How is Molded Pulp Packaging Made?
Molded pulp products is made from plant fibers such as bagasse, straw, and recycled paper. The fibers are mixed with water, refined into a slurry, and formed when a vacuum draws the mixture onto a mold. After drying and hot pressing at high temperature and pressure, the material becomes dense, strong, and smooth. The pieces are then demolded, trimmed, and assembled if needed.Thanks to their natural fiber network, molded pulp products offer strong shock absorption, impact resistance, and anti-static performance, protecting items during transport. They contain no harmful substances and follow international rules on reducing hazardous materials and single-use plastics. With better technology and design, molded pulp is becoming a complete, sustainable packaging solution.
What is the process of molded pulp packaging manufacturing?
Pulping
Based on raw pulpboard, waste paper, cartons and other fibrous materials, the paper is converted into fibers and suspended in water through a series of processes such as breaking and refining, forming a pulp slurry. Depending on the characteristics required for the final product, the fiber length and pulp concentration can be flexibly adjusted to meet production needs.
Forming
The pulp slurry is dewatered on the mold through vacuum suction to form a green body. The prepared pulp is transferred to the forming mold via the suction system, where it forms a wet molded blank. At this stage, the blank has no hardness and contains a large amount of moisture, but the basic shape of the product has already been formed.
Drying
After pulping and forming, molded pulp products usually contain a relatively high moisture content. To ensure their performance and quality, they must be processed through a drying operation. The formed molded pulp products are then dried in hot air at 180–220 °C. Driven by fans, the moisture evaporated from the products is extracted from the drying chamber.
Hot Pressing
After the forming and drying stages, the pulp products are basically set in shape. They are then subjected to hot pressing under high temperature and relatively high pressure so that their appearance becomes neat and smooth, while their toughness and shock resistance are improved. The process typically operates at temperatures of 180–250 °C.
Demolding
The wet molded blank formed on the forming mold undergoes hot setting, during which about 98% of its moisture is evaporated by electric heating, giving the product good toughness and strength. Depending on requirements for product precision and surface smoothness, the demolding time is generally between 120 and 180 seconds.
Trimming
After hot setting, the molded products still have burrs around the edges. Through the trimming process, the finished products become more refined. Trimming is generally divided into straight cutting and ring cutting. Different trimming methods can be selected according to product requirements.
Bonding and Assembly
Bonding can also be regarded as a laminating or compositing process. To enhance strength, products are often made by bonding two molded pulp parts together. In addition to providing better rigidity, the overall packaging appearance is also more refined compared with single-piece packaging.
What is molded pulp made of?
Molded pulp products are functional packaging items made by using dedicated molds to shape plant-based fiber materials—such as bagasse from sugarcane and straw—into predetermined structural forms, providing protection and display for the packaged contents. The raw materials come from nature, and the waste after use can be recycled and is biodegradable, making molded pulp a typical environmentally friendly, green packaging material. View more molded pulp products, click here .
What is moulded paper pulp used for?
Moulded paper pulp products have excellent shockproof, impact-resistant, anti-static and anti-corrosion properties, and they do not pollute the environment. They comply with global export standards, helping manufacturers’ products enter both domestic and international markets.
They are widely used in many industries, including catering, food, electronics, electrical appliances, computers, mechanical parts, industrial instruments, glass crafts, ceramics, toys, pharmaceuticals and decorative products.
According to their application scenarios, molded pulp products can be divided into four main categories: industrial packaging, agricultural packaging, food packaging and medical product packaging.
