WOCG guides

NEW 2008

BPG 7
Introduction
Digital workflows have increased the speed and efficiency of offset printing. They have also enabled the development of Alternate Screening Technologies (AST) that can add value to offset printed images by improving their visual quality. However, the digital printing workflow chain also has multiple potential sources of colour and quality deviations. This guide focuses on optimising the conventional AM digital workflow process which is also the prerequisite to the successful use of ASTs such as FM, Hybrid FM/AM and high lpi AM screenings.
This guide is complimentary to the work of ICC, Ifra, GATF, IDEAlliance and other organisations and its objectives are to help optimise best practices that improve quality, consistency and productivity. As part of this project, 35 current users have shared some of their experiences with ASTs that confirms our conclusions that that key process success factors include:
• An integrated industrial manufacturing strategy (that combines standardisation, colour management, process control and effective maintenance) is essential to achieve consistent high quality and productivity benefits.
• Successful AST users indicate that the window of operating variability is tighter for AST and requires better control of all process variables.
• An optimised conventional AM workflow is the absolute prerequisite to assess, select and introduce ASTs.
Best practices are a tool to improve overall performance. Each contributing company plays a role in an inter-related production chain within which the combined expertise helps to improve overall process performance. Two other Web Offset Champion Group guides that focus on process optimisation are “How to get colour approved rapidly and maintain it” and “Productivity maintenance”

IMPORTANT SAFETY NOTE !
Always check a machine is in its specified safe position before working on any component (e.g. with compressed air, electrical power and gas disconnected). Only trained maintenance personnel adhering to safety regulations should perform maintenance work. A general guide cannot take into account the specificity of all products and procedures. We therefore strongly recommend that this guide be used in addition to information from your suppliers, whose safety, operating and maintenance procedures take preference.
This guide is produced for printers worldwide. However, there are some regional variations of terminology, materials and operating procedures. Care should be taken before applying US printing reference values outside of North America as variations may include different ink strengths, densitometry filters, screen rulings, and platemaking (US mainly uses negative processing and any slight over exposure spreads the dot, whereas in positive processing this sharpens the dot).

BPG7 Content 1	Page
Introduction	1
Digital Process Workflow Chain Colour Management	2
Standards & Profiles	4
Screening Technologies	6
What are ASTs	7
Why use ASTs?	10
BPG7 Content 2	Page
Process essentials	12
What dot size?	13
Digital Tonal Reproduction & Tone Value Increase (TVI)	14
BPG7 Content 3	Page
Optimise the process workflow	16
Proofing	17
Premedia	19
Making profiles	20
Platemaking	22
Printing	23
Print characteristic curves examples	24
Key influences on quality	26
BPG7 Content 4	Page
AST How to evaluate an AST?	30
Survey of AST users	31

BPG 6
BPG6 GB
This guide looks at the underlying issues of the 4Es of Energy, Economy, Efficiency, Ecology and how to apply the 4 Rs - Redesign, Reduce, Reuse, Recycle - to improve overall performance. Best practices are an important tool that combines the generic expertise of Web Offset Champion Group members, printers, associations and other experts to help improve the efficiency of the production process chain.

A responsible environmental policy has compelling business advantages - the opportunity to reduce costs, increase competitiveness, become more innovative and enhance staff and customer confidence, whilst avoiding the potentially expensive risks of non-compliance. In many cases, companies may also qualify for funding opportunities, tax incentives and reduced insurance premiums. In addition, environmentally aware printers benefit from an increasingly positive brand value perception, particularly as more and more of their customers are adopting third-party certified Corporate Social Responsibility reporting. Businesses that take only a minimum compliance approach miss all of these opportunities and have a higher risk of fines and remedial costs.

Environmental considerations have an important role in improving overall business performance. Equipment, materials and operational effectiveness are the three pillars of productivity that need to work effectively together to optimise manufacturing efficiency. Each pillar incorporates standard procedures, maintenance and environmental issues; poor performance in any one will have a negative impact on productivity. Product quality is a key environmental issue and getting it “right first time” is a joint environmental and economic necessity. A systematic waste minimisation programme can often cut waste by 25% — this means that if total waste is 12% of turnover, 3 % can be added to company profits through cost savings. Waste reduction has become even more important because industrial raw materials (oil, metals, energy) have increased in price by 54% in the three years ending 2004. Paper, however, maintains a relatively stable price that has changed little in real terms since the early 1990s. Waste is often seen as valueless but its recycling/re-use value can be much higher than the cost of its disposal.

