This means in practice that moulds, which are designed and manufactured to very tight tolerances (of 0.05mm) are rarely maintained to original specification and that furthermore in most cases there is no formally agreed tolerance for repaired moulds that would substitute for the original mould drawing specification. The question to be asked is: if moulds are designed and made to such tight tolerances, why is there not the same focus on the repaired equipment?

And where this question cannot be adequately answered, this means simply that the running moulds that reach the shop floor, may well not conform to any agreed specification and may well not be fit for purpose, with a direct result on operational performance and quality that is discussed below.

Conversely, there is good news because once the importance of mould design, materials and repair are understood and highlighted then improvements that will have a direct impact on performance can made with relative ease and low cost.

In order to show and prove the value of focus in this area, the first step is to identify and wherever possible, measure the links between mould equipment and operational performance:

• Defects linked to Mould and Neck Ring equipment are easily identified and are frequently in the top 10 defects for a factory. In a 2015 clearPerformance project check in the finish and neck of various kinds accounted for over 5% loss in Pack to Melt. Not surprisingly, deeper investigation showed there was also a clear correlation between these defects and poorly maintained mould equipment – especially the blank/ring match.
• Other mould-related defects are obvious and common place, with blank/mould seams and deep/badly matched baffles being two examples, with both of these issues a potential major issue for carbonated ware.
• Speed limitations can also be caused by mould equipment: the material and design of blanks, moulds and neck rings. Experience has proved that a simple redesign of for example, venting in blanks or neck rings can be a major factor in removing the barrier to speed up.
• Downtime for mould changes due to out of specification equipment is rarely managed and measured but can represent a major loss. Each mould change will cost 10-15 minutes of lost production based on stop time and ramp up.
• Cost of moulds and variable mould equipment is heavily impacted by the scrapping of components and replacement. Much of this is due to poor repair and cleaning methods; handling and transportation around the factory and storage.

These examples are all too familiar to Production and Forming teams and anybody who has been in a factory Production meeting be familiar with the cry of “it is the moulds”.

Of course moulds are not the only cause or culprit (machine set up and operation as well as condition of variable are other critical factors) but the high correlation between mould equipment and poor performance is often not matched by a proportionate response in troubleshooting and improvement initiatives.

These improvements can mostly be achieved by focusing on Standard Operating Procedures, training and skill development in three broad areas:

• Design
• Inspection
• Repair

Measurable progress (dependent on the issues) can generally be achieved within months (or with a particularly motivated team, within weeks) and have direct impact of performance, productivity and profit.

DESIGN

Design Standards are an essential foundation for consistent, effective and quality mould equipment. But surprisingly less than a quarter of the multi-site companies that clearPerformance has worked with have a company-wide, documented design standard, often because their growth has come from acquisition of different factories with different machine types, cooling systems and ways of working.

Even many single site operations do not have a clear Design Standards and often depend on mould makers, either fully or partially, for their designs.

Container companies clearly can function without a clear, written and agreed (between design and production) mould design standard but there are pitfalls.

• Missing best practice
• Consistency of design
• Repeated errors
• Transferability of moulds
• Purchasing efficiency

The development of a common standard takes time, commitment and teamwork but the longer term benefits are there to achieve.

As well as a common a Design Standard the development of best practice mould design will have direct benefits for quality and efficiency.

Blank/parison design is the obvious example but this extends equally to other components and mould features. Real examples from clearPerformance projects include a change to stippling design on a sparkling wine bottle and re-design of the heel radius on an NNPB beer bottle that drastically reduced pressure breakage and increased the Pack to Melt.

Design is just as crucial for successful New Product Development where equipment is a major factor in the success of sampling and production and specifically poor design can be a major reason for resampling, leading to plant disruption and increased cost.

The importance of best design is clear but clearPerformance has seen examples where for various reasons this does not exist in glass companies. For some it is a matter using a default position based on history, like the company that based new product moulds on an existing cavity shape and for whom clearPerformance made recommendations on parison run, blank shape and neck ring cooling.

Given the importance of mould design best practice, this can be developed in a number of ways:

• Exchange of experience and methods between factories in multi-site companies – an obvious opportunity but surprisingly under-used as each location is often convinced that their ways are best.
• Establishing formal feedback and communication between design and production. Again obvious but rarely done properly. Simple methods include: designers attending samplings; an effective Job Off and Defect correction process and the appointment of a Mould Engineer to provide the interface between operations, design and New Product Development.
• Take control of Design, even if it is contracted out, with a robust internal approval process that involves all the key departments in both signing off new developments and modifications.
• Develop the skills of designers.

All of the above can be done independently by glass manufactures but it is in this kind of project that  clearPerformance can support and accelerate the change needed.

REPAIR

Considering the cost of moulds, the extremely tight specifications of design and manufacture and their importance for efficiency and quality, mould repair often does not receive the attention it deserves and in the experience of clearPerformance the opportunities in Mould Repair Operations fall into two broad categories:

1. Inspection
2. Repair methods

Inspection is the first step in making sure that correct and fit for purpose equipment reaches the shop floor and the essential requirements for this are:

• A separate well lit, properly equipped Inspection area (see photo).
• Gauges to inspect critical dimensions. clearPerformance list 13 different gauges required for mould inspection it is rare to find a complete set on site. Without gauges there is no way of effectively checking and inspecting the equipment to ensure that it meets specification. In some cases without a gauge, there is no way of accurately checking certain design features, with dovetail angles being a good example. Apart from the essentials there is also the opportunity to achieve best practice by using electronic gauging that feeds data directly to a computer, improving accuracy and productivity.
• A regime for inspecting a sample of new incoming equipment.
• Running equipment (jobs on the machine or for job change) should be subject to 100% inspection. This is not uncommon and means equipment is cleaned/repaired and can be returned to the machine out of specification in critical dimensions like mould and blank diameters and match sizes that can lead to glass defects.
• There should be fully trained inspector who checks the equipment independently of the repairer.
• Standard Operating Procedures should be in place for each inspection operation. clearPerformance provides over 20 Inspection SOP’s as part of a mould improvement project.