"制带的材料" can be translated as "materials for belt making" or "materials used in belt production" in English.
Here are some example sentences to illustrate the usage:
* We need to select high-quality materials for belt making to ensure the durability and performance of the belts.
（我们需要选择高质量的制带材料，以确保皮带的耐用性和性能。）
* The company is constantly researching new materials used in belt production to improve product quality.
（该公司一直在研究用于皮带生产的新材料，以提高产品质量。）