BPG6 Content 1	Page
Introduction Integrated environmental	1
business strategy Main environmental	2
management issues	3
Considerations for print buyers & designers	4
Considerations in printers' supply chain	5
Paper and the environment	6
BPG6 Content 2	Page
The web offset environment	8
Process inputs and outputs	9
Measure and minimise waste	10
Optimise consumables	10
Reduce packaging	11
Separate waste	11
Volatile Organic Compounds (VOCs)	12
Cleaning products	12
Consumable materials	14
Water and liquid waste	15
Paper and sold waste	16
BPG6 Content 3	Page
Production process	18
Prepress	18
Ink	19
Dampening	20
Blankets & washing systems	22
Air emission compliance & Control	23
Postpress	26
BPG6 Content 4	Page
Energy Efficiency Where are the wasted kWh's?	30
Machines	31
Buildings & services	36
Lighting	38
Noise and the environment	39

BPG5
The fifth guide in the best practice series addresses not only production best practice but also the interaction with the customer and design agency necessary to produce a completely satisfactory printing job. This guide addresses both the on-press aspects of Colour OK and, equally as importantly, the total process that begins with the specification and creation of the printed job. Adopting this approach implies that the workflow begins with the finished job.

Correct colour setting, one of the primary tasks for obtaining a press OK, depends significantly on how humans see, understand and communicate colour. Print production methods have changed from a process of separate analogue steps to a continuous digital workflow from image creation to printing. The trend to ‘print by numbers’ is also being driven by customer requirements for verifiable quality control, the growth of CtPlate, use of industry standards, closed-loop production control, globalisation and remote-site printing using pre-press data transmitted with numeric control values. The primary elements for improved performance include:
• An integrated industrial manufacturing strategy that combines standardisation, process-control and defined procedures is essential to achieve higher quality and productivity benefits. Standardisation and process-control are core elements of effective colour management. Without them, colour management loses the “ground from under its feet”, is “process blind” and cannot fulfil its objectives .
• Adequate planning, specification and job preparation by the customer and the printer.
• Complete and coherent control of the printing workflow. Each output step needs to be controlled (PDF, digital proof, CtPlate, printing) with measuring techniques and methods that achieve a predictable outcome. Success requires that the customer, pre-press supplier and printer work together within this approach.
• Appropriate on-press colour approval method. Human factors are often overlooked in the colour approval process. These include subjective and varying perceptions of colour, communication and expectations also different viewing environments between customer, agency and printer.
• Effective maintenance and standard operating procedures are key success factors to ensure rapid start-up, optimum quality, productivity and on-time delivery (see guide N° 4 “Productivity Maintenance”).

Best practices are a tool to improve overall performance. Each contributing company plays a role in an interrelated production chain within which the combined expertise is a positive way to help improve overall process performance.

IMPORTANT SAFETY NOTE ! Always check a machine is in its specified safe position before working on any component (e.g. with compressed air, electrical power and gas disconnected). Only trained maintenance personnel adhering to safety regulations should perform maintenance work. A general guide cannot take into account the specificity of all products and procedures. We therefore strongly recommend that this guide be used in addition to information from your suppliers, whose safety, operating and maintenance procedures take preference.

BPG5 Contents	Page
The process colour system: Improve cost, time and quality performance	2
What is a colour OK	2
Steps to effective colour OK ?	3
Some colour basics	4
Picture Contrast Theory	6
Process control & standardisation	7
Colour management & profiles	8
Print job preparation: Specifications begin with the finished job	10
Paper selection & profile	10
Bindery considerations	12
Design & pre-press	13
Select proofing system	15
Specify quality category	16
Printing plates	17
Alternative screening techniques	19
On-press approval customer’s role	20
Heatset start-up	21
Printing with metallic inks	23
Coldest start-up	24
Makeready	26
Common problems	28
Tips to achieving & maintaining colour	29
Key role of blankets	30
Glossary	31

BPG4
Maintenance has a major impact on printing productivity but it does not always attract the attention it deserves. Its importance was underlined at the TAGA 2001 conference in the keynote presentation of RR Donnelley & Sons’ VP of Technology, Grant Miller. He listed the biggest causes of lost time and increased costs as equipment failures, set-up and adjustment, idling and minor stoppages, reduced speeds, defects in the process and start-up and reduced yields. “The bottom-line is that the overall equipment effectiveness today has much room for improvement.”

