Metal vs Plastic Belts
As belting continues to evolve in food processing manufacturing many processors debate between the uses of Metal vs. Plastic. As a full service spiral system manufacturer, IJ White works closely with our customers and various belt manufacturers to ensure the correct belt for the correct application.
This section is intended for those who are considering the use of plastic vs. metal belts on their spirals, either to replace metal belts on existing units or designing new spirals using plastic modular belts. Many new plastic belts and combination plastic/stainless steel are coming onto the market. Also, new metal belt materials are coming on the market with substantial better fatigue resistant qualities. In all cases, you should make sure the belts you are selecting are specifically designed for the applied use in a spiral.
With new materials and many new design features, solid application support and extended warranties, the use of plastic belts on your next spiral application is an important consideration.
The following chart is a comprehensive review of the use of plastic belts versus metal belts. It does not take into consideration the new combination of plastic and stainless belts which are available.
If you are planning new installation design or replacement, let us consult on your requirement and we will provide specific analysis of the belts you are considering based on your specific product and environment. We can help you choose the best belt type and style for the application Contact an IJ White System Specialist
Technology: Advantage: Plastic
With more resources and R&D being spent on plastic materials and new design belt types including multiple collapse factors, lateral stiffness increases, plastic belts have been ahead of metal in this area.
Experience: Advantage: Plastic/Metal
The uses of metal belt on spirals dates back to 1964 and are a known factor in the industry. That being said we at I J White have been using plastic belting since 1987 for certain applications. While there are various reasons why one material may be better than another, your application and temperature conditions is what makes the difference.
Strength: Advantage: Plastic
As of this publication; plastic belts carry a higher load rating factor than metal, but strengths of belts are not as important as radius weight factors and belt cycle life, either way plastic belts have an advantage over metal.
Weight: Advantage: Plastic
In general, plastic belts have an advantage because they weigh less than metal belts, and carry a lower friction, which has a running tension effect on a belt. Assuming no strength loss, plastics are better from a total weight perspective.
Fatigue: Advantage: Plastic
Plastic belts do not have an expected cycle life as metal belts, so fatigue or work hardening of metal belts going through a spiral at expected life of 100,000 cycles are not an issue with plastic belts. Plastic belts are expected to last >1, 000,000 cycles, given all other things being equal.
Collapse: Advantage: Plastic/Metal
Both plastic and metal belts have as small as a 1:1 to 1 ratioo of belt width to inside radius collapse factor, so they are equal. This reduced radius gives you the ability for a smaller footprint spiral diameter, but must be evaluated in processing items as the height requirements increase for the same dwell times.
Open Area: Advantage: Metal
The most open area metal belts (rod type) have more open area than the most open plastic belts. Metal belts provide more Open Area, given all else equal.
Sanitation: Advantage: Metal
The most open area metal belts (rod type) are easier to clean than the most open area plastic belts. Detailed documentation on cleaning comparisons between the 2 materials should be reviewed by the belt manufacturer you are choosing.
Product Release: Advantage: Plastic
The contact surface of plastic belts offers a more non-stick surface than metal belts. Plastic belts are a better choice when the application calls for non-stick surfaces.
Belt Widths: Advantage: Plastic
Plastic belts have the advantage as they can go up to 72″ in width. Metal belts are limited to 60″. In all cases theses widths are application dependent.
Spiral Framework: Advantage: Plastic/Metal
Metal belts would generally be considered as less complicated on the frame construction primarily due to the belt support system used. A typical 36″ wide metal belt takes 2 supports for this width, while it takes 3 to properly support a plastic belt (due to lateral belt deflection). Hybrid Plastic/Metal belts avoid this issue.
Belt Speeds:Advantage: Plastic
Plastic belting has proven to be a better alternative when the application calls for higher belt speeds, as metal belts have generally been used only in applications where these speeds do not exceed 200FPM. Plastic belts can go over 300FPM in a given application.
Lubrication: Advantage: Plastic
With less friction on plastic belts, and a higher drive ratio on the belt to cage interface, plastic belts normally do not require lubrication in areas where metal belts have before. This reduced friction gives plastic belts an advantage in this area and allows for better sanitation.
Belt Life: Advantage: Metal/Plastic
Since plastic belts have a lower friction factor and generally run at less belt tensions than metal, we expect plastic belts to outlast metal on a given suitable application, although plastic belts on spirals are slightly less of a known factor, your application, load factors and operational environment all are critical in choosing a belt material.
Heat: Advantage: Metal
Metal belt is the best choice for now (over 220ºF), due to both plastic material composition and costing associated with high temperature materials.
Radius Weight: Advantage: Plastic
In all applications, available strength factors and expected belt tensions for both metal and plastic are related to the “radius weight factor” which is the weight of the product and the belt multiplied by its radius. A lighter belt allows for more capabilities.
Air Flow: Advantage: Metal
The most open material for airflow is metal, allowing for better vertical and horizontal airflow. Depending on air flow patterns and application the material demands can change. Please review your application requirements.
Thermal Conductivity: Advantage: Metal
Metal belts have better thermal conductivity than plastic belts. We are finding that there is a 1 degree difference in temperatures when freezing a product on a 1 hour dwell time basis.
Flammability: Advantage: Metal
Metal belts do not support a flame, while the standard plastic belts can. Note: There are plastic belt materials that are flame retardant. Contact an IJ White Belt Specialist Today
Drive Ability: Advantage: Plastic
Plastic belts have a greater drive surface contact area than metal, making them a better choice for lower tension systems.
Particulates: Advantage: Plastic
Metal belts can generate filings or metal particulates due to connector rod and belt link interface, or due to hold down rail to belt interface, all in selected applications. Plastic belts do not have this issue.
Repair Ability Advantage: Plastic
Since plastic belts are modular in design, maintenance and repairs made in the field are easier and quicker. No welding or grinding of metal in the product area is required, so plastic is better.
Cost: Advantage: Metal
The least expensive metal belt is less expensive than the least expensive plastic belt. Metal belts have an advantage overall because they are not petroleum based, making belt prices per linear foot less expensive in many cases. Costs vary daily so check with your belt supplier or Contact an IJ White Belt Specialist Today
Warranty: Advantage: Plastic
The typical metal belt carries a 12 month warranty and does not include application warranties. Many plastic belt manufacturers offer multiple year warranties and cover application suitability warranties. Plastic is a better choice from a warranty perspective. IJ White offers extended warranties for most belting product Contact an IJ White Belt Specialist Today