Whether a plastic product is suitable for manufacturing with rotational molding, or whether rotational molding is the best choice for this product, must be comprehensively judged according to the shape, size, material, cost, quantity and other factors of the product. If there are several plastic molding methods that can be considered to make this plastic product, you can refer to the advantages and disadvantages of the rotational molding process and apply the exclusion method to select the best molding method.

1. Confirm whether it is a hollow product

If it is not a hollow product or a foamed solid product, it can basically rule out the production of rotational molding. In the case of hollow products, there are several methods to form hollow products, such as blow molding, thermal molding and roll molding, and each molding method has its advantages and disadvantages. There will be some overlap in the selection of methods. It can only be said that rotational molding is one of the choices for manufacturing this product.

2. See product size

If the volume of plastic products to be made is large, and at least one of the dimensions of length, width and height exceeds the capacity of the current blow molding machine, or the width of thermoformed sheet available in industry, blow molding or thermoforming can be basically excluded, that is, this kind of products can only be produced by roll molding.

3. Look at the shape

If the three-dimensional dimensions of the product are within the production capacity of the above three molding methods, the next step is to see the shape of the product. If the shape is complex, such as filter residue container, the whole product cannot be produced by blow molding or thermoforming. At this time, it can only be made of rotational molding.

4. Look at the material composition

That is to see what raw materials are used to make the products. If the material of this product is polypropylene, it is difficult to make it by thermoforming. If liquid PVC plasticized paste is used, it can only be produced by roll molding.

5. Look at the product structure

If the product contains a closed parallel double wall structure, rotational molding is the preferred molding method, because thermoforming requires more complex and expensive multifunctional molds. When the wall thickness of the product is required to be uniform or the outer corners should be strong, rotational molding has also become the best choice.

6. Look at the mold composition

If the mold is complex or composed of multiple pieces, and it is difficult for the machine to demould automatically, the product cannot be produced by thermoplastic molding or blow molding. The demoulding of rotational molding is basically completed manually. Even more complex molds can be completed manually, so this product can only be produced by rotational molding.

7. Look at the inlay

If the product has inserts and inserts, the processing method should be selected according to the complexity of the combination of inserts and products. The complexity of rotational molding is higher than that of blow molding and hot molding. At the same time, using rotational molding to embed the embedded parts, its combination fastness is also the best of the three molding methods.

8. Look at efficiency and cost

If these three methods are still feasible after using the above comparison method, the production cost and efficiency of this product will be compared. Although the blow molding method usually has high mold cost, it has fast production speed and high production efficiency. As long as the output and efficiency are calculated, the cost price can be obtained. If the demand for this hollow product is large, generally speaking. Blow molding is the lowest cost. The cost of rotational molding mold is less than that of blow molding method, and the delivery time in small batch is also less than that of blow molding method. However, due to the relatively low production efficiency of rotational molding, when the demand for product quantity is large, the cost will rise, and its advantages will be reduced or even lost. The efficiency and cost of thermoforming are generally between blow molding and roll molding. Therefore, when the product demand is small, it is cost-effective to use rotational molding; When the demand for products is large, blow molding or thermoforming should be selected.

In short, the final choice of a molding method to manufacture a plastic product does not mean that other molding methods must not be selected, but only the best choice after comprehensive comparison of various factors.