(1) Cavity and stiffener. The buffering effect of paper holder is mainly realized by using the elastic deformation of the paper wall to slow down and counteract the external force when it is impacted. The elasticity of the paper holder material itself is not high, which mainly depends on the design of the reinforcing rib and the buffer cavity formed by the product. The design of the cavity and reinforcing rib plays a crucial role in the elastic deformation of the paper holder, that is, the buffer capacity. The basic basis of the design of the cavity and stiffener is the shape and use of the product itself. In the structural design of paper holder, cavity is set to ensure the dynamic cushioning performance of paper holder, and the reinforcement rib is designed to increase the strength of paper holder. Several cavities with simple shape and good dynamic buffering performance are evenly distributed in the paper holder structure, which can buffer, stabilize and improve the strength. For the problems of structural instability and strength reduction caused by large area cavities to the paper holder structure, some or symmetrical stiffeners can be set to solve the problems. The setting of cavities and stiffeners should fully consider the convenience of production, simple processing and The distribution is uniform and the gravity of the product is evenly distributed.

(2)固定支撑面。这是纸托结构设计中基本的一点，固定支撑面可以根据被包装产品的要求以及外形尺寸和外包装物的内部尺寸来确定。例如，要设计一个电器产品的纸托包装，可以裉据被包外形尺寸和外包装物的内部尺寸来确定纸托的长度、宽度和相应的结构形式，并由此确定纸托的固定支撑面。同时要了解包装的侧是在强度上还是在缓冲上，一些重量大、强度高的产品的包装侧在强度上，但作为缓冲包装其缓冲性能也必须保持，而一些贵重产品的包装侧在缓冲上，其包装也要具有一定的强度。设计中要将两者恰当地结合在一起，根据被包装产品的外形结构、重力和强度选择适当的基点，再由这些基点确定固定支撑面。

(2) Fix the support surface. This is the most basic point in the structural design of paper holder. The fixed supporting surface can be determined according to the requirements of the packaged product, the external dimension and the internal dimension of the outer package. For example, in order to design a paper holder package of an electrical product, the length, width and corresponding structural form of the paper holder can be determined according to the external dimension of the package and the internal dimension of the outer package, and then the fixed supporting surface of the paper holder can be determined. At the same time, we should understand whether the emphasis of packaging is on strength or cushioning. Some heavy and high-strength products should focus on strength, but as cushioning packaging, its cushioning performance must also be maintained. While the packaging of some valuable products focuses on cushioning, its packaging should also have a certain strength. In the design, the two should be properly combined. According to the shape structure, gravity center and strength of the packaged products, the appropriate base points should be selected, and then the fixed supporting surface should be determined by these base points.

(3)相关参数。根据被包装产品的要求和纸托制品结构设计的特点确定设计中的相关参数。

(3) Related parameters. According to the requirements of the packaged products and the characteristics of the structure design of paper support products, the relevant parameters in the design are determined.

①尺寸与壁厚。纸托制品结构设计的基本要求是要保证与被包装物之间紧密接触，防止被包装物在流通过程中产生串动，在此基础上再考虑缓冲和防震问题，因此在结构设计中尺寸一定要紧凑，尺寸的紧凑是由固定支撑面和空腔以及加强筋的综合配合来解决的。

① Size and wall thickness. The most basic requirement of the structure design of paper holder products is to ensure close contact with the package to prevent the package from moving in the circulation process. On this basis, the buffer and anti shock problems are considered. Therefore, the size must be compact in the structural design. The compact size is solved by the comprehensive cooperation of fixed support surface, cavity and reinforcing rib.

结构设计中应根据纸托的使用条件和采用的纸料纤维种类来确定纸托的壁厚。壁厚是影响纸托强度的重要因素，壁厚的增加不但增加原材料消耗，而且在吸附成型时会降生产，壁厚的增加还会增加湿纸模烘干过程的能耗，并易使纸托产生凹陷、缩孔和夹心等质量缺陷。在满足纸托强度的前提下应尽量降壁厚。采用真空吸附成型工艺时壁厚在0.5--6mm之间，采用压制成型工艺时壁厚在3--20mm之间。

In the structural design, the wall thickness of the paper holder should be determined according to the service conditions of the paper holder and the type of paper fiber used. Wall thickness is an important factor affecting the strength of paper holder. The increase of wall thickness not only increases the consumption of raw materials, but also reduces the production during adsorption molding. The increase of wall thickness also increases the energy consumption in the drying process of wet paper mold, and easily leads to the quality defects such as depression, shrinkage cavity and sandwich. On the premise of meeting the strength of paper holder, the wall thickness should be reduced as much as possible. The wall thickness is between 0.5-6 mm when using vacuum adsorption molding process, and 3-20 mm when using pressing molding process.

②过渡圆弧。纸托结构设计中，纸托的内外表面转角处、立筋与主体联接处和立筋的终端都必须用圆弧过渡，避免直棱直角。圆弧过渡有利于模具的制造和附网，有利于湿纸模转移时脱模，有利于纸浆液料在吸附成型时的流动，也有利于避免应力集中造成包装破损。过渡圆弧的半径可根据具体产品和纸料性能以及包装的特殊要求来确定，一般为2--5mm。

② Transition arc. In the design of paper holder structure, the corner of the inner and outer surface of the paper holder, the joint between the vertical rib and the main body and the end of the vertical rib must be used for the transition, so as to avoid the straight edge and right angle. Arc transition is conducive to mold manufacturing and mesh attachment, demoulding during transfer of wet paper mold, flow of liquid pulp during adsorption molding, and avoiding package damage caused by stress concentration. The radius of the transition arc can be determined according to the specific product and paper properties as well as the special requirements of packaging, which is generally 2-5mm.

③脱模斜度。在纸模成型过程中，湿纸模紧贴在网模上而且纸料纤维还会镶嵌在网模的网孔中，为了便于湿纸模的转移，与脱模方向平行的纸托表面都应该有个合理的脱模斜度。斜度越大脱模越方便，斜度过小则脱模困难，还会造成纸托表面拉痕或破裂。斜度过大将会降纸托尺寸精度，还会影响纸托的承载能力和弹性回复力。 一般脱模斜度取3°--6°。

③ Demoulding slope. In the paper mold forming process, the wet paper mold is close to the mesh mold, and the paper fiber will be embedded in the mesh of the mesh mold. In order to facilitate the transfer of the wet paper mold, the surface of the paper holder parallel to the demoulding direction should have a reasonable demoulding slope. The larger the slope is, the more convenient the demoulding will be. If the inclination is too small, it will be difficult to demould, and it will also cause tensile marks or cracks on the surface of the paper holder. If the inclination is too large, it will reduce the dimensional accuracy of the paper holder, and also affect the bearing capacity and elastic resilience of the paper holder. Generally, the demoulding slope is 3 ° to 6 °.