EP Conveyor Belt EP400/3,EP500/4,EP630/4,EP800/4-SUNGDA GROUP

General Introduction:

In the specification description of conveyor belts, we often see specifications such as EP315/3, EP400/3, EP500/4, EP630/4, EP800/4, EP1000/4, etc. What grades of conveyor belts do they represent?

EP conveyor belt is also called polyester conveyor belt (NP conveyor belt in the U.S), the “EP” is short for Polyester fabric, which includes polyester toward longitudinal(warp) and polyamide for latitude(weft), EP fabric plies are sandwiched between rubber skim coats for adhesion and load support, bottom and top cover compounds are added for maximum protection of the belt carcass.

The EP conveyor belt consisting of 2 to 6 EP fabric plies, EP rubber conveyor belt has the same merit as Nylon(NN) conveyor belt, its tensile carcass is made of warp polyester and weft nylon knitted fabric, its performance is characterized by low elongation in the warp direction and excellent troughing formation in the longitudinal direction. The strength of the EP conveyor belt will not decrease in a humid environment, no mildew occurs also, the initial modulus of the polyester is high, and a lower safety factor can be taken, it is suitable for conveying materials under medium, long-distance, and high load and high-speed conditions.

EP rubber conveyor belt is widely used in the mining and processing industries for transporting bulk or lumpy materials such as quarrying, ore, coke, aggregates, crops, sand, clinker, chemicals, construction materials, etc. EP fabric has the advantages of:

1.Lower longitudinal elongation.

2.Full resistance to mildew, moisture and rotting.

3.Good flexibility and trough ability.

4.Short take-up lengths.

5.Suitable for middle and long-distance transportation of higher load and speed.

EP fabric also has excellent compatibility with other rubbers, so it can be combined with any type of cover grade to make it a perfect match for almost any application, this allows EP conveyor belt to convey basically any type of product in any environment, from fine powders to large lumps, from dry to greasy materials, from extremely cold to very hot conditions.

Due to the above excellent performance of EP conveyor belt and its very economical price, it has become the most widely used type of conveyor belt in the world, taking light and heavy duty carrying work in the fields of seaport, steel mill, mining, cement plant, metallurgy, agriculture, electric power, chemical industry etc.

Key Symbols of EP Conveyor Belt:

Representation method of EP conveyor belt: EP1000/5 900*5 (6.5+3.0)=200m
The polyester layer represented by EP, EP1000 means the total tensile strength of belt is 1000N/mm, 5 represents the number of EP layers, so each EP layer will be 200N/mm(each EP layer type is EP200 correspondingly), 900 represents the width of the conveyor belt, , 6.5 represents the thickness of the upper cover rubber, and 3.0 represents the bottom cover rubber. the 200 represents the length of the conveyor belt.

Other Specification:

Tensile strength and width produced by SUNGDA: Tensile strength: 300~3200N/mm Width: 500~5500mm.
As for single EP layer type, the existing types are: EP100, EP150, EP200, EP250, EP300, EP350, EP400. The EP200 is used more and meets the basic required pulling force, the EP150 is second, and the EP400 is basically not used except super heavy duty field or long distance above 350 meters. The common ep conveyor belt type could be:

2-ply belts: EP315/2 EP400/2 EP500/2 EP630/2 EP800/2
3-ply belts: EP315/3 EP500/3 EP630/3 EP800/3 EP1000/3 EP1250/3
4-ply belts: EP630/4 EP800/4 EP1000/4 EP1250/4 EP1600/4
5-ply belts: EP800/5 EP1000/5 EP1250/5 EP1600/5 EP2000/5

In addition, EP has different characteristics such as heat resistance, cold resistance, oil resistance, acid and alkali resistance, flame retardancy and anti-static, The above characteristics allow EP conveyor belts to have different application variants, such as EP heat-resistant conveyor belts, EP fire resistant conveyor belts, EP oil-resistant conveyor belts, EP Chevron conveyor belts, and EP pipe conveyor belts etc.

What is the Safety Factor of Conveyor Belt?

