Frymaster YFPRE18E User manual

Frymaster, a member of the Commercial Food Equipment Service Association, recommends
using CFESA Certified Technicians.
24-Hour Service Hotline [phone] OCTOBER 2008
www.frymaster.com E-mail: [email protected] *8196383*
YFPRE1817E
YFPRE18E
Installation & Operation Manual

NOTICE
IF, DURING THE WARRANTY PERIOD, THE CUSTOMER USES A PART FOR THIS ENODIS
EQUIPMENT OTHER THAN AN UNMODIFIED NEW OR RECYCLED PART PURCHASED
DIRECTLY FROM FRYMASTER DEAN, OR ANY OF ITS AUTHORIZED SERVICE CENTERS,
AND/OR THE PART BEING USED IS MODIFIED FROM ITS ORIGINAL CONFIGURATION, THIS
WARRANTY WILL BE VOID. FURTHER, FRYMASTER DEAN AND ITS AFFILIATES WILL NOT BE
LIABLE FOR ANY CLAIMS, DAMAGES OR EXPENSES INCURRED BY THE CUSTOMER WHICH
ARISE DIRECTLY OR INDIRECTLY, IN WHOLE OR IN PART, DUE TO THE INSTALLATION OF
ANY MODIFIED PART AND/OR PART RECEIVED FROM AN UNAUTHORIZED SERVICE CENTER.
NOTICE
This appliance is intended for professional use only and is to be operated by qualified
personnel only. A Frymaster Dean Factory Authorized Service Center (FASC) or other qualified
professional should perform installation, maintenance, and repairs. Installation, maintenance,
or repairs by unqualified personnel may void the manufacturer’s warranty. See Chapter 1 of
this manual for definitions of qualified personnel.
NOTICE
This equipment must be installed in accordance with the appropriate national and local codes of
the country and/or region in which the appliance is installed. See NATIONAL CODE
REQUIREMENTS in Chapter 2 of this manual for specifics.
NOTICE TO U.S. CUSTOMERS
This equipment is to be installed in compliance with the basic plumbing code of the Building
Officials and Code Administrators International, Inc. (BOCA) and the Food Service Sanitation
Manual of the U.S. Food and Drug Administration.
NOTICE
Drawings and photos used in this manual are intended to illustrate operational, cleaning and
technical procedures and may not conform to onsite management operational procedures.
NOTICE TO OWNERS OF UNITS EQUIPPED WITH COMPUTERS
U.S.
This device complies with Part 15 of the FCC rules. Operation is subject to the following two
conditions: 1) This device may not cause harmful interference, and 2) This device must accept
any interference received, including interference that may cause undesired operation. While
this device is a verified Class A device, it has been shown to meet the Class B limits.
CANADA
This digital apparatus does not exceed the Class A or B limits for radio noise emissions as set
out by the ICES-003 standard of the Canadian Department of Communications.
Cet appareil numerique n’emet pas de bruits radioelectriques depassany les limites de classe A
et B prescrites dans la norme NMB-003 edictee par le Ministre des Communcations du Canada.
DANGER
Improper installation, adjustment, maintenance or service, and unauthorized alterations or
modifications can cause property damage, injury, or death. Read the installation, operating,
and service instructions thoroughly before installing or servicing this equipment.

DANGER
The front ledge of this appliance is not a step! Do not stand on the appliance. Serious injury
can result from slips or contact with the hot cooking oil/shortening.
DANGER
Do not store or use gasoline or other flammable liquids or vapors in the vicinity of this or any
other appliance.
DANGER
The crumb tray in fryers equipped with a filter system must be emptied into a fireproof container
at the end of frying operations each day. Some food particles can spontaneously combust if left
soaking in certain shortening material.
WARNING
Do not bang fry baskets or other utensils on the fryer’s joiner strip. The strip is present to seal
the joint between the fry vessels. Banging fry baskets on the strip to dislodge shortening will
distort the strip, adversely affecting its fit. It is designed for a tight fit and should only be
removed for cleaning.
DANGER
Adequate means must be provided to limit the movement of this appliance without depending
on or transmitting stress to the electrical conduit. A restraint kit is provided with the fryer. If
the restraint kit is missing contact your local Frymaster Factory Authorized Service Center
(FASC) for part number 826-0900.
DANGER
Prior to movement, testing, maintenance and any repair on your Frymaster fryer, disconnect all
electrical power from the fryer.

