Exhaust pipe mould is a kind of casting mould that consists of a cavity, cross gate, and water gaps. The cross gate is provided with a sprue, while the water gaps are connected to the mould cavity by the riser. Each water gap has an inclined plane on the upper wall surface. The riser is situated at the junction between the cross gate and the water gap. It extends downwards to the mould cavity.

The exhaust pipe is an essential component of a motor vehicle, with many functions including noise reduction, installation ease, and lasting performance of the exhaust muffler system. Exhaust pipes are intricately crafted, with many small welds and complex structures. Therefore, processing precision for the mould's inner cavity is extremely strict. 3D scanning has penetrated various industries, including automobile manufacturing. By scanning, full 3D data can be obtained. This data helps mold makers to calculate deviations, which is difficult to do through traditional inspection methods.

It is essential to judge the direction of the flow of exhaust before the injection moulding process begins. Incorrect judgment may result in the wrong exhaust position, wrong processing, and incorrect placement. The direction of flow is crucial, as the wrong direction will lead to the incorrect exhaust position, obsolete processing, and no solution to the problem. The process of flow material and flow direction are illustrated in Table 3.20. When the incorrect direction of flow is wrongly judged, it will affect the mechanical strength and dimensional accuracy of the final product.

When the material flows through the mold to the G point, it is discharged along the fitting position. This eliminates the problem of trapped air in the exhaust pipe mould. If the air-trapping level is not high enough, it will lead to a failure of the mould. To prevent this, an insert should be used. In addition, the front mold's high-convex gate should have two small recesses, and an insert structure should be made in this position.

Although most physicians don't know much about mold toxicity, they are generally unaware of the symptoms of mould toxicity. Symptoms can range from a runny nose to irritations of the eyes, skin, and lungs. Because symptoms vary so widely, the correct diagnosis can lead to optimal health, whereas the wrong one can lead to misery and disability. It's vital to remember that your body's reaction to mold toxicity is different from other common diseases and allergies.