Textile Cores & Roller Blind Cores

Convolute cores / parallel tubes or spirally wound core – that is the question ?

 

There are two main types of cardboard cores & tubes – namely  : convolute tubes / parallel or spirally wound cores, but which one is best for you ?

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Convolute (synonymous with parallel) is the much older of the two technologies but does retain some advantages. Convolute tubes are produced from a single sheet of paperboard & the fibres in the paperboard run in the same direction down the length of the tube thus yielding a good ratio of strength over length, known as beam strength. Unfortunately with convolute cores have a lot less flexibility when it comes to inner diameter, length and wall, and therefore are not suitable for many key industries such as flexible film cores, vinyl wrap cores, laminate cores, label cores and tape cores.

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Convolute cores & convolute tubes are usually now somewhat restricted to textile tubes & fabric cores in the UK due to the fact that they offer excellent beam strength and are relatively low-cost, mainly due to the high speed of production. They have largely fallen out of favour with industrial cores & cardboard tubes manufacturers in the UK due to the relatively high cost of maintaining & mandrel tooling of such machines. These additional costs struggle to be built into the selling price of textile cores or fabric tubes.

 

The cost of a new mandrel is normally more than twice as expensive as its spirally wound cores equivalent, & thus are not as readily replaced.  Convolute cores or convolute tubes machines in the UK are of much older & less advanced technology & cores produced have much less accuracy in dimension than its modern spirally wound cores counterpart & thus convolute cores are not suited to high-speed take-offs. The flat crush strength of a convolute is much less than that of a spirally wound core where the individual fibres contained within the fibreboard run at an angle to the length of the core resulting in a much higher flat crush strength. This means that convolute cores work well if you are just using the textile cores to support a wide fabric, but if you want to wrap a lot of material, or in the industrial cores market, a lot of plastic, non-woven fabric around the cardboard tubes, spirally wound cores are the way to go, due to their increased crush strength.

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Convolute cores used to provide the backbone of carpet cores in the UK, but no more, that industry has succumbed to the benefits of spirally wound cores produced by Just Paper Tubes (JPT), and others.

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Due to advancements in technology of paperboard, adhesives, & having a “state-of-the-art” plant JPT can offer all categories of spirally wound cardboard cores & tubes produced to a high level of accuracy & cost efficiency, & also, thanks to our new core & tube drying facility, unique in the UK, we can achieve the shortest of lead times too !

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Even if you are using convolute cores, get in touch we probably have spiral cardboard tubes that give better performance.