1. Differences in Construction Operations and Techniques
Use of Release Agents: Wooden formwork must be coated with a release agent before use, and residual cement often needs to be cleaned after demolding. In contrast, PP hollow plastic formwork has a smooth surface and excellent release properties from concrete, requiring no release agent. After demolding, the surface remains free of cement adhesion, eliminating the need for cleaning and maintenance procedures.
Ease of Demolding: Due to its wood grain and water absorption, wooden formwork bonds relatively tightly to concrete, making demolding laborious and potentially damaging to both the formwork and the concrete surface. PP hollow plastic formwork, however, has a vastly different thermal expansion coefficient from concrete, allowing it to detach automatically upon curing. It can be easily removed with a light tap, without damaging the concrete edges and corners.
Splicing and Sealing: Wooden formwork tends to swell and deform when exposed to moisture, leading to grout leakage at the joints. PP hollow plastic formwork is non-absorbent, crack-resistant, and non-delaminating, offering extremely high dimensional stability. When combined with sealing tape at the joints, it effectively prevents grout leakage.
Processing and Reinforcement: Both types of formwork can be sawed, planed, and nailed, and their reinforcement methods are fundamentally the same. However, when nailing PP formwork, moderate force should be applied, and there are specific requirements for nail length (usually 30–50mm); nails should be neither too long nor too short.
2. Differences in Performance and Turnover Lifespan
Number of Reuses: Traditional wooden formwork is typically limited to 5–10 reuses due to moisture erosion and construction impacts. PP hollow plastic formwork, characterized by high strength, strong toughness, and corrosion resistance, can be reused up to 50–100 times, requiring almost no replacement from the foundation to the roof capping.
Weather and Water Resistance: Wooden formwork is prone to absorbing moisture and can easily delaminate, rot, or suffer from insect infestation when soaked. PP hollow plastic formwork boasts extreme moisture resistance, acid and alkali resistance, and corrosion resistance, making it particularly suitable for use in damp environments such as basements, bridges, and tunnels.
Surface Finish Quality: Concrete surfaces demolded from wooden formwork are relatively rough and usually require secondary plastering. Concrete surfaces demolded from PP hollow plastic formwork are flat and smooth, meeting the finish requirements for fair-faced concrete, thereby eliminating the need for secondary plastering.
3. Differences in Cost and Economic Benefits
Procurement and Amortized Costs: Although the initial purchase price of wooden formwork is relatively low, its limited number of reuses results in a higher amortized cost (approximately 5.6 RMB/sqm). While PP hollow plastic formwork has a higher upfront purchase price, its exceptionally long service life leads to an extremely low amortized cost per use (approximately 1.2 RMB/sqm), demonstrating a clear advantage in total life-cycle costs.
Salvage Value and Recycling: Discarded wooden formwork has virtually no salvage value, and disposing of it incurs additional costs. Conversely, discarded PP hollow plastic formwork, including waste boards and offcuts, can be 100% recycled and reused (with a recycling value of approximately 30–50 RMB/sheet), further reducing the total cost of ownership.
Labor and Schedule Costs: PP hollow plastic formwork is lightweight (only 1/21 the weight of steel), making handling, erection, and dismantling fast and convenient. Its installation and demolding efficiency can be increased by about 40% compared to wooden formwork, significantly saving labor hours and effectively shortening construction schedules.
4. Differences in Environmental Performance
The production of wooden formwork consumes vast amounts of natural forest resources, and burning discarded wood generates pollution. PP hollow plastic formwork is made from a polypropylene (PP) base material that is non-toxic and odorless. It not only reduces the felling of forests but also enables resource recycling, aligning with national green environmental protection and "dual carbon" policy guidelines.
