oSIST prEN 1417:2021

Plastics and rubber machines - Two-roll mills - Safety requirements

This European Standard deals with all significant hazards, hazardous situations and events relevant to two-roll mills for the processing of rubber and/or plastics, when they are used as intended and under conditions of misuse which are reasonably foreseeable by the manufacturer (see Clause 4).
This European Standard covers two-roll mills as defined in 3.1.
This European Standard does not deal with the design of a local exhaust ventilation system that may be necessary in specific applications of the machine not known by the manufacturer.
This European Standard is not applicable to two-roll mills manufactured before the date of its publication as an European Standard.

Kunststoff- und Gummimaschinen - Walzwerke - Sicherheitsanforderungen

Dieses Dokument behandelt alle signifikanten Gefährdungen, Gefährdungssituationen und Gefährdungsereignisse, die für Walze zur Verarbeitung von Kunststoff und/oder Gummi relevant sind, wenn sie bestimmungsgemäß und unter Bedingungen, die vom Hersteller als Fehlanwendung vernünftigerweise vorhersehbar sind, verwendet werden (siehe Anhang A). Die Gefährdungen sind unter Berücksichtigung sämtlicher Phasen der Lebensdauer der Maschine nach EN ISO 12100:2010, 5.4, identifiziert worden.
Dieses Dokument gilt für Walzwerke gemäß der Definition in 3.1.
Dieses Dokument behandelt folgende Zusatzgeräte als integraler Bestandteil der Maschine:
- Kraftbetätigte Führungsbacken;
- Streifenschneideinrichtung;
- Stockblender;
- Rückführband;
- Wendeeinrichtungen;
- Nebenwalze.
Dieses Dokument behandelt nicht die Konstruktion einer lokalen Absaugeinrichtung, die bei bestimmten Anwendungen der Maschine erforderlich sein können und dem Hersteller nicht bekannt sind.
Dieses Dokument gilt nicht für Walzwerke, die vor Veröffentlichung dieser Europäischen Norm hergestellt wurden.

Machines pour les matières plastiques et le caoutchouc - Mélangeurs à cylindres - Prescriptions de sécurité

Le présent document traite de tous les phénomènes dangereux, situations dangereuses ou événements dangereux significatifs pertinents pour les mélangeurs à cylindres pour le traitement du caoutchouc et / ou des plastiques (voir Annexe A), en cas d’utilisation normale ou de mauvais usage raisonnablement prévisible par le fabricant pendant toutes les phases de la vie de la machine, tel que décrit dans l'EN ISO 12100:2010, 5.4.
Le présent document traite des mélangeurs à cylindres tels que définis en 3.1.
Le présent document traite de l’équipement auxiliaire suivant faisant partie intégrante de la machine :
-   oreilles motorisées ;
-   dispositif de coupe de bande ;
-   blender (unité d’homogénéisation) ;
-   tapis releveur ;
-   socs de mélangeage relevables ;
-   rouleau annexe.
Le présent document ne traite pas de la conception du système d'aspiration locale qui peut être nécessaire dans des applications spécifiques de la machine non connues du fabricant.
Le présent document ne s'applique pas aux mélangeurs à cylindres fabriqués avant sa date de publication comme Norme Européenne.

Stroji za predelavo gume in plastike - Dvovaljni gnetilniki - Varnostne zahteve

General Information

• Status: Not Published
• Public Enquiry End Date: 22-Dec-2021
• ICS: 83.200 - Equipment for the rubber and plastics industries
• Technical Committee: VSN - Safety of machinery
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 13-Oct-2021
• Due Date: 02-Mar-2022
• Completion Date: 05-Jan-2022
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: FprEN 1417 - Plastics and rubber machines - Two-roll mills - Safety requirements

Relations

• Revised: SIST EN 1417:2015 - Plastics and rubber machines - Two roll mills - Safety requirements
• Effective Date: 11-Nov-2020
• Revised: SIST EN 1417:2015 - Plastics and rubber machines - Two roll mills - Safety requirements
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 1417:2021
01-december-2021
Stroji za predelavo gume in plastike - Dvovaljni gnetilniki - Varnostne zahteve
Plastics and rubber machines - Two-roll mills - Safety requirements
Kunststoff- und Gummimaschinen - Walzwerke - Sicherheitsanforderungen

Machines pour les matières plastiques et le caoutchouc - Mélangeurs à cylindres -

