Few weeks back, I shared Jacob Peled’s presentation ‘The Future of Tire Plants’ and more recently, ‘Visions of the Future’ on our LinkedIn Page. On reading, an industry friend asked me this question – ‘Will Post Cure Inflator Machinery Ever Die?’
While Jacob’s presentation envisions the shortening of curing time by use of higher temperatures and pressure, automation, development of bladder, materials etc, there have been no specific mention of Post Cure Inflators.
So where did this question rise from, I was curious.
Historically, the process of Post Curing Inflation has seen its popularity rise and fall at different time intervals. Tyre technology has been evolving to embrace increased efficiency at all stages of manufacturing. And Post Curing Inflation is not really an energy efficient process, reasoned my friend clarifying the basis for his question.
So, what is Post Cure Inflator Machinery?
Post Cure Inflator (PCI) machinery cools the tyre under pressure immediately after it has been cured.
For the tyre, this stage involves mounting them on the flanges, inflating it and cooling it according to a selected procedure. You may do this for one or two cycles (Note: one cycle is equal to the time taken for one curing cycle) depending on the specification arrived at for the time your cured tyre takes to cool down to room temperature.
Types of Post Cure Inflator Machinery
There are two types of Post Cure Inflator machinery, viz. Automatic and Semi-Automatic, in the market for use with tyres of passenger cars, light trucks, trucks and off-the-road equipment.
- Automatic Post Cure Inflator units are installed at the rear of tyre curing presses, to receive the cured tyres from the curing presses. The tyres are cooled to ambient temperature under controlled air pressure to avoid distortion of plies. After cooling, tyres are discharged onto the takeaway conveyor rollers. Post Cure Inflators are available in 2-position and 4-position designs, which allow for inflation time equivalent to curing time and double the curing time respectively.
- Semi Automatic Post Cure Inflator units are located in the curing area and cured tyres are loaded into these units. Tyres are cooled to the ambient temperature under controlled air pressure and are manually discharged from these units.
Machinery suppliers offer design features like adjustable inflation, auto/manual rotation, and adjustable bead width. These features enable Post Cure Inflator machinery to also function as a testing stand for secondary, manual inspection of sidewall or runout rejects.
To examine the importance of this tyre machinery further, let’s understand the process deeper.
Post Curing Inflation Process & its Significance
Post Curing Inflation is recommended especially for tyres of nylon carcass construction. This is because nylon has a unique property of shrinking while it is heated. When you have nylon in your tyre carcass (i.e. the skeleton of the tyre), there is a tendency for it to shrink as you heat the tyre to vulcanize.
Since vulcanizing of the tyre happens inside a curing press, it is not possible for these nylon cords to shrink. This is because there is high pressure inside the tyre which keeps these nylon cords in the stretched condition. But when the curing is completed and you release the pressure inside the bladder, the nylon cords tend to shrink since your tyre is still hot.
To avoid this hot or thermal shrinkage, the tyre is to be cooled under pressure. If you skip this process, the tyres may lose shape or get distorted or have changes in dimensions.
Post Cure Inflator machinery stabilizes the shape of your tyre in production. When you delay Post Curing Inflation, the damage caused would be irreversible and highly undesirable – both for your company’s reputation and customers safety.
If your customer is given a tyre which was affected by Post Curing Inflation delay, its dimensions will be different from normal tyres. This leads to uneven wear, problems to the axle and bearings of their vehicle. The distortion in shape further leads to tyre uniformity problems that adversely impacts the level of comfort and performance of tyres in the highly advanced vehicles. Last but not the least, a distorted tyre is not safe and lead to accidents. Needless to say, all of the above creates a negative impact on the company’s image and lead to economic and legal implications for your company.
When the design of your tyre construction changes, Post Curing Inflation process allow your tyres to maintain their designed profile and performance characteristics as they reach road temperatures.
Summarizing, while the popularity of Post Curing Inflation process (and hence Post Cure Inflator Machinery) may shift back and forth, this tyre machinery will not die soon.
What do you think?
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