{"id":3309,"date":"2026-05-14T03:17:23","date_gmt":"2026-05-14T03:17:23","guid":{"rendered":"https:\/\/sprocket-chain.net\/?p=3309"},"modified":"2026-05-14T03:17:23","modified_gmt":"2026-05-14T03:17:23","slug":"rubber-top-and-attachment-chain-functional-surface-modifications-for-conveyor-applications","status":"publish","type":"post","link":"https:\/\/sprocket-chain.net\/zh\/rubber-top-and-attachment-chain-functional-surface-modifications-for-conveyor-applications\/","title":{"rendered":"Rubber-Top and Attachment Chain: Functional Surface Modifications for Conveyor Applications"},"content":{"rendered":"
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<\/p>\n

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<\/div>\n
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Rubber Top<\/div>\n
Polyurethane Top<\/div>\n
K-Attachment<\/div>\n
A-Attachment<\/div>\n<\/div>\n
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<\/div>\n

Conveyor Chain \u00b7 Surface Modifications<\/span><\/p>\n<\/div>\n

Rubber-Top and Attachment Chain: Functional Surface Modifications for Conveyor Applications<\/h1>\n

Standard roller chain carries nothing \u2014 it transfers rotation. Attachment chain and rubber-top chain convert that same drive element into a conveying surface, a part carrier, a product spacer, or a positioning fixture. Selecting the right modification requires understanding what each attachment type actually does structurally, not just what it looks like in a catalogue.<\/p>\n

Specify Your Attachment Chain Configuration<\/a><\/p>\n<\/div>\n<\/div>\n

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<\/p>\n

A bottling plant in Busan ran a product accumulation conveyor using standard #60 roller chain as the drive element for a flat-top plastic modular belt for four years without incident. In 2023, a decision was made to switch from modular plastic belt to a direct rubber-top chain conveyor \u2014 reducing the width from 400 mm to two parallel 19 mm chain runs, eliminating the belt tracking hardware, and reducing the overall conveyor height by 55 mm. The engineering team selected hardened natural rubber top attachments on ANSI #60 chain, 50A durometer. Within three months, the rubber tops on the return run were cracking longitudinally along the bond line between the rubber block and the steel mounting tab. Investigation showed that the return run sagged due to chain weight, and the rubber blocks were contacting the return rail guide at the mid-span low point \u2014 creating a peeling load at the bond line that the vulcanised rubber-to-steel bond was not designed to resist. The solution was a change to polyurethane top attachments (same geometry, 90A Shore, significantly higher peel resistance) and the addition of a midspan return support rail. Both fixes cost less than the first three rubber top replacement sets.<\/p>\n

Rubber-top and attachment chain applications fail primarily not because the wrong chain pitch was selected but because the attachment type and geometry were selected for the working run without considering the return run loading \u2014 a design step frequently omitted by engineers who think of the attachment as a product-handling element rather than as a structural component that the chain must support through the full circuit.<\/p>\n

\"\u6a61\u80f6\u9876\u6eda\u5b50\u94fe\"<\/p>\n

<\/p>\n

The Attachment Chain Family: What Each Configuration Does<\/h2>\n

Attachment chain is standard ANSI roller chain with extended or modified link plates \u2014 the drive geometry (pitch, roller diameter, break load) is unchanged, but one or both link plates on selected links are extended or shaped to provide mounting points for fixtures, flights, buckets, or surface materials. The attachment designation encodes both the type (A, K, SA, SK) and the pattern (every link, every second link, etc.).<\/p>\n

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A-1 \/ A-2<\/div>\n
Single bent tab \u00b7 one side<\/div>\n

One or two holes on an outward-bent plate tab, one side of chain only. A-1 = one hole; A-2 = two holes. Used for mounting paddles, flights, and product pushers where one-sided attachment is sufficient. The number suffix (A-1) denotes the hole count, not the frequency.<\/p>\n<\/div>\n

