egg tray machine: The features of pulp molding industry in oversea r...

egg tray machine: The features of pulp molding industry in oversea r...: Pulp molding products, such as  egg tray  or egg box, are widely used in oversea counties. Take U.S. for instance, almost all the pulp mold...

egg tray machine: Raw material of egg tray and the molding process

egg tray machine: Raw material of egg tray and the molding process: Virgin paper   and other   recycled materials  can be used directly  for the  egg tray machine .  The  composition  of wasted paper  is ver...

The features of pulp molding industry in oversea regions

Pulp molding products, such as egg tray or egg box, are widely used in oversea counties. Take U.S. for instance, almost all the pulp molding products come from waste paper. The yearly consumption of waste paper is 45000 tons, with annually increasing rate of 40%. The total consumption reached 810000 tons up to 2000. In 1989, there were 600 factories focus on pulp molding production, 200 of which targeted on waste paper, the other 300 used 50% of waste paper. The features of the pulp molding industry in oversea countries include:

Wider application, such as automobile, metal ware, pharmaceutical, furniture, stationery, etc. The paper pulp molding products can be said to penetrate into every aspect of people’s daily life.

Computer engineering had been used for the assistance of mold design and development. Some software, such as Pro/Engineer, Solid works are used for the 3 dimension design of the mold with more accuracy and rationality. The data developed and collected from those software can be utilized directly in mold

http://www.egg-tray.com/molding.html

The shaping, drying and hot pressing of egg box

Normally, the products coming out of the egg box machine is loosed and soft in texture, it’s necessary to condense the egg box into a solid consistency, or density. One of the solution is to use condense machine, the semi-fiinshed egg box is placed between two molds, when the molds are closed, the extra moist will be squeezed out. This function is included in the egg box shaping sections.

The water proportion ranges between 100%~300% after coming out of the egg box molding machine, the desired proportion is 9%~10%, sometimes even 3%~4%.  The drying of egg box is finished inside a closed continuous and circulated tunnel. Direct solar drying is also adopted in some egg box plants, even though the drying result can not be described as satisfactory. There are several kinds of drying oven: fuel type, steam type, electric type. The microwave type had been developed in recent year but is not in commercial use yet.

For a perfect appearance, the egg box should be hot pressed to adjust the shape. For egg tray production, this section is sometimes removed as there is too much requirement for egg tray appearance. After hot press, there can be a edge trimming machine to cut off the extra burr on the box products.

Raw material of egg tray and the molding process

Virgin paper and other recycled materials can be used directly for the egg tray machine. The composition of wasted paper is very complex, some in straw-basedprinting material, such in wood-based waste newspaper, some in grass pulp mixed waste cartons. Egg trayproduced by the different components have differentproperties, therefore, to obtain better economic resultsand performance, different pulp composition can be mixed in the real egg tray production.

The egg tray molding solution in China is called vacuum shaping solution. The molding equipment are a copycat from British Thomson’s two-station moldingequipment and transmission type linear automatic production line. Two-position device is currently ismainstream models. It also includes rotary types and reciprocating types.

Rotary type machine has higher level of technique, whose midge process is commonly known as “reversesuck” type, it can adapt to higher productivity and larger products, but the price is slightly higher. Thereciprocating type is cheaper in price ,  the molds sink into slurry tank during production, commonly known as “upper suction” type, it could normally cause uneven thickness in large molding products.

http://www.egg-tray.com/molding.html

Definition of egg tray pulp packaging industry

Paper pulp packaging industry adopts paper pulp, virgin pulp or waste paper, as raw material, by shaping through molds with filtration mesh, the water will be hydrated by negative air pressure, the remaining fiber will form the final package shape. Now the typical Chinese paper pulp industry follows below procedures:

Hydra pulping – pulp pools – shape molding – drying (naturally or by force) – hot press shaping – edge cutting – packaging.

Compared with other packaging stuffs, there are lots of advantage for paper pulp packaging stuff: research shows that in the same condition, the buffer features of paper pulp is better than EPS. According to social survey, there are two major industry that the paper pulp 

package are active: food container, such as egg tray and egg box, and industrial package, to be specified, including food package, egg tray, pharmaceutic package, phytosanitary plant package, medical tools package,  electric package, fragile package, military package, etc.

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Diagram of egg tray production

Diagram of egg tray production

The complete egg tray plant includes basically 3 sections: pulping section, molding section and drying section. Some assistant equipments are required as well such as air compressor, vacuum pumps, hot pressing machine, burners, etc.