Prescriptions de sécurité
Ta slovenski standard je istoveten z: prEN 1417
ICS:
83.200 Oprema za gumarsko Equipment for the rubber and
industrijo in industrijo plastics industries
polimernih materialov
oSIST prEN 1417:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 1417:2021
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oSIST prEN 1417:2021
DRAFT
EUROPEAN STANDARD
prEN 1417
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2021
ICS 83.200 Will supersede EN 1417:2014
English Version
Plastics and rubber machines - Two-roll mills - Safety
requirements

Machines pour les matières plastiques et le caoutchouc Kunststoff- und Gummimaschinen - Walzwerke -

- Mélangeurs à cylindres - Prescriptions de sécurité Sicherheitsanforderungen

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 145.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1417:2021 E

worldwide for CEN national Members.
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oSIST prEN 1417:2021
prEN 1417:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction..................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions.................................................................................................................................... 8

4 Safety requirements and/or protective/risk reduction measures ............................................ 11

4.1 General ............................................................................................................................................................. 11

4.2 Control systems ............................................................................................................................................. 12

4.2.1 General ............................................................................................................................................................. 12

4.2.2 Starting ............................................................................................................................................................. 12

4.2.3 Normal stopping ........................................................................................................................................... 12

4.2.4 Emergency stop ............................................................................................................................................. 12

4.2.5 Failure of energy supply ............................................................................................................................ 12

4.3 Mechanical hazards ..................................................................................................................................... 12

4.3.1 Requirements applicable to all types of two-roll mills ................................................................... 12

4.3.2 Specific requirements applicable to large two-roll mills (D > 200 mm) .................................. 18

4.3.3 Specific requirements applicable to small two-roll mills (D ≤ 200 mm) ................................. 22

4.4 Electrical hazards ......................................................................................................................................... 27

4.4.1 Electrical shock or burns caused by direct or indirect contact with live parts ..................... 27

4.4.2 Electrical shock, or fire due to electrostatic discharge ................................................................... 27

4.5 Hazards due to electromagnetic interference ................................................................................... 27

4.6 Thermal hazards ........................................................................................................................................... 27

4.7 Hazards caused by gases, dusts or vapours hazardous to health ............................................... 27

4.8 Hazards generated by neglecting ergonomic principles................................................................ 27

4.9 Hazards generated by noise ..................................................................................................................... 28

4.9.1 Main noise sources ....................................................................................................................................... 28

4.9.2 Noise reduction at source by design ...................................................................................................... 28

4.9.3 Noise reduction by devices ....................................................................................................................... 28

4.9.4 Information connected with noise hazards ........................................................................................ 28

5 Verification of safety requirements and/or protective/risk reduction measures............... 28

6 Information for use ...................................................................................................................................... 31

6.1 General ............................................................................................................................................................. 31

6.2 Instruction handbook ................................................................................................................................. 32

6.2.1 General ............................................................................................................................................................. 32

6.2.2 Two-roll mills equipped with a trip bar as in 4.3.2.1 ...................................................................... 32

6.2.3 Two-roll mills equipped with a trip device as in 4.3.3.2 ................................................................ 33

6.2.4 Two-roll mills equipped with light curtains as in 4.3.3.3.3 ........................................................... 33

6.2.5 Laboratory two roll mills ........................................................................................................................... 33

6.2.6 Noise emission ............................................................................................................................................... 33

6.3 Marking ............................................................................................................................................................ 33

6.4 Warning notice/signs on two-roll mills equipped with a trip bar as in 4.3.2.1 ..................... 34

6.5 Warning notice/signs on two-roll mills equipped with a trip device as in 4.3.3.2 ............... 34

Annex A (informative) List of significant hazards ........................................................................................... 35

Annex B (normative) Positioning of the trip devices specified in 4.3.3.3.2 ........................................... 39

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B.1 Production applications ............................................................................................................................. 39

B.2 Laboratory applications ............................................................................................................................. 41

Annex C (normative) Noise test code ................................................................................................................... 42

C.1 Introduction ................................................................................................................................................... 42

C.2 Determination of the A-weighted emission sound pressure level at the workstation ....... 42

C.2.1 Basic standards and measurement procedure .................................................................................. 42

C.2.2 Measurement uncertainty ......................................................................................................................... 43

C.3 Determination of the A-weighted sound power level ..................................................................... 43

C.3.1 Basic standards and measurement procedure .................................................................................. 43

C.3.2 Measurement uncertainty ......................................................................................................................... 43

C.4 Mounting and operating conditions ...................................................................................................... 43

C.5 Information to be recorded and reported ........................................................................................... 44

C.5.1 General ............................................................................................................................................................. 44

C.5.2 General data ................................................................................................................................................... 44

C.5.3 Mounting and operating conditions ...................................................................................................... 44

C.5.4 Standards ........................................................................................................................................................ 44

C.5.5 Noise data ........................................................................................................................................................ 44

C.6 Declaration and verification of noise emission values ................................................................... 45

Annex D (informative) Positioning of trip bar .................................................................................................. 47

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2006/42/EC aimed to be covered ...................................................... 48

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oSIST prEN 1417:2021
prEN 1417:2021 (E)
European foreword

This document (prEN 1417:2021) has been prepared by Technical Committee CEN/TC 145 “Plastics and

rubber machines”, the secretariat of which is held by UNI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1417:2014.
A transition period of 12 months (dav + 6 months + 6 extra months) is proposed.

