Roving Bobbins
ABS and PP roving tubes for Rieter, Toyota, Howa, Zinser, LMW and Jingwei frames.
View details →Home / Products / Choosing Spinning Bobbins
Most bobbin complaints do not start on the spinning floor — they start on the purchase order. A tube bought against a photo instead of a drawing, a polymer chosen for price instead of process temperature, or a taper that is “close enough” all come back later as end breaks, sloughing packages and lost doffing time. This guide sets out the eight questions we ask every mill before we quote, and the numbers we need to answer them.
A bobbin is not a standalone part. It is the interface between a spindle and a yarn package, and the interface is fixed by the machine. Before comparing quotations, write down four things: machine make, model and year (a Zinser 351 and a Zinser 668 do not use the same tube length); spindle type and drive arrangement, because the wharve or drive seat defines the bottom bore; tube length and bore diameter measured on the tube you run today; and the spindle speed and yarn count you actually operate at, which decides how much balance quality you need.
One drawing, or three measured samples, removes nine out of ten fit problems before a mould is even quoted. If neither exists, send the frame model and we will match it against tubes already tooled on our side — that is faster than starting from a catalogue drawing.
Three polymers cover almost every spinning application, and each one has a temperature ceiling that no amount of good moulding can overcome:
| Polymer | Typical use | Continuous service | Why it is chosen |
|---|---|---|---|
| PP homopolymer | Roving bobbins, ring bobbins, economical tubes | up to about 80 °C | Lowest cost per piece, good resistance to spin finishes |
| ABS | Roving and ring bobbins, colour-coded lots | −20 to +80 °C | High impact strength, stable dimensions, clean colour match |
| PC, heat-stabilised | Dyeing tubes, package dyeing | 135 °C steam cycles | Resists hydrolysis in dye liquor and keeps its roundness after repeated cycles |
Regrind content is the hidden variable. A tube with 30% regrind can look identical on the pallet, then relax under steam and go oval — which reads on the floor as sloughing and broken ends, never as a material problem. Ask what percentage of regrind is in the compound, and ask for the dimensional report after a heat cycle, not only at moulding.
Cone bobbins are defined by their taper. 3°30′, 4°20′ and 5°57′ are the angles you will meet most often, and the bobbin taper has to agree with the drum or the dye carrier it runs on. A mismatch does not fail immediately; it builds a package that is wound unevenly, so the yarn slips at the nose or beds down and traps at the base. Ring bobbins are parallel instead, and there the critical fit is the bore-to-spindle clearance: too loose and the tube lifts and chatters, too tight and doffing becomes a two-handed job that slows every creel change.
Every rotating bobbin carries a runout figure — the total indicator reading of the outer surface relative to the bore. At high spindle speeds half a millimetre of runout turns into vibration that passes straight into the yarn balloon and the traveller. Rimzer holds runout at 0.3 mm or less, bore tolerance of ±0.1 mm and length tolerance of ±0.5 mm as standard, and a sample from every batch is measured in our own laboratory before it ships.
The practical advice is simple: ask for the number, not the adjective. “High precision” is not a specification, and it cannot be checked when a container arrives.
A polished bore and a clean gate area matter more than they look. A visible weld line or a sharp gate scar on the inside wall drags on the yarn and shows up as a recurring break at the same package position. Anti-static compound is worth specifying where mills run polyester at low humidity, because charged tubes collect fly and lint that end up in the yarn. UV-stabilised colorants cost very little and prevent the fading and embrittlement that ruins tubes stored on a sunlit loading dock for a season.
A bobbin at USD 0.60 and a bobbin at USD 0.90 look far apart on a quotation. They are not, once you count what a broken end costs. One extra end break per thousand spindle hours, multiplied across a mill, usually outweighs the whole price difference on the tubes. Build the comparison on three numbers: expected service life in cycles, breakage rate per thousand tubes per year, and how much time colour coding saves during doffing and lot changes. Mills that run this calculation almost always move to the better tube.
Machine model and year; a drawing or sample with bore, length, taper and wall thickness; quantity per size and per colour; process temperature, especially for dyeing; packaging and pallet format; destination port and Incoterm. With those six items a bobbin quotation can be firm rather than indicative, and the lead time you are given will be one you can plan a creel change around.
ABS and PP roving tubes for Rieter, Toyota, Howa, Zinser, LMW and Jingwei frames.
View details →Tell us the machine model and the dimensions you run today, and our engineers will confirm fit, material and price within one working day. Email sales@rimzer.com, use the contact form, or read the bobbin FAQ for MOQ, samples and lead times.