The current status of the design of pulp molded industrial packaging products has initially proposed a design specification based on the unit structure of pulp molded products. This design specification is helpful to standardize and standardize the design of pulp molded products, and improve the efficiency of pulp molded product design.
Pulp molded lining design and blister packaging design have the same purpose, effectively combining curved surfaces, chambers, ribs and other structures to form a product. Different from plastic products, pulp molding is a semi-flexible material, and the material strength is far less than that of plastic. Stress concentration should be avoided during design, which will improve the structural strength of the product throughout the entire life cycle.
1、Clarify the nature of the packaged product
The packaged product is the research object of the pulp molded product design. Before the structural design, its main properties related to the design must be clarified, mainly including the shape, quality, size, brittle value, vulnerable parts, accessories and other components of the packaged product. size etc. In addition, it is also necessary to understand the customer's design requirements and product positioning, and choose the slurry and process within a reasonable cost range. For example, some high-end cosmetic pulp molded packaging requires simple and delicate wet-pressed pulp trays, while rough dry-pressed pulp trays do not meet the tonality and positioning of the packaged objects.
2、Clarify the circulation environment of the package
All external factors that come into contact with in the circulation link are the circulation environment factors. Circulation environmental factors are the main external factors leading to package damage. The environmental factors affecting the design of pulp molded cushioning pads mainly fall into the following three categories:
- Physical and mechanical factors mainly refer to external factors such as shock and vibration in the transportation link, and stacking in the storage link. Before designing the pulp molded buffer liner, it is advisable to fully understand the loading and unloading equipment, loading and unloading height, transportation mode and means in the transportation link, as well as the stacking layers in the storage link. Vibration can cause fibers on the surface of the pulp molded cushioning pad to fall off and scratch the surface of the packaged product, making relative adjustments for different product characteristics.
- Biochemical factors, mainly including temperature, humidity, rain, salt spray, radiation, harmful gases, microorganisms and other natural conditions. Among them, the humidity in the transportation and storage links has the greatest impact on the pulp molded cushioning pad, which may lead to the risk of damp failure of the cushioning pad.
- Human factors, mainly refer to rough loading and unloading, violent transportation, etc. The drop impact caused by the loading and unloading process is the most serious damage to the package and is the main consideration.
3、Pulp Molded Cushion Pad Design Principles
- It has good shock energy and vibration energy absorption, which can reduce the shock and vibration transmitted to the product. In logistics environments such as transportation, it can avoid product damage caused by shock and vibration, especially in harsh logistics environments, such as harsh road conditions. , violent loading and unloading, etc. For example, pulp molding with a thicker wall has excellent impact resistance and vibration resistance. Within the allowable range of cost, use pulp molding with a thicker wall as much as possible to improve the packaging protection effect.
- Disperse the stress acting on the product, avoid stress concentration, and protect the surface and raised parts of the product. Through the arrangement of the molded product cavity and the position of the ribs, the convex part of the product can be effectively avoided, the concave part of the product can be filled, and the product can be provided with personal protection, which is also a problem that needs to be paid attention to on the design side.
- Prevent the product from moving in the packaging container, fix the product, prevent the products from contacting each other, and avoid scratches. The angle between the side wall of the structural unit of the pulp molded product and the demoulding direction is called the draft angle. Theoretically, the smaller the draft angle, the closer the pulp molding can be to the product to avoid product displacement. Due to the limitations of the process, the current wet press pulp molding can achieve 0.5°, and it is still difficult to achieve 0° draft.
- It has good damage resistance, environmental stability (temperature and humidity stability) and physical compatibility (anti-static, etc.). For example, products shipped overseas will experience harsh environments such as high temperature, high humidity, salt spray, etc., requiring pulp Molded products have a certain stability.
- Recyclable, easy to handle waste.
4、Pulp molding slurry selection
According to the different production raw materials and their proportions, the dry press pulp molding materials mainly include five kinds of paper pulp, waste corrugated cardboard, waste newspaper, paper scraps, and corrugated paper and newspaper mixed materials. The wet press pulp molding materials mainly include wood pulp, bamboo pulp, sugarcane pulp, straw pulp, reed pulp and other plant fiber pulp. Of course, various slurries need to be mixed and proportioned for use.
The performance of pulp molding materials depends on factors such as raw material ratio, production process, production equipment, etc.
According to the specific design requirements such as the nature and cost of the packaged product, select the appropriate pulp molding material.
- Small and lightweight electronic products have low cushioning performance requirements but high appearance requirements, and waste newspapers and raw pulp with soft material properties can be selected.
- Medium, heavy or expensive electronic products have high requirements on strength and cushioning performance. According to the nature of specific products, choose corrugated paper and newspaper mixed materials with different ratios.
5、Pulp Molded Cushion Pad Design
Formulation of the design plan: In addition to fully understanding the circulation environment of the package, the nature of the packaged product, and selecting suitable pulp molding materials, it is also necessary to understand the customer's design requirements, the size of the outer packaging box of the packaged product, etc., and formulate on this basis Several possible options.
- Up and down pad type. Limited by the outer packaging box, this packaging method has a small buffer area and requires high structural design, but the pad size is small and the production cost is low. For products with a large width, it may be considered to use the upper and lower bottom corner pads for packaging.
- Front and rear padded. Compared with the upper and lower pad type, the front and rear pad type has a larger protection area, more structural design methods, and less design difficulty, but the pad size is smaller and the production cost is high. For products with a small thickness, this packaging method tends to be comprehensive packaging.
- Overlap pad type. This packaging form is based on the above two forms. In addition to being suitable for product packaging with high strength and cushioning requirements, it is also used for packaging with a long distance between the product cushioning support surface and the inner surface of the outer packaging box.
- Combined pad. For heavy or expensive electronic products, pulp molding materials alone cannot meet the cushioning design requirements, and corrugated cardboard structural parts or honeycomb cardboard can be added as an auxiliary. In terms of protecting the appearance of packaged products, it may be considered to cover the product with plastic film or corrugated cardboard structural parts; in order to prevent the pulp molding material fibers from adhering to the product, it is advisable to cover the product with plastic film.