In comparison with the previous edition EN 1417:2014, the following technical modifications have been

made:
a) the structure of the document is modified;
b) covered ancillary equipment clarified in scope;
c) the list of significant hazards is moved to an informative annex;
d) technical developments in safeguards are taken into account;
e) revised type-A and type-B standards are taken into account;

f) removed the class of intermediate two-roll mills (requirements integrated in large and/or small two-

roll mills);
g) requirements for braking system adapted to the state of the art;
h) requirements for trip bar modified;
i) hazard and measures related to secondary roller added;
j) requirements for small mill rolls modified.

This document has been prepared under a Standardization Request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of EU

Directive(s) / Regulation(s).

For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part

of this document.
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oSIST prEN 1417:2021
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Introduction
This document is a type-C standard as stated in EN ISO 12100.

This document is of relevance, in particular, for the following stakeholder groups representing the market

players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);

— health and safety bodies (regulators, accident prevention organizations, market surveillance, etc.).

Others can be affected by the level of machinery safety achieved with the means of the document by the

above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);

— machine users/employees (e.g. trade unions, organizations for people with special needs);

— service providers, e.g. for maintenance (small, medium and large enterprises);
— consumers (in the case of machinery intended for use by consumers).

The above-mentioned stakeholder groups have been given the possibility to participate at the drafting

process of this document.

The machinery concerned and the extent to which hazards, hazardous situations or hazardous events are

covered are indicated in the Scope of this document.

When requirements of this type-C standard are different from those which are stated in type-A or type-B

standards, the requirements of this type-C standard take precedence over the requirements of the other

standards for machines that have been designed and built according to the requirements of this type-C

standard.
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oSIST prEN 1417:2021
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1 Scope

This document deals with all significant hazards, hazardous situations or hazardous events relevant to

two-roll mills for the processing of rubber and/or plastics (see Annex A), when it is used as intended and

under conditions of misuse which are reasonably foreseeable by the manufacturer during all the phases

of the life of the machine as described in EN ISO 12100:2010, 5.4.
This document covers two-roll mills as defined in 3.1.

This document deals with the following ancillary equipment as integral part of the machine:

— powered stock guides;
— strip cutting device;
— stock blender;
— recovery conveyor belt;
— retractable ploughs;
— secondary roller.

This document does not deal with the design of a local exhaust ventilation system that may be necessary

in specific applications of the machine not known by the manufacturer.

This document is not applicable to two-roll mills manufactured before the date of its publication as a

European Standard.
2 Normative references

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.

EN 60204-1:2018, Safety of machinery — Electrical equipment of machines — Part 1: General requirements

(IEC 60204-1:2016, modified)

EN IEC 61000-6-2:2019, Electromagnetic compatibility (EMC) — Part 6-2: Generic standards — Immunity

for industrial environments (IEC 61000-6-2:2016)

EN IEC 61000-6-4:2019, Electromagnetic compatibility (EMC) — Part 6-4: Generic standards — Emission

standard for industrial environments (IEC 61000-6-4:2018)

EN IEC 61496-1:2020, Safety of machinery — Electro-sensitive protective equipment — Part 1: General

requirements and tests (IEC 61496-1:2020)

EN IEC 61496-2:2020, Safety of machinery — Electro-sensitive protective equipment — Part 2: Particular

requirements for equipment using active opto-electronic protective devices (AOPDs) (IEC 61496-2:2020)

EN ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise

sources using sound pressure — Engineering methods for an essentially free field over a reflecting plane

(ISO 3744:2010)

EN ISO 3746:2010, Acoustics — Determination of sound power levels and sound energy levels of noise

sources using sound pressure — Survey method using an enveloping measurement surface over a reflecting

plane (ISO 3746:2010)
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EN ISO 4413:2010, Hydraulic fluid power — General rules and safety requirements for systems and their

components (ISO 4413:2010)

EN ISO 4414:2010, Pneumatic fluid power — General rules and safety requirements for systems and their

components (ISO 4414:2010)

EN ISO 4871:2009, Acoustics — Declaration and verification of noise emission values of machinery and

equipment (ISO 4871:1996)