i
YFPRE18E Electric Fryer
Installation and Operation Manual
TABLE OF CONTENTS
CHAPTER 1: Introduction
1.1 General Information ..........................................................................................................1-1
1.2 Safety Information.............................................................................................................1-1
1.3 Computer Information.......................................................................................................1-2
1.4 Installation, Operating and Service Personnel ..................................................................1-2
1.5 Definitions.........................................................................................................................1-2
1.6 Shipping Damage Claim Procedure .................................................................................1-3
1.7 Service Information...........................................................................................................1-3
CHAPTER 2: Installation Instructions
2.1 General Installation Requirements....................................................................................2-1
2.2 Power Requirements..........................................................................................................2-3
2.3 Positioning the Fryer Station.............................................................................................2-3
CHAPTER 3: Operating Instructions
3.1 Setup and Shutdown Procedures.......................................................................................3-2
3.2 Controller...........................................................................................................................3-3
CHAPTER 4: Filtration Instructions
4.1 Draining and Manual Filtering..........................................................................................4-1
4.2 Preparing the Built-In Filtration System for Use .............................................................. 4-2
4.3 Operation of the Filter.......................................................................................................4-5
4.4 Disassembly and Reassembly of the Magnasol Filter.......................................................4-7
4.5 Draining and Disposing of Waste Oil ...............................................................................4-8
CHAPTER 5: Preventive Maintenance
5.1 Cleaning the Fryer.............................................................................................................5-1
5.1.1 Daily Checks and Service..................................................................................................5-1
5.1.3 Weekly Checks and Service..............................................................................................5-2
5.2 Annual/Periodic System Inspection .................................................................................. 5-2
CHAPTER 6: Operator Troubleshooting
6.1 Introduction ......................................................................................................................6-1
6.2 Troubleshooting.................................................................................................................6-2
6.2.1 Troubleshooting Controller and Heating Problems ..........................................................6-2
6.2.2 Troubleshooting Error Messages and Display Problems .................................................. 6-4
6.2.3 Troubleshooting the Basket Lift........................................................................................6-7
6.2.4 Troubleshooting the Built-In Filtration System ................................................................6-7

1-1
YFPRE18EELECTRIC FRYERS
CHAPTER 1: INTRODUCTION
1.1 General
Read the instructions in this manual thoroughly before attempting to operate this equipment. This
manual covers current configurations of YFPRE18E.
1.2 Safety Information
Before attempting to operate your unit, read the instructions in this manual thoroughly.
Throughout this manual, you will find notations enclosed in double-bordered boxes similar to the
one below.
DANGER
Hot cooking oil causes severe burns. Never attempt to move a fryer containing hot
oil or to transfer hot oil from one container to another.
CAUTION boxes contain information about actions or conditions that may cause or result in a
malfunction of your system.
WARNING boxes contain information about actions or conditions that may cause or result in
damage to your system, and which may cause your system to malfunction.
DANGER boxes contain information about actions or conditions that may cause or result in
injury to personnel, and which may cause damage to your system and/or cause your system to
malfunction.
Fryers in this series are equipped with the following automatic safety features:
1. Two high-temperature detection features shut off power to the elements should the temperature
controls fail.
2. A safety switch built into the drain valve prevents the elements from heating with the drain valve
even partially open.
1.3 Computer Information
This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC rules. While this device is a verified Class A device, it has been
shown to meet the Class B limits. These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a commercial environment. This equipment
generates, uses and can radiate radio frequency energy and, if not installed and used in accordance
with the instruction manual, may cause harmful interference to radio communications. Operation of

