SIST EN 12355:2022

SLOVENSKI STANDARD
01-december-2022
Nadomešča:
SIST EN 12355:2003+A1:2010
Stroji za predelavo hrane - Stroji za odstranjevanje kože - Varnostne in higienske
zahteve
Food processing machinery - Derinding-, skinning- and membrane removal machines -
Safety and hygiene requirements
Nahrungsmittelmaschinen - Entschwartungs-, Enthäutungs- und Entvliesmaschinen -
Sicherheits- und Hygieneanforderungen
Machines pour les produits alimentaires - Machines à découenner, éplucher et peler -
Prescriptions relatives à la sécurité et à l'hygiène
Ta slovenski standard je istoveten z: EN 12355:2022
ICS:
67.260 Tovarne in oprema za živilsko Plants and equipment for the
industrijo food industry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12355
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2022
EUROPÄISCHE NORM
ICS 67.260 Supersedes EN 12355:2003+A1:2010
English Version
Food processing machinery - Derinding-, skinning- and
membrane removal machines - Safety and hygiene
requirements
Machines pour les produits alimentaires - Machines à Nahrungsmittelmaschinen - Entschwartungs-,
découenner, éplucher et peler - Prescriptions relatives Enthäutungs- und Entvliesmaschinen - Sicherheits-
à la sécurité et à l'hygiène und Hygieneanforderungen
This European Standard was approved by CEN on 13 June 2022.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12355:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Safety requirements and/or protective/risk reduction measures . 9
4.1 General . 9
4.2 Mechanical hazards . 14
4.3 Electrical hazards . 26
4.4 Electromagnetic compatibility . 28
4.5 Hazards from loss of stability . 28
4.6 Noise reduction . 28
4.7 Ergonomic requirements . 28
4.8 Hygiene and cleaning . 30
5 Verification of the safety requirements and/or protective/risk reduction measures . 32
6 Information for use . 32
6.1 General . 32
6.2 Instruction handbook . 33
6.3 Marking . 36
Annex A (normative) Noise test code for derinding, skinning and membrane removal
machines (grade 2) . 37
Annex B (normative) Design principles to ensure the cleanability of derinding, skinning
and membrane removal machines . 40
Annex C (informative) Performance level required . 46
Annex D (informative) List of significant hazards . 47
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 49
Bibliography . 51

European foreword
This document (EN 12355:2022) has been prepared by Technical Committee CEN/TC 153 “Machinery
intended for use with foodstuffs and feed”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2023, and conflicting national standards shall
be withdrawn at the latest by January 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12355:2003+A1:2010.
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.
The significant changes with respect to the previous version EN 12355:2003+A1:2010 are listed below:
— structure adapted to CEN Guide 414:2017;
— figures were improved, partly exchanged or newly inserted;
— Clause 1 Scope: simplified, the description of machine types has been integrated in Clause 4, technical
features have been transformed into requirements;
— Clause 2 Normative references: completed and updated;
— Clause 3 Terms and definitions: completed and updated;
— Clause 4 Safety requirements: safety requirements were revised;
— Clause 5 Verification: adapted to the requirements of Clause 4;
— Clause 6 Information for use: improved and supplemented with references to the relevant clauses;
— Annex A Noise test code: updated;
— Annex B Design principles to ensure the cleanability: updated;
— Annex C Performance level required: added to give a quick-view summary of PLr for each safety
function;
— Annex D List of significant hazards: contains the former Clause 4;
— Annex ZA Relationship to Directive 2006/42/EC: improved and updated.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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, Türkiye and the United
Kingdom.
Introduction
This document is a type-C-standard as stated in EN ISO 12100:2010.
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.
1 Scope
This document deals with all significant hazards, hazardous situations or hazardous events relevant to
derinding, skinning and membrane removal machines, when they are used as intended and under
conditions of misuse which are reasonably foreseeable by the manufacturer (see Annex D).
This document deals with the hazards which can arise during all the lifetime of the machinery
(see EN ISO 12100:2010, 5.4).
This document is not applicable to derinding, skinning, and membrane removal machines for domestic
purposes, hand-guided machines and table-top machines.
This document is not applicable to fish heading and filleting machines as described in EN 15467:2014.
This document is not applicable to derinding, skinning and membrane removal machines manufactured
before the date of its publication.
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 614-1:2006+A1:2009, Safety of machinery — Ergonomic design principles — Part 1: Terminology and
general principles
EN 619:2022, Continuous handling equipment and systems — Safety requirements for equipment for
mechanical handling of unit loads
EN 1005-1:2001+A1:2008, Safety of machinery — Human physical performance — Part 1: Terms and
definitions
EN 1005-2:2003+A1:2008, Safety of machinery — Human physical performance — Part 2: Manual
handling of machinery and component parts of machinery
EN 1005-3:2002+A1:2008, Safety of machinery — Human physical performance — Part 3: Recommended
force limits for machinery operation
EN 1005-4:2005+A1:2008, Safety of machinery — Human physical performance — Part 4: Evaluation of
working postures and movements in relation to machinery
EN 1672-2:2020, Food processing machinery — Basic concepts — Part 2: Hygiene and cleanability
requirements
EN 60204-1:2018, Safety of machinery — Electrical equipment of machines — Part 1: General
requirements (IEC 60204-1:2016, modified)
EN 60529:1991 , Degrees of protection provided by enclosures (IP code) (IEC 60529:1989)
EN 61496-1:2013, Safety of machinery — Electro-sensitive protective equipment — Part 1: General
requirements and tests (IEC 61496-1:2012)