Comparison of RMA and DIN Standard for Conveyor Belts

EP Conveyor Belt Layer is the More the Better?

EP Fabric Technical Specification(per ply):

Muti-ply EP Fabric Grade (Tensile Strength kg/cm, PIW):

The Most Popular Rubber Cover Standard of EP Conveyor Belt and Applications:

Above cover rubber grades can provide excellent abrasion resistance & cut /tear resistance.
These cover rubbers are used for heavy impact, large sized lumps, and sharp material.

Above cover rubber grades are widely used for general purpose with resistance to abrasion, ozone, cutting
and suitable for handling crushed rock, limestone,coal, slag, etc.

The following sheet is currently the main internationally popular EP conveyor belt implementation standard:

Cover Grade	Country	Applicable Standards	Min.Tensile Strength(Mpa)	Min.Elongation at Break(%)	Max.Abrasion Loss(mm³)
DIN-Z	Germany	DIN22102	15	350	250
DIN-Y	Germany	DIN22102	20	400	150
DIN-X	Germany	DIN22102	25	450	120
DIN-W	Germany	DIN22102	18	400	90
RMA-I	U.S.A	RMA	17	400	150
RMA-II	U.S.A	RMA	14	400	200
ARPM RMA-I	U.S.A	ARPM	17	400	125
ARPM RMA-II	U.S.A	ARPM	14	400	175
ISO-L	International	ISO -10247	15	350	200
ISO-H	International	ISO -10247	24	450	120
ISO-D	International	ISO -10247	18	400	100
AS-N	Australian	AS -1332	17	400	200
AS-M	Australian	AS -1332	24	450	125
AS-A	Australian	AS -1332	17	400	70
SANS-N	South Africa	SANS-1173	17	400	150
SANS-M	South Africa	SANS-1173	25	450	120
SANS-A	South Africa	SANS-1173	18	400	70
BS-M	UK	BS-490	24	450	120
BS-N	UK	BS-490	17	400	200
IS-N-17	India	IS 1891	17	400	200
IS-M-24	India	IS 1891	24	450	150
JIS-G	Japan	JIS-K 6332	14	400	250
JIS-L	Japan	JIS-K 6332	15	350	200
JIS-D	Japan	JIS-K 6332	18	400	100
JIS-H	Japan	JIS-K 6332	24	450	120
GB-H	China	GB/T 7984	24	450	120
GB-D	China	GB/T 7984	18	400	100
GB-L	China	GB/T 7984	15	350	200

Related Literatures：

Top 5 China Rubber Conveyor Belt Manufactures In 2026

Formulation Composition of High-Quality Conveyor Belts (from ContiTech & Dunlop)

Why 87.6% of companies choose Chinese conveyor belt manufactures?

How to choose right EP conveyor belt?

6 Steps to help you judge the quality of the EP conveyor belt in 1 minute.

10 Technical FAQs About Fabric (EP) Conveyor Belts for Heavy-Duty Conveying

1. How do I accurately calculate the required EP belt tension rating (EP Grade)?

Unlike steel cord belts, fabric belts are designated by their total carcass nominal breaking strength across all plies (e.g., an EP800/4 belt consists of 4 plies, each rated at 200 N/mm, yielding a total nominal breaking strength of 800 N/mm).

Selecting the correct EP grade requires evaluating the maximum belt tension (T_max) under steady-state operating conditions and dynamic transients (starting and stopping):

Required Nominal Belt Strength (EP)≥T_max /W x S₀

(Where T_{_max} is the maximum belt tension in kN, W is belt width in meters, and S_₀ is the safety factor).

For multi-ply fabric belts, static and dynamic safety factors (S₀) typically range from 10:1 to 12:1 under standard CEMA / DIN 22102 design rules to account for ply-to-ply load distribution variations and mechanical fastener or vulcanized splice efficiency.

