Five methods for quickly judging surface quality defects of mill finish aluminum profiles 　

Five methods for quickly judging surface quality defects of mill finish aluminum profiles

Five methods for quickly judging surface quality defects of mill finish aluminum profiles

Quickly judging surface quality defects of mill finish aluminum profiles 　

Surface quality defects of mill finish aluminum profiles quick judging 5 methods

Due to the particularity of the manufacturing process of extruded aluminum profiles, the surface defects of aluminum profiles caused by the mold polishing quality or the process conditions directly or indirectly during the hot extrusion process are as follows: coarse grain, color separation, dark zone, light zone, Scratching line, poor color finish, etc.

In the extrusion production of aluminum profiles, the common defects are relatively obvious, such as bending, twisting, deformation, slag inclusions, etc.

The initial judgment of the surface quality is generally carried out when the 2-3 pieces billets are extruded.

The first inspection sample preliminary judges whether the surface quality is qualified, and then inspects other items after the surface is qualified.

Five methods for quickly judging the surface quality defects of mill finish aluminum profiles as follows:

1. Hand touch:

Touch the surface of the substrate with your hand, or the line with your fingernail, you can feel the concave and convex bones, and judge whether there is an obvious feel.

Applicable to the determination of various surface treatments.

2. Pencil scratches:

During the extrusion process of aluminum profiles, use pencils to scratch the surface of aluminum profiles.

Use hand feel and continuity of pencil scratches to determine whether there are rough lines. Scribing and ditching are suitable for the surface determination of anodizing materials.

3. Paint spraying test:

When sampling at the first inspection, the surface of the substrate is sprayed with automatic spray paint to simulate the spraying effect.

After 1-2 minutes of surface drying, observe and judge whether there are defects such as scratch lines, concave bones, convex bones and so on. Applicable to the surface judgment of powder coating.

4. Alkali washing test:

When sampling at the first inspection, take a 300mm sample from the third billet and soak in the mold processing alkali tank for 30-40 seconds.

(Note: The alkali concentration and the tank temperature, if the concentration and temperature are too low, Extend the immersion time, generally not more than 60 seconds).

After the alkaline cleaning of the substrate surface, you can see whether there are defects such as color separation, scratch, mold welding line, and so on.

Suitable for anodizing materials with high surface requirements.

5. Surface polishing:

When sampling at the first inspection, take a 300mm sample profile and polish the surface of the substrate horizontally with an industrial cleaning cloth.

After polishing, the surface of the substrate is easier to observe relatively small defects. It is used to judge the surface defects such as slight lines, concave bones (not easily nailed), convex bones and the above four methods.

It is suitable for the surface determination of powder coating, anodizing material and fluorocarbon material.

The first inspection to quickly determine whether the surface quality is qualified is the first step. Even if the first piece is qualified, abnormal conditions will also happen during the extrusion process.

So in the actual production process, it is necessary to choose the corresponding method to make judgments; make timely and accurate judgments according to the different degrees of substrate defects and what surface Processing methods, combined with the quality requirements of orders and customers, according to the requirements of the operation instructions, formulate a reasonable inspection frequency, based on the principle of not misjudgement or omission of judgment.

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