EN ISO 9614-2:1996, Acoustics — Determination of sound power levels of noise sources using sound

intensity — Part 2: Measurement by scanning (ISO 9614-2:1996)

EN ISO 11201:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission

sound pressure levels at a work station and at other specified positions in an essentially free field over a

reflecting plane with negligible environmental corrections (ISO 11201:2010)

EN ISO 11202:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission

sound pressure levels at a work station and at other specified positions applying approximate environmental

corrections (ISO 11202:2010)

EN ISO 11204:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission

sound pressure levels at a work station and at other specified positions applying accurate environmental

corrections (ISO 11204:2010)

EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk

reduction (ISO 12100:2010)

EN ISO 13732-1:2008, Ergonomics of the thermal environment — Methods for the assessment of human

responses to contact with surfaces — Part 1: Hot surfaces (ISO 13732-1:2006)

EN ISO 13849-1:2015, Safety of machinery — Safety-related parts of control systems — Part 1: General

principles for design (ISO 13849-1:2015)

EN ISO 13850:2015, Safety of machinery — Emergency stop function — Principles for design

(ISO 13850:2015)

EN ISO 13851:2019, Safety of machinery — Two-hand control devices — Principles for design and selection

(ISO 13851:2019)

EN ISO 13854:2019, Safety of machinery — Minimum gaps to avoid crushing of parts of the human body

(ISO 13854:2017)

EN ISO 13855:2010, Safety of machinery — Positioning of safeguards with respect to the approach speeds

of parts of the human body (ISO 13855:2010)

EN ISO 13856-2:2013, Safety of machinery — Pressure-sensitive protective devices — Part 2: General

principles for design and testing of pressure-sensitive edges and pressure-sensitive bars (ISO 13856-2:2013)

EN ISO 13857:2019, Safety of machinery — Safety distances to prevent hazard zones being reached by

upper and lower limbs (ISO 13857:2019)

EN ISO 14119:2013, Safety of machinery — Interlocking devices associated with guards — Principles for

design and selection (ISO 14119:2013)

EN ISO 14120:2015, Safety of machinery — Guards — General requirements for the design and construction

of fixed and movable guards (ISO 14120:2015)
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3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN ISO 12100:2010 and the

following apply.

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

— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
two-roll mill

machine with two counter-rotating cylinders (known as mill rolls) which are not covered, which may be

smooth or grooved, and whose axes are on substantially the same horizontal plane for the mixing of

plastics or rubber
Note 1 to entry: See Figure 1:
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oSIST prEN 1417:2021
prEN 1417:2021 (E)
Key
1 frame 6 stock blender
2 mill roll 6.1 stock blender rolls
3 drive and transmission unit 6.2 stock blender carriage
4 stock guide 6.3 guiding rolls of stock blender carriage
5 strip cutting device 6.4 guiding roll below stock blender carriage
7 mill tray
Figure 1 — Example of a two-roll mill shown without safety devices
3.1.1
large two-roll mill
two-roll mill with a mill roll diameter D > 200 mm
3.1.2
small two-roll mill
two-roll mill with a mill roll diameter D ≤ 200 mm

Note 1 to entry: Small two-roll mills are usually not equipped with stock blenders and strip cutting devices.

3.2
principal crushing zone

zone extending over the full length of the mill rolls indicated by V in Figure 2 and Figure 3

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prEN 1417:2021 (E)
Dimensions in millimetres

Figure 2 — Principal crushing zone V, safety limits S and stopping angle α on a large two-roll mill

Dimensions in millimetres

Figure 3 — Principal crushing zone V, safety limit S and stopping angle α on a small two-roll mill

3.3
stopping angle α

angle through which the mill rolls rotate from the stop signal triggered by a protective device until the

mill rolls have come to rest with the machine unloaded, and running at maximum rated speed

3.4
safety limit

vertical plane indicated by Line S in Figure 2 and Figure 3 demarcating the zone which is unsafe for

operators who can reach into it without actuating the trip bar
3.5
stock guide (also known as “ear”)
part which prevents material being processed from going beyond the mill roll end
Note 1 to entry: See Figure 1, Location 4.
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3.6
strip cutting device

device equipped with rotating discs or stationary blades to cut off strips of processed material from a mill

roll
Note 1 to entry: See Figure 1, Location 5.
3.7
stock blender

equipment used to continuously recirculate the material being processed to obtain a uniform mixing,

distributing it with a reciprocating motion along the length of the mill rolls
Note 1 to entry: See Figure 1, Location 6.
3.8
mill tray
equipment for catching material which falls under the mill rolls
Note 1 to entry: See Figure 1, Location 7.
3.9
recovery conveyor belt
equipment for recirculating material which falls under the mill rolls
Note 1 to entry: See Figure A.3.
3.10
retractable plough

equipment which can be moved towards the mill roll in order to cut and turn over the material, and which

can be retracted
Note 1 to entry: See Figure A.2.
3.11
secondary roller
additional roller, which is used to support the mixing process
Note 1 to entry: See Figure 7.

