Following his exploration on different steps to be taken towards optimising forming process stability and reducing the weight of glass containers, in the coming issues Paul Schreuders addresses amazing discoveries related to XPAR Vision’s BlankRobot development. Introduced at last year’s glasstec exhibition, the BlankRobot is a true revolution in glass forming, whereby the amount of disturbances to the forming process is reduced drastically, hence paving the way for effective forming process automation. Here, the focus is on swabbing and the BlankRobot itself.
As explained in issue 74 and subsequently, following the Paris Climate Change Conference (COP21) and taking their social responsibility seriously, many if not all food and beverage packing companies are actively working to reduce their carbon footprint. Since packaging is a substantial part of this carbon footprint, supply chain collaboration is a key for success. Knowing the competitive field of metal, plastics and bio-based packaging, for glass the keys to survival are to recycle and reduce weight (improving the content-to-glass ratio). Reducing weight requires further optimisation of forming process stability.
For 20 years, XPAR Vision from the Netherlands has been leading the development of hot end sensors for improved glass container forming. At the recent glasstec event in Dusseldorf, the company launched its own Blank Robot device.
As the name suggests, the BlankRobot is designed not only for swabbing but for other applications as well. For swabbing, by applying a special lubricant together with a highly precise application, swabbing frequency is reduced to once every three hours only, leaving enough time for the robot to execute other functions.
This article explains the necessity for knowledge about all aspects of swabbing in order to support users in the effective application of swabbing robots.
In daily operation
The previous XPAR Vision’s “Amazing discoveries…” articles (parts 18-20) stipulated the do’s and dont’s of robotized swabbing in glass container manufacturing. The basics of the XPAR Vision’s BlankRobot concept, limiting the disturbance of swabbing for increased process stability was described in part 18. The crucial element of using the right lubricant with dedicated swabbing application has been outlined in part 19, followed by part 20 describing the importance of the swabbing robot supplier providing knowledge and assistance how the tool (robot) and the lubricant work together optimized for the product produced.
XPAR Vision maintains several of its BlankRobot systems in daily operations at various customers. In this article the relevant aspects of robotized swabbing in blow-blow production are discussed and reviewed.
In the previous article it has been outlined which aspects influence the effectiveness of automated swabbing in terms of bottle quality, efficiency, coating of blanks and stand time of blanks. From BlankRobot systems being continuously operated in blow-blow production the learnings confirm the influencing factors as impact of loading, the consistence of the gob loading position into the blanks and the profile design of the blank mould.
The weight of blow-blow bottles where the BlankRobots perform the swabbing automatically is in a range of 500 -800 grams with production speeds of 130-200 bottles per minute. Experiences come from both green and flint glass productions.
When reviewing the various influencing effects the swabbing performance is mainly determined by the profile of the blank. As example, a narrow conic blank design requires a delicate balance between the thickness of the applied layer of lubricant and the area of the profile where the lubricant is applied. Wider blank profiles have different requirements, logically. Immediate effects when these swabbing parameters are not balanced are loading marks due to increased friction when the graphite layer is applied too thinly or not consistently. Effectively the challenge is to find a good balance between layer thickness of the lubricant applied and swabbing interval. This pleads for robot technology where layer thickness of graphite and application toward the neck area of the blank profile is precisely to be determined. The BlankRobot from XPAR Vision is designed to handle this with accuracy. Swabbing robots not using in-mould swabbing (e.g. spray inside blank opening) or acetylene cracking will not perform in blow-blow bottle production.
In the end numbers are leading to determine the performance of swabbing automatically. With reference to the BlankRobots in daily operation at different customers in blow-blow productions XPAR Vision is delivering to the expectations set during the introduction of the BlankRobot concept at Glasstec 2018. Expectations set then summarize to deliver effective automatic swabbing resulting in extended swab intervals. With less swab cycles the disturbance to the forming process due to swabbing the stability of the forming process increases with better efficiency and better quality of bottles as result. Moreover, forming process stability opens the way to production improvements in terms of lighter product produced at higher speeds, while at the same time meeting the needs and requirements of your customers.
With BlankRobot swabbing automation our customers run their blow-blow productions at swabbing intervals of 120 minutes, compared to 20-30 minutes or less for competitive swabbing robots or for manual swabbing. This is the proof of the BlankRobot concept! Gains in process stability and direct financial gains in terms of less hot end losses due to swabbing!
From the quality perspective: in average cold end rejects for loading marks bottles are equal or better than with manual swabbing, while glass distribution (wall thickness variation) has improved significantly.
Besides the positive effects to the bottle and the forming process it is important to evaluate the effect on production means as well. One important factor here is the time (blank) mould sets can be used effectively. The experiences show an at least equal stand time of the blanks, which means no negative effect on lifetime of blanks.
Additionally, not anticipated for, but very positive side effect seen with automatic swabbing with BlankRobot is that customers who were normally (with manual swabbing) using a coating to their blanks to maintain stand times are now using only polished blanks in their blow-blow production. The cost of coating and maybe even more important the health and safety of the mould shop workers are not compromised anymore, as well as environmental impact by not having to apply the hazardous coating substances.
The experiences from customers using the BlankRobot in daily operation are confirming the XPAR Vision BlankRobot concept: while using special lubricant from LubriGlass in a dedicated manner by unique application technology of the BlankRobot the expectations are met and even exceeded when considering the positive side effects. Swabbing intervals are increased to 120 minutes compared to maximum of 30 minutes by manual swabbing or competitive robot swabbing.
Gains are found in process stability with direct opportunities for bottle weight reduction and production speed increase and direct financial gains in terms of less hot end losses due to swabbing!
With blow-blow bottle production the dynamics are different than with press-blow production. As well as the dynamics with neck ring swabbing. In future articles we will come back to the effects with (narrow-neck) press-blow production and neck ring swabbing experiences with the BlankRobot by XPAR Vision.