Henkelman Boxer Series User manual

Vacuum Packaging Machine
Boxer, Lynx, Neo, Toucan
User Manual
Art No. 0895001
Original Instructions for Use
©Henkelman 2017-2019

• The machine is not suitable for the packaging of toxic, corrosive, irritant or potentially
explosive materials.
• All persons responsible for the operation of this machine must at least fully read and
understand the chapters about the operation and safety provided in these operating
instructions.
• All persons responsible for the assembly, installation, maintenance and/or repairs must
fully read and understand these operating instructions.
• The user is at all times responsible for the interpretation and use of this manual.
Contact the owner or the manager in case of questions or doubts about the correct
interpretation.
• This manual should be kept near the machine and should be within reach for its users.
• All major maintenance work, modifications to the machine and observations must be
kept in a logbook; see Logbook on page 105.
• Modifications to the installation/machine are not allowed without the prior written
consent of the supplier.
• For specific maintenance work not included in this manual, please contact the supplier.
• Comply with the safety requirements as set out in Safety on page 12 at all times.
• The correct operation and safety of the system can only be guaranteed if the
recommended maintenance is performed on time and properly.
• Illustrations shown may differ from your machine.
Copyright ©Henkelman BV 2017-2019
Henkelman BV reserves the right to change specifications and/or spare parts without prior notice.
The content of this user manual may also be changed without prior notice.
For information about settings, maintenance and repairs not provided for in this user manual, please contact the technical department of your supplier.
Henkelman BV accepts no liability for damage and/or problems arising from the use of spare parts not supplied by Henkelman BV.
This user manual has been compiled with all possible care. Henkelman BV assumes no responsibility for any errors in this manual and/or the
consequences of an erroneous interpretation of the instructions.
All rights reserved. No part of this publication may be reproduced, stored in computerised databases, or made public, in any form or by any means,
either electronic, mechanical, through photocopying, recording or otherwise, without the prior written consent of Henkelman BV. This also applies to the
associated drawings and diagrams.

Contents
List of Figures................................................................................................................................. 7
1 Preamble....................................................................................................................................... 9
1.1 List of the Symbols Used in this Manual...............................................................................9
1.2 Qualified personnel................................................................................................................ 9
1.3 Storing the manual...............................................................................................................10
1.4 Regulatory information......................................................................................................... 10
1.5 Terms of Warranty...............................................................................................................10
1.6 Liability..................................................................................................................................10
1.7 Terms and abbreviations......................................................................................................11
2 Safety...........................................................................................................................................12
2.1 Pictograms on the Machine.................................................................................................12
2.2 General Warnings................................................................................................................ 12
2.3 Warnings During Use...........................................................................................................13
2.4 Warnings for Operating Personnel.......................................................................................14
3 Introduction.................................................................................................................................15
4 Description of the Machine.......................................................................................................16
4.1 Boxer series......................................................................................................................... 16
4.1.1 Overview of the Main Components..............................................................................17
4.2 Lynx series...........................................................................................................................18
4.2.1 Overview of the Main Components..............................................................................18
4.3 Neo series............................................................................................................................19
4.3.1 Overview of the Main Components..............................................................................20
4.4 Toucan series.......................................................................................................................21
4.4.1 Overview of the Main Components..............................................................................22
4.5 Description of the Packaging Process/Machine Functions..................................................23
4.5.1 Packaging Process/Machine Functions........................................................................23
4.5.2 General Functions........................................................................................................27
4.6 Sealing System.................................................................................................................... 28
5 Installation...................................................................................................................................29
5.1 Transportation and Installation.............................................................................................29
5.2 Connecting the Machine...................................................................................................... 29
5.3 Prior to the First Use........................................................................................................... 30
6 Operation.....................................................................................................................................31
6.1 10-Programme Control System (10-PCS)............................................................................31
6.1.1 Operating Elements......................................................................................................31
6.1.2 Starting the Machine....................................................................................................32
6.1.3 Starting the Packaging Cycle.......................................................................................32
6.1.4 Proceeding to the Next Step in the Cycle....................................................................33
Contents 3

