Schlafhorst, operating today under the Saurer Group brand, is one of the oldest and most respected names in automatic winding technology. The Autoconer 338, X5, and X6 are found in spinning mills across Europe, Asia, and the Americas — particularly in markets like Turkey, India, Bangladesh, Pakistan, and Germany where high-speed ring-spun yarn production is concentrated.
These machines are not forgiving of cone specification errors. The Schlafhorst Autoconer is built around a precision pneumatic cone transfer system — including, in the X5 and X6 generations, the Bobbin Cloud automatic bobbin handling system — that requires consistent cone geometry to function reliably at high throughput.
This guide covers the exact paper cone specifications for the Autoconer 338, X5, and X6, including the Bobbin Cloud compatibility requirements specific to the X5 and X6 platform.
The Schlafhorst Autoconer Model Family
Schlafhorst Autoconer 338
The Autoconer 338 is a widely installed workhorse winder across global spinning mills. Installed in large numbers through the 1990s and 2000s, the 338 remains in service in many mills globally. It uses the 5°57′ cone as standard and typically requires V-notch or Y-notch depending on the auto-doffer configuration installed. Many 338 machines have been retrofitted with upgraded doffer arms over their service life — confirm the notch type against your current machine configuration, not against a general 338 specification.
Schlafhorst Autoconer X5
The Autoconer X5 introduced Schlafhorst's Bobbin Cloud intelligent logistics system as an option. The X5 operates at winding speeds up to 2,200 metres per minute with enhanced yarn clearing and package monitoring. It uses the 5°57′ cone as standard. The X5's auto-doffer is factory-set for Y-notch in most configurations, though regional market variants may differ.
Schlafhorst Autoconer X6
The Autoconer X6 is the current-generation flagship, featuring advanced package monitoring, RFID-based bobbin tracking, and Saurer's proprietary process automation suite. The X6 uses the 5°57′ cone specification and Y-notch as standard across most configurations. For mills installing new X6 machines, confirm the notch type with the Schlafhorst/Saurer commissioning engineer before placing the first cone order.
Primary Cone Specification: Autoconer 338, X5, and X6
Taper angle: 5°57′ (five degrees, fifty-seven minutes)
All three Autoconer models use the 5°57′ taper as the standard cone geometry. This is consistent with the global autoconer standard and ensures that switching cone suppliers does not require machine recalibration — provided the dimensional tolerances are met.
Length: 170mm standard (some X5/X6 configurations accept 173mm)
170mm is the global standard. The Autoconer X5 and X6 with Bobbin Cloud have slightly more flexibility in package specification — some installations are configured for 173mm cones when a larger finished package diameter is required. Confirm your specific machine's package setting before specifying cone length.
Acceptable length tolerance: ±1mm.
Inner diameter at nose: 27mm to 28.5mm, tolerance ±0.25mm
The Schlafhorst Autoconer uses a pneumatic cone insertion mechanism that grips the cone at the nose before seating it on the cradle. A cone with nose ID outside ±0.25mm of specification will not grip correctly in the insertion arm, causing mis-insertion and cone ejection.
Inner diameter at base: 67.5mm to 68.5mm, tolerance ±0.25mm
Weight: 40g to 42g
For Autoconer X5 and X6 running at maximum speed with compact-spun or synthetic yarn, 42g cones are recommended for improved burst strength under high winding pressure.
Paper grade: 350-450 GSM kraft paper
Notch Specification for Schlafhorst Autoconers
The notch type varies across Schlafhorst models and auto-doffer configurations. This is the most common source of specification errors when mills with mixed Schlafhorst fleets order cones from a new supplier.
Autoconer 338: V-notch or Y-notch (depends on doffer configuration)
The 338 was manufactured over a long period and sold into many regional markets. Some 338 installations use V-notch; others use Y-notch. Do not assume based on the model number alone. Inspect the current cones on your machine and measure the notch geometry, or ask your Schlafhorst service engineer which doffer arm is installed.
Autoconer X5: Y-notch (standard)
The Autoconer X5 in most factory configurations uses Y-notch. The Y-notch is a wider, more open cut at the cone nose compared to the V-notch, designed to interface with the X5's enhanced automatic doffing arm geometry. Using a V-notch cone on an X5 configured for Y-notch will typically cause yarn-tail catch failures on a portion of doff cycles — particularly at high machine speed where the timing window for tail capture is tightest.
Autoconer X6: Y-notch (standard)
The Autoconer X6 uses Y-notch as standard across most configurations. For mills running new X6 installations, confirm this with the Saurer commissioning engineer at machine startup.
Critical note on mixed fleets: Many spinning mills operate a combination of Autoconer 338s alongside newer X5s or X6s. If the 338 uses V-notch and the X5/X6 uses Y-notch, you must maintain separate cone stocks for each machine generation. This is a procurement and inventory management requirement — confirm with your floor supervisor which cones go to which machines before placing a combined order.