1-2
the equipment in a residential area is likely to cause harmful interference in which case the user will
be required to correct the interference at their own expense.
The user is cautioned that any changes or modifications not expressly approved by the party
responsible for compliance could void the user's authority to operate the equipment.
If necessary, the user should consult the dealer or an experienced radio and television technician for
additional suggestions.
The user may find the following booklet prepared by the Federal Communications Commission
helpful: "How to Identify and Resolve Radio-TV Interference Problems". This booklet is available
from the U.S. Government Printing Office, Washington, DC 20402, Stock No. 004-000-00345-4.
1.4 Installation, Operating, and Service Personnel
Operating information for Frymaster equipment has been prepared for use by qualified and/or
authorized personnel only, as defined in Section 1.6. All installation and service on Frymaster
equipment must be performed by qualified, certified, licensed, and/or authorized installation
or service personnel, as defined in Section 1.6.
1.5 Definitions
QUALIFIED AND/OR AUTHORIZED OPERATING PERSONNEL
Qualified/authorized operating personnel are those who have carefully read the information in this
manual and have familiarized themselves with the equipment functions, or who have had previous
experience with the operation of the equipment covered in this manual.
QUALIFIED INSTALLATION PERSONNEL
Qualified installation personnel are individuals, firms, corporations, and/or companies which, either
in person or through a representative, are engaged in and are responsible for the installation of
electrical appliances. Qualified personnel must be experienced in such work, be familiar with all
electrical precautions involved, and have complied with all requirements of applicable national and
local codes.
QUALIFIED SERVICE PERSONNEL
Qualified service personnel are those who are familiar with Frymaster equipment and who have been
authorized by Frymaster, L.L.C. to perform service on the equipment. All authorized service
personnel are required to be equipped with a complete set of service and parts manuals, and to stock
a minimum amount of parts for Frymaster equipment. A list of Frymaster Factory Authorized
Service Centers (FASC) is included with the fryer when shipped from the factory. Failure to use
qualified service personnel will void the Frymaster warranty on your equipment.

1-3
1.6 Shipping Damage Claim Procedure
What to do if your equipment arrives damaged:
Please note that this equipment was carefully inspected and packed by skilled personnel before
leaving the factory. Frymaster does not assume responsibility for damage or loss incurred in transit.
The freight company assumes full responsibility for safe delivery upon acceptance of the equipment.
1. File Claim for Damages Immediately—Regardless of extent of damage.
2. Visible Loss or Damage—Be sure this is noted on the freight bill or express receipt and is signed
by the person making the delivery.
3. Concealed Loss or Damage—If damage is unnoticed until equipment is unpacked, notify the
freight company or carrier immediately and file a concealed damage claim. This should be done
within 15 days of date of delivery. Be sure to retain container for inspection.
1.7 Service Information
For non-routine maintenance or repairs, or for service information, contact your local Frymaster
Authorized Service Center (FASC). Service information may also be obtained by calling the
Frymaster Technical Services Department (1-800-24FRYER) or by e-mail at
[email protected].The following information will be needed in order to assist you efficiently:
Model Number_________________________
Serial Number _________________________
Voltage ______________________________
Nature of the Problem___________________
____________________________________
____________________________________
RETAIN AND STORE THIS MANUAL IN A SAFE PLACE FOR FUTURE USE.

2-1
YFPRE18E ELECTRIC FRYER
CHAPTER 2: INSTALLATION INSTRUCTIONS
2.1 General
Proper installation is essential for the safe, efficient, trouble-free operation of this appliance.
Qualified, licensed, and/or authorized installation or service personnel, as defined in Section
1.6 of this manual, should perform all installation and service on Frymaster equipment.
Failure to use qualified, licensed, and/or authorized installation or service personnel (as
defined in Section 1.6 of this manual) to install or otherwise service this equipment will void
the Frymaster warranty and may result in damage to the equipment or injury to personnel.
Where conflicts exist between instructions and information in this manual and local or
national codes or regulations, installation and operation shall comply with the codes or
regulations in force in the country in which the equipment is installed.
Service may be obtained by contacting your local Factory Authorized Service Center.
NOTICE
All fryers shipped without factory supplied cords and plug assemblies must be
hardwired using flexible conduit to the terminal block located on the rear of the fryer.
These fryers should be wired to NEC specifications. Hardwired units must include
installation of restraint devices.
DANGER
Adequate means must be provided to limit the movement of this appliance without
depending on or transmitting stress to the electrical conduit. A restraint kit is
provided with the fryer. If the restraint kit is missing contact your local Frymaster
Factory Authorized Service Center (FASC) for part number 826-0900.
NOTICE
If this equipment is wired directly into the electrical power supply, a means for
disconnection from the supply having a contact separation of at least 3-mm in all
poles must be incorporated in the fixed wiring.
NOTICE
This equipment must be positioned so that the plug is accessible unless other
means for disconnection from the power supply (e.g., a circuit breaker) is provided.
NOTICE
If this appliance is permanently connected to fixed wiring, it must be connected by
means of copper wires having a temperature rating of not less than 167°F (75°C).
NOTICE
If the electrical power supply cord is damaged, it must be replaced by a Frymaster
Dean Factory Authorized Service Center technician or a similarly qualified person in
order to avoid a hazard.