As impacted by EN 60529:1991/A1:2000 and EN 60529:1991/A2:2013.
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)
EN ISO 4871:2009, Acoustics — Declaration and verification of noise emission values of machinery and
equipment (ISO 4871:1996)
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 workstation and at other specified positions applying approximate environmental
corrections (ISO 11202:2010)
EN ISO 11688-1:2009, Acoustics — Recommended practice for the design of low-noise machinery and
equipment — Part 1: Planning (ISO/TR 11688-1:1995)
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
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 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)
EN ISO 21920-2:2022, Geometrical product specifications (GPS) — Surface texture: Profile — Part 2:
Terms, definitions and surface texture parameters (ISO 21920-2:2021)
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
strip
mechanical process for stripping off skin or membrane from rotating machine parts
3.2
stripper comb
comb-shaped insert to strip off the product residues from the tooth roller
3.3
stripper rake
rake-shaped device to strip skin or membrane or product residues off the hold-down roller
3.4
stripper roller
shaft with teeth to strip skin or membrane off the transport roller
3.5
hold-down roller
device for pushing down the product
Note 1 to entry: The roller may consist of one undivided piece or be divided into several segments. Each roller
may be profiled on the perimeter and/or the width. The inner rollers may also have smaller diameters.
3.6
cutting device
device for cutting the rind, skin or membrane from the product, consisting of blade holder and straight
blade
3.7
blade holder
device to act as a holding tool for the straight blade
Note 1 to entry: The blade holder is not intended for circular blades.
3.8
blade roller
rotating cutting tool with circular blades for the slashing or cutting of products
Note 1 to entry: One or more circular blades are spread across the width. Each circular blade may be profiled on
the perimeter. The inner circular blades may also have smaller diameters. This roller is considered divided.
3.9
combined roller
blade roller with segments of hold-down roller placed between the circular blades
3.10
round product
product of nearly round shape
EXAMPLE Pickled knuckle of pork, hind ham.
3.11
fixed bar
stable element that supports the belt in the area of the inlet and outlet and is strongly connected to the
belt frame
3.12
tunnel-shaped cover
element covering the area between inlet and outlet
3.13
transport roller
component with exclusively longitudinal teeth for moving the product towards the knife
3.14
tooth roller
component with longitudinal teeth as well as stripper grooves for moving the product towards the knife
3.15
cutting thickness
distance between the rotating tooth / transport roller and the tip of the straight blade
3.16
easily cleanable
designed and constructed to be cleanable by a simple cleaning method, if necessary after removing parts
that can be easily dismantled
3.17
stripper grooves
circumferential grooves in the roller for guiding the stripper comb
4 Safety requirements and/or protective/risk reduction measures
4.1 General
Derinding, skinning and membrane removal machines (see Figure 1, Figure 2, Figure 3, Figure 4 and
Figure 5) 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
the hazards relevant but not significant, which are not dealt with by this document.
Key
1 tooth/transport roller 6 foot switch
2 cutting device 7 drive
3 outfeed table 8 sliding plate
4 infeed table h table height
5 ON-/OFF-switch
Figure 1 — Open derinding, skinning and membrane removal machine
a) open derinding machine b) open membrane removal machine
Key
1 product 6 removed product (rind, skin, membrane)
2 infeed table 7 stripper comb
3 blade holder 8 transport roller
4 tooth roller 9 stripper roller
5 straight blade t cutting thickness
Figure 2 — System of open machines

