ISO/DIS 14890:2025(en)

ISO TC 41/SC 3

Secretariat: SAC

Date: 2024-12-19

Conveyor belts —Specification for rubber-or plastics-covered conveyor belts of textile construction for general use

© ISO 2025

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Contents

Page

Foreword iii

Introduction iv

1 Scope 1

2 Normative references 1

3 Terms and definitions 1

4 Designation 3

4.1 Belting designation 3

4.2 Examples for ordering 3

5 Construction 5

6 Length 5

7 Width 6

8 Rubber cover 7

9 Tolerances on total belt thickness and cover thickness 7

9.1 Tolerance on total belt thickness 7

9.2 Tolerance on cover thickness 8

10 Transverse fabric joints in multi-ply belting 8

10.1 General 8

10.2 Outer plies 8

10.3 Inner plies 8

10.4 Adjacent plies and non-adjacent plies 8

10.5 Joints in the same ply 8

10.6 Mono-ply,duo-ply and solid woven belting 9

11 Longitudinal fabric joints in multi-ply belting and duo-ply belting 9

11.1 Spacing of joints 9

11.2 Number of joints 9

12 Longitudinal fabric or carcass joints in solid woven and mono-ply belting 9

13 Elongation 9

14 Full thickness tensile strength 10

15 Adhesion 10

16 Troughability 11

17 Sampling 11

18 Identification 11

Annex A (informative) Items to be agreed between the manufacturer and purchaser 12

Annex B (informative) Helpful information to be supplied by the purchaser 13

Annex C (informative) Lateral drift —Straight running 16

Bibliography 17

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 41 Pulleys and belts (including veebelts), Subcommittee SC 3,Conveyor belts .

This third edition cancels and replaces the second edition (ISO14890:2013), which has been technically revised and minor editorial revised.

The main changes are as follows:

— Remove code letter G and its correspondent yarn of Glass from Table 1;

— Revise longitudinal joints numbers of Table 7;

— Include more tensile strength categories into Table 8 ;

A list of all parts in the ISO 14890 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

In the preparation of this International Standard, consideration has been given to the work of ISO Technical Committee ISO/TC41/SC3, and the following International Standards for conveyor belts have been followed as closely as possible:

— ISO 251;

— ISO 252;

— ISO 282;

— ISO 283;

— ISO 433;

— ISO 583;

— ISO 703.

Conveyor belts —Specification for rubber-or plastics-covered conveyor belts of textile construction for general use

This document specifies requirements for rubber and/or plastics covered conveyor belting of textile construction for general surface use on flat or troughed idlers.

This document is not suitable or valid for light conveyor belts as described in ISO 21183-1.

Items that are not requirements of this document, but need to be agreed between the manufacturer and the purchaser, are included in Annex A.

A list of the details intended to be supplied by the purchaser of belting with an enquiry is given in Annex B.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties

ISO 188, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests

ISO 252, Conveyor belts — Adhesion between constitutive elements — Test methods

ISO 282, Conveyor belts — Sampling

ISO 283, Textile conveyor belts — Full thickness tensile strength, elongation at break and elongation at the reference load — Test method

ISO 583, Conveyor belts with a textile carcass — Total belt thickness and thickness of constitutive elements — Test methods

ISO 703, Conveyor belts — Transverse flexibility (troughability) — Test method

ISO 4649, Rubber, vulcanized or thermoplastic — Determination of abrasion resistance using a rotating cylindrical drum device

ISO 10247, Conveyor belts — Characteristics of covers — Classification

ISO 16851, Textile conveyor belts — Determination of the net length of an endless (spliced) conveyor belt

EN 12882, Conveyor belting for general purpose use — Electrical and flammability safety requirements

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp

— IEC Electropedia: available at https://www.electropedia.org/

3.1

tensile strength

greatest measured force during the tensile test divided by the width of the test piece

Note 1 to entry: It is expressed in newton per milimetre (N/mm).

3.2

reference force

10 % of the nominal tensile strength in the longitudinal direction multiplied by the width of the test piece in millimetres

Note 1 to entry: It is expressed in Newton.

