Pouring is the process of pouring the mixed liquid polyurethane into the mold. In order to ensure product quality and increase the rate of product authenticity, correct pouring methods must be used. Commonly used pouring methods include vertical pouring method, inclined pouring method, bottom injection method and spraying method.

Vertical casting

This method refers to the pouring method in which the mold is placed vertically and the pouring material is poured down the wall. This method is often used for forming urethane rollers. According to the difference between the diameter of the rubber roller core and the inner diameter of the mold, the following methods can be used. The castable is poured from the top of the mandrel, and the glue slowly flows along the surface of the mandrel to the bottom of the mold until the mold is filled. If the height of the product is not large and the mold cavity is wider, it is easy to observe, and it can also be poured from the bottom of the mold. The outlet of the pouring hose is close to the rubber surface and lifts as the rubber surface rises to prevent bubbles from being flushed. In short, according to the shape of the product and the distribution of the mold clamping surface, consider whether the mold needs to be properly tilted before pouring, in which direction, and where the pouring hose outlet is selected, whether it is fixed or gradually moved. The purpose is to make the glue After the material reaches the lowest part of the cavity smoothly, the air in the cavity is gradually driven up, toward the direction of the clamping surface. Never drive air and bubbles to the dead corner (the gas is easy to run up or to the side, it is difficult Run down), so the selection of the clamping surface during mold design is extremely critical.

Tilt pouring method

The inclined casting method refers to the operation method in which the mold is inclined and the glue flows down the inner wall of the mold. It is usually used where the skeleton and the cavity have a horizontal plane and the bubbles are difficult to remove. This casting method can be used to manufacture rubber wheels and rubber rollers. Tilt the mold, and the outlet pipe is poured directly into the inner wall of the upper lower end of the mold. With the continuous improvement of the pouring level, the mold is gradually straightened.