C518 Cylinder Foam Boring Threading Machine 50-80 mm Hole for Peeling Lines

Cylinder Foam Boring Machine with 3.7 kW Motor Power and 50-80 mm Hole Diameter for 500-2300 mm Bore Hole Length

The C518 is the boring and bar-threading station that sits between a vertical cylinder foaming machine and a foam peeling or skiving machine. It drills a centered hole through a cylindrical PU foam block and feeds the hanging bar through that hole in the same clamped cycle, so the block reaches the peeling machine ready to rotate. The standard configuration accepts blocks of 1200–1500 mm diameter, bores 50–80 mm holes over a 500–2300 mm length, and runs on a 3.7 kW motor. The machine weighs 2000 kg and occupies 6500×2000×2500 mm.

This page approaches the C518 from one specific direction: peel yield. A boring station is often treated as a preparation step, yet the position of the bore decides how evenly the block rotates on the peeling machine, how much foam has to be left as a safety allowance, and how much of each block becomes saleable sheet instead of scrap. The sections below cover bore geometry, clamping, tooling, threading, acceptance checks, cycle planning and maintenance in the order a production engineer would evaluate them.

• ModelC518
• Hole diameter50–80 mm
• Bore hole length500–2300 mm
• Sponge diameter1200–1500 mm
• Motor power3.7 kW
• Machine weight2000 kg
• Overall dimension6500×2000×2500 mm
• CertificationCE

• Direct effect on peel yield: a bore that sits close to the geometric center keeps the minimum wall thickness uniform, so the peeling machine can take a thinner first cut and leave less foam in the scrap bin.
• Stable clamping on soft material: three-direction clamping distributes the holding force around the circumference, which limits ovality and prevents the block from springing away from the drill axis.
• Re-referenced every block: automatic center positioning measures each block instead of relying on a fixed position, so diameter variation between foaming cycles does not turn into bore variation.
• One setup for two operations: drilling and bar threading happen without releasing the block, which removes a re-clamping step and the misalignment that usually follows it.
• Matched to the cylinder line: the working range covers 1200–1500 mm blocks and 500–2300 mm bore lengths, which is the normal envelope of a vertical cylinder foaming and peeling line.
• Compact utility demand: a 3.7 kW motor and a 2000 kg frame keep the station easy to place between two larger machines without rebuilding the plant power distribution.

The operator sequence is short, but each step has a quality consequence. The cycle below is the standard sequence used during commissioning and operator training.

1. Load the block. Bring the cylindrical block to the station with a crane, hoist or roller conveyor and set it on the support. Confirm that the block is seated and that the ends are clear of the clamps.
2. Clamp in three directions. Close the clamps so the block is held around its circumference. The block should not be able to rotate or lift when the drill enters.
3. Find the center. Let the center-positioning function reference the block. Do not manual-mark the center unless the block shape is outside the normal range.
4. Drill the bore. Advance the drill along the axis at the feed that suits the foam grade. Watch the entry and exit for tearing and listen for a change in drill sound.
5. Thread the bar. With the block still clamped, feed the bar through the finished bore along the same axis. Confirm that the bar passes without forcing.
6. Release and transfer. Open the clamps, unload the bar-threaded block and move it to the peeling machine infeed without re-clamping it on another station.

Peeling removes material from the outside of a rotating block. The minimum radius the blade can reach is set by the bar axis plus the wall that must remain around the bore. If the bore is off center by an amount e, the wall on the thin side is reduced by e, and the operator has to end the peel earlier on that side to avoid cutting into the bore. The foam left on the thick side becomes scrap.

The relationship is easy to state: for a block of diameter D and a bore of diameter d, the nominal wall is (D − d) / 2. An eccentricity e makes the minimum wall (D − d) / 2 − e. Every millimetre of eccentricity either becomes lost sheet or forces a thicker safety allowance around the whole block. On a 1200–1500 mm block, that allowance is paid on every block, all shift.

The point of the table is diagnostic. Each bore defect points to a different cause, and the cause is usually in the clamping, the tooling or the feed, not in the foam itself.