6.1.5 Terminating a Programme............................................................................................33
6.1.6 Changing the Programme Settings..............................................................................33
6.1.6.1 Vacuum.................................................................................................................33
6.1.6.2 Vacuum (automatic)............................................................................................. 34
6.1.6.3 Vacuum+ (optional).............................................................................................. 34
6.1.6.4 Gas (optional).......................................................................................................34
6.1.6.5 Gas+ (optional).....................................................................................................35
6.1.6.6 Liquid Control (optional).......................................................................................35
6.1.6.7 Liquid Control+ (optional).....................................................................................36
6.1.6.8 Red Meat (optional)..............................................................................................36
6.1.6.9 Multi-Cycle Vacuum (optional)..............................................................................36
6.1.6.10 Seal.....................................................................................................................37
6.1.6.11 Soft-Air................................................................................................................37
6.1.6.12 External Vacuum (optional)................................................................................38
6.1.7 Example programmes.................................................................................................. 38
6.1.8 Guideline for Function Values......................................................................................40
6.2 Advanced Control System (ACS).........................................................................................41
6.2.1 Operating Elements......................................................................................................42
6.2.1.1 Changing the ACS Settings................................................................................. 43
6.2.1.2 Importing/Exporting Data......................................................................................46
6.2.1.3 Data Log ID..........................................................................................................46
6.2.2 Starting the Machine....................................................................................................48
6.2.3 Starting the Packaging Cycle.......................................................................................48
6.2.4 Proceeding to the Next Step in the Cycle....................................................................48
6.2.5 Changing the Programme Settings..............................................................................49
6.2.5.1 Programming the ACS Control Using the PC......................................................50
6.2.5.2 Functions.............................................................................................................. 50
6.2.5.3 Vacuum.................................................................................................................50
6.2.5.4 Vacuum (automatic)............................................................................................. 51
6.2.5.5 Vacuum+ (optional).............................................................................................. 51
6.2.5.6 Gas (optional).......................................................................................................51
6.2.5.7 Gas+ (optional).....................................................................................................52
6.2.5.8 Liquid Control (optional).......................................................................................52
6.2.5.9 Liquid Control+ (optional).....................................................................................53
6.2.5.10 Red Meat (optional)............................................................................................53
6.2.5.11 Sequential Vacuum (optional)............................................................................ 53
6.2.5.12 Marinating (optional)...........................................................................................54
6.2.5.13 Tenderising (optional).........................................................................................55
6.2.5.14 Jars (optional).....................................................................................................55
6.2.5.15 Seal.....................................................................................................................55
6.2.5.16 Soft-Air................................................................................................................56
6.2.5.17 External Vacuum (optional)................................................................................56
6.2.5.18 Dealer Information..............................................................................................57
6.2.6 Terminating a Programme............................................................................................57
6.2.7 Printer...........................................................................................................................57
6.2.7.1 Connecting a Printer.............................................................................................57
6.2.7.2 Creating a Label...................................................................................................58
Contents 4

6.2.7.3 Replacing a Printer Roll....................................................................................... 58
6.2.7.4 Aligning the Printer...............................................................................................60
6.2.8 Example programmes.................................................................................................. 61
6.2.9 Guideline for Function Values......................................................................................62
6.3 Touch Control System (TCS)...............................................................................................64
6.3.1 Operating elements......................................................................................................65
6.3.2 Starting the machine....................................................................................................65
6.3.3 Selecting a programme................................................................................................66
6.3.4 Changing the programme............................................................................................ 66
6.3.4.1 Changing the vacuum settings (icon 16)..............................................................66
6.3.4.2 Changing the gas settings (icon 17).................................................................... 66
6.3.4.3 Changing the seal time (icon 18).........................................................................66
6.3.4.4 Changing the soft air time (icon 19).....................................................................66
6.3.5 Running the packaging cycle.......................................................................................66
6.3.6 Proceeding to the next cycle step................................................................................67
6.3.7 Cleaning the pump.......................................................................................................67
6.3.8 Selecting options on the machine in the option menu.................................................67
6.3.8.1 Liquid control (icon 4)...........................................................................................67
6.3.8.2 Red meat (icon 5)................................................................................................ 67
6.3.8.3 Step vacuum (icon 6)...........................................................................................67
6.3.8.4 Marinating (icon 7)................................................................................................68
6.3.9 Terminating a Programme............................................................................................68
6.3.10 Switching off the machine..........................................................................................68
6.3.11 Using the App.............................................................................................................68
6.3.11.1 Downloading the App.........................................................................................68
6.3.11.2 Programmes in the App..................................................................................... 69
6.3.12 Printer.........................................................................................................................71
6.3.12.1 Connecting a Printer...........................................................................................71
6.3.12.2 Creating a Label (App only)...............................................................................71
6.3.12.3 Replacing a Printer Roll..................................................................................... 73
6.3.12.4 Aligning the Printer.............................................................................................75
6.3.13 Data Log ID................................................................................................................76
6.3.14 Notifications................................................................................................................ 77
6.3.15 Example programmes................................................................................................ 78
6.3.16 Guideline for Function Values....................................................................................79
7 Maintenance................................................................................................................................82
7.1 Running the Pump Cleaning Programme............................................................................82
7.2 Maintenance Schedule.........................................................................................................82
7.3 Cleaning the Machine.......................................................................................................... 83
7.4 Replacing the Sealing Wire................................................................................................. 84
7.5 Replacing the Silicone Rubber of the Silicone Holders....................................................... 86
7.6 Replacing the Lid Gasket.....................................................................................................86
7.7 Inspecting the Lid Springs................................................................................................... 87
7.8 Vacuum Pump maintenance................................................................................................87
7.8.1 Overview.......................................................................................................................87
7.8.1.1 Pump 8 m3/h........................................................................................................ 88
Contents 5