Key
1 outfeed conveyor 5 tooth / transport roller
2 tunnel-shaped cover 6 infeed conveyor
3 hold-down roller, blade roller, combined roller 7 drive
4 cutting device 8 sliding plate
Figure 3 — Automatic machine
Key
1 hold-down roller, blade roller, combined roller 5 stripper comb / roller
2 infeed conveyor 6 cutting device
3 product 7 outfeed conveyor
4 tooth / transport roller 8 hold-down roller, blade roller, combined roller (optional)
Figure 4 — System of an automatic machine

a) hold-down roller (divided)
b) hold-down roller (undivided)

c) blade roller (divided) d) combined roller (divided)
Figure 5 — Examples of rollers
On derinding, skinning and membrane removal machines, a normal stop device shall be provided on each
workstation to stop the machine. The normal stop device requires a performance level PL of at least “c”
r
in accordance with EN ISO 13849-1:2015. The stopping function of the normal stop device shall be in
accordance with EN 60204-1:2018, 9.2.2, Category 0. In the instruction handbook the manufacturer shall
indicate that the normal stop device shall be operated immediately after each use of open derinding,
skinning and membrane removal machines (see 6.2 d)).
When power is recovered or when the power supply is switched on, restarting of the machine shall be
prevented.
Figure 6 is showing the significant danger zones of the different machine types.

a) Derinding machine b) Skinning and membrane removal machine

c) Automatic machines
Key
1 zone 1
2 zone 2
3 zone 3
4 zone 4
5 zone 5
Figure 6 — Danger zones on machines
4.2 Mechanical hazards
4.2.1 General
Machines shall be designed and constructed in accordance with the requirements mentioned below.
The interlocking devices associated with guards shall at least comply with EN ISO 14119:2013 Type 1 or
Type 3 and shall not be positioned in the food area (e.g. inside the machine housing or another housing).
Machine safety functions are implemented and assured through Safety-Related Parts of the Control
System (SRP/CS) that shall achieve a required Performance Level (PL) in accordance with
r
EN ISO 13849-1:2015. This requirement is given for each safety function in the relevant subclauses of
Clause 4.
Table C.1 summarizes PL for each safety function; however, the provisions of Clause 4 remain the sole
r
and complete normative set of requirements and explanations.
The access to the danger points on the drive system shall be prevented by the following measures:
— at the drive system guards (e.g. doors) shall be provided according to EN ISO 14120:2015. The
guards shall be:
— fixed or;
— movable and interlocked, the required performance level PL of the safety-related parts of the
r
control system shall present at least a performance level “c” according to EN ISO 13849-1:2015;
— openings in the guard shall comply with EN ISO 13857:2019, Table 4.
Fixing systems of fixed guards shall remain attached to these guards or to the machine when the guards
are removed.
4.2.2 Open derinding machine
4.2.2.1 General
When operating an open machine, the operator shall wear protective gloves. Metal wire mesh gloves, or
metal wire reinforced gloves or synthetic fibre reinforced gloves shall not be worn. In the instruction
handbook the manufacturer shall indicate the use of protective gloves (see 6.2 d)).
4.2.2.2 Rotating tooth roller and straight blade — Zone 1
The access to the cutting area and gap between the rotating tooth roller and the cutting device shall be
prevented. This shall be achieved by the following measures:
The cutting thickness of the straight blade shall be t ≤ 5 mm (see Figure 7).
The pitch of the tooth shall be P ≤ 6,5 mm and the depth d ≤ 5 mm (see Figure 7).
Key
1 tooth roller
2 straight blade
3 stripper groove
p tooth pitch
d tooth depth
t cutting thickness
Figure 7 — Dimensions of the tooth roller
The straight blade and the blade holder shall be designed in such a way that the straight blade can only
be placed in a defined position (see Figure 8).