2-2
DANGER
This appliance must be connected to a power supply having the same voltage and
phase as specified on the rating plate located on the inside of the appliance door.
DANGER
All wiring connections for this appliance must be made in accordance with the wiring
diagram(s) furnished with the appliance. Refer to the wiring diagram(s) affixed to the
inside of the appliance door when installing or servicing this equipment.
DANGER
Frymaster appliances equipped with legs are for stationary installations. Appliances
fitted with legs must be lifted during movement to avoid damage to the appliance
and bodily injury. For movable installations, optional equipment casters must be
used. Questions? Call 1-800-551-8633.
DANGER
Do not attach an apron drainboard to a single fryer. The fryer may become unstable,
tip over and cause injury. The appliance area must be kept free and clear of
combustible material at all times.
In the event of a power failure, the fryer(s) will automatically shut down. If this occurs, turn the
power switch OFF. Do not attempt to start the fryer(s) until power is restored.
This appliance must be kept free and clear of combustible material, except that it may be installed on
combustible floors.
A clearance of 6 inches (15cm) must be provided at both sides and back adjacent to combustible
construction. A minimum of 24 inches (61cm) should be provided at the front of the equipment for
servicing and proper operation.
WARNING
Do not block the area around the base or under the fryers.
DANGER
Prior to movement, testing, maintenance and any repair on your Frymaster fryer, disconnect
all electrical power from the fryer.
2.1.2 Electrical Grounding Requirements
All electrically operated appliances must be grounded in accordance with all applicable national and
local codes, and, where applicable, CE codes. A wiring diagram is located on the inside of the fryer
door. Refer to the rating plate on the inside of the fryer door for proper voltages.
2.1.3 Australian Requirements
To be installed in accordance with AS 5601 / AG 601, local authority, gas, electricity, and any other
relevant statutory regulations.

2-3
2.2 Power Requirements
Three (3) Phase Requirements
MODEL VOLTAGE
WIRE
SERVICE
MINIMUM WIRE
SIZE
AWG (mm)
AMPS
(per leg)
YFPRE1817E 208 3 6 (4.11) 48
240 3 6 (4.11) 41
480 3 6 (4.11) 21
220/380 4 6 (4.11) 26
240/415 4 6 (4.11) 24
230/400 4 6 (4.11) 25
2.3 After Fryers Are Positioned At the Frying Station
DANGER
No structural material on the fryer should be altered or removed to accommodate
placement of the fryer under a hood. Questions? Call the Frymaster Dean Service
Hotline at 1-800-551-8633.
1. Once the fryer has been positioned at the frying station, use a carpenter’s level placed across the
top of the frypot to verify that the unit is level, both side-to-side and front-to-back.
To level fryers equipped with legs, the bottom of the legs can be screwed out up to one inch for
leveling. Legs should also be adjusted so that the fryer(s) are at the proper height in the frying station.
For fryers equipped with casters, there are no built-in leveling devices. The floor where the
fryers are installed must be level.
When the fryer is leveled in its final position, install the restraints provided with the unit to limit
its movement so that it does not depend on or transmit stress to the electrical conduit or
connection. Install the restraints in accordance with the provided instructions (see illustration
below). If the restraints are disconnected for service or other reasons, they must be reconnected
before the fryer is used.
NOTE:If you need to relocate a fryer installed with legs, remove all weight from each leg
before moving. If a leg becomes damaged, contact your service agent for immediate repair or
replacement.

2-4
DANGER
Hot oil can cause severe burns. Avoid contact. Under all circumstances, oil must be
removed from the fryer before attempting to move it to avoid oil spills, falls and
severe burns. This fryer may tip and cause personal injury if not secured in a
stationary position.
2. Close fryer drain-valve(s) and fill frypot with water to the bottom oil level line.
4. Clean, and fill frypot(s) with cooking oil. (See Equipment Setup and Shutdown Procedures in
Chapter 3.)