7.8.1.2 Pump 16 - 21 m3/h...............................................................................................88
7.8.2 Removing Oil, Refilling Oil...........................................................................................89
7.8.3 Replacing the Oil Exhaust Filter.................................................................................. 90
7.8.3.1 Pump 8 m3/h........................................................................................................ 90
7.8.3.2 Pump 16 - 21 m3/h...............................................................................................91
7.8.4 Running the Pump Cleaning Programme.................................................................... 91
8 Troubleshooting and Error Codes........................................................................................... 93
9 Terms of Warranty.....................................................................................................................96
10 Disposal.....................................................................................................................................97
11 Appendices............................................................................................................................... 98
11.1 Technical Data................................................................................................................... 98
11.1.1 Boxer series............................................................................................................... 98
11.1.2 Lynx series............................................................................................................... 100
11.1.3 Neo series................................................................................................................ 101
11.1.4 Toucan series...........................................................................................................102
11.2 Electrical Installation.........................................................................................................103
11.3 Vapour Pressure Curve of Water.....................................................................................104
11.4 Logbook............................................................................................................................105
Contents 6

List of Figures
Figure 1: Overview of the Main Components.................................................................................17
Figure 2: Overview of the Main Components.................................................................................19
Figure 3: Overview of the Main Components.................................................................................20
Figure 4: Overview of the Main Components.................................................................................22
Figure 5: Overview of the Sealing System.....................................................................................28
Figure 6: Control Panel of the 10-Programme Control System......................................................31
Figure 7: External Vacuum Adapter Set (10-Programme Control System).....................................38
Figure 8: Control Panel of the Advanced Control System (ACS)...................................................42
Figure 9: Possible Display Modes.................................................................................................. 43
Figure 10: Possible Display Modes................................................................................................ 43
Figure 11: Overview of the Menus................................................................................................. 45
Figure 12: Example of an Exported Data Log................................................................................47
Figure 13: Screenshot of the navigation mode and the operating buttons of the ACS................... 49
Figure 14: External Vacuum Adapter Set (ACS)............................................................................57
Figure 15: Replacing the Printer Roll..............................................................................................59
Figure 16: Aligning the Printer........................................................................................................60
Figure 17: Printing the First Label..................................................................................................60
Figure 18: Neo control panel.......................................................................................................... 65
Figure 19: Replacing the Printer Roll..............................................................................................74
Figure 20: Aligning the Printer........................................................................................................75
Figure 21: Printing the First Label..................................................................................................75
Figure 22: Vapour Pressure Curve of Water..................................................................................81
Figure 23: Removing the Sealing Bar (Plastic Lid).........................................................................84
Figure 24: Removing the Sealing Bar (Metal Lid).......................................................................... 84
Figure 25: Replacing the Sealing Wire...........................................................................................85
Figure 26: Replacing the Silicone Rubber of the Silicone Holders.................................................86
Figure 27: Replacing the Lid Gasket..............................................................................................87
Figure 28: Overview of the Pump...................................................................................................88
Figure 29: Overview of the Pump...................................................................................................88
Figure 30: Mounting Plate Boxer 52...............................................................................................89
Figure 31: Replacing the Oil Exhaust Filter....................................................................................90
Figure 32: Replacing the Oil Exhaust Filter....................................................................................91
Figure 33: Overview of the Electrical Installation..........................................................................103
List of Figures 7

