Advantages and weaknesses of pulp molding products

Second, the structural design of pulp molding products

1. The structural characteristics of paper molded products Traditional polyethylene foamed plastics mainly rely on the elastic modulus of the material to play a role in seismic buffering, while pulp molded products mainly rely on their own structural seismic. Therefore, the structural design of pulp molding products is very important.

Pulp molded products have the strength, stiffness and toughness of general paper products. Products of various complex shapes can be made according to the functional requirements of use. When used as a disposable fast food appliance, the shape is relatively simple and the strength requirements are not high.

When used as an industrial inner packaging, its shape is very complex, must meet the three major requirements of industrial inner packaging: First, positioning requirements, paper products must ensure the fixed position of the packed items in the packaging box, requiring the shape of the paper products and the packaged items to be consistent, appropriate contact, accurate size.

The second is the buffering requirements, the paper mold products as a whole should have a certain toughness and flexibility, the surface should also be some soft, and the contact friction with the packaged goods will not damage the shiny surface of the packaged goods, and can eliminate the impact of shock and vibration during transportation and loading and unloading.

The third is the bearing requirements, the paper mold products must have a certain strength and stiffness to support the packaged goods and external pressure.

2. Structure design of paper molded products Pulp molded products as a new material used in buffer packaging time is short. At present, its structural design is still in the experience design stage, the design of pulp mold products should be based on the appearance size of the packaged product, the size of the outer container to be reasonably determined.

Pulp molded products in each side must consider its damping effect, so the convex to achieve the purpose of buffering, so that it on each surface of the section line are broken lines, to improve the strength of the paper die. The strength of the paper die is inversely proportional to its buffering performance. The more convex ribs are added, the greater the strength is, but at the same time its buffering performance decreases.

Pulp mold products have a smooth surface (with the surface of the molding mold) and a rough surface, the shape and size of the smooth surface to be packaged products are consistent with the surface; The rough surface should be able to implement good support and fixation in the outer packaging of the product (such as cartons, etc.).

Pulp molding products are formed by vacuum adsorption process, and the absolute thickness and thickness difference of each part are limited by the forming conditions. Under normal circumstances, the absolute thickness of the pulp mold products is 2 ~ 5mm, which requires us to ensure the overall dynamic buffer performance by setting the cavity on the appropriate part, and set a certain number of reinforcement to ensure its overall strength, although the thickness of each part of the pulp mold products can be controlled by adjusting the opening rate of the corresponding part of the molding mold. But too large thickness difference in the molding and drying process is difficult to ensure the quality of pulp molding products. When forming, the dryness of the wet paper mold blank is about 10%, and the slurry still has a certain fluidity, which is easy to produce fiber flow in the vertical direction, causing local fiber flocculation phenomenon, affecting the molding quality, especially for the pulp mold products with larger vertical size, this situation is more serious. Therefore, it is necessary to design a certain slope in the vertical direction of the pulp mold product, which is also conducive to the demudding of the wet paper mold blank. Under normal circumstances, its slope design is 2o ~ 5o. At the surface corner of the pulp molding product, it is necessary to avoid right Angle or acute Angle contact, otherwise, it is easy to produce stress concentration phenomenon here, and the reasonable treatment method is to use rounded corner transition.

In the structural design of pulp molding products, the edge structure should be properly considered, and the edge structure of paper molding products has a boundless structure, a flanging structure and a double edge structure. The boundless structure is suitable for disposable tableware and some industrial internal packaging products with light weight and low strength requirements; Flanging structure and double edge structure are mostly suitable for industrial inner packaging products, which can improve the overall strength of paper mold products, buffer performance and beautify the appearance of products.

The mold design of the pulp molding products is the key to the entire production process

First of all, it must meet the structural requirements of the pulp molded products and the above molding process conditions (that is, the impact of pulp molding on the molding mold, dehydration and drying process), and then it must meet the requirements of mold design and manufacturing.