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Mantis Polypropylene Hollow Sheet (PP Hollow Sheet): Characteristics, Application and Market Prospects

• May 26, 2023

Overview of PP Hollow Sheet.PP Hollow Sheet (PP Hollow Sheet), also known as PP Honeycomb Sheet or Wantong Sheet, is a lightweight sheet made of polypropylene (Polypropylene) as the main raw material through extrusion molding. Its unique structural feature is that the cross section of the sheet presents a regular arrangement of rectangular or circular holes, forming a “hollow” sandwich structure. This design greatly reduces the weight while ensuring the strength of the sheet, making it an ideal substitute for traditional solid plastic sheets.

PP Hollow Sheet has an excellent strength-to-weight ratio. Its impact strength can reach more than 80% of that of a solid sheet of the same thickness, while its weight is only 30-50%. The typical density range is 0.4-0.8g/cm³, depending on the wall thickness and hollow structure design. The surface flatness error of the sheet is usually less than 0.5mm/m, and it can be processed into a variety of surface effects such as glossy, matte or embossed as needed.Chemical Properties.Polypropylene material itself has excellent chemical corrosion resistance. PP Hollow Sheet can resist the erosion of most acid, alkali and salt solutions, and is especially suitable for humid and chemical environments. Its water absorption rate is less than 0.01%, and it is almost unaffected by humidity. The operating temperature range is usually between -20℃ and 80℃, and special formulas can be extended to -40℃ to 100℃.Environmental advantages.PP materials are non-toxic and odorless, meet FDA food contact standards, and are 100% recyclable. Compared with halogen-containing materials such as PVC, PP Hollow Sheet does not release toxic substances such as dioxins when burned. Lead-free heat stabilizers and environmentally friendly colorants are widely used in modern production processes, making the products fully compliant with international environmental directives such as RoHS and REACH.Economic advantages.The hollow structure saves raw materials, making the cost of PP Hollow Sheet 20-40% lower than that of solid sheets. Its lightweight characteristics can save transportation and handling costs, and its easy installation also reduces labor costs. In long-term use, its strong weather resistance reduces the frequency of replacement, and the comprehensive use cost is significantly lower than many traditional materials.Production process and technology.Raw material selection.The main raw material of PP Hollow Sheet is polypropylene resin (PP), and the grades with a melt flow rate (MFR) between 0.5-4g/10min are usually selected. The following auxiliary materials are often added to improve performance:Anti-ultraviolet agent: improve outdoor weather resistance.Antioxidant: extend service life.

Masterbatch: provide various colors.Flame retardant: meet fire protection requirements.Reinforced fiber: improve mechanical strength.Core production process.Modern PP Hollow Sheet production adopts a one-step continuous extrusion process:Raw material pretreatment: Mix PP resin with various additives according to the formula ratio.Melt extrusion: Heat and plasticize through a twin-screw extruder (temperature 180-230℃).Mold forming:A specially designed flat die head forms a hollow structure.Cooling and shaping: Use a multi-stage vacuum shaping box for gradual cooling.Traction cutting: Cut to length or roll into a coil.Post-processing: Surface treatment, printing or composite processing.Key technical parameter control.Temperature control: The temperature deviation of each section of extrusion must be controlled within ±2℃.Vacuum degree: The fixed vacuum degree is usually -0.06～-0.09MPa.Pulling speed: Matching with extrusion speed, generally 2-10m/min.Wall thickness uniformity: Controlled within ±0.05mm.Quality inspection standards.The quality inspection of PP Hollow Sheet mainly includes:.Dimensional accuracy: thickness, width, flatness.Physical properties: impact resistance, bending strength, thermal deformation temperature.Appearance quality: surface defects, color uniformity.Characteristics of the Chinese market.China has become the world’s largest producer of PP Hollow Sheet, with an annual production capacity of more than 1 million tons. The industry is concentrated in Guangdong, Zhejiang, Jiangsu and other places, forming a complete supply chain. Domestic products are cost-effective, but the high-end market is still occupied by imported brands. Exports have grown rapidly in recent years, mainly to Southeast Asia, the Middle East and Africa.

Overall, PP Hollow Sheet, as a new material with excellent performance and environmental friendliness, will replace traditional materials in more fields and provide lightweight solutions for various industries. Its development potential still needs to be further explored.