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SA-1 \/ SA-2<\/div>\n
Symmetric double tab \u00b7 both sides<\/div>\n

Both sides of the chain have matching A-type tabs. Used where the attachment must be centred on the chain (flights, cross-bars, symmetrical product pushers). SA = “symmetric A”; the number suffix is the hole count per side.<\/p>\n<\/div>\n

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K-1 \/ K-2<\/div>\n
Extended flat plate \u00b7 one side<\/div>\n

One side link plate is extended outward in the plane of the chain \u2014 flat, not bent. Provides a wider mounting surface for buckets, product carriers, and rubber or polyurethane top blocks. K-1 = one hole; K-2 = two holes per plate.<\/p>\n<\/div>\n

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SK-1 \/ SK-2<\/div>\n
Symmetric extended flat \u00b7 both sides<\/div>\n

Both sides have extended flat K-type plates. Used for bucket elevator chains, large carrier attachments, and double-sided mounting applications. Widest attachment footprint in the standard ASME B29.1 attachment series.<\/p>\n<\/div>\n

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Rubber Top<\/div>\n
Vulcanised block \u00b7 direct mounting<\/div>\n

Natural or synthetic rubber block vulcanised directly to an extended or standard link plate. The rubber provides a non-slip conveying surface for packaged goods, glass containers, cans, and fragile products. The block geometry, durometer, and compound are specified separately from the chain.<\/p>\n<\/div>\n

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PU \/ UHMW Top<\/div>\n
Polyurethane \/ plastic block<\/div>\n

Polyurethane (PU) or UHMW polyethylene top block bolted or bonded to attachment plates. Better chemical and abrasion resistance than natural rubber; higher peel strength at the metal interface; wider temperature range. Standard for food processing, washdown environments, and chemical exposure.<\/p>\n<\/div>\n<\/div>\n

<\/p>\n

Attachment Frequency Notation: Reading the Full Chain Specification<\/h2>\n

A complete attachment chain specification includes four elements: the base chain ANSI number, the attachment type, the attachment frequency (every Nth link), and whether the attachment is on inner or outer links. A specification written as #60-K2-E2P<\/strong> decodes as: #60 chain pitch; K-2 attachment (extended flat plate, two holes); E = “every”; 2 = every second link; P = outer plate (P-series) attachment.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Notation Element<\/th>\n\u4ee3\u7801<\/th>\nMeaning<\/th>\nApplication implication<\/th>\n<\/tr>\n<\/thead>\n
Base chain<\/td>\n#60<\/td>\nANSI #60, 19.05 mm pitch<\/td>\nDetermines roller OD, plate thickness, break load<\/td>\n<\/tr>\n
Attachment type<\/td>\nK2<\/td>\nK-type extended flat plate, 2 holes per plate<\/td>\nBolt-down mounting for rubber blocks, buckets<\/td>\n<\/tr>\n
Frequency prefix<\/td>\nE<\/td>\n“Every” \u2014 regular interval pattern<\/td>\nE = regular; some OEMs use “EP” for every pitch<\/td>\n<\/tr>\n
Frequency number<\/td>\n2<\/td>\nAttachment on every 2nd link<\/td>\nSpacing = 2\u00d7 pitch = 38.1 mm between attachment points<\/td>\n<\/tr>\n
Plate type<\/td>\nP<\/td>\nOuter plate (P-series attachment)<\/td>\nP = outer plate; some configs use inner plate (different tab geometry)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Counter-intuitive: attachment chain with attachments on every link does not have twice the carrying capacity of attachment chain with attachments on every second link.<\/strong> The base chain’s break load is unchanged regardless of attachment frequency \u2014 adding more attachment plates does not strengthen the chain. However, attachment frequency directly affects the load carried per attachment point: at every-second-link frequency (E2), each attachment carries the full spacing distance of 38.1 mm worth of product weight. At every-link frequency (E1), each attachment carries only half that weight per attachment point but the chain requires twice as many attachment components and the bending stiffness of the chain increases significantly, which can cause sprocket engagement problems on small-radius drives. E2 or E3 patterns are generally preferred over E1 for this reason.<\/div>\n