Figure 8 — Design examples for defined position of the straight blade
The free part of the tooth roller between knife and front edge of the table is not allowed to be more than
35° of the circumference of the roller for a table height between 800 mm and 1 050 mm. In the case of
exceptionally tall round products an infeed table can be used which permits a free part of the tooth roller
not more than 120° for a table height ≥ 800 mm (see Figure 9). The processing of exceptionally tall round
products shall be indicated in the instruction handbook (see 6.2 d)).
Key
1 tooth roller
2 straight blade
3 product
4 infeed table raised
5 infeed table lowered
Figure 9 — Free part of the tooth roller
The operation switch for the drive system of the tooth roller shall be a hold-to-run control. The tooth
roller shall stop within 2 s after the operator has released the operation switch. The required
performance level PL of the safety-related parts of the control system shall present at least a
r
performance level “c” according to EN ISO 13849-1:2015. The operation switch can be e.g. foot-, knee- or
belly-operated and shall be protected against unintentional actuation.
If the blade holder is equipped with a second blade, at least the following residual hazards shall be
indicated in the instruction handbook (see 6.2 d)):
— cutting at the second blade;
— drawing-in point between installed second blade and toothed roller.
The instruction handbook (see 6.2 d)) shall indicate that the operator must switch off the machine with
the OFF-button and remove the second blade when quitting the machine.
4.2.2.3 Rotating tooth roller and stripper comb — Zone 2
The access to the in-running nip between tooth roller and stripper comb shall be prevented. This shall be
achieved by the following measures:
— the angle between tooth roller and stripper comb shall be > 90° (see Figure 10 a));
— an interlocked stripper comb to prevent the operation of the machine without the stripper comb, the
required performance level PLr of the safety-related parts of the control system shall be at least a
performance level “c” according to EN ISO 13849-1:2015.
a) without protective bar b) with protective bar
Key
1 tooth roller
2 stripper comb
3 fixed machine part
4 protective bar
d distance without protective bar
e distance with protective bar
Figure 10 — tooth roller with stripper comb
4.2.2.4 Rotating tooth roller and fixed machine parts — Zone 3
Access to the in-running nip between rotating tooth roller and fixed machine parts shall be prevented.
This shall be achieved by the following measures:
— the distance between a rotating tooth roller and a fixed machine part shall be d ≥ 80 mm
(see Figure 10 a)), or
— the distance shall be guarded by a protective bar, where the distance between protective bar and
tooth roller shall be e ≤ 2 mm (see Figure 10 b)); when the protective bar is not fixed, it shall be
interlocked with the machine to prevent the operation of the machine without the protective bar; the
required performance level PL of the safety-related parts of the control system shall present at least
r
a performance level “c” according to EN ISO 13849-1:2015.
4.2.3 Open skinning and membrane removal machine
4.2.3.1 General
Open skinning and membrane removal machines are intended to remove skin or membrane from flat and
round products, this shall be indicated in the instruction handbook (see 6.2 d)).
When operating an open machine, the operator shall wear protective gloves. Metal wire mesh gloves, or
metal wire reinforced gloves or synthetic fibre reinforced gloves shall not be worn. In the instruction
handbook the manufacturer shall indicate the use of protective gloves (see 6.2 d)).
4.2.3.2 Rotating transport roller and straight blade — Zone 1
Access to the cutting edge and the pinch point between the rotating transport roller and the straight blade
shall be prevented. This will be achieved by the following measures:
The cutting thickness shall be t ≤ 0,5 mm (see Figure 11).
The pitch of the grooves shall be P ≤ 2,5 mm and the groove depth d ≤ 2,0 mm. The transport roller shall
not have circumferential grooves (see Figure 11).