3–1
YFPRE18E ELECTRIC FRYER
CHAPTER 3: OPERATING INSTRUCTIONS
FINDING YOUR WAY AROUND THE YFPRE18E ELECTRIC FRYER
TYPICAL CONFIGURATION (YFPRE1817E SHOWN)
NOTE: The appearance of your fryer may differ slightly from that
shown depending upon the configuration and date of manufacture.
Tilt Housing
Basket Hanger
Lift Rod
Top Cap
Bezel
Control Panel
YUM Wingstreet controller
shown.
Drain and Filter Handles
Built-in Filtration
Unit
Drain
Filter Pan
Fuse
Power Switch

3–2
3.1 Equipment Setup and Shutdown Procedures
Setup
DANGER
Never operate the appliance with an empty frypot. The frypot must be filled to the fill
line with water, oil or shortening before energizing the elements. Failure to do so
will result in irreparable damage to the elements and may cause a fire.
DANGER
Remove all drops of water from the frypot before filling with oil. Failure to do so will
cause spattering of hot liquid when the oil is heated to cooking temperature.
1. Fill the frypot with oil to the bottom OIL LEVEL line located on the rear of the frypot. This will
allow for oil expansion as heat is applied. Do not fill cold oil any higher than the bottom line;
overflow may occur as heat expands the oil.
NOTE: If solid shortening is used, first raise the elements, then pack the shortening into the
bottom of the frypot. Lower the elements, and then pack the shortening around and over the
elements. It may be necessary to add shortening to bring the level up to the proper mark after the
packed shortening has melted.
DANGER
Never set a complete block of solid shortening on top of the heating elements.
When using solid shortening, always pre-melt the shortening before adding it to the
frypot. If the shortening is not pre-melted, it must be packed down into the bottom of
the frypot and between the elements, and the fryer must be started in the melt-cycle
mode.
Never cancel the melt-cycle mode when using solid shortening. Doing so will result
in damage to the elements and increase the potential for a flash fire.
2. Ensure that the power cord(s) is/are plugged into the appropriate receptacle(s). Verify that the
face of the plug is flush with the outlet plate, with no portion of the prongs visible.
3. Ensure that the power is switched on. The fryer is equipped with a master switch located behind
the fryer door cabinet on the front panel of the component box, next to the fuse. See page 3-1.
4. Ensure that the computer / controller is switched ON.
5. Ensure that the oil level is at the top OIL LEVEL line when the oil is at its cooking temperature.
It may be necessary to add oil or shortening to bring the level up to the proper mark, after it has
reached cooking temperature.
Shutdown
1. Turn the fryer off.
2. Filter the cooking oil and clean the fryers (See Chapters 4 and 5).
3. Place the frypot covers on the frypots.

3–3
3.2 Controllers
This fryer will be equipped the following YUM Wingstreet controller:
CAUTION
If this is the first time the fryer is being used after installation, refer to the frypot Boil-Out Procedure
on Page 5-2.
Refer to the separate Frymaster Wingstreet Controller User’s Manual furnished with your fryer for
the specific controller operating instructions. An overview for the controller is provided below.

3–4

YFPRE18E ELECTRIC FRYER
CHAPTER 4: BUILT-IN FILTRATION
4-1
WARNING
Drawings and photos used in this manual are intended to illustrate operational,
cleaning and technical procedures and may not conform to on-site management
operational procedures.
WARNING
The on-site supervisor is responsible for ensuring that operators are made aware of
the inherent hazards of operating a hot oil filtration system, particularly the aspects
of oil filtration, draining and cleaning procedures.
WARNING
When operating the filtration system, never leave the filter unattended. The action of
the oil moving through the hose lines could jolt a flexible return hose (where
applicable) out of the filter pan, spraying hot oil and causing severe burns.
DANGER
The crumb tray in fryers equipped with a filter system must be emptied into a
fireproof container at the end of frying operations each day. Some food particles
can spontaneously combust if left soaking in certain shortening material.
IMPORTANT
Cooking oil/shortening should be filtered at least daily, or more frequently if cooking
is heavy. This assures the longest life possible for the oil and minimizes flavor
transfer.

