1. Evaluation of equipment capacity: misunderstanding of equipment output

1. How to measure the capacity of pulp molding equipment

When producing different products, the output is different. In order to facilitate the comparison of the production capacity of the equipment, the national industry standard uniformly stipulates that the daily production standard 10-inch disc (21 grams weight) is used as the standard to calculate the production capacity of the equipment, but in actual production, the weight of the 10-inch disc is Basically, it is 20 grams, so a 20-gram standard 10-inch disc is generally used as the measurement standard.

2. When new customers measure the production capacity of equipment, they usually have the following misunderstandings, which are easy to produce the illusion of production capacity:

Misunderstanding ①, the production capacity of the equipment is measured by the square box products with a higher gram weight. The same machine can produce 1 out of 9 20 grams of 10-inch discs 600 kg per day, and can also produce 1 out of 10 40 grams of square box products per day 1-1.2 tons. Before distinguishing the measurement standards, it is easy to produce the illusion of productivity. Equipment with a daily output of 600 kg will be mistaken for a 1 ton machine.

Misunderstanding ②, taking the 9-inch disc as the measurement standard, since the 9-inch disc is slightly smaller than the 10-inch disc, it is more economical to arrange 9-inch discs in many pulp molding equipment, but the number of 10-inch discs decreases sharply. Small.

Misunderstanding ③, the output is plus or minus 10% trap. The equipment capacity in this industry refers to the minimum output, which usually cannot be less than 10%. When talking about the output, the output is not allowed to be minus 10%, but many users generally take it seriously.

3. How to avoid the illusion of productivity

The equipment capacity in this industry refers to the minimum daily output that is not prepared, and is based on a standard 10-inch disc (20 grams) as the acceptance standard. Any product with a heavier square box, a 10-inch disc of 22 grams, or a 17-gram 9-inch disc as the measurement standard, and the yield is allowed to be plus or minus 10%, will produce an illusion of production.

2. Misunderstandings about edge-free energy saving and low cost

The definition of free trimming in the "Industry Standard for Pulp (Plant Fiber) Molded Disposable Tableware Production Lines" issued by the Ministry of Industry and Information Technology of the People's Republic of China is: "Using a special process, no blade or punching process is used to achieve the same edge trimming. process with the same effect". Performance requirements for edge-free trimming: "Edge-free products should have no cracks, missing edges, and no damage; and when 100 products are stacked together, there should be no obvious white areas and obvious burrs around, and the edge deviation of the products should not be. more than ±0.5mm”.

The problem of free trimming has been explored for more than 20 years, and a patent on free trimming was applied for in 1998. From the theoretical calculation and practical summary, the free trimming process consumes more energy than the trimming process.

1. According to the process of free trimming, if the concentration of pulp is high, the effect of free trimming will be poor, and the burrs will be serious. Therefore, when producing products without trimming, the concentration of pulp is much lower than that of trimming. Generally, the concentration of pulp for trimmed products: 4-5%; for trim-free products, 2-3%. For the same production of 1 ton of products, the drainage volume during vacuum suction filtration molding will increase a lot, almost 2 times or more. That is to say, the amount of vacuum consumed to produce trim-free products is much larger than that of trimmed products. Vacuum and heating are the main energy-consuming links in the pulp molding production process.

2. In order to achieve the effect of reducing burrs, the process of free trimming requires a long virtual pressing process during hot-pressing and clamping, otherwise there will be a phenomenon of "fried edges" or more burrs. The so-called "virtual pressing" means that the upper and lower hot pressing molds are not compressed when they are closed, and the "wet blank" in the mold is baked for a certain period of time, and the "wet blank" is baked to a certain degree of dryness. After the temperature is reached, the clamping force is applied for hot pressing.

This virtual pressure baking process wastes a lot of heat, and another negative consequence is that the density of the product is very low. For example, the same 300 10-inch disc products are stacked together, and the trim-free products are 30-50CM higher than the normal products, which greatly increases the packaging and transportation costs.

3. The problem of raw materials for edge-free products. According to feedback from many manufacturers who have used edge-free production, the use of 100% straw pulp such as bagasse pulp and wheat straw pulp cannot achieve the same edge-free effect. A certain amount of wood pulp should be added for the production. Mixing the pulp can achieve a certain effect.

4. The price of the molding die without trimming is high

5. The output of free trimming is lower than that of non-free trimming. It can be seen from the above points that (1) the edge trimming-free process has a large displacement and a long suction and filtration time, resulting in a reduction in production capacity; (2) a longer virtual pressure process results in a reduction in production capacity.

6. The problem of size and edge, because the thermal expansion of the mold is inevitable, and the suction filter molding mold has no thermal expansion. Therefore, when the wet blank is transferred to the hot pressing mold, there will inevitably be offset, so the problem of large and small edges is inevitable. Especially large platen (above 1500 platen) equipment.

Based on the above and practical verification, the production cost of trim-free products is about 20% higher than that of trimmed products.

3. Before selecting the equipment, the user needs to understand clearly the "molding cleaning cycle"

Wet-pressing pulp molding equipment requires regular dismantling of the mold to clean the carbon deposits. The automatic equipment for producing meal kits and the automatic equipment for producing fine work bags have different mold removal and cleaning cycles. Due to the high price of high-quality work kits, focusing on quality and light output, the goal is often to make ideal products; the production of meal kits is different, with homogeneous competition, comparability, winning by output, and paying great attention to production costs. Generally, the fully automatic equipment for producing meal packs usually has a mold removal and cleaning cycle of about 30 days. However, due to different equipment processes, the mold removal cleaning cycle is also different. If the demoulding cleaning cycle is too short, it will not be competitive. Before selecting equipment, users need to understand the problem of "molding cleaning cycle".

Fourth, the problem of back carbon

The so-called "back carbon" refers to the small carbon compounds that fall off the hot pressing upper die during the production of pulp molded products, fall on the surface of the product (usually the back of the product), and are attached to the back of the product. Small black spots of carbonization.

Due to the different production processes of the equipment, some equipments run for about a week, and the products will appear "back carbon". It needs to be removed and cleaned to remove it.

Before choosing equipment, users need to know whether there will be a "back carbon" problem.

Fifth, the automation of pulp molding equipment must be combined with the process

Just like "washboard + robot ≠ washing machine". Good automatic pulp molding equipment is not just a simple "manual molding machine + manipulator" can be achieved.