The influence of PVC material on the weight of baseball is mainly reflected in the following aspects:
Material density and base weight: The density range of PVC material is usually 1.38-1.45 g/cm³, which is higher than that of natural leather and other materials. This means that under the same volume, a baseball made of PVC material weighs more. The base weight of a PVC baseball may be 5 to 15 grams higher than that of a traditional leather baseball, depending on the filling and structural design.
Fillers and weight adjustment: To control the total weight of the baseball, PVC material baseball usually uses low-density fillers, such as hollow foam materials or low-density polyethylene cores. This design can balance the weight increase brought by the PVC material itself, making the total weight of the baseball close to the standard range (such as 5-5.25 ounces). However, this adjustment may cause the baseball to feel too hard, affecting the user experience.
The influence of structural design on weight: Due to the rigidity requirements of PVC material, when designing baseball, the thickness of the shell and the fit of the filling material need to be considered. For example, increasing the thickness of the shell will enhance durability, but it will also increase the weight. To address this issue, some PVC baseballs adopt an equal-thickness design or lightweight coating to reduce the problem of uneven weight distribution.
Manufacturing process and weight control: The injection molding process of PVC material will affect the weight accuracy of the baseball. Insufficient mold accuracy may lead to wall thickness deviation, which in turn affects the consistency of the weight of a single ball. Optimizing injection molding processes (such as multi-stage injection molding) can enhance material utilization and reduce weight differences. In addition, post-processing techniques (such as drilling for weight reduction) can also be used to adjust the weight, but they may affect the water resistance and durability of the baseball.
Application scenarios and weight adaptation: The weight design of PVC material baseball needs to be adjusted according to specific uses. For example, training baseballs may control their weight by reducing the density of PVC or decreasing their size to meet safety standards (such as children’s balls weighing ≤4.5 ounces). Recreational baseball, on the other hand, may enhance durability by increasing the density of the filler, but its weight may exceed the standard range (such as 5.5-5.8 ounces).