Typical DIN/ISO-Type Fabric Belt Specifications:

EP Designation	Number of Plies	Individual Ply Rating	Total Nominal Strength	Max Recommended Working Tension (Tperm)*
EP400/3	3	133 N/mm	400 N/mm	~40 N/mm
EP500/4	4	125 N/mm	500 N/mm	~50 N/mm
EP630/4	4	157 N/mm	630 N/mm	~63 N/mm
EP800/4	4	200 N/mm	800 N/mm	~80 N/mm
EP1000/5	5	200 N/mm	1,000 N/mm	~100 N/mm
EP1250/5	5	250 N/mm	1,250 N/mm	~125 N/mm

*Based on a standard 10:1 working safety factor; actual allowable tension varies depending on joint type (vulcanized vs. mechanical).

2. What makes EP (Polyester/Polyamide) superior to NN (Nylon/Nylon) fabric belts?

Understanding fabric composition is essential for avoiding premature belt stretch and tracking failures:

Warp Fabric (Polyester / E): Runs longitudinally along the conveyor length. Polyester provides an exceptionally low dynamic elongation (typically <1.5% at nominal working load), which drastically reduces take-up stroke requirements compared to Nylon warp fabric.

Weft Fabric (Polyamide / P): Runs transversely across the belt width. Polyamide (Nylon) provides superior transverse flexibility, impact resistance, and mechanical fastener retention.

Compared to NN belts (Nylon warp and weft), EP belts exhibit lower operational stretch, higher resistance to moisture and mold, and superior thermal stability, making them the industry standard for medium-to-long distance bulk material handling.

3. Is more plies always better for heavy-duty applications?

No. Increasing the number of plies adds total tensile strength, but over-plying causes severe mechanical disadvantages:

1.Reduced Troughability: Excessively thick, multi-ply belts become overly stiff across their width, preventing proper contact with the center idler when empty and leading to severe mistracking.

2.Increased Minimum Pulley Diameters: Additional plies increase the total carcass thickness (e), raising inter-ply shear stress during bending. An EP1000/5 belt requires significantly larger pulleys than an EP1000/3 belt to prevent ply separation.

3.Higher Bending Fatigue: Repeated flexure over small drive pulleys causes inter-ply delamination over time.

Engineering best practice dictates choosing fewer plies with higher individual ply ratings (e.g., EP800/3 instead of EP800/5) to maximize troughability and reduce bending stress.

4. What is the realistic service life expectation for an EP conveyor belt?

Engineering life assessments must decouple Carcass Fatigue Life from Cover Rubber Wear Life:

EP Fabric Carcass: Under normal continuous operation, an EP carcass is engineered for a 5 to 10-year fatigue design life. Unlike steel cords, synthetic fibers experience gradual flexural fatigue and moisture aging.

Top/Bottom Covers: Cover wear is governed by material lump size, sharp edges, drop height at transfer points, and loading frequency. In heavy mining or aggregate crushing, top covers may wear down in 2 ~ 4 years, requiring cold-bonding repair or re-covering while the EP core remains structurally sound.

5. What are the key troughability and pulley diameter limits for EP belts?

Belt troughability must be verified against idler angle (20℃, 35℃, or 45℃) to ensure the unladen belt molds into the idler trough. Minimum drive pulley diameters (DA) per DIN 22102 are governed by total carcass thickness and stress levels:

EP Designation	Carcass Thickness (Approx.)	Min. Drive Pulley DA (100% Load)	Min. Troughability Width (35∘ Idlers)
EP400/3	~3.6 mm	315 mm	500 mm
EP630/4	~4.8 mm	400 mm	650 mm
EP800/4	~5.2 mm	500 mm	800 mm
EP1000/5	~6.5 mm	630 mm	1,000 mm
EP1250/5	~7.2 mm	800 mm	1,200 mm

Procurement Warning: Installing an EP1000/5 belt on a system designed with 400 mm pulleys will cause rapid inter-ply delamination within months of commissioning.

6. Hot Vulcanized, Cold Bonded, or Fastened: Which splice method should be specified?

The choice of joint method directly determines allowable working tension and system reliability:

Hot Vulcanized Splices (Efficiency: 85% – 90%): The gold standard for permanent installations. Uses step-matching ply techniques under heat and pressure. Required for high-tension EP belts (≥EP630).

