An Overview of Hollow Blow Molding（B）
4. Process Control
The quality of hollow blow-molded products is influenced by multiple factors, including parison temperature, blowing pressure, blowing speed, blow-up ratio, and mold temperature. Controlling these factors is crucial for achieving optimal product quality.
• Parison Temperature: Too high a temperature can lead to low melt viscosity and easy deformation, while too low a temperature can result in internal stresses in the product, causing deformation and stress cracking during use.
• Blowing Pressure: Air pressure typically ranges from 0.2 to 0.7 MPa, depending on the plastic type and parison temperature. Suitable pressure ensures clear appearance and patterns on the molded product.
• Blowing Speed: To obtain a product with uniform thickness and good surface quality, the blowing speed should be as high as possible but not excessively to avoid defects.
• Blow-up Ratio: The ratio of product size to parison size. It is determined by plastic type, product shape, size, and parison size.
• Mold Temperature: Affects cooling time and product deformation. The mold temperature should be adjusted according to the glass transition temperature of the plastic.
5. Applications
Hollow blow molding is widely used in the production of containers for daily necessities, cosmetics, pharmaceutical packaging, and industrial products. With the development of technology, its application has expanded to office supplies, household appliances, furniture, cultural and recreational products, and automotive parts.
6. Market Trends
According to statistics and forecasts by QYR, the global hollow blow molding machine market sales reached35.35billionin2024andareexpectedtoreach35.35 billion in 2024 and are expected to reach 35.35billionin2024andareexpectedtoreach40.25 billion in 2031, with a compound annual growth rate (CAGR) of 1.9% from 2025 to 2031. Europe is the largest market for hollow blow molding machines, followed by China and the Asia-Pacific region (excluding China).