Note 2 to entry: Examples are take-off rollers or pressure rollers applying pressure on the material processed by

the two-roll mill. The pressure can be applied by the weight of the roller or by a power-driven actuator.

3.12
knee plate

pressure sensitive protective device installed at a height so that it can be activated by the knee of the

operator
4 Safety requirements and/or protective/risk reduction measures
4.1 General

Two-roll mills shall comply with the safety requirements and/or protective/risk reduction measures of

this clause. In addition, the machine shall be designed according to the principles of EN ISO 12100:2010

for relevant but not significant hazards which are not dealt with by this document.

The hydraulic equipment and its components shall be designed in accordance with EN ISO 4413:2010.

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The pneumatic equipment and its components shall be designed in accordance with EN ISO 4414:2010.

4.2 Control systems
4.2.1 General

The electrical part of the control system shall be designed in accordance with EN 60204-1:2018, Clause 9

and in addition with the specific requirements given in this standard.

The safety related parts of the control system (SRP/CS) shall be designed in accordance with

EN ISO 13849-1:2015. The required performance level (PL ) for each safety function is specified in the

relevant subclauses.
4.2.2 Starting

The start of an operation shall be possible only when all safeguards are in place and functional (see

EN 60204-1:2018, 9.2.3.2). The machine shall only be started by actuation of the start device provided

for that purpose.
4.2.3 Normal stopping

A normal stop device (e.g. a push button) shall be provided to stop the mechanical movements.

The normal stop command shall function as a stop category 0 or 1 in accordance with EN 60204-1:2018,

9.2.2, depending on the actuators and braking systems used.
4.2.4 Emergency stop

Emergency stop devices shall be positioned on the control panel and on each working side of the two-roll

mill and shall conform to EN ISO 13850:2015 and to category 0 or 1 according to EN 60204-1:2018, 9.2.2,

whichever provides the best stopping performance.

Actuation of emergency stop devices shall stop all hazardous movements of the mill rolls and associated

equipment.

On machines equipped with a trip bar or trip devices, actuation of emergency stop devices shall cause the

effects as in 4.3.2.1.5, 4.3.2.1.6, 4.3.3.2 and 4.3.3.3.

Emergency stop devices shall stop the hot fluid supply except when a manual shut-off actuator is

installed.
See also 6.2.1.
4.2.5 Failure of energy supply

An interruption or a failure of the power supply shall not result in a loss of safety function and restoration

of the energy supply shall not result in the automatic restarting of the machine (see EN ISO 12100:2010,

6.2.11.4 and 6.2.11.5).
4.3 Mechanical hazards
4.3.1 Requirements applicable to all types of two-roll mills

4.3.1.1 Hazards of drawing-in and crushing between the mills rolls during normal (forward and

reverse) operation
4.3.1.1.1 General

Access to the principal crushing zone, as defined in 3.2, shall be prevented by guards. See also 4.3.2.1 and

4.3.3. On two-roll mills with roll diameter > 200 mm, a trip bar may be used as alternative, provided that

the requirements in 4.3.2.1.2 are met.
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Guards shall be designed in accordance with EN ISO 14120:2015 and positioned according to

EN ISO 13857:2019, Table 2, Table 3 and/or Table 4 unless specified different in specific clauses of this

standard.

Interlocking guards shall be designed and selected in accordance with EN ISO 14119:2013.

Interlocking guards shall be positioned in accordance with EN ISO 13855:2010, Clause 9, taking into

account the braking performance achieved by the braking system described in 4.3.1.1.2. Opening of an

interlocking guard shall stop the rotation of the rolls in accordance with PL = d.

If EN ISO 13855:2010, Clause 9 cannot be respected, interlocking guards with guard locking shall be

adopted. The unlocking signal for the guard locking shall be in accordance with PL = c.

Where the smallest horizontal distance between the guard in its closed position and the mill rolls is more

than 100 mm and it is possible to stand between the guard in its closed position and the mill rolls, a

manual reset actuator shall be designed and located in accordance with EN ISO 13849-1:2015, 5.2.2 and

with PL = d.
4.3.1.1.2 Braking system
The two-roll mill shall be equipped with a two-c
...