Foam is compressible, and that is the whole difficulty of boring it. A two-point clamp lets the block flatten slightly under drilling thrust; the section goes oval, the drill follows the softer path and the bore drifts. Three-direction clamping spreads the force around the circumference, so the block stays round and the drill sees a more uniform resistance.

Center positioning then removes the operator judgement from the setup. Instead of marking a center by eye, the machine references the block and positions the drill axis against the geometric center before penetration. This matters when blocks come from different foaming cycles: diameter and roundness vary slightly, and a fixed position that suits one block is slightly off for the next.

Two operating habits protect the result. First, clean the clamp pads at the end of each shift; foam dust builds up unevenly and changes the effective clamping diameter. Second, confirm the block is fully seated before the clamp closes. A block resting on a chip or a scrap of foam is clamped off center, and no amount of center positioning can correct a block that is not sitting square on the support.

The drill is the only part of the machine that touches the bore wall, so its condition sets the surface quality. A sharp drill with clean flutes cuts foam; a dull or loaded drill rubs, heats and tears. For the 50–80 mm hole range, the drill should be matched to the bar diameter and to the foam grade, and it should be inspected at the start of each shift rather than replaced only when the bore looks poor.

• Sharpness: a dull edge tears the entry and exit, and torn foam cannot be repaired by the peeling blade.
• Flute clearance: foam chips must leave the hole. Packed flutes increase friction and heat, and the drill starts to wander.
• Mounting: a drill that is not seated squarely runs off axis even when the clamp is perfect.
• Feed: too fast a feed compresses the foam ahead of the edge; too slow a feed rubs and generates heat.

Chip removal is a housekeeping issue as much as a tooling issue. Foam chips accumulate around the clamp and the center-positioning components, and a build-up changes how the next block seats. Cleaning at the end of each shift is faster than diagnosing a bore problem caused by a chip under the clamp.

On a conventional line, the bar is pushed through the bore by two operators with a guide, after the block has been released from the drill and often re-clamped. That sequence is slow, it exposes operators to a heavy bar, and it introduces the misalignment that spoils an otherwise good bore.

The C518 feeds the bar while the block is still clamped in the centered position, along the same axis as the drill. The practical results are:

• No second handling step: the block is not released, rolled or re-clamped between drilling and threading.
• Bore wall protected: a bar that follows the drill axis does not scrape or enlarge the bore during insertion.
• One operator: the threading step does not need a second person holding and guiding the bar.
• Safer station: operators are not standing in line with a bar being pushed through a foam block.

Bar condition still matters. A bent bar will not follow a straight bore, and forcing it damages the bore wall. Check the bar for straightness before loading, and keep the bar feed guide clean and aligned.

1. Vertical cylinder foaming: produces the round block.
2. Block curing: the block rests until it is stable enough to handle and drill.
3. C518 boring and threading: center hole plus bar, in one clamped cycle.
4. Peeling or skiving: the bar-threaded block rotates against the blade to produce continuous sheet.
5. Sheet winding or cutting: the peeled sheet goes to winding, cutting or lamination.

Layout matters more than it appears. The C518 is 6500 mm long, and the block has to be brought in, aligned and taken out with a crane, hoist or roller conveyor. Leave clear access at both ends and keep the operator station clear of stacked material. If the discharge height is set to match the peeling machine infeed during layout, the block can be transferred without lifting it twice.

The station is not a substitute for a horizontal boring machine used on rectangular block foam. Cylinder blocks and block bales follow different routes, and re-clamping a round block on equipment designed for rectangular bales loses the centering advantage that the C518 is built around.

The four working figures — hole diameter, bore length, sponge diameter and motor power — define what the standard C518 accepts. Blocks outside these ranges need a different configuration and should be checked against the actual block size before ordering.

Bore quality starts with the block that arrives at the station. Three incoming checks prevent the majority of bore problems before the drill moves:

• Diameter: confirm the block sits inside the 1200–1500 mm range and that it is round enough for the clamps to hold evenly.
• Length: confirm the block is within the 500–2300 mm bore length so the drill can pass through in one stroke.
• Condition: check for a torn skin, a soft end or a block that has cured unevenly. A soft end can collapse under clamp pressure and pull the bore off line.