EXAMPLE  

Nominal tensile strength = 1 600 N/mm;

reference force = 160 N/mm;

reference force for 25 mm test piece = 25 mm × 160 N/mm = 4 000 N.

3.3

slab belt

conveyor belt made in wide widths and long lengths for subsequent slitting and cutting into narrower widths and shorter lengths to suit individual conveyor installations

3.4

solid woven belt

conveyor belt consisting of a carcass of more than one ply, the plies being interlocked in the weave or bound together by binding threads in the course of weaving

3.5

mono-ply belt

conveyor belt with a carcass consisting of one ply of woven textile fabric

3.6

duo-ply belt

conveyor belt with a carcass consisting of two plies of woven textile fabric, bonded together by an intermediate layer of elastomer of sufficient thickness to allow the incorporation of a tension element in the joint

3.7

multi-ply belt

conveyor belt with a carcass of two or more plies of woven textile fabric, the adjacent plies being bonded together by an intermediate layer of elastomer

3.8

primary yarn

load carrying yarn that contributes more than 50 %of the tensile strength

3.9

secondary yarn

load carrying yarn that contributes less than 50 %of the tensile strength

Belting is designated by reference to the following conveyor belt characteristics:

a) a reference to this International Standard, i.e. ISO 14890;

b) the required length, in metres;

c) the required width, in millimetres (see Table 4); the top cover thickness, in millimetres; the bottom cover thickness, in millimetres (where relevant, see Clause 5);

d) the fibre type of the carcass, in both the warp and weft directions, e.g.polyester (E) (warp) and polyamide (P) (weft) (EP) (see Table 1);

e) the full thickness tensile strength, in newton per millimetre, of belt width (see Table 8);

f) the number of plies or belt type (see Clause 3);

g) the cover classification (see Table 5), where appropriate;

h) the safety category in accordance with EN 12882.

The following are examples for ordering.

a) EXAMPLE 1 Multi-ply belt

A 400 m long belt, 1 200 mm wide, textile material in the longitudinal direction of polyester (E) and in the transverse direction of polyamide (P), having a minimum full thickness tensile strength of 1 000 N/mm belt width, with five plies and a top cover thickness of 4 mm, a bottom cover thickness of 2 mm, a cover classification of H in accordance with Table 5, and complying with the safety requirements of category 1 of EN 12882.

Example 1 — Designation

b) EXAMPLE 2 Duo-ply belt

A 200 m long belt, 1 000 mm wide, textile material in the longitudinal direction of polyester cotton (EB) and in the transverse direction of polyamide cotton (PB), having a minimum full thickness tensile strength of 800 N/mm, with two plies and a top and bottom cover of 1,5 mm, complying with the safety requirements of category 2A of EN 12882.

Example 2 — Designation

c) EXAMPLE 3 Mono-ply

A 150 m long, 1 200 mm wide Mono-ply belt, having a polyester warp (E) and a polyamide weft (P), a full thickness tensile strength of 630 N/mm belt width and a top cover thickness of 6 mm, a bottom cover thickness of 2 mm, and a cover classification of D in accordance with Table 5, complying with safety requirement of category 1 of EN 12882.

Example 3 — Designation

d) EXAMPLE 4 Solid woven belt

A 300 m long, 1 600 mm wide Solid Woven belt having a combined polyester and polyamide warp (EP) and a polyamide cotton weft (PB) and an integrally woven cotton (B) warp pile, having a minimum tensile strength of 1 250 N/mm belt width and 1,5 mm top and bottom covers, complying with safety requirement of category 3A of EN 12882.

Example 4 — Designation

Table 1 — Code designation of yarn

The carcass shall consist either of one or more plies of woven fabric or of solid woven fabric and shall be impregnated or coated with a rubber or plastics mix.

Where a breaker consisting of open mesh fabric, woven fabric, cord fabric or metal cord layer, is placed between the cover and carcass, or is embedded in the cover for the purpose of carcass protection, such a layer shall be considered part of the cover thickness and shall not be counted as a fabric ply.

