Timing Belt Backing and Cover Options
Timing Belt Backing and Cover Options
Belt backings are materials bonded to the tooth side or back side (non-tooth side) of a polyurethane timing belt to provide specific surface properties for conveying, product handling, noise reduction, or surface protection. Texas Belting offers over 18 backing types ranging from high-friction rubber for grip to low-friction coatings for accumulation, cushioning foams for delicate products, and chemical-resistant covers for harsh environments.
Backings can be applied to any T-Series, AT-Series, ATP, or HTD polyurethane timing belt. For food-grade applications, FDA-compliant backing materials are available. For welded conveying attachments (flights, cleats, dividers), see profile belts.
- 18+ backing materials available
- High-friction: Linatex, Supergrip, Minigrip
- Low-friction: PAZ, PAR polyamide fabric
- Cushioning: Porol foam, Celloflex, felt
- Chemical-resistant: NBR, PVC, silicone
- Tooth side (DL) or back side (DR) application
- FDA food-grade backing options available
- Custom backing combinations on request
High-Friction Backings
These backings provide maximum grip for conveying products that tend to slide on bare polyurethane surfaces. Commonly used on inclined conveyors and in packaging applications where product control is critical.
| Backing | Material | Key Properties |
|---|---|---|
| Linatex | Natural rubber | Highest grip, excellent abrasion resistance, industry standard for conveying |
| Supergrip | Natural rubber | Textured surface, high coefficient of friction, commonly used on inclines |
| Minigrip | Rubber | Fine textured grip for smaller, lighter products |
Polyurethane Backings
Thick polyurethane layers bonded to the belt back for applications requiring a machinable surface. These backings can be CNC-machined after bonding to create custom product-holding pockets, slots, or contoured surfaces. See modifications and machining for details.
| Backing | Material | Key Properties |
|---|---|---|
| T-Cover / PU-385 | Polyurethane | Thick PU layer, machinable for custom profiles and pockets |
| PU Yellow | Polyurethane | Color-coded PU backing for visual identification |
| D15 | Polyurethane | Extra thick PU for deep machining profiles and complex shapes |
PVC Backings
PVC backings offer oil resistance, clean surfaces, and various texture options for product control.
| Backing | Material | Key Properties |
|---|---|---|
| PVC Blue | PVC | Oil resistant, food-grade compatible, detectable color |
| PVC White | PVC | General purpose, clean surface |
| PVC White Herringbone | PVC | Directional grip pattern for inclined conveying |
| PVC White Nub | PVC | Raised nubs for product separation and control |
| Correx | Corrugated PVC | Textured corrugated surface for gripping irregular products |
Specialty Backings
| Backing | Material | Key Properties | Typical Use |
|---|---|---|---|
| PAZ | Polyamide fabric (tooth side) | Reduces noise 3 to 5 dB, protects teeth, lowers friction | Noise-sensitive drives, all profiles |
| PAR | Nylon fabric (back side) | Low friction, wear-resistant back surface | Back-side idler contact, accumulation conveyors |
| Porol | Foam | Soft cushioning, compresses under product weight | Delicate products, glass, electronics |
| Celloflex | Foam PVC | Lightweight cushioning | Light product handling, protective transport |
| Linatrile (NBR 65) | Nitrile rubber | Oil and chemical resistant | Oily environments, machine tools |
| RP 430 | Natural rubber | High abrasion resistance | Abrasive products, heavy wear applications |
| Chromleder | Leather | Traditional leather friction surface | Paper handling, printing equipment |
| TT60 | Rubber | Temperature resistant | Elevated temperature conveying |
Frequently Asked Questions
Backings are bonded to the tooth side or back side of timing belts to add functionality such as increased friction for product grip, reduced noise during pulley engagement, product protection through cushioning, chemical resistance for harsh environments, or specialized surface textures for conveying control.
PAZ (polyamide fabric on the tooth side) is the most commonly specified backing. It reduces engagement noise by 3 to 5 dB, protects the tooth surface from wear when engaging pulleys, and slightly reduces the coefficient of friction for smoother operation. PAZ is specified on the tooth and surface options page and is available on all profiles.
Yes. Belts can have different backings on the tooth side (DL designation) and back side (DR designation). A common combination is PAZ on the tooth side for noise reduction and Supergrip rubber on the back side for product conveying. This creates a dual-function belt that handles both power transmission and product transport.
Backing thickness varies by material: polyamide fabric (PAZ/PAR) is 0.5 to 0.8mm, rubber coatings are 1 to 3mm, felt is 1 to 2mm, foam is 2 to 5mm, and PU backings (T-Cover, D15) can be 5mm or thicker for deep machining. Total belt thickness including backing should be considered when designing the drive to ensure adequate pulley clearance.
Tooth-side backings (DL) slightly reduce power capacity because the backing sits between the belt teeth and pulley grooves. The reduction is typically 5% to 10% depending on material and thickness. Back-side backings (DR) do not affect tooth engagement and have no impact on power capacity. For applications where maximum power is critical, use back-side backings only or account for the DL reduction in belt width selection.
Yes. FDA-compliant backings are available including food-grade silicone, FDA-approved polyamide fabric, and detectable blue PVC. These maintain food contact compliance when used with FDA-grade belt compounds and stainless steel tension members. Contact Texas Belting at 888-203-2358 for specific food-grade backing availability.
For inclined conveying, Supergrip or Linatex rubber backings provide the highest friction to prevent product slippage. PVC Herringbone provides directional grip for moderate inclines. For steep inclines, combine a high-friction backing with welded profiles (flights or cleats) to physically carry products upward. For self-tracking belts on inclines, the V-guide keeps the belt centered while the backing grips the product.
Yes. Polyurethane backings (T-Cover/PU-385 and D15) are specifically designed for post-bonding CNC machining. Product-holding pockets, slots, channels, and contoured surfaces can be machined into the backing layer to create custom conveying surfaces. See the modifications and machining page for more detail on custom machining capabilities.
Need Help Selecting a Backing?
Send us your application details including product type, conveying angle, environment, and required surface properties. We will recommend the best backing material and configuration.