IFRA’s Special Report 3.33 Optimising Productivity published in 2001 observes that: “Usually the only way to improve productivity is to reduce the time the press is not running either by faster make readies or by avoiding disturbances during running. Disturbances either consume production time or increase waste. They fall into three types : sudden events that can stop the press (e.g. broken parts, electronic failures, web breaks) ; cumulative, where the printer can choose when to stop the press (e.g. blanket piling) ; and those that reduce speed or quality (e.g. mis-register, wrinkles).” The report’s findings included that :
• People (and their training) have the biggest single impact on productivity
• Productivity cannot be increased by decreasing quality
• Adequate time and resources need to be allocated for systematic maintenance
• Materials should be optimised according to press and quality requirements.
• Importance of pre-press influence on press operation (on-time plate delivery and quality)

There is an intrinsic relationship between productivity, reliability and maintenance. An additional dividend is to reduce the stress on production staff generated by breakdowns. The Champion Group survey of printers who have introduced pro-active maintenance systems unanimously report significant performance improvements from :
• Fewer unscheduled press stops
• Higher press net output
• Less waste
• More consistent quality
• Fewer accidents

Best practices are a tool to improve overall performance. The contributing companies play a role in an inter-related production chain and the combination of their expertise is a positive way to help improve overall process performance. The purpose of this guide is to give web offset printers an overview of maintenance as part of the production system and to provide practical ideas to make it more effective. It draws strongly on the methodology of Total Productive Maintenance (TPM) developed by Seiichi Nakajima that integrates preventive, predictive, quality and autonomous maintenance.

IMPORTANT SAFETY NOTE ! Always check machine is in its specified safe position before working on any component (e.g. with compressed air, electrical power and gas disconnected). Only trained maintenance personnel adhering to safety regulations should perform maintenance work. A general guide cannot take into account the specificity of all products and procedures. We therefore strongly recommend that this guide be used in addition to information from your suppliers, whose safety, operating and maintenance procedures take preference over this guide.

BPG4 Contents	Page
Why maintain	2
A cost or an investment ?	3
Maintenance strategy	4
Predictive maintenance tools	6
Press system issues	9
Materials and storage	13
Components
Pre-press	14
Paper handling system	16
Inking & Dampening	18
Rollers	20
Blankets	22
Print units	24
Heatset system	26
Folder	28
Signature delivery systems	30
Glossary	31

BPG3
Best practices are a tool to improve overall performance. The purpose of this guide is to provide heatset and coldset web offset printers with a base reference to best practice. The contributing companies play a role in an inter-related production chain and the combination of their expertise is a positive way to help improve overall production process performance :
            • Avoidance of predictable problems
            • Correct use of materials and equipment
            • Systematic problem diagnoses with appropriate remedial actions

"How to avoid surprises when changing paper grades" There is a continuing trend to more frequently change paper grade, weight and process. Different papers have variable process requirements that impact pre-press, printing, finishing and total cost. Many publishers, advertising agencies and printers have suffered under-performance from change. Whilst others have optimised their total production process by working closely with their suppliers. By focusing on three grades of paper (LWC, SC, INP) we show what changes to expect and best practices to improve performance. The economic models and research results indicate the importance of different variables. They should not be taken as absolute values because of the diversity of the web offset process and its materials. We therefore recommend that printers monitor their own performance to calculate their own specific position.

Optimised printing on variable paper grades
Technology and material changes have led to pre-press becoming progressively even more important to optimum printing performance. The single most important factor affecting total cost and quality is the matching of pre-press profiles to paper grade and press. Effective use of industry reference targets for “printing by numbers” are critical to the integration of digital workflows, creating ICC profiles and the effective use of CTP. Other key influences are maintenance, press settings, environmental conditions and the selection of the right combination of consumables for each press.

Important note : a general guide cannot take into account the specificity of all products and therefore we recommend that it is used in addition to information from your suppliers, particularly the manufacturers of equipment whose safety, operating and maintenance procedures take preference over this guide. This guide is produced for printers world-wide. However, there may be some regional variations of terminology, materials and operating procedures that are not included.

