Why does aluminum section produce bubbles (Include solutions)

Air bubbles on the surface of the aluminium section will affect the appearance, and understanding the causes can be better solved. Sometimes the aluminum section will also appear in scratches, how to avoid it is also a skill we need to master.

About bubbles

The bubbles generated in the aluminium section are the partial continuous or intermittent separation between the surface metal of the profile and the base metal, which is shown as a circular or partially continuous bulge.

Main reason

1. Because the size of the extrusion cylinder is out of tolerance after long-term use, the gas in the cylinder is not eliminated during extrusion, and the deformed metal surface flows out along the elastic area at the front end, causing bubbles;

2. There are grooves on the surface of the ingot or pores in the structure of the ingot. The ingot is filled with gas when the ingot is thick, and the gas enters the metal surface during extrusion;

3. During extrusion, the ingot or mold contains water and oil stains. Because water and oil stains are heated to volatilize into gas, they are drawn into the surface of the profile in the high temperature and high pressure metal flow to form gas;

4. The equipment exhaust device is not working properly;

5. Metal filling is too fast, resulting in bad extrusion and exhaust.

Specific solution

1. Reasonably select and equip extrusion tools, check and replace them in time;

2. Strengthen the quality management of ingots and strictly control the surface quality and gas content of ingots;

3. Ensure that the exhaust system of the equipment works normally;

4. Scissors, extrusion cylinders and molds should be oiled as little as possible or no oil;

5. Reasonably control the extrusion speed, and exhaust as required.

How to avoid scratches in aluminum section

There are rough longitudinal or transverse grooves on the surface of the extruded product.

Why scratches happened

Scratches and scratches are common surface defects in the aluminum section extrusion process.

Scratches recessed from the surface are mostly caused by foreign matter stuck to the mold or rough processing at the empty knife.

The raised scratches at the corners of the product are caused by cracks in the extrusion die.

Horizontal scratches or scratches are mainly caused by hard objects protruding on the cooling bed and scratching the products when the products are transported from the sliding table to the finished sawing table, and they are also generated during loading and transportation.

How to eliminate it

1) The working belt of the extrusion die should be processed smoothly, and the empty cutter of the extrusion die should also be processed smoothly.

2) When installing the mold, check carefully to prevent the mold with small cracks from being used. Pay attention to the fillet radius when designing the mold.

3) Frequently check the cooling bed and finished product storage table to prevent hard protrusions from scratching the product.

4) When loading, place a spacer that is softer than the product, and the transportation and lifting should be stable and carefully operated.