Key
1 transport roller
2 roller with circumferential grooves (not allowed as transport roller)
3 divided transport roller
p groove pitch
d groove depth
t cutting thickness
Figure 11 — Dimensions on the transport roller
For removing the membrane and the tendons at the same time a divided transport roller is necessary.
This transport roller has fine and also rough grooves. The length of the rough grooves shall be ≤ 50 % of
the length of the transport roller.
At the rough side, the pitch of the grooves shall be P ≤ 5,5 mm and the groove depth d ≤ 3,5 mm
(see Figure 11).
The straight blade and the blade holder shall be designed in a way that the straight blade can only be
placed in a defined position (see Figure 8).
The operation switch for the drive of the transport roller shall be a hold-to-run control device. The
transport roller shall stop within 2 s after the operator has released the operation switch. The required
performance level PL of the operation switch shall present at least a performance level “c” according to
r
EN ISO 13849-1:2015. The operation switch can be e.g. foot-, knee- or belly-operated and shall be
protected against unintentional actuation.
4.2.3.3 Rotating tooth roller and stripper roller — Zone 2
The access to the pinch point between the rotating tooth roller and the stripper roller shall be prevented.
This shall be achieved by the following measures:
To prevent the risk of drawing in, these rollers shall have the same direction of rotation.
4.2.3.4 Rotating roller and fixed machine parts — Zone 3
The access to the pinch point between the rotating roller and fixed machine parts shall be prevented.
This shall be achieved by the measures of 4.2.3.3.
4.2.4 Automatic machines
4.2.4.1 General
Movable guards shall be prevented against falling into the closed position. This shall be achieved by the
following measures:
— the moveable guard in its open position shall be ≥ 5° behind the vertical plane through the point of
balance;
— when the point of gravity of the guard in its rest position is < 5° behind the vertical plane through
the point of balance the guard shall be supported by a counterweight, a spring or a mechanical locking
device to prevent unexpected closing.
Injury by cutting when handling with the cutting device / blade roller shall be prevented. This shall be
achieved by the following measures:
— for handling, transport and storage a container shall be provided;
— the manufacturer shall describe the residual risks when handling the blades and working in the
cutting zone, especially during cleaning and maintenance operations in the instruction manual
(see 6.2 d)). The use and handling of the blade guard shall be described in the instruction manual
(see 6.2 d));
— the instruction manual shall state that cut-resistant gloves shall be worn when handling the blades
and working in the cutting zone (see 6.2 d)). The instruction manual shall also include information
about storage, transportation, maintenance, cleaning and use of the blades (see 6.2 d)).
4.2.4.2 Rotating transport roller and straight blade — Zone 1
Access from infeed side to the cutting edge shall be prevented. This shall be achieved by the following
measures:
a) the product shall be fed to the tooth/transportation roller and the hold-down roller by means of a
conveyor belt;
b) the frame of the infeed conveyor shall be provided with a fixed bar in the area of the infeed opening;
c) a tunnel-shaped cover shall be provided:
1) a movable tunnel-shaped cover (see Figure 12 a)) shall be interlocked, the machine shall stop
within 2 s after the tunnel-shaped cover has been opened by more than dimension B
(see Table 1), the required performance level PL of the safety-related parts of the control system
r
shall present at least a performance level “c” according to EN ISO 13849-1:2015;
2) a fixed tunnel-shaped cover shall be provided with a trip device (e.g. trip bar or light barrier) at
the upper edge of the infeed opening (see Figure 12 b)), actuating the trip device, the machine
shall stop within 2 s, the required performance level PL of the safety-related parts of the control
r
system shall present at least a performance level “c” according to EN ISO 13849-1:2015;
3) the dimensions of the tunnel-shaped cover depend on the distance from the infeed opening to
the first danger point on the cutting edge of the first blade (straight or circular) or the pinch point
(see Figure 13) and shall meet the following requirements:
i) the tunnel-shaped cover shall cover also the hold-down roller;
ii) openings in the guard, except the infeed and outfeed openings, shall comply with
EN ISO 13857:2019, Table 4;
iii) the infeed and outfeed openings of the tunnel-shaped cover, either itself or in combination
with a light barrier (ESPE electro-sensitive protection equipment) over the infeed conveyor,
shall meet the dimensions in Table 1;
iv) by using a light barrier / light curtain, the length of the solid part of the guard shall be
E ≥ 200 mm (see Figure 12 b)) and the opening height shall be C instead of B;
v) the force to open the movable tunnel-shaped cover shall be ≤ 50 N;
vi) electro-sensitive protection equipment shall comply with ESPE Type 2 of EN 61496-1:2013,
if an active optoelectronic protective device (AOPD, e.g. light curtain) is used, the sensor
detection capability of the electro-sensitive protective device shall be ≤ 40 mm.

