What Is the Paper Pulp Molding Process?
Before investing in an egg tray machine, learning the complete paper pulp molding process helps you match production equipment. Shuliy Machinery sorts out every production step, raw material option, mold, and drying solution for new recyclable packaging factory owners.
The whole paper pulp molding process relies on waste paper as an eco-friendly raw material. Recycled cartons, newspapers, waste books, and used egg trays can all be processed into pulp, which is cheap, easy to source, and fully biodegradable. All production links are divided into three core modules: pulping, forming, and drying.
Paper pulp molding process: 3 core production stages
This core section fully explains the standard paper pulp molding process for Shuliy egg tray lines.
- Pulping system: mix waste paper and water at a 3:1 ratio in the hydraulic pulper for 40 minutes to break paper into uniform pulp. After stirring in the pulp beater, the qualified slurry flows into the supply tank and waits for forming.
- Forming system: the vacuum pump draws pulp onto custom molds, and extra water is drained away. Wet egg trays take fixed shapes automatically without manual shaping.
- Drying system: high-temperature drying removes moisture from wet blanks to get finished rigid egg trays. Three drying modes are available for different factory budgets and weather conditions.
Mold options to match different pulp molding demands
Shuliy supplies two main mold types for the paper pulp molding process, with distinct service life and cost features.
- Plastic molds: low-cost, one-year warranty, over 2 years of service life. Ideal for small startups with frequent product style changes.
- Aluminum molds: corrosion-resistant, fully customizable, with a 2-year warranty and 3+ years’ service life, widely adopted by large-scale egg tray manufacturers.
You can select manual hourly mold cleaning or automatic high-pressure washing to cut labor workload.
Flexible drying & capacity choices for all factory scales
Shuliy pulp molding machines have output ranging from 1,500 to 8,000 egg trays per hour, adjustable by machine model and mold sets.
For drying, multi-layer metal drying lines are the most popular choice. It takes only 25 minutes to dry wet trays, unaffected by rainy weather, with compact size and flexible heat sources like LNG, diesel and natural gas. Small workshops can also choose natural air drying or brick drying rooms to lower initial investment.
Fully automatic paper pulp molding lines integrate pulping, forming, drying, and packaging into one flow. Though the upfront cost is higher, it drastically cuts labor expenses and brings faster investment returns for large pulp packaging factories.