After drilling, the acceptance check is a trial measurement rather than a visual judgement. Measure the bore position, the bore diameter and the wall thickness at several points along the length. A block that passes is released to the peeling machine; a block that fails is quarantined and the machine settings are checked before the next block.

Boring is a single-station operation, so its output is set by cycle time, not by motor power. The cycle is the sum of loading, clamping, center positioning, drilling, retracting, threading and unloading. Throughput in blocks per hour is 3600 divided by that cycle in seconds.

Two levers usually matter more than drill speed:

• Material handling: if the block is craned in and out with a single hoist, the handling time can exceed the drilling time. A roller conveyor or a transfer table shortens it.
• Buffer between stations: the C518 should not be starved by the foaming machine or blocked by the peeling machine. A small buffer at each side keeps the station running at its own cycle.

Balance the line around the peeling machine, not around the drill. The peeling machine is usually the capacity constraint, and the boring station only needs enough output to keep it fed. Pushing the drill faster while the peeling machine waits adds wear without adding saleable sheet.

The standard C518 covers 1200–1500 mm blocks, 500–2300 mm bore lengths and 50–80 mm holes. Within that envelope, a changeover touches four settings:

1. Clamp opening: set for the new block diameter so the pads contact the full circumference without over-compressing the foam.
2. Center reference: confirm the positioning function re-references the new diameter correctly.
3. Drill and bar: match the drill and bar to the new hole diameter. A bar that is loose in the bore lets the block shift during peeling.
4. Stroke: set the bore length for the new block so the drill does not exit short or run past the end.

Run one trial block after every changeover and measure it before releasing the batch. The trial block is the lowest-cost quality gate in the plant.

The C518 is used wherever cylindrical PU foam is peeled into continuous sheet or prepared for a bar-based handling system.

• Mattress comfort layers: peeled sheet from bar-threaded cylinder blocks for mattress upper layers and quilting.
• Upholstery padding: sheet for sofa, chair and headboard padding where thickness consistency matters.
• Packaging inserts: thin foam sheet for protective packaging and case lining.
• Lamination substrate: peeled sheet fed to a cold laminating line before bonding to fabric or film.
• Technical foam rolls: continuous rolls for gaskets, filters and industrial foam parts.
• Automotive interior foam: sheet for seat padding, door trim backing and floor insulation.
• Care and support cushions: foam sheet for seating pads and pressure-relief cushions.

Installation starts with a level, load-bearing floor. The machine weighs 2000 kg, and the clamping forces must not be allowed to walk the frame over time, so the frame is leveled, anchored and checked for twist before any block is loaded.

The single key commissioning step is the alignment between the drill axis and the bar feed axis. If the two are offset, the bore can be straight and still misaligned with the bar, and the problem only shows up as a tight or scraped bore during threading. After alignment, run a trial block: verify center positioning, drill the bore, thread the bar and measure the wall thickness around the bore.

The 3.7 kW motor needs a dedicated supply with correct earthing and a local isolator within reach of the operator. Any pneumatic or hydraulic functions used for clamping and bar feeding need a clean, dry air supply; moisture and oil carry-over are a common cause of erratic clamping. Confirm the final utility requirements against the machine diagrams before installation.

The station combines a rotating drill, a heavy bar and a clamping system that holds a compressible block. Guards cover the drill and the clamp area, and the halt circuit must be reachable from the operator position.

• Do not reach into the clamp or drill area while the machine is energised.
• Keep hands away from the bar path during threading.
• Confirm the block is seated before the clamp closes.
• Halt the cycle if the drill sound changes or the bar does not advance smoothly.
• Lock out the machine before clearing jammed foam or changing the drill.
• Keep the floor clear of foam chips, which become slippery under foot.

Operator training should cover three habits: seated block, clear bar path, and an immediate halt when the sound changes. These three habits prevent the majority of bore defects and near-misses at the station.