Figure 34: Vapour Pressure Curve of Water................................................................................104
List of Figures 8

1 Preamble
This is the manual for your Henkelman vacuum packaging machine series: Boxer, Lynx, Neo and
Toucan.
This manual is intended for anyone who works with or services the machine.
This manual contains information and instructions for installation, operation and maintenance
of the machine. We recommend that you carefully read this manual before use and follow the
procedures and instructions strictly. This will ensure that you get the best out of the machine and
prevents possible accidents and serious injury.
1.1 List of the Symbols Used in this Manual
For all operations in which the safety of the operator and/or technician is at stake and where
caution should be exercised, the following symbols are used.
Indicates a hazardous situation that, if not avoided, could result in serious injury or death
and/or material damage if one does not obey the safety instructions.
Indicates a hazardous situation that, if not avoided, could result in minor or moderate
injury and/or material damage if one does not follow the safety instructions.
Provides additional information that is helpful to do a task or to avoid problems.
This symbol warns for high voltage.
1.2 Qualified personnel
This document is intended for qualified personnel.
The term "qualified personnel" is defined here as individuals who thoroughly understand
the equipment and its safe installation, operation or maintenance. Qualified personnel are
physically capable of performing the required tasks, are familiar with all relevant and local
safety rules and regulations and have been trained to safely install, operate or maintain the
equipment. It is the responsibility of the company installing, operating or maintaining this
equipment to ensure that its personnel meet these requirements.
Preamble 9

1.3 Storing the manual
This manual is a part of your product. Store the manual in the immediate vicinity of the product.
Always present a copy of the manual to operators and engineers working on the Vacuum
Packaging Machine.
1.4 Regulatory information
The Henkelman Boxer, Lynx, Neo and Toucan Vacuum Packaging Machine is designed to comply
with the following directives:
• 2006/42/EC: Machinery Directive
• 2014/30/EG: EMC Directive
• 2014/35/EC: Low Voltage Directive
The CE Declaration is available upon request. Please contact the manufacturer.
1.5 Terms of Warranty
The warranty is subject to the following limitations. The warranty period for products supplied by
Henkelman BV is 3 years from the date indicated on the purchase document. This warranty is
limited to manufacturing and machining defects and therefore does not cover breakdowns involving
any part of the product that is exposed to any form of wear and tear. Normal wear and tear that
may be expected with the use of this product is therefore hereby excluded.
• The responsibility of Henkelman BV is limited to replacing defective parts; we shall not
acknowledge claims for any other kind of damage or costs.
• The warranty automatically expires in case of overdue or poor maintenance.
• If there are doubts about the maintenance activities or if the machine fails to work correctly,
always contact the supplier.
• The warranty does not apply if the defect is the result of incorrect or negligent use, or
maintenance that was conducted contrary to the instructions given in this manual.
• The warranty is void in the event of repairs or modifications to the product by third parties.
• Defects due to damage or accidents caused by external factors are excluded from the warranty.
• If we replace parts in compliance with the obligations of this warranty, then the replaced parts
become our property.
The provisions regarding the warranty and liability are part of the general terms and conditions of
sale, which can be sent to you upon request.
1.6 Liability
• We exclude all liability insofar as far as it is not required by law.
• Our liability shall never exceed the total amount of the machine value in question.
Preamble 10

• With the exception of the applicable legal regulations of public order and good faith, we are
not liable to pay for any damage of any sort whatsoever to the counterparty or to third parties,
directly or indirectly, including lost profits, damage to movable or immovable property or
personal injury.
• We are in no way liable for damages arising from or resulting from the use of the product used,
or the unsuitability thereof for the purpose for which the other party decided to purchase the
product.
1.7 Terms and abbreviations
10-PCS 10-Programme Control System
ACS Advanced Control System
TCS Touch Control System
Machine Vacuum packaging machine
Pump Vacuum pump
Preamble 11

