In modern industrial logistics in 2026, modular belts have become the undisputed solution for automating food, packaging, and pharmaceutical lines. Unlike solid belts, modular designs represent a complex kinematic system, where every millimeter of step and every degree of rotation determine the stability of the entire cycle. For engineers and procurement specialists, understanding the physics of processes—from the chord effect to the chemical resistance of polymers—is key to minimizing operating costs.

With over 20 years of experience supplying components, Belting Rezina offers not just products, but deep technical expertise in selecting configurations perfectly tailored to your production needs.

Materials Science: Physical and Chemical Analysis of Polymers

The choice of material is the foundation of reliability. Depending on the temperature conditions and the aggressiveness of the environment, three main types of thermoplastics are used. Each has a unique molecular structure, which determines its operational limits.

Comparative characteristics of materials (Table 1)

Characteristic	POM (Polyacetal)	PP (Polypropylene)	PE (Polyethylene)
Temperature range	$-40°C \dots +90°C$	$+5°C \dots +105°C$	$-70°C \dots +65°C$
Tensile strength	High	Average	Low
Coefficient of friction	Short	Average	Very low
Impact toughness	High	Average	Very high
Chemical resistance	To oils and fuels	To acids and alkalis	To extreme cold

POM (Polyacetal) is the most popular material due to its rigidity and low coefficient of friction. However, in washing lines that use strong acids, PP (Polypropylene) is preferred. When it comes to blast freezing, PE (Polyethylene) remains the only choice, as it maintains its elasticity at extremely low temperatures.

Physics of Motion: Chord Effect and Load Dynamics

One of the most critical factors in belt geometry is the chord effect (or polygon effect). This phenomenon occurs as the links pass through the drive sprockets. Since the belt moves in a polygonal, rather than a perfect circle, cyclical variations in linear speed occur.

Consequences of the chord effect:

• Pulsation: Vertical and horizontal vibrations of the web.
• Load vibration: Risk of tipping over of unstable containers (bottles, narrow vials).
• Wear: Increased load on shafts and bearing assemblies.

Mathematically, the pulsation amplitude depends on the sprocket's tooth count ($z$) and module pitch ($P$). The fewer sprocket teeth and the larger the module pitch, the higher the vibration level. For high-speed filling lines, Belting Rezina recommends using belts with a small pitch (12.5 mm or 25.4 mm) and sprockets with the highest possible number of teeth to ensure smooth operation.

Surface Types: Flush Grid vs. Flat Top

The surface structure determines the belt's functional purpose. The choice between mesh and solid fabric is always a balance between hygiene, drainage, and load-bearing capacity.

Flush Grid

Open area belts (20% to 60%) are indispensable in processes requiring air circulation or liquid drainage:

1. Cooling: Maximum airflow to the product after the oven.
2. Washing: Free flow of water and disinfectant solutions.
3. Drainage: Removing excess glaze or breading.

Flat Top

The flat surface ensures maximum stability. It's an ideal choice for transporting small parts or products prone to jamming. The absence of holes makes these belts easier to clean with scrapers, which is critical for the meat and confectionery industries.

Belting Rubber Advantages: We supply modular belts with special surface types (Rubber Top, Friction Top) for inclined conveying, ensuring reliable adhesion without the use of partitions.

Turning Geometry: Calculating Turning Sections

For conveyor systems with complex trajectories (L-shaped, U-shaped, or spiral conveyors), the turning radius ($R_{min}/W$) is a critical parameter. Incorrect calculation of the turning radius leads to modules being pulled out of the guides and pins being damaged.

Dependence of the turning radius on the tape width (Table 2)

Tape width (W)	Radius of inner edge (Rmin)	Reversal coefficient
200 mm	400 mm	2.0
400 mm	880 mm	2.2
600 mm	1320 mm	2.2
1000 mm	2500 mm	2.5

Note: Data is averaged for standard rotary belts. When using specialized series, the radius may be reduced.

FAQ: Frequently Asked Questions

1. How often should the pins in the modular belt be replaced?

Pins (axles) are a major consumable item. When operating 24/7 in abrasive environments (sand, dust), they should be inspected every six months. Using Belting Rezina's original polymer compounds extends the service life by 30%.

2. Is it possible to combine modules made of different materials?

Technically, yes, but it's not recommended. Due to the different coefficients of thermal expansion of POM and PP, the tape may warp when exposed to temperature changes, causing lateral movement.

3. What should I do if the belt pulsates at high speed?

Check the number of teeth on the drive sprocket. To eliminate the chord effect, it is recommended to upgrade to sprockets with a higher tooth count or replace the belt with a smaller pitch model.

4. Are modular belts suitable for working in oil?

Yes, provided you choose POM material. Polyacetal has exceptional resistance to vegetable and mineral oils, does not swell, and maintains pitch geometry.

Selecting a modular belt is a precision process that requires consideration of materials science, kinematics, and product specifics. Proper selection of module pitch and surface structure not only extends the service life of the equipment but also significantly improves the sanitary and hygienic performance of the production process.

Belting Rezina is your reliable partner in the world of industrial components. We offer:

• Direct deliveries from leading global manufacturers;
• Engineering calculation and audit of your conveyor systems;
• Our own warehouse and operational logistics.

Don't risk the stability of your production – trust professionals with 20 years of experience.Leave a request for belting.uz or get a specialist consultation by phone right now!