\"\u94fe\u8f6e<\/p>\n

Rubber Top vs Polyurethane Top: Property Comparison and Selection Criteria<\/h2>\n

 <\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n
\u8d22\u4ea7<\/th>\nNatural Rubber (NR\/NBR)<\/th>\nPolyurethane (PU)<\/th>\n\u8d85\u9ad8\u5206\u5b50\u91cf\u805a\u4e59\u70ef<\/th>\n<\/tr>\n<\/thead>\n
Shore hardness range<\/td>\n30A\u201380A<\/td>\n50A\u201395A \/ up to 70D<\/td>\n63D\u201365D (fixed)<\/td>\n<\/tr>\n
Friction coefficient (dry)<\/td>\n0.6\u20130.9 (highest)<\/td>\n0.5\u20130.8<\/td>\n0.1\u20130.2 (low \u2014 design intent)<\/td>\n<\/tr>\n
Oil\/solvent resistance<\/td>\nPoor (swells in oil)<\/td>\nGood\u2013Excellent<\/td>\n\u51fa\u8272\u7684<\/td>\n<\/tr>\n
Temperature range<\/td>\n\u221240\u00b0C to +80\u00b0C<\/td>\n\u221230\u00b0C to +100\u00b0C<\/td>\n\u2212200\u00b0C to +80\u00b0C<\/td>\n<\/tr>\n
Peel strength (metal bond)<\/td>\nModerate (vulcanised bond)<\/td>\nHigh (adhesive or bolt)<\/td>\nBolt-on (mechanical \u2014 no bond failure)<\/td>\n<\/tr>\n
\u8010\u78e8\u6027<\/td>\n\u7f13\u548c<\/td>\n\u9ad8\u7684<\/td>\n\u975e\u5e38\u9ad8<\/td>\n<\/tr>\n
Food contact compliance<\/td>\nNBR only (with FDA compound)<\/td>\nYes (FDA\/EU grade)<\/td>\nYes (food-grade UHMW)<\/td>\n<\/tr>\n
Cost relative<\/td>\n\u6700\u4f4e<\/td>\nModerate (+30\u201360%)<\/td>\nModerate (+20\u201345%)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

<\/p>\n

Return Run Loading: The Design Step That Most Attachment Chain Failures Come From<\/h2>\n

On the working run, rubber or PU top blocks carry product weight \u2014 a load largely in compression and shear. On the return run (underside of the conveyor), the same blocks hang below the chain and are loaded in tension and bending as the chain sags between support rails. For attachments with low peel strength (vulcanised rubber) or large moment arms (tall blocks, wide overhanging tops), the return run bending load can exceed the attachment’s structural capacity even when the working run load is well within limits.<\/p>\n

Four return run design parameters must be checked for every rubber-top chain installation:<\/p>\n

    \n
  1. Return support span.<\/strong> Maximum unsupported return run span = the attachment-to-rail clearance divided by tan(permissible sag angle). For most rubber-top chains with block heights below 30 mm, maximum unsupported span is 300\u2013400 mm. Add return support rails at this spacing on the underside of all rubber-top chain conveyors.<\/li>\n
  2. Block height and overreach.<\/strong> A block that extends 40 mm below the chain centreline and 20 mm to each side creates a significant cantilever moment under gravity on the return run. The bending stress at the base of the attachment tab is proportional to the block mass \u00d7 overreach distance. Calculate this moment and verify it against the tab’s bending strength at the specification attachment interval.<\/li>\n
  3. Return rail contact point.<\/strong> Where return support rails contact the chain, the load path goes through the rail surface into either the chain rollers (preferred) or the attachment tabs (to be avoided). Design return rail height to contact the roller surface, not the attachment tab or rubber block bottom.<\/li>\n
  4. Accumulation zone clearance.<\/strong> If the return run passes through any zone where product can fall from the working surface onto the returning chain (common in accumulation conveyors), the impact load on the upward-facing attachment tabs on the return run must be included in the attachment strength assessment.<\/li>\n<\/ol>\n

