Which plants can be used for powder molding?

2026-01-17 18:48

Plant-powder molding is an environmentally friendly technology that involves grinding agricultural and forestry waste and other plant-based raw materials into fine powders, then mixing them, applying adhesives (or using adhesive-free methods), and subjecting the mixture to hot or cold pressing within molds to form products of specific shapes. The core principle lies in leveraging the inherent properties of plant fibers themselves or using auxiliary agents to achieve bonding and solidification. This process boasts advantages such as being green, highly efficient, and customizable, and it finds wide-ranging applications in sectors including home furnishings, packaging, and cultural-creative industries. The following sections provide a detailed overview from the perspectives of core elements, process parameters, key technologies, applications, and emerging trends:

I. Core Raw Materials, Additives, and Formulations

Core ingredient
- Main sources: agricultural and forestry processing residues such as bamboo powder, wood powder, rice husk powder, straw powder, and bagasse powder—low-cost and environmentally friendly.
- Raw material requirements: Particle size is typically controlled within the range of 80–120 mesh, with a moisture content of 5%–12%. Impurities must be removed by screening to ensure uniform pelletizing.
Common additives (add as needed)

Additive type	Effect	Common species	Addition amount (weight ratio)
Adhesive	Enhance adhesion	Urea-formaldehyde glue, phenol-formaldehyde glue, starch glue, vegetable protein glue	5% - 15%
Waterproofing agent	Improve water resistance	Paraffin emulsion, silicone oil	1% - 3%
Hardener	Accelerated thermosetting	Ammonium chloride, oxalic acid	0.2% - 1%
Coupling agent	Improve the interface	Silane coupling agent	0.1% - 0.5%

Typical Recipe Example
- Glue-free formula: 90% bamboo powder + 10% rice husk powder (purely physically pressed, relying on the thermoplastic properties of lignin).
- Standard formulation: Wood powder 70% + Straw powder 20% + Urea-formaldehyde resin 8% + Water repellent 2%.

II. Production Process and Key Parameters

Process Flow (Taking the Hot-Pressing Method as an Example)
1. Crushing and Screening: After the raw materials are crushed, they are screened to control particle size and impurity content.
2. Mixed sizing: The raw materials and additives are uniformly mixed in a high-speed mixer to ensure even coating of the sizing agent.
3. Dry air conveying: Hot-air drying controls moisture content, and secondary screening ensures dispersibility.
4. Metering and molding: After precisely measuring according to the product weight, the material is loaded into the mold.
5. Thermocompression curing: The material is cured and shaped by maintaining it at a set temperature and pressure for a specified period of time.
6. Post-processing: Deburring, surface finishing (spraying/painting / laminating), inspection, and packaging.
Key process parameters

Process stage	Parameter range	Impact
Hot-pressing temperature	100–180℃	If the temperature is too low, bonding will be insufficient; if it’s too high, carbonization and deformation are likely to occur.
Molding pressure	30-250MPa	Pressure determines density and strength; it’s essential to match the raw materials with the structure of the finished product.
Hot pressing time	30-300s	Too short a curing time leads to insufficient curing; too long a curing time results in low efficiency.
Moisture content	5% - 12%	Too low a temperature can easily cause brittleness and cracking; too high a temperature can easily lead to bubbling and deformation.

III. Core Technologies and Equipment

Comparison of Forming Technologies

Technology Type	Features	Applicable Products	Energy consumption
Hot pressing	Strong adhesion, high density	Sheets, furniture accessories	Middle and high
Cold pressing and forming	Low energy consumption, long cycle.	Lightweight packaging, cushioning materials	Low
Glue-free molding	Pure physical pressurization, environmentally friendly	Tableware, cultural and creative products	middle

Key equipment
- Crushing equipment: hammer crushers and ball mills, ensuring uniform particle size.
- Mixed equipment: high-speed mixer and ribbon blender, ensuring uniform dispersion of additives.
- Molding equipment: hot press machines (flat/curved molds), cold press machines, and molding production lines, which control temperature, pressure, and time.
- Post-processing equipment: sanding machines and painting lines, enhancing appearance quality.

4. Product Performance and Testing Standards

Core Performance Metrics
- Physical properties: Density 0.8–1.2 g/cm³, flexural strength 15–35 MPa, water absorption rate 5%–20% (depending on formulation).
- Environmental performance: Glue-free products are fully biodegradable; glue-containing products must meet the E0 formaldehyde emission standard (≤0.5 mg/L).
Common testing methods
- Mechanical Properties: Flexural and compressive strengths are tested according to GB/T 17657.
- Environmental indicators: Formaldehyde emission levels are tested according to GB 18580.
- Weather Resistance: Assessed through high- and low-temperature cycling and damp-heat aging tests.

V. Application Scenarios and Market Prospects

Main application areas
- Home building materials: decorative panels, baseboards, picture frames, coat hangers, and more.
- Packaging materials: pulp molded alternatives, cushioning liners, food-grade tableware.
- Cultural and Creative Industries: Toys, handicrafts, and festive decorations—offering personalized customization services.
- Landscape and municipal engineering: biodegradable products such as flower pots, tree guards, and landscape ornaments.
Market and Trends
- Driving factors: The ban on plastics and environmental policies are boosting the shift away from traditional plastics and wood, while the demand for the resource utilization of agricultural and forestry waste is on the rise.
- Development trends: glue-free, high-efficiency, intelligent (automated production lines), and multi-functional (flame-retardant and antimicrobial modification).
- Challenges: Cost control, enhanced water resistance, and stability in scaled-up production.

6. Differences from pulp molding

Comparison item	Plant powder molding	Pulp molding
Raw material form	Dry powder	Wet pulp
Process characteristics	Dry forming, with little wastewater.	Wet forming requires dehydration and drying.
Density intensity	High density, high strength	Low density, good cushioning.
Production efficiency	Short cycle, suitable for mass production.	Longer cycle, suitable for complex shapes
Cost	Low raw material costs, moderate energy consumption.	High energy consumption, high wastewater treatment costs.

VII. Summary

Plant-based powder molding uses agricultural and forestry waste as raw materials, achieving efficient and environmentally friendly shaping through rational formulation and optimized processing techniques. In the context of green transformation, this technology holds tremendous growth potential. Optimizing raw material pretreatment, precisely controlling hot-pressing parameters, and developing glue-free or bio-based additives are key areas for enhancing product competitiveness.

Advantages of Pulp Molding Coffee Cup Coasters in Production and Application

This factory has achieved a major breakthrough: plant-based powders can now be directly molded into products of various shapes, replacing plastics, wood products, and bamboo products.

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