Several issues that pulp molding enterprises should pay attention to

Due to the unfamiliarity of newly established pulp molding production enterprises with pulp molding equipment, pulp molding products, and processes, it is easy to create some misconceptions and enter some misconceptions. The summary is as follows for reference by new entrants.
1, Evaluation of Equipment Capacity: Misunderstandings of Equipment Production Capacity
How to measure the production capacity of pulp molding equipment
When producing different products, the output varies. In order to facilitate the comparison of equipment production capacity, the national industry standard uniformly stipulates that the daily production standard of 10 inch discs (21g weight) is used as the standard to calculate equipment production capacity. However, in actual production, the weight of 10 inch discs is basically 20g, so the measurement standard is generally 20g standard of 10 inch discs.
2. New customers in the industry often have the following misconceptions when measuring the production capacity of equipment, which can easily lead to the illusion of production capacity:
Misconception ①: Using square box products with higher weight to measure the production capacity of equipment, the same machine can produce 600kg of 20g 10 inch discs with a daily output of 1-9, or 1-1.2 tons of 40g square box products with a daily output of 1-10. Before distinguishing measurement standards, it is easy to create a production capacity illusion. A device with a daily output of 600 kilograms will be mistaken for a 1-ton machine.
Misconception 2: Using a 9-inch disc as the measurement standard, due to the fact that the 9-inch disc is slightly smaller than the 10 inch disc, many pulp molding equipment can arrange 9-inch discs more economically, but the quantity decreases sharply when making 10 inch discs.
Misconception ③, the trap of positive or negative 10% production capacity. In this industry, the equipment production capacity refers to the minimum production capacity, which usually cannot be reduced by 10%. When discussing production capacity, it is not allowed to be negative 10%, but many users generally do not take it seriously.
3. How to avoid the illusion of production capacity
The equipment production capacity referred to in this industry refers to the minimum daily production capacity that is not available, and is accepted based on a standard 10 inch disc (20 grams). Any heavier square box products, 10 inch discs weighing 22 grams, or using 17 grams and 9 inch discs as measurement standards, with a production allowance of plus or minus 10%, will produce an illusion of production capacity.
2, Misunderstandings about energy-saving and low cost without cutting edges
The Industry Standard for Pulp (Plant Fiber) Moulded Disposable Catering Utensils Production Line released by the Ministry of Industry and Information Technology of the People's Republic of China defines non cutting edge as "a process that achieves the same effect as cutting edge using special techniques without the use of blades or punching processes.". Performance requirements for non cut edges: "Non cut edge products should have no cracks, missing edges, or damage; and when 100 products are stacked together, there should be no obvious white areas or burrs around the edges, and the deviation of the product edges should not exceed ± 0.5mm.".
The problem of edge free cutting has been explored for more than 20 years, and a patent on edge free cutting was applied for in 1998. From theoretical calculations and practical summaries, it can be concluded that edge cutting is more energy-efficient than edge cutting technology.
According to the process of no trimming, if the concentration of the pulp is high, the effect of no trimming will be poor, and the burrs will be severe. So when producing edge free products, the concentration of the pulp is much lower than that of the cut edge. Generally, the concentration of cut edge product pulp is 4-5%; 2-3% of products without cutting edges. When producing 1 ton of products, the drainage volume during vacuum filtration molding increases significantly, almost twice or more. That is to say, the vacuum required to produce edge free products is much greater than that of edge cut products. Vacuum and heating are the main energy consuming processes in pulp molding production.
2. In order to achieve the effect of reducing burrs, the non cutting edge process needs to go through a long period of virtual pressing during hot pressing, otherwise there will be "edge explosion" or more burrs. The so-called "virtual pressing" refers to the process of hot pressing and closing the mold, where the upper and lower hot pressing molds are not compressed at first, and the "wet blank" inside the mold is baked for a certain period of time. After the "wet blank" is baked to a certain dryness, the clamping force is applied for hot pressing and shaping.
This virtual pressure baking process wastes a lot of heat, and another adverse consequence is that the compactness of the product is very low. For example, if 300 10 inch disc products are stacked together, the edge free products will be 30-50CM higher than normal products, greatly increasing packaging and transportation costs.
3. Regarding the issue of raw materials for edge free products, according to feedback from multiple manufacturers who have used edge free production, using 100% straw pulp such as bagasse pulp and wheat straw pulp cannot achieve the same edge free effect. A certain amount of wood pulp needs to be added for blending to achieve a certain effect.
4. The cost of forming molds without cutting edges is high
5. The yield of edge free cutting is lower than that of non edge free cutting. From the above points, it can be seen that ① the non cutting edge process has a large drainage volume and a long filtration time, leading to a decrease in production capacity; ② The longer virtual pressure process leads to a decrease in production capacity.
6. The issue of large and small edges is due to the inevitable thermal expansion of the mold, while the suction molding mold does not have thermal expansion. So when the wet billet is transferred to the hot pressing mold, there will inevitably be displacement, so the problem of large and small edges is inevitable. Especially for large platens (platens above 1500) equipment.
Based on the above and practical verification, the production cost of edge free products is about 20% higher than that of edge cut products.
3, Before selecting equipment, users need to have a clear understanding of the "mold removal and cleaning cycle"
Wet pressing pulp molding equipment requires regular removal of molds to clean accumulated carbon. The fully automatic equipment for producing meal bags has a different mold removal and cleaning cycle from the fully automatic equipment for producing high-quality work packages. Due to the high selling price of high-quality work packages, which focus on quality and light production, the goal is often to create ideal products; The production of meal bags is different, with homogeneous competition, comparability, winning by output, and a great emphasis on production costs. Generally, fully automatic equipment for producing meal bags usually has a demolding and cleaning cycle of about 30 days. But due to different equipment processes, the dismantling and cleaning cycles also vary. If the dismantling and cleaning cycle is too short, it is not competitive. Before selecting equipment, users need to have a clear understanding of the "mold removal and cleaning cycle" issue.
4, Back charcoal problem
The so-called "back charcoal" refers to the small carbonized particles that fall off the hot pressing mold during the production of pulp molded products, which fall on the surface of the product (usually the back of the product) and adhere to the back of the product.
Due to different production processes of the equipment, some products may have "back char" after running for about a week. It needs to be removed and cleaned before it can be eliminated.
Before selecting the device, users need to understand whether there will be "back carbon" problems.
5, The automation of pulp molding equipment must be combined with the process
Just like "washboard+robotic arm ≠ washing machine". A good fully automatic pulp molding equipment is not just a simple "manual molding machine+mechanical arm" that can be achieved.