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No Gap Reverse Forming Process Pull Down Timing Belt with Silicone for Packing Machine
Premium integrated silicone coated timing belts with no-gap reverse forming technology. Ideal for high-speed film feed lines in Bosch and Ishida packaging machinery. 100% delamination-proof construction with precise CNC vacuum hole options from YONGHANG factory.
- Introduction
Introduction
In high-speed Vertical Form Fill Seal (VFFS) packaging machinery, the continuous pull-down timing belt is the heartbeat of the system. It is responsible for drawing down packaging film at precise indexing intervals to form pouches, bags, or sachets.
A No-Gap Reverse Forming Process represents the highest tier of manufacturing for these belts. It refers to a specialized vulcanization technique where a thick layer of premium silicone coating is molded seamlessly over the base polyurethane timing belt without any visible seams, splice gaps, or joint interfaces.
Here is the technical breakdown of the performance engineering behind the T10 and T10.5 series vacuum pull-down belts used in the automated packaging sector.
1. Material Science: The Seamless Silicone Coating
Standard pull-down belts are often made by gluing a strip of rubber or silicone onto a timing belt base, leaving a distinct seam or "gap" where the ends meet. The No-Gap Reverse Forming Process eliminates this flaw by liquid-injecting or vulcanizing the coating directly over a continuous, endless belt core.
High Coefficient of Friction: Silicone provides a consistent, high-grip surface that grabs plastic, foil, or laminated packaging films securely without slipping—even under high-speed acceleration.
Non-Marking & Food-Safe: Premium silicone is chemically inert, non-toxic, and completely non-marking. It transfers zero pigment or adhesive residue to the packaging film, which is critical for food and pharmaceutical safety.
Wear & Tear Resilience: The seamless structural matrix eliminates the leading cause of belt failure—edge peeling or delamination at the splice point under constant mechanical bending.
2. Technical Specifications & Dimension Matrix
These specific configurations (T10-630, T10-720, T10-920, T10.5-934.5) are industry-standard dimensions calibrated to fit global VFFS machine brands (such as Bosch, Ishida, Hayssen, Matrix, and Rovema).
| Product Code | Tooth Pitch(mm) | Total Length (mm) | Tooth Count (z) | Core Reinforcement | Target Packaging Film |
| T10-630 | 10mm | 630 mm | 63 teeth | High-Tensile Steel / Kevlar | High-gloss PP, PE laminates |
| T10-720 | 10mm | 720 mm | 72 teeth | High-Tensile Steel / Kevlar | Matte, thick foil composites |
| T10-920 | 10mm | 920 mm | 92 teeth | High-Tensile Steel / Kevlar | Large-format bulk bag films |
| T10.5-934.5 | 10mm | 934.5 mm | 89 teeth | High-Tensile Steel / Kevlar | Specialized OEM VFFS machinery |
The T10.5 Pitch Note: The $10.5\text{mm}$ pitch is a highly specialized, proprietary geometry utilized by specific European packaging machinery manufacturers to maintain strict mechanical synchronization under advanced high-speed cycles.
| Layer | Material Composition | Engineering Functionality |
| Top Film Face | Seamless Liquid Silicone (Red/White/Blue) | High friction, non-slip film drawing; zero joint gaps. |
| Base Core | Thermoplastic Polyurethane (TPU) | Rigid tooth profile for 100% slip-free pulley engagement. |
| Tension Member | Multi-Strand Steel or Aramid Cords | Prevents longitudinal stretch; handles high start-stop torque. |
| Customization | Vacuum Holes / Back Slots | (Optional) CNC-machined holes to allow vacuum suction. |
4. Key Performance Advantages in Packaging Lines
A. Perfect Vacuum Sealing and Air Extraction
For VFFS machines utilizing vacuum-assisted pull-down mechanisms, a seamless belt is mandatory. Any gap or uneven seam in the coating will cause instantaneous vacuum pressure drops, resulting in film slippage, bag length variations, or structural machine jams. The no-gap forming process guarantees a continuous, hermetic seal against the film.
B. Consistent Bag Length Accuracy
Because the silicone layer is uniform in thickness down to the millimeter, the pull-down force remains constant throughout the entire 360-degree rotation of the belt. This eliminates the minor speed fluctuations common in spliced belts, ensuring that cutting and sealing eyes read registration marks with absolute precision.
C. Superior Temperature Resistance
VFFS sealing jaws operate at high temperatures directly adjacent to the pull-down belts. The silicone formulation used in the reverse forming process handles ambient heat radiation effortlessly without softening, glazing, or losing its high-friction characteristics.
5. Industrial Manufacturing Excellence
Achieving a flawless, long-lasting pull-down belt requires advanced manufacturing control.
At YONGHANG (Yonghang Transmission Belt Factory), we utilize specialized reverse-molding equipment to produce integrated silicone timing belts. By injecting the silicone compound directly onto the polyurethane base, we eliminate the use of traditional industrial glues. Additionally, our automated CNC machining centers can introduce custom-milled vacuum holes or transverse back slots to perfectly match your specific packaging equipment configuration.