YFPRE18E ELECTRIC FRYER
CHAPTER 4: BUILT-IN FILTRATION
4-2
4. 1 General
Frymaster YFPRE18E fryers come equipped with a built-in filtration system. Photos used in the
procedural illustrations may differ slightly from the filter unit that came with the frying system. The
following procedures apply to all YFPRE18E fryers equipped with built-in filter systems.
4.2 Filtration Preparation
On initial installation and before each use, remove all loose parts from the filter, wash the filter pan
and all accessories in hot, soapy water and dry thoroughly.
4.2.1 Assembling the Filter
The YFPRE18E filter system uses filter paper
held in place by a hold-down ring to filter
impurities and debris from the cooking
medium. The filter pan is assembled with the
following components (see illustration):
1. Filter pan.
2. Filter support grid.
3. Filter paper.
4. Hold-down ring.
5. Crumb screen.
5
4
2
1
3

YFPRE18E ELECTRIC FRYER
CHAPTER 4: BUILT-IN FILTRATION
4-3
4.2.1 Assembling the Filter (cont.)
Assemble the filter as follows:
1. Place the support grid in the bottom of filter
pan.
2. Center the hold-down ring on a clean sheet of
filter paper, ensuring is overlaps all edges of
the ring.
3. Position the hold-down ring and paper on top
of the filter pan, sliding it into position
toward the pickup tube. Ensure the hold-
down ring seals around the support grid,
which prevents air from entering the system.
Support grid properly placed in filter pan.
Ensure the filter paper extends
past the edge of the hold-down
ring.
Hold-down ring shown with ample extension of
filter paper.

YFPRE18E ELECTRIC FRYER
CHAPTER 4: BUILT-IN FILTRATION
4-4
4. 2.1 Assembling the Filter (cont.)
4. Sprinkle one packet of filter powder on the filter
sheet. Ensure the powder covers the filter paper
evenly.
(Filter powder is not included with the filtering
tools; see Section 4.3.2 for more information.)
5. Place the crumb screen in the filter pan. Allow
the crumb screen to rest on the top edges of the
hold-down ring.
6. Place filter pan cover onto the filter pan
assembly. Ensure the front cover is
correctly positioned over the slip fitting.
The filter pan is shown partially inserted under the
fryer.
Crumb tray shown in place.
Sprinkle the proper amount of filter powder evenly
over the paper.

YFPRE18E ELECTRIC FRYER
CHAPTER 4: BUILT-IN FILTRATION
4-5
4.2.2 Installing the Filter
Slide the filter inside the fryer cabinet. Ensure the male-female slip-fitting coupling is fully
engaged.
4.3 Daily Filtration Operation
DANGER
Use caution and wear proper protective clothing. The oil to be filtered is at or near
350°F (177°C). Ensure all hoses are connected properly and drain handles are in
their proper position prior to operating any switches or valves. Failure to do this can
result in severe burns.
NOTICE
Drawings and photos used in this manual are intended to illustrate operational,
cleaning and technical procedures and may not conform to on-site management
operational procedures.
4.3.1 General Overview
The filter pump is turned on only after the oil is brought to operating temperature and drained into
the prepared filter pan. The filter motor is then engaged and oil is drawn through filter paper and
pumped back into the frypot. The frypot’s drain remains open during the filtering process. Allow
the oil to cycle through the filter paper for approximately 30 minutes. At the end of 30 minutes,
close the drain valve and allow the pump to fill the frypot to the top OIL LEVEL line. Leave the
pump running for 30-45 seconds after bubbles appear in the frypot to ensure all oil is pumped from
the drain pan and the lines. If the oil-return safety microswitch (activated by the oil-return handle)
should fail, the filter can be operated with the manual by-pass switch, located inside the left-bottom
of the fryer cabinet. Ensure the oil return valve is open prior to engaging the by-pass switch, and
closed prior to disengaging the by-pass switch. Use the manual by-pass switch only until the
microswitch can be repaired.
4.3.2 Filtering Tools
Assemble tools to be used for filtering. These are supplied with the filter starter kit included with
the fryer/filter system:
•Frypot/Filter Brush - used to clean frypot and filter pan sides and bottom and to dislodge
sediment during filtration or shortening/oil change.
•Clean-Out Rod (design may vary)- used to dislodge heavy debris in the drain tube (when
needed).
•Filter Paper.