How sequin yarn is made.

Sequin discs are punched from a film — PVC for most colours, metallised polyester for metallics and holographics — and threaded onto a fine carrier thread in a continuous string. This is what the trade calls sequin string, and it is what we load onto the machine. At our scale it is bought in rather than punched here.

The first quality check happens before anything runs. We look at disc flatness, hole centring and colour consistency down the length of the string. A disc punched off-centre will not lie flat in the finished yarn, and a batch where the shade drifts from one end of the string to the other will show up as banding in a knitted panel. Both are rejected at this stage, because after this point they are impossible to fix.

We buy the string in the exact size the order needs — 2, 3, 4, 5 or 6 mm. Size is not adjustable on the machine. It is decided here.

This is the part that gives the machine its name. The spindle is hollow and carries a bobbin of binder thread on its outside. The base yarn and the sequin string are fed down through the middle of it. As the spindle turns, the binder unwinds off that bobbin and wraps around the core passing through — so the wrapping happens without the core itself ever being twisted.

That matters. On a conventional twisting frame you would have to rotate the whole package to get a wrap, and a string of rigid discs will not tolerate that. The hollow spindle wraps the binder around a core that is travelling straight, which is the only practical way to lock a flat disc onto a yarn at speed.

Feed is where the operator earns their money. The sequin string has to come in at the same rate the core is being drawn through, or the discs bunch up and jam at the spindle eye. Our machines run at spindle speeds in the region of 15,000 rpm with a delivery speed around 30 metres a minute. The operator watches the feed continuously — this is not a machine you set and walk away from.

Two numbers come out of this stage and both belong on the order sheet.

Twist rate — wraps of binder per metre of finished yarn — is a function of spindle speed against delivery speed. We run most qualities between 380 and 520 wraps per metre. Smaller discs get more wraps, because a 2mm disc has less surface for the binder to bear on and needs to be caught more often. Larger discs on a heavy core get fewer, since over-wrapping a 6mm quality stiffens it without holding the disc any better.

Sequin pitch — discs per metre — is set by the ratio of sequin string feed to delivery. This is the number that decides what the garment looks like. Around 240 discs to the metre on a 3mm quality gives even coverage with base yarn still visible between discs, which is what most knitwear buyers want. Push the pitch up and the discs overlap into a solid line; open it out and you get a scattered, quieter effect. Both are available, but pitch changes the yield per kilo, so it has to be agreed before costing, not after.

Pitch is measured, not eyeballed. We pull a metre off the machine at the start of a run and count.

Finished yarn is wound onto cones with an even traverse and a controlled build. The aim is a cone that unwinds cleanly at knitting speed without the yarn catching on the layer beneath it. Sequin yarn is less forgiving here than a plain yarn — a disc that snags on an underlying wrap will either stop the machine or tear itself off the binder.

Cone weight is agreed with the buyer. Some knitting units want uniform cones for creel balance and will pay for the sorting; others take mixed weights and save money. Say which you need at order stage.

Every cone is labelled with the shade code, disc size, base yarn, batch and net weight. Buyers who take repeat orders should keep the batch number, because it is the fastest way for us to match a shade six months later.

Packing is polybag then carton. For viscose qualities we seal the bag, because viscose picks up moisture and a cone that has been sitting open in a humid store will not run the way it did when it left here.