If a fabric pile is integrally woven with the carcass on either one or both of the surfaces of the carcass, it shall be considered part of the carcass thickness.

NOTE The external surfaces of the conveyor belt generally consist of a defined thickness and quality of elastomeric material. Belting can also be supplied with one or both surfaces consisting of bare or coated fabric, as appropriate for the conveyor design and intended duty.

6.1 Belting that is ordered to an open-ended length shall be supplied subject to the tolerances specified in Table 2.

6.2 The length of belting supplied in the spliced endless formshall be described by the term "net endless length". The net endless length shall be supplied subject to the tolerances specified in Table 3 when measured in accordance with ISO 16851.

It is recommended that purchasers, where placing orders for belting, specify a length of belting which includes the lengths required for testing and any additional lengths necessary for vulcanized joints.

Table 2 — Tolerances on open-end lengths of belting

Table 3 — Tolerances on endless lengths of belting

The width of the belting and its associated tolerance shall be one of those given in Table 4.

Table 4 — Widths and tolerances on width of conveyor belting

NOTE see Table 5.

8.1 If the rubber cover is designated as type H, D or L category it shall comply with the appropriate requirements of Table 5, and, after ageing for 168 h at 70 °C in accordance with ISO 188, the values obtained for tensile strength and elongation at breakshall not vary from the original unaged values by more than 25 % of those values.

8.2 If the thickness of the rubber cover,as measured by the method described in ISO 583, is between 0,8 mm and 1,6 mm, the thickness of the test pieceshall be the maximum obtainable and a tolerance of -15 % shall be permitted on the tensile strength and elongation values given in Table 5.

Table 5 — Classification of conveyor belt rubber covers

If the mean of the 3,5 or 8 values of total belt thickness, when measured by the method in ISO 583, is 10 mm or less, the maximum permissible difference between the maximum thickness and the minimum thickness shall be not greater than 1 mm. For solid woven belting the maximum permissible differenceshall be not greater than 1,5 mm.

If the mean of the 3,5 or 8 values of the total belt thickness, when measured by the method in ISO 583, is greater than 10 mm, the maximum permissible difference between the maximum thickness and the minimum thickness shall be not greater than 10 % of the mean value. For solid woven belting, the maximum permissible difference shall be <15 %.

When measured by one of the methods described in ISO 583,the mean value of the cover thickness shall not be less than the specified thickness by more than the amounts given in Table 6.

Table 6 — Tolerance on cover thickness

Transverse joints shall be at an angle of between 45°and 70°to the centre line of the belt.

Neither outer ply shall have more than one transverse joint per 100 m length of belt.

No inner ply shall have more than two transverse joints per 100 m length of belt.

Transverse joints in adjacent plies and non-adjacent plies shall be not less than 3 m apart.

Transverse joints in the same ply shall be 5 m apart or more.

Transverse joints are not permitted in mono-ply,duo-ply or solid woven belting.

Longitudinal joints shall be at least 100 mm from the edge of the carcass. Each longitudinal jointshall be at least 100 mm from the joints in the other plies. The longitudinal joints in one ply of any piece of belting shall be separated by at least 300 mm where the width of the belting permits two joints in the same ply.

The maximum number of longitudinal joints in the plies shall be as given in Table 7.

Table 7 — Maximum number of longitudinal joints

Longitudinal fabric or carcass joints are not permitted in solid woven or mono-ply belting.

The elongation of the finished belting in the longitudinal direction at the reference force (see 3.2) when tested by the method described in ISO 283 shall be not greater than 4 %.

The value of full thickness tensile strength (see Clause 3) in the longitudinal direction of the finished belting, in newton per millimetre belt width, when determined by the method described in ISO 283, shall be not less than the value given in Table 8 for the designated belt type (see Clause 4).

Table 8 — Minimum full thickness tensile strength

The adhesion strengths when determined by the method described in ISO 252, shall be not less than the value given in Table 9 or Table 10, as appropriate.

Table 9 — Minimum adhesion strength of belts with synthetic filament carcass

Table 10 — Minimum adhesion strength of belts with textile carcass containing natural fibres

When tested in accordance with the method described in ISO 703,the minimum values for the ratio F/L shall be in accordance with those shown in Table 11, relative to the values for the angle of inclination shown.