a) Movable tunnel-shaped cover b) Fixed tunnel-shaped cover
Key
1 movable cover 3 trip bar
2 fixed cover 4 light barrier or light curtain
A distance from the infeed/outfeed opening to the first danger point
B height of the infeed/outfeed opening at the front edge of the guard or trip bar where the interlocking is
activated to the surface of the belt
C distance from the light barrier to the surface of the belt at the front edge of the guard
E length of the solid part of the tunnel-shaped guard from the first danger point
a
The distances A, B and C are given in Table 1.
Figure 12 —Examples of tunnel-shaped cover
Table 1 — Relation of opening height B and C to distance A
Dimensions in millimetres
A ≥ 230 ≥ 450 ≥ 550 ≥ 850
B ≤ 40 ≤ 95 ≤ 150 ≤ 250
C ≤ 50 ≤ 125 ≤ 180 ≤ 280
A = distance from the infeed/outfeed opening to the first danger point
B = height of the infeed/outfeed opening at the front edge of the guard or
trip bar where the interlocking is activated to the surface of the belt
C = distance from the light barrier to the surface of the belt at the front edge
of the guard
a) hold-down roller (divided) and tooth / b) hold-down roller (undivided) and tooth /
transport roller transport roller

c) raised hold-down roller and raised cutting d) blade / combined roller and tooth /
device and tooth / transport roller transport roller
e) hold-down roller and blade roller (instead f) blade roller (instead of hold-down roller
of tooth / transport roller and cutting device) and cutting device) and transport roller

g) blade roller and transport roller (without h) hold-down roller and tooth / transport
cutting device) with upstream hold-down roller roller with upstream blade roller
Key
1 product 8 hold-down roller (undivided)
2 infeed conveyor 9 hold-down roller (divided)
3 outfeed conveyor 10 blade roller
4 fixed bar 11 combined roller
5 tunnel-shaped cover 12 transport roller
6 cutting device 13 tooth roller
7 stripper rake t cutting thickness
A distance from the infeed/outfeed opening to the first danger point
B height of the infeed/outfeed opening at the front edge of the guard or trip bar where the interlocking is
activated to the surface of the belt
D distance between hold-down roller and tunnel-shaped cover
F distance between transport roller and hold-down roller
G = 25 mm
a
The distances A and B are given in Table 1.
Figure 13 — Examples of automatic machines with different types and arrangement of rollers
4.2.4.3 Rotating tooth roller and the stripper comb / stripper roller— Zone 2
Access to the in-running nip between the rotating tooth roller and the stripper comb / stripper roller
shall be prevented. This shall be achieved by the following measures:
Safety requirements see 4.2.2.3, Zone 2.
The pitch of the teeth shall be P ≤ 12 mm and the depth d ≤ 5 mm (see Figure 14).
Key
1 tooth roller
p tooth pitch
d tooth depth
Figure 14 — Dimensions of the tooth roller
4.2.4.4 Rotating roller and fixed machine parts — Zone 3
Access to the in-running nip between the rotating roller and fixed machine parts shall be prevented. This
shall be achieved by the following measures:
Safety requirements see 4.2.2.4, Zone 3.
4.2.4.5 Access from outfeed side — Zone 4
4.2.4.5.1 General
The hazard of drawing in between the blades and rollers shall be prevented. This shall be achieved by the
following measures:
a) the cutting thickness shall be t ≤ 8 mm and the distance between transport roller and hold-down
roller shall be F ≤ 35 mm;
b) the product shall be removed by means of:
1) an outfeed conveyor where the frame shall be provided with a fixed bar in the area of the outfeed
opening (see Figure 13), or
2) by a sliding plate (see Figure 1), whereby the dimensions which refer to the upper surface of the
outfeed conveyor (see Figure 13) also apply to the upper surface of the sliding plate.
4.2.4.5.2 Rotating hold-down roller and stripper rake
Access to the in-running nip between the hold-down rollers and guard shall be prevented. This shall be
achieved by the following measures:
a) undivided hold-down roller, see Figure 13 b), whereby the distance between an undivided hold-
down roller and the guard shall be 80 mm ≤ D ≤ 160 mm;
b) divided hold-down roller, see Figure 13 a), provided with a stripper rake, whereby the stripper rake
shall meet the following requirements (see Figure 15)):
1) the angle between the hold-down roller and the stripper rake shall be α > 90°;
2) the distance between the hold-down roller and the rake bar shall be w ≥ 25 mm;
3) the distance between two stripping elements shall be w ≤ 50 mm;
4) the distance between the stripping elements and the roller segment shall be w3 ≤ 5 mm;
5) the width of the roller segment shall be w4 ≤ 40 mm.