2 Safety
Your vacuum packaging machine has been carefully designed and expertly built to be operated
safely. This is corroborated by the EC Declaration of Conformity. However, there are always
dangers and safety risks that cannot be eliminated. These dangers and risks are the result of the
use functions of the machine and operation of the machine by the user. This section discusses
safety instructions and precautions, how they will be pointed out to you and the requirements
the user must meet. It is essential that you are well aware of these safety instructions and
requirements and observe them at all times!
2.1 Pictograms on the Machine
Pictograms and warnings have been fitted on the machine to warn users of the possible risks.
Warning sign "High Voltage"
• Is located on the back of the machine
Warning sign "Heat"
• Is located on the sealing bars and on the vacuum pump
Warning sign "Gas Connection" (optional)
Forbidden to connect oxygen
• Is located on the back of the machine
Warning sign "Gas Connection" (optional)
Maximum allowed gas pressure of the gas flush system
• Is located on the back of the machine
Machine plate
• Is located on the back of the machine
Regularly check whether the pictograms and markings are still clearly recognisable and
legible. Replace them if this is not the case.
2.2 General Warnings
• All persons responsible for the operation of this machine must at least fully read and
understand the chapters Safety on page 12 and Operation on page 31.
Safety 12

• Failure to follow or disregard of the safety instructions may result in serious injury.
• Never pack products that can be damaged by vacuum.
• Never vacuum live animals.
• Warranty and/or liability is void if any damage is caused by repairs and/or modifications
that are not authorised by the supplier or any of its distributors.
• In case of malfunction, contact the supplier.
• High pressure cleaning is not allowed. This may cause damage to the electronics and
other components.
• Prevent water from entering the ventilation inlet of the chamber or the exhaust of the
pump. This causes irreversible damage to the pump.
• The work space around the machine must be safe. The owner of the machine must take
the necessary precautions to operate the machine safely.
• It is forbidden to start the machine in an explosive environment.
• The machine has been designed in such a way that production is safe under normal
ambient conditions.
• The owner of the machine must ensure that the instructions in this manual are actually
complied with.
• The available safety devices may not be removed.
• The correct operation and safety of the system can only be guaranteed if the
recommended maintenance is performed on time and properly.
• If work must be carried out on the machine, it must be disconnected and blocked from
the power supply and, if applicable, from the gas supply.
• Only a technical expert may perform work on the electrical installation.
• Internal procedures and monitoring must be in place to ensure that all relevant power
supplies are disconnected.
• The machine may not be used during cleaning, inspection, repair or maintenance and
must be disconnected from the power supply by disconnecting the plug.
• Never perform welding work on the machine without first disconnecting the cable
connection to the electrical components.
• Never use the power supply of the control unit to connect other machines.
• All electrical connections must be connected to the terminal strips according to the
wiring diagram.
2.3 Warnings During Use
• Before starting the machine, make sure no work is being performed on the installation
and that the machine is ready for use.
• The machine may not be operated by unauthorised persons. This should be monitored
by the machine operator(s).
• Immediately contact the service technician of your technical department or dealer if
something does not seem right, such as unusual vibrations or unusual noise.
Safety 13

• Components of the sealing system can become very hot. Contact with these
components may cause injuries.
• Improper use, such as switching off the machine while it is creating a vacuum, is
strongly discouraged. Such actions may cause oil leaking back to the vacuum chamber.
2.4 Warnings for Operating Personnel
• Operating personnel must be 18 years or older.
• Only authorised persons are allowed to perform work on or with the machine.
• Personnel may only perform work for which it was trained. This applies to both
maintenance and normal use.
• The machine may only be operated by trained personnel.
• Operating personnel must be familiar with all circumstances, so quick and effective
action can be taken in case of an emergency.
• If an operator notices errors or risks or disagrees with safety measures, he or she
should report this to the owner or manager.
• Safety shoes are mandatory.
• Appropriate work clothing is mandatory.
• All personnel must obey the safety regulations to avoid danger to themselves and
others. Always strictly follow the work instructions.
Safety 14

3 Introduction
Henkelman BV is a supplier of ultra-modern vacuum packaging machines. Our machines are
developed and manufactured to meet the highest standards. They combine a sleekly built and
functional design with optimal ease of use and a long service life. After mounting the plug, it is just
a matter of "plug & pack". The clever design ensures compliance with the hygiene standards at all
times.
The Boxer, Lynx, Neo and Toucan series comprises tabletop models with various options suitable
for a variety of applications. These machines have several programmes and options for optimal
packaging.
Introduction 15