Wasted paper pulping system for egg tray production

Wasted paper pulping system for egg tray production

The pulping system is a simple paper mill. The waste paper is fed into hydra pulper, which can be placed above ground or underground. The paper is crushed and shredded inside the drum where water is fed inside as well, making the pulp consistency around 4%~5%.

Water proof chemicals and dyes are added in this section.

Shape molding system for egg tray production

Shape molding system for egg tray production

The egg tray molding system is the key section of the whole production line. It's a rotary drum, on which groups of forming mold were fixed. The forming mold is made from ABS hard plastic or aluminum alloy, depending on final products. By changing the mold, different pulp products can be made.

During produciton, the drum ratates at the uniform speed, with one face of mold immersed in the pulp tank where the 1% consistency pulp is pumped from the pool. The vacuum pump is turned on to suck pulp, make it adhered to the mold surface and remove the extra water which will flow back to the pulp pools.

The drum keep rotating when the mold with fibre comes to the position where another transfer snatcher will suck the fiber out and at the same time, there is a air puff from the forming mold to push the fibre outwards. The transfer snatch finally release the pulp fibre onto a conveying tray, which will soon enter the drying tunnel.

Drying tunnel for egg tray production

Drying tunnel for egg tray production

After shaping, the semi-finised pulp products are fetched by the transfer arm and placed on a metal tray. The chain conveyor carries the tray into the drying oven where the moisture will be evaporated by the circulated hot wind, leaving 5~8% wet.

Two types of drying tunnels can be chosed from, single layer type and multi layer type:

The single one occupies larger space with longer distance. It can be built by bricks or metal frame with insulation panel. Chaines trays or stainless steel mesh can be used of the placing egg trays. To adopt such drying oven, the cost is cheaper while it consumes more heat and occupy more space.

The multi-layer one is a container-sized oven where the chained trays zigzag inside. Although it costs more investment by the drying efficiency is higher while it only uses small space. The oven structure is made from metal frame between which the insulation panel fill in. Metal trays are used for placing the products.

At the ends of both types of oven, a counter is used to count products that come out.

Various fuels can be used for the drying, including coal, diesel, natural gas, biomass, sawdust, propane, etc. By alter the ignitor of the burner, the fuels can be switched in between.

Other pulp molding products

Other pulp molding products

Different region has different standards of egg tray, with various egg loading capacity, 30 (5*6) eggs trays are the most common type. By changing the molds, different shapes of egg trays can be produced. The molds for egg tray adopts ABS plastic with high tension.

Bagasse pulp tableware production line

Bagasse pulp tableware production line

Bagasse is the newly developped material for the production of tableware. Compared with other raw material, bagasse tableware has better appearance and longer life span, compared with polyester, bagasse is more environmental friendly, which can be recycled or absorted easily. The production of bagasse tableware is similar with egg tray production. Bagasse pulp, which can be obtained from paper making plants, is used as raw material, after pulping, molding & drying section, the tableware will go through sterilization and edge trimming section before packaging. As the profit margin is much higher than other consumable tableware, it‘s another excellent choice for entrepreneurs who wants enter the local market.

Bagasse pulp tableware production line

Bagasse pulp tableware production line



Bagasse is newly used in the production of tableware, it's clean, hyguine and cause less pollutions to the environment. To produce tableware from bagasse, the profit margin is much more higher.


bagasse pulp table ware production line, bagasse plate machine

The current situation of China’s paper pulp industry

At the beginning of 1900s, the paper making had become a world-wide industry instead of family-size mill, various types of paper and paper pulp products had enter all aspects of people’s daily life.

The industry is very prosperous in France, U.S., Japan, Canada, Iceland, U.K., Denmark, Singapore and Netherland with large scale production. The development of China’s paper pulp industry starts very late but with rapid speed.

The first paper pulp production line was introduced in 1983, since then, the total quantity of paper-pulp related enterprise had reached 200~300. However, until 1990s, we only focus on the simple production such as egg trays, fruit trays and fast food tableware. It’s only until several years ago we start focus on producing paper pulp product with delicate appearance and complicate technique. Now, in terms of production equipment, product varieties, techniques, we have reached top level of the world, with the penetration into the world market.

http://www.egg-tray.com/

Egg tray machine, egg box machine

Egg tray machine, egg box machine