    <\/p>\n

    Application-Specific Attachment Chain Selection<\/h2>\n

    Glass container conveying (bottling lines).<\/strong> The most demanding rubber-top application in Korean beverage packaging is glass bottle conveying \u2014 the product is fragile, the conveyor must not mark or chip the bottle base, and the conveying surface must be compliant enough to absorb the vibration energy from bottle-to-bottle contact during accumulation. The correct specification is natural rubber (NR), 40A\u201350A durometer, on ANSI #60 or #80 K-2 attachment chain<\/a> at E2 or E3 frequency. The lower durometer (softer rubber) is essential \u2014 70A+ rubber at the contact zone produces bottle base chipping at line speeds above 60 m\/min. NBR rubber (oil-resistant) is specified only if the line uses bottle base lubricants that would swell NR; otherwise NR provides better coefficient of friction and longer service life.<\/p>\n

    Metal part washing and degreasing lines.<\/strong> Automotive parts washing conveyors transport pressed steel and cast iron parts through alkaline degreasing baths, rinse stages, and drying tunnels. The rubber-top or PU-top specification must be resistant to the degreasing chemistry \u2014 typically 3\u20135% NaOH at 60\u201380\u00b0C. Natural rubber attacks in hot alkaline environments within weeks; EPDM rubber provides moderate resistance; polyurethane (ester-based PU degrades in alkaline, ether-based PU is acceptable) or UHMW polyethylene is the correct choice. Specify ether-based PU or UHMW HDPE for alkaline washdown environments. The bolt-on construction of UHMW top blocks (versus bonded rubber or PU) provides an additional advantage \u2014 individual damaged blocks can be replaced without chain removal.<\/p>\n

    Food packaging infeed and outfeed conveyors.<\/strong> For packaged food product conveyors (pouches, cartons, trays) in Korean food processing plants, the attachment chain specification must satisfy three simultaneous requirements: food-contact compliance of the top surface material, resistance to frequent CIP (clean-in-place) chemical cycles, and adequate friction for product positioning and orientation. FDA\/EU-compliant PU top blocks on stainless steel attachment chain<\/a> in 304 or 316L is the standard specification for this application. The stainless chain body handles the CIP washdown chemistry; the PU top blocks handle food contact and chemical exposure.<\/p>\n

    Bucket elevator grain legs.<\/strong> Agricultural bucket elevator legs use SK-1 or SK-2 attachment chain with welded or bolted bucket mounts. For grain service (non-corrosive, light abrasion), standard carbon steel #80 or #100 chain with SK-2 inner plate attachments is the typical specification. The bucket spacing determines the chain pull calculation \u2014 closer bucket spacing reduces peak load per bucket but requires more attachment hardware. For outdoor or wet grain applications, matched bucket elevator sprockets<\/a> with the correct plate spacing for the SK configuration are required \u2014 standard simplex sprockets will not accommodate the wider SK chain correctly without plate-width verification.<\/p>\n

    \"\u94fe\u8f6e\u548c\u94fe\u6761\u5e94\u7528<\/p>\n

    Complete Attachment Chain Specification: Required Information<\/h2>\n
    \n
    \n
    01<\/div>\n
    Chain specification<\/div>\n

    ANSI pitch number, strand count, chain material (carbon steel \/ stainless 304 \/ stainless 316L). For food applications, specify stainless grade.<\/p>\n<\/div>\n

    \n
    02<\/div>\n
    Attachment type and frequency<\/div>\n

    ASME B29.1 designation: A-1, A-2, SA-1, SA-2, K-1, K-2, SK-1, SK-2. Frequency: E1, E2, E3, etc. Side: inner or outer plate.<\/p>\n<\/div>\n