4 Description of the Machine
This section provides an short introduction to the machine and an overview of it's main
components and functions. If detailed information is available in this manual, you will be referred to
the specific sections.
4.1 Boxer series
Boxer series vacuum packaging machines ensure an easy and secure vacuum packaging process.
With the unique possibility to store your settings in the 10 program memory, standard on every
Boxer.
Basic vacuum packaging machine for the food packaging of products with all shapes and
dimensions. Available as a basic table-top model and as a full option vacuum packaging machine.
• Standard 10 program memory
• Standard double seal
• Free options: Cut-off an wide seal
• Standard delivered with insert plates
Description of the Machine 16

4.1.1 Overview of the Main Components
The figure below shows the main components of the Boxer series. The model shown may differ
from your machine.
Figure 1: Overview of the Main Components
1. Lid
The lid closes the vacuum chamber during the application of the vacuum. A rubber is mounted
in the lid to ensure proper closing. Silicone holders are mounted in the lid as counter beams of
the sealing bar(s).
2. Vacuum chamber
The products to be packaged are placed on the work surface with the openings of the vacuum
bags on the sealing position.
3. Seal system
Depending on the model, one or two sealing bars are mounted in the vacuum chamber. These
close the vacuum bag.
4. Control panel
This serves to operate the available control functions. Depending on your model, your
machine will have the 10-Programme Control System (10-PCS) or the Advanced Control
System (ACS).
5. Machine housing
The machine housing contains all the components necessary for the functioning of the
machine.
6. Vacuum pump
The vacuum pump creates the vacuum.
7. Power connection
This serves to connect the machine to the power supply.
8. Gas flush system connector (optional)
After applying vacuum, a gas is injected into the packaging to create a modified atmosphere to
protect the shape of the product or increase the shelf life of the product.
Description of the Machine 17

4.2 Lynx series
The Lynx series is standard equipped with Advanced Control System (ACS) including a 20
program memory, full colour screen and a USB connection. The Lynx table-top models are HACCP
compliant and compatible with a direct label printer.
The design and the wide variety of functions on the ACS add significant value to your every day
packaging.
• Hygienic design with round edges
• Standard Sensor control
• Standard with 20 program memory
• Compatible with label printer
• 4.7" LCD screen
• HACCP compliance
• USB connection
• Multilevel access
4.2.1 Overview of the Main Components
The figure below shows the main components of the Lynx. The model shown may differ from your
machine.
Description of the Machine 18

Figure 2: Overview of the Main Components
1. Lid
The lid closes the vacuum chamber during the application of the vacuum. A rubber is mounted
in the lid to ensure proper closing. Silicone holders are mounted in the lid as counter beams of
the sealing bar(s).
2. Vacuum chamber
The products to be packaged are placed on the work surface with the openings of the vacuum
bags on the sealing position.
3. Seal system
Depending on the model, one or two sealing bars are mounted in the vacuum chamber. These
close the vacuum bag.
4. Control panel
This serves to operate the available control functions.
5. Machine housing
The machine housing contains all the components necessary for the functioning of the
machine.
6. Vacuum pump
The vacuum pump creates the vacuum.
7. Power connection
This serves to connect the machine to the power supply.
8. Gas flush system connector (optional)
After applying vacuum, a gas is injected into the packaging to create a modified atmosphere to
protect the shape of the product or increase the shelf life of the product.
4.3 Neo series
The Neo series brings vacuum packaging technology to the next level. Smart. Wireless. Full
option. Extensive and intuitive. And finally, the contemporary design qualifies these models as true
eye-catchers.
Description of the Machine 19

Basic functionality can be programmed on the machine. To operate all other options and functions,
download the VacAssist app. Easy to use and efficient in every day packaging.
• Hygienic design with round edges
• Standard Sensor control
• Standard Touch control
• Standard with 20 program memory
• Standard Bluetooth connection
• Free VacAssist app available
• Compatible with label printer
4.3.1 Overview of the Main Components
The figure below shows the main components of the Neo. The model shown may differ from your
machine.
Figure 3: Overview of the Main Components
Description of the Machine 20