Step-by-Step Paper Egg Tray Production Introduction

Eggtray Production Process Details

Although the egg tray production theory is the same, the production process can differ depending on the supplier of the egg tray production line. After more than 12 years of upgrading pulp molding technology, AGICO has formed the best egg tray production processes. Here is the detailed introduction of 6 major steps: material preparation and pulping → pulp mixing and preparation → molding and dewatering → drying and setting → shaping and cutting → stacking and packaging, which are further subdivided into 12 smaller steps.

1. Material Preparation and Pulping Section

The first step is waste paper collection and pulp making process, various waste paper materials are sorted and filtered, and then made into paper pulp by the pulping machine.

1. Raw material sorting: waste cardboard boxes, waste paper from books, scrap paper, straw fiber, remove plastic, tape, metal debris to avoid damaging equipment and producing defective products.
2. Waste paper is fed into a hydrapulper , water is added and the paper is stirred and broken up. The paper is then broken down into fiber pulp by the rotor’s tearing action. The pulp is then soaked and crushed at room temperature. The conventional pulping time is 20 to 40 minutes.
3. Waste paper pulp is screened by a sand remover and a vibrating screen to remove mud, sand and hard impurities, resulting in pure coarse slurry.

2. Mixing and Additive Preparation

Pulp needs to be added to water to a certain concentration, and then other additives are added to make the pulp molded trays with better strength and waterproof function.

When pulp is diluted and pumped into the storage tank. Water is added to adjust the pulp concentration: the commonly used concentration for egg trays is 2.5% to 4%.

Functional additives (as needed)

• Waterproofing agent: Added during the production of moisture-proof egg trays for cold chain processing;
• Enhancer: Improves the hardness and impact resistance of egg trays; standard for export orders; after thorough mixing, it is fed into the molding and feeding tank.

3. Pulp Forming – Vacuum Filtration

Our pulp molding machine can be configured for the production of various paper tray products, such as egg trays, bottle trays, shoe insert trays, fruit and vegetable trays, and high-quality industrial package trays. Here are the pulp-forming process details:

1. The pulp mold die is immersed in the slurry pool, the inner cavity of the mold is filled with fine filter screens, and a vacuum pump is connected to the back of the mold to create negative pressure.
2. Negative pressure adsorption molding adsorbs fibers onto the mold surface, while water content is drawn away through a filter screen. This is how the fibers accumulate to form a wet egg tray blank, this single pulp adsorption time is usually set at 3 to 8 seconds.
3. Then the demolding mold is raised, compressed air is used to blow back the mold, and the wet egg tray falls off the mold and onto the conveyor belt.
4. Customer can change the mold easiliy for other pulp tray productions, such as egg trays, duck egg trays, fruit trays, and industrial paper trays can be produced.

4. Eggtray Drying Process

AGICO can offer 2 types of auto drying solutions, civil engineering (brick drying) and metal drying.

The wet egg tray has a moisture content of 65%–75% and must be dried.

1. The wet billet is conveyed into a multi-layer enclosed drying tunnel by a conveyor belt;
2. Heat source: four types: natural gas, steam, coal, and electric heating (the 2026 energy-saving model mostly uses natural gas). The drying zone is temperature-controlled in sections: the first section is 80-110 ℃, the middle section is 120-160 ℃, and the last section is for cooling and dehumidification.
3. After drying, the moisture content of the finished product is controlled at 8% to 12%, and the hardness meets the standard.

5. Paper Tray Shaping & Hot Pressing

The completed paper trays are produced with extra parts at the edge, and their shape and dimensions are not accurate. AGICO offers a trimming and hot-pressing machine for a better paper tray quality level.

1. Trimming and finishing: The edges and corners of the dried egg trays are trimmed and cleaned with a cutter, resulting in a neat appearance.
2. Secondary pressing and leveling (high-end export model): hot pressing and leveling reduce warping and meet European and American procurement appearance standards.

6. Sorting, Packing, and Warehousing

After the eggtrays are dried, they need to be sorted and packed before delivery. AGICO offers automation solution for this process, the related equipment are auto packer, balling machine, etc.

1. Manual/Automatic sorting: Remove damaged or missing parts;
2. Automatic stacking, bundling, and packaging; finished products are then stored and ready for sale.

Additional information: Simple dry-process egg tray technique

Waste paper shredding → dry powder fiber mixed with adhesive → hot pressing molding in a mold. It does not require a lot of water, and the product is relatively hard, but the cost is high. It is mostly used in high-end special trays. 90% of egg trays on the market are made using the wet process.