Bobbin Cloud Compatibility: X5 and X6
The Bobbin Cloud is Schlafhorst's automated bobbin logistics system available on the Autoconer X5 and X6. It uses a conveyor-based system to automatically transport ring bobbins from the ring frame to the winding head, eliminating manual bobbin handling between ring spinning and autoconer operations.
In terms of paper cone specification, the Bobbin Cloud system does not change the cone requirement for the winding head itself — the 5°57′ taper, nose/base ID, Y-notch, and weight specifications remain the same on Bobbin Cloud-equipped machines.
However, Bobbin Cloud machines have one additional paper cone consideration: package density and dimensional consistency affect the automated package transfer system downstream. If your Bobbin Cloud feeds directly into an automated packaging or palletising line, package-to-package diameter consistency depends on cone dimensional consistency. A batch of cones with high within-batch nose ID variation will produce packages of varying diameter, which can cause intermittent failures in automated package transfer systems.
For Bobbin Cloud installations, specify cone suppliers who can provide batch-level standard deviation data on nose and base ID — not just individual specimen results.
Surface Finish for Schlafhorst Applications
Natural fibre yarn (cotton, ring-spun): Smooth finish is standard and adequate.
Synthetic yarn (polyester, nylon, technical fibres): Velvet finish is required. The Autoconer X5 and X6 are increasingly used in technical textile applications — automotive yarns, medical textiles, performance sportswear yarn — where smooth-finish cones cause yarn slippage on the first layer.
Blended yarns: Specify velvet finish as the default if synthetic content exceeds 30 percent of the yarn blend.
Quality Requirements for Schlafhorst Autoconer Cones
Burst strength: minimum 2.5 kg/cm²
For X5 and X6 operating at maximum winding speed, the preferred minimum is 3.0 kg/cm².
Roundness: maximum 0.3mm ovality at nose, mid-body, and base
The Schlafhorst cone insertion arm is particularly sensitive to nose ovality — an oval cone nose causes the insertion arm's grippers to misalign, leading to intermittent insertion failures that generate a difficult-to-reproduce stop pattern.
Batch consistency: statistical process data required
For high-speed Autoconer X5 and X6 installations, request batch-level dimensional data — not just individual specimen measurements. A batch with all individuals within tolerance but with high within-batch variability (wide standard deviation) will perform worse than a batch with slightly lower average values but very tight consistency.
Common Schlafhorst Autoconer Stoppages Linked to Cone Specification
Insertion arm failure / cone not seating: Nose ID out of tolerance or high nose ovality. Measure 20 cones from the current batch. If insertion failures are machine-wide rather than head-specific, the cone batch is the first suspect.
Yarn tail catch failure on doff cycle: Wrong notch type for the installed doffer configuration. Visually inspect the notch geometry on the current cones and compare with the machine doffer arm geometry on a stopped head.
Package vibration / stop at clearer on first layer: Cone ovality at nose or taper angle inconsistency. Run roundness measurements on a sample from the current batch.
Cone ejection during high-speed winding: Burst strength below the machine's winding pressure at maximum speed. Request burst strength data from the supplier for the current batch.
Variable package diameter across the machine (Bobbin Cloud installations): Within-batch nose ID variation. Request standard deviation data from the supplier for the current batch.
Frequently Asked Questions
Can I use the same paper cone on Autoconer 338, X5, and X6? On taper angle, length, weight, and diameter — yes. On notch type — not necessarily. Confirm the notch type required by each model in your specific installation. If 338 and X5/X6 require different notch types in your mill, maintain separate cone stocks.
We operate an Autoconer X6 with Bobbin Cloud. Should we specify a heavier cone? Bobbin Cloud itself does not require a heavier cone. However, if your X6 runs at or near maximum speed with compact-spun or synthetic yarn, 42g with 3.0 kg/cm² burst strength minimum is prudent regardless of Bobbin Cloud status.
Does Saurer (Schlafhorst's parent) publish approved cone specifications? Saurer/Schlafhorst publishes package specifications in the machine manual that define the cone geometry requirements. Cone compatibility is defined by dimensional compliance — there is no approved brand list. Any cone meeting the geometric and quality specifications above is compatible.
We recently upgraded from Autoconer 338 to X6. Our previous cones are causing issues. What changed? The most likely difference is notch type — 338 may have been using V-notch and your X6 requires Y-notch. Check the notch type on your current cone stock against the X6's doffer arm geometry. Also verify that the insertion arm settings on the X6 were calibrated for the specific cone nose ID of your current supplier's batch.
The Alishan 5°57′ auto-machine paper cone from Aziz Packaging Limited is available in Y-notch configuration for Schlafhorst Autoconer X5 and X6, and V-notch for Autoconer 338. Contact us to specify the correct configuration for your machine installation.
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[Download Alishan 5°57′ Full Specification Sheet →]
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