BPG3 Contents	Page
Definitions & glossary	2
Why change paper grades ?	4
Operating and economic impact of change	6
Process system	8
20 Common problems from change	9
Printing by numbers	12
Input and output profiles	13
Pre-press	15
Workflows & Profiles	18
Paper-Ink-Drying relationships	19
Ink & dampening on paper	22
Heatset system	26
Web tension, printing units, blankets, folder	29
Signature delivery systems	31

BPG2
The purpose of this booklet is to provide heatset and coldset web offset printers with a base reference to best practice. The contributing companies play a role in an inter-related production chain and the combination of their expertise is a positive way to help improve overall production process performance :
            • Avoid predictable problems.
            • Correctly use materials and equipment.
            • Systematic problem diagnoses with appropriate remedial actions.
Best practices are a tool to improve performance. Ideally they should be available as checklist procedures for operators and maintenance staff.

Web breaks : no single simple cause
Web breaks and mis-splices are usually caused by the simultaneous occurrence of different disturbances. They are often triggered by a minor change in one factor. Our survey of 50 international printers found that web breaks are a significant problem for 95 % of them ; and what is an important web break cause at one printer may be relatively unimportant to another. This variability is due to different technologies, papers, materials and environments. Data on web break causes are also variable making extrapolation of cause and effect more difficult.

What can be done to minimise web breaks ?
1. Measure and analyse mis-splices and web breaks causes to identify priority areas for improvement.
2. Introduce best practice to reduce web break probability from both individual and combined causes.
3. Train and motivate staff to apply best practice systematically.
This guide provides a diagnosis aid to 140 web break and mis-splice causes and identifies best practice to avoid and minimise them where possible.

IMPORTANT NOTE : a general guide cannot take into account the specificity of all products and therefore we recommend that it is used in addition to information from your suppliers, particularly the manufacturers of equipment whose safety, operating and maintenance procedures take preference over this guide. This guide is produced for printers world-wide. It incorporates existing international standards where appropriate (e.g. IFRA, TAPPI). There are some variations between the US and Europe of materials (e.g. plates, ink, dampening solutions, paper ph), operating procedures, and terminology which for reasons of space and clarity may not have always been addressed

BPG2 Contents	Page
Economic impact of web breaks	2
Web break analysis	3
Definitions, Web break, web wander & shift	4
Creases & Wrinkles	5
Glossary and abbreviations	5-6
Detection and control	6
Web breaks in relation to production system	7
Web tension	8
Ambient press environment	10
Web breaks and mis-splices related to:
Paster/Splicer	12
Infeed and web guide	17
Ink and dampening	18
Printing units	20
Heatset drying system and air turns	22
Chill roll stand	24
Folder	25
Roll and paper diagnosis	27

BPG 1
The purpose of this guide is to provide heatset and coldset web offset printers with a base reference to best practice as a tool to improve overall performance. The contributing companies play a role in an inter-related production chain and the combination of their expertise is a positive way to help improve overall process performance:
• Avoidance of predictable problems.
• Correct use of materials and equipment.
• Systematic problem diagnoses with appropriate remedial actions.

The content and value of this publication have been helped by the assistance of IFRA who publish excellent material for coldset newspaper production. We gratefully acknowledge IFRA's help and permission to include some of their material and specifications. We also gratefully acknowledge the printers from all over the world who gave willingly of their time and expertise to review and improve this guide. Roll to web processing is not only the start of the printing process but also paper is its largest expense (50-70% of total operating costs) making it essential to minimise waste from all causes. IFRA states that "often roll preparation produces such surprisingly high and unnecessary amount of waste that the productivity of the entire printing press can be affected. Any miss-splice, following a careless preparation, or any web break due to an inaccurate check of the roll will cause a long production interruption with the corresponding consequences. The successful preparation of the splice greatly depends on the skill and experience of the staff."

This guide has been prepared for press room staff to provide them with a useful aid in their daily work with both flying paster and zero speed splicer technologies.

To achieve consistent splice efficiency of over 99% requires (a) optimum combination of tape and tab qualities; (b) correct splice preparation; and (c) a paster maintained and operated to ensure an efficient splice cycle. Many runnability problems are also directly related to poor roll storage and handling, temperature and humidity variations.

BPG1 Contents	Page
Paper grades and qualities	2
Ink-paper relationship	3
Roll to web processing system	4
Common problems	5
Web tension	6
Humidity and temperature	7
The paper roll	8
Roll handling and storage	10
Paster & Splicer characteristics	12
Splice pattern selection	14
Splice tapes and tabs	16
Splice tails	18
Paster make ready	19
Roll to web processing steps	20
V & W splices	24
Straight splices	26
All-in-one splices	28
Zero speed splices	30
Preventative maintenance	31

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