Cold Bonded Splices (Efficiency: 70% – 80%): Uses specialized two-part cement at ambient temperatures. Ideal for underground or hazardous locations where hot vulcanizing presses cannot be operated.

Mechanical Fasteners (Efficiency: 50% – 65%): Plate or wire-hook fasteners offer rapid repair times but create stress concentrations and wear out scrapers. Recommended only for temporary applications, low-tension short runs, or emergency repairs.

7. How do I select the right cover rubber grade (DIN 22102 / ISO 10247)?

The rubber cover protects the load-bearing EP carcass from impact, abrasion, and environmental degradation. Standard cover grades are categorized by mechanical properties:

Grade W (ISO ‘D’): Premium abrasion resistance (≤90mm3loss). Recommended for highly abrasive materials like quartz, iron ore, and heavy sinter.

Grade X (ISO ‘H’): Balanced high abrasion and cut/gouge resistance (≤120mm3 loss). Ideal for large lump limestone, granite, and sharp metallic ores.

Grade Y (ISO ‘L’): Standard duty abrasion resistance (≤150mm3 loss). Suited for coal, sand, gravel, and general bulk materials.

Special Duty Compounds: Heat-resistant (HR / HRT up to 200°C), Oil-resistant (OR), and Flame-retardant (FR) formulations must be specified if chemical, thermal, or underground safety criteria apply.

8. What causes ply delamination, and how can it be prevented during procurement?

Ply delamination—the separation of adjacent fabric plies—is the leading cause of premature fabric belt failure. It is caused by:

Insufficient Inter-Ply Adhesion Strength: Low rubber-to-fabric bond strength during manufacturing.

Excessive Bending Stress: Running the belt over undersized pulleys or reverse bends.

Because synthetic fabrics exhibit higher elastic and permanent elongation than steel cords, gravity or hydraulic take-up units require significantly longer travel distance:

Chemical / Oil Ingress: Hydrocarbons or chemicals penetrating edge cuts and dissolving the skim rubber layer.

Procurement Rule: Always specify Inter-Ply Peel Strength ≥4.5N/mm (per ISO 252 testing) and ensure full rubber-sealed edges (Molded Edges rather than Cut Edges) for wet or chemically aggressive environments.

9. How does take-up travel calculation differ between EP belts and steel cord belts?

Take-Up Travel Allowance≈1.5%~ 2.5%) x Conveyor Center Distance

EP Belts: Require approximately 1.5~2.0% of total center distance in take-up stroke (e.g., a 200 m conveyor needs 3.0~4.0m of take-up travel).

Comparison with NN Belts: NN belts require up to 3.5% ~ 4.0% travel stroke, whereas Steel Cord belts require only 0.2% ~ 0.5%.

If take-up space is physically constrained on an existing structure, retrofitting from NN to EP—or specifying a high-modulus low-stretch EP weave—is mandatory to prevent take-up carriage bottoming out.

10. How should condition monitoring be conducted on fabric EP conveyor belts?

Unlike steel cord belts, which rely on electromagnetic scanners, multi-ply EP belts require a combination of visual, mechanical, and ultrasonic diagnostics:

Cover Thickness Ultrasonic Profiling: Non-destructive ultrasonic gauges measure remaining top and bottom cover rubber over time to schedule re-topping or replacement.

Visual & Thermographic Joint Monitoring: Infrared cameras detect anomalous heat buildup at splices caused by internal ply friction or dynamic joint slip prior to separation.

Automated Edge Inspection: Optical sensors monitor edge wear and ply fraying caused by structure rubbing, catching tracking issues before moisture penetrates the internal carcass.

Transitioning from time-based replacement to state-of-the-art condition-based monitoring ensures maximum tonnage throughput while eliminating catastrophic carcass snaps.

SUNGDA Conveyor Belt Vulcanization Workshops

SUNGDA Conveyor Belt Testing Lab:

We also supply conveyor idler roller, pulley and conveyor bracket, please log to our branch company official website www.conveyoroller.com or click below picture for idler roller producing video.