Industry News

How can the top white and surface elevation of the mold be solved

• 2025-08-26

How can the top white and surface elevation of the mold be solved

The top white of the mold is one

Phenomenon: During the production process of electrical appliance casing products, the surface of the products turns extremely white.

Analysis: The product is unbalanced during demolding, and the required demolding force exceeds the range that the product can withstand.

Characteristics of injection molding machines

Grade :HT-120T, clamping force :120t, plasticizing capacity: 90g

(2) Mold characteristics

Mold ejection number :1x2, glue injection method: point gate, ejection method: Ejection by ejector pin, ejection by inclined ejector, mold temperature 115℃ (constant temperature machine)

(3) Product characteristics

Material :PC, Color: White, Product weight (single piece) : 5.5g, nozzle weight :7.5g

(4) Analysis of causes of defects

The main runner of the mold is quite large, and the glue injection method is single-point injection, making it difficult for the product to demold. The mold design has a slanted top position on one side of the product.

The demolding is unbalanced, and the required demolding force exceeds the range that the product can withstand, resulting in a white top phenomenon on the product surface.

(5) Countermeasures

1. The inclined top position of the mold is less smooth, and the top white position and bone position are less smooth.

2. Add cold material hooks to the round top pin position on the other side of the mold.

3. Adopt multi-stage injection molding, adjust the injection position near the high position of the feed top, and adjust the slow injection speed. Appropriately extend the holding pressure

Time.

Automobile dashboard mold Manufacturer in China (jfmoulds.com)

The top white of the mold is two

Phenomenon: The transparent protective cover turns white at the top pin position of the rear mold when the product is demolded during the production process.

Analysis: The bone position of the mold product is not demolding smoothly. The top force of the product is insufficient.

Characteristics of injection molding machines

Grade :HT-120T, clamping force :120t, plasticizing capacity: 150g

(2) Mold characteristics

Mold ejection number :1x2, injection method: point gate, ejection method: flat top ejection, mold temperature :110℃ (constant temperature machine).

(3) Product characteristics

Material :PC IR2200N, color: transparent, Product weight (single piece) : 4.5g, nozzle weight: 4.2g

(4) Analysis of causes of defects

The main channel of the mold is quite large. The injection method is to insert the glue at a small point while it is submerged. Due to the influence of the product structure, the filling requires a very high pressure and fast injection

The product is difficult to demold after sticking. The product's bone position is not demolding smoothly. The top force of the mold's flat top is insufficient, resulting in a white top when the product exits the mold.

(5) Countermeasures

1. The bone position of the mold product is smooth.

2. Change the ejection of the mold ejector pin to the ejection of the ejector block.

3. Appropriately shorten the cooling time during molding.

Commodity Mould_Taizhou Jiefeng Mould Co.,Ltd. (jfmoulds.com)

The surface of the mold is raised

Reason: The product demolding was not smooth, and the surface of the front mold was raised.

Characteristics of injection molding machines

Grade: DEMAG, clamping force :80t, plasticizing capacity :133g

(2) Mold characteristics

Mold ejection number :1×8, injection method: direct injection into the gate, ejection method: push plate ejection, mold temperature: 120℃ (constant)

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(3) Product characteristics

Material :PC, Color: Transparent, Product weight (single piece) : 1g, nozzle weight: 3g

(4) Analysis of causes of defects

1. The draft Angle of the product is insufficient.

2. The glue position at the punch hole exit is in the front mold. When opening the mold, the pulling force of the rear mold is insufficient, while that of the front mold is large.

(5) Countermeasures

1. Increase the draft Angle of the front die column position needle.

2. Or make an inversion on the ejector pin to assist the rear die in pulling the product.

3. Push the hole through the needle out of the rear die to reduce the tension of the front die.