Table 11 — Minimum troughability

Sampling shall be conducted in accordance with ISO 282.

It shall be possible to identify the name of the manufacturer of the conveyor belt, the fact that it conforms to this International Standard, its safety category in accordance with EN 12882, and the date of manufacture. The manner in which these data are identified shall be decided by the manufacturer or by agreement with the purchaser.

Where it is decided to mark the conveyor belt using impression moulding, the depth of the impression should not exceed 1,5 mm and the characters should be between 20 mm and 80 mm high, repeated at longitudinal spacing of approximately 15 m. In the case of slab belting,the marks may be in the transverse direction.

1. 
   (informative)
   
   Items to be agreed between the manufacturer and purchaser

The following items should be agreed between the manufacturer and the purchaser:

a) For long haul conveyors: for certain long haul conveyors, the maximum elongation at the reference force.

b) For plastic belts: the identification of plastic belts.

c) For testing: if testing is not to be carried out by the manufacturer, this should be agreed between the manufacturer and the purchaser when the order is placed.

d) Conditions of use: a statement of whether or not the conveyor belting is not for conventional use.

e) Any particular characteristics not specified by this International Standard.

1. 
   (informative)
   
   Helpful information to be supplied by the purchaser
   1. Applicability

When ordering belting, purchasers should define their requirements by making reference to Clause 4 (designation).

NOTE This annex is informative and,therefore, not a (mandatory) requirement of this International Standard.

• 1. Replacement belting

Where the belt is to be replaced on an existing conveyor, the following information should be supplied:

a) details of existing belt;

b) belt width, in millimetres;

c) belt speed, in metres per second;

d) pulley diameters, in millimetres, indicating any that are crowned;

e) method of take-up and amount available;

f) type of drive, including coupling and configuration of drive;

g) whether drive pulleys are lagged or bare;

h) pitch and angle of carrying idlers, including transition distances;

i) profile sketch, indicating position of drive, take-up, tripper and vertical curve radii;

j) belt length, in metres;

k) type of belt joint;

l) motor power installed;

m) type of start;

n) safety category required in accordance with EN 12882, i.e. 1, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B or 5C.

• 1. Additional information for a new installation

Where applicable, the following additional information should, if possible, be supplied:

a) material to be conveyed;

b) conditions, i.e.:

1) wet, dry, sticky, greasy or abrasive;

2) if hot or cold;

3) temperature (if known) or description of conditions;

4) whether or not cleaners are required;

c) bulk density of material;

d) size, in millimetres, of largest lumps (three dimensions);

e) average size, in millimetres, of materials;

f) approximate screen analysis of material (see ISO 7806 and ISO 9045);

g) method of handling the material immediately prior to feeding the belt;

h) whether the feed is to be regulated and type of feeder preferred;

i) conveyor duty in terms of mass per hour per day, stating day length in hours;

j) method of discharging conveyor;

k) amount of lift or fall;

l) initial length (centres of head and tail pulleys);

m) ultimate length (centres of head and tail pulleys);

n) position of drive;

o) contour sketch of proposed installation;

p) preferred idler arrangement and troughing angle;

q) environmental conditions;

r) any special features or test requirements;

s) safety category required in accordance with EN 12882, i.e. 1, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B or 5C.

1. 
   (informative)
   
   Lateral drift —Straight running

The conveyor belting, when running on a correctly aligned conveyor and loaded centrally, should not deviate from the central track by more than ±40 mm for a belt width up to and including 800 mm, or by more than ±5 % (±75 mm max.) of the belt width for widths of over 800 mm.

Bibliography

[1] ISO 251, Conveyor belts with textile carcass — Widths and lengths

[2] ISO 433, Conveyor belts — Marking

[3] ISO 7806, Industrial plate screens — Codification for designating perforations

[4] ISO 9045, Industrial screens and screening — Vocabulary

[5] ISO 21183‑1, Light conveyor belts — Part 1: Principal characteristics and applications