Key
w1 distance between rake bar and roller segment 1 roller segment
w distance between stripping elements 2 stripping element
w3 distance between stripping element and roller segment 3 rake bar
w4 width of roller segment 4 tunnel-shaped cover
α angle against the rotation direction between hold-down roller and stripper rake
Figure 15 — Dimensions of the stripper rake
4.2.4.5.3 Rotating tooth roller/transport roller, blades and hold-down rollers
Access from outfeed side to the blades and the rollers shall be prevented. This shall be achieved by the
following measures:
a) under the following technical conditions, a tunnel-shaped cover shall be provided (Figure 13 c)
to h)):
1) by using of a blade roller (see Figure 13 d) to g));
2) by using of a combined roller with hold-down rollers and circular blades (see Figure 13 d));
3) for a cutting thickness t > 8 mm (see Figure 13 c));
4) for a raised hold-down roller with a permanent distance between transport / tooth roller and
hold-down roller F > 35 mm (see Figure 13 c));
5) by use of a blade roller instead of tooth / transport roller and cutting device (see Figure 13 e));
b) the tunnel-shaped cover shall meet the following requirements:
1) the tunnel-shaped cover (see Figure 12 a)) shall be movable and interlocked, the machine shall
stop within 2 s after the tunnel-shaped cover has been opened by more than dimension B
(see Table 1), the required performance level PL of the safety-related parts of the control system
r
shall present at least a performance level “c” according to EN ISO 13849-1:2015;
2) the tunnel-shaped cover shall meet the dimensions in Table 1;
c) under the following technical conditions, it is permissible to reduce the distance A on the outlet
opening (see Figure 13 c) to h) and Table 1) by using a flapper gate (see Figure 16):
1) the distance to the hazard point shall be H ≥ 120 mm;
2) the flapper gate shall cover the entire width of the outfeed opening and shall consist of several
flaps;
3) the flaps shall only pivot in the direction of transport;
4) the flaps shall not be able to lock in the open position;
5) the flaps shall return to their closed position K ≤ 6 mm by themselves;
6) the distance between the flaps shall be ≤ 20 mm;
7) the flaps shall withstand a force of 200 N against elastic deformation in the axial direction of the
outfeed;
8) flaps that have undergone plastic deformation or those that are broken off shall be replaced
immediately, corresponding information shall be provided in the operating instructions
(see 6.2 d)).
a) distance to the straight b) distance to the upper surface of the conveyor
blade
Key
1 flapper gate 6 outfeed conveyor
2 cutting device 7 flap
3 roller H distance between flap and straight blade
4 tunnel-shaped cover K distance between flap and upper surface of the conveyor
5 fixed bar
a flap in closed position b flap in open position
Figure 16 — Dimensions of the flapper gate
4.2.4.6 Rotating conveyor belt and drive and guide roller — Zone 5
Access to the drawing-in points of the conveyor belts and also the drive and guide rollers shall be
prevented by one of the following measures:
— a fixed guard shall be installed (e.g. lateral cover plate), the dimensions shall be in accordance with
EN ISO 13857:2019, Table 4;
— a nip guard (see Figure 17) according to EN 619:2022, 4.2.1.1.6, the gap x between the belt and the
roller shall not exceed 5 mm.
Key
1 belt
2 roller
3 in-running nip
x gap
Figure 17 —Example of a nip guard
4.2.5 Combining machine
Combining machines are used either as automatic or open machines by simple conversion work by the
operator. In the instruction handbook the manufacturer shall indicate the procedure of the conversion
work (e.g. tunnel-shaped cover, different rollers) needed (see 6.2 d)).
After the conversion work has been completed by the operator, the combining machine shall meet the
requirements for the respective machine type:
— open derinding machine according to 4.2.2;
— open skinning and membrane removal machine according to 4.2.3;
— automatic ma
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