Impurities appear on the surface of the product (PC material is even worse)

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