    \n
    03<\/div>\n
    Top block material and geometry<\/div>\n

    NR \/ NBR \/ EPDM \/ PU (ether or ester based) \/ UHMW. Shore hardness. Block dimensions (H \u00d7 W \u00d7 L). Mounting method (vulcanised \/ adhesive \/ bolt-on).<\/p>\n<\/div>\n

    \n
    04<\/div>\n
    Total chain length<\/div>\n

    Number of links. For attachment chain, the total link count must be divisible by the attachment frequency (E2 \u2192 total links must be even; E3 \u2192 divisible by 3) to ensure consistent attachment spacing around the circuit.<\/p>\n<\/div>\n

    \n
    05<\/div>\n
    Compliance requirements<\/div>\n

    FDA \/ EU food contact grade for top material if applicable. NSF H1 lubricant compatibility. KOSHA guarding interaction. Material certificates if required for quality records.<\/p>\n<\/div>\n<\/div>\n

    <\/p>\n

    \u5e38\u89c1\u95ee\u9898\u89e3\u7b54<\/h2>\n
    \nDoes the attachment reduce the chain’s rated break load?<\/summary>\n
    The attachment plates reduce the break load at attachment links by introducing a stress concentration at the base of the extended tab. The ASME B29.1 standard specifies minimum attachment plate dimensions to limit this reduction, but the effective break load at an attachment link is typically 5\u201310% lower than at a standard link in the same chain. For most conveyor applications where the working load is well below 20% of the chain’s rated break load, this reduction is not significant. For high-load applications (bucket elevators, inclined conveyors with heavy product), calculate the tight-side tension including the weight of all attachments and product, and verify the safety factor against the attachment link break load rather than the standard link break load.<\/div>\n<\/details>\n
    \nCan rubber-top blocks be replaced individually without removing the full chain?<\/summary>\n
    For bolt-on UHMW and PU blocks mounted with through-bolts, individual blocks can be replaced on the chain in-situ by loosening the mounting bolts, sliding the worn block off the attachment tab, and sliding a replacement on. This requires only that the conveyor be stopped and the specific link positioned at an accessible working height. For vulcanised rubber blocks, individual replacement is not practical \u2014 the block is permanently bonded to the attachment plate, and replacement requires cutting out the entire attachment link and installing a new attachment link with a fresh block. This is one of the practical advantages of bolt-on PU or UHMW tops over vulcanised rubber in high-wear applications where individual block replacement frequency is high.<\/div>\n<\/details>\n
    \nIs there a maximum speed for rubber-top chain conveyors?<\/summary>\n
    Yes \u2014 rubber and PU top conveyors are limited by the centrifugal force on the attachment blocks at the drive and tail sprockets. At high chain speed, centrifugal force on the block mass can be large enough to peel the block away from the attachment plate at the sprocket wrap zone. Practical speed limits depend on the block mass, the sprocket radius, and the bond strength. For standard rubber-top chain conveyors with blocks under 200 g, the practical speed limit is approximately 40\u201360 m\/min (0.67\u20131.0 m\/s). For heavier blocks (200\u2013500 g), the limit drops to 20\u201330 m\/min. Above these speeds, bolt-on blocks with positive mechanical retention (through-bolts, not adhesive or vulcanised bond) are required to prevent centrifugal ejection. Most food packaging line speeds (30\u201380 m\/min) fall in the range where standard rubber-top chain is appropriate at the lower end and bolt-on PU is required at the higher end.<\/div>\n<\/details>\n

    <\/p>\n

    \n
    \n

    Attachment Chain With Rubber, PU or UHMW Tops Made to Your Specification<\/h2>\n

    Send chain pitch, attachment type and frequency, top block material, hardness, and dimensions \u2014 we confirm the return run design adequacy and manufacture to your full specification including compliance documentation for food-grade applications.<\/p>\n<\/div>\n

    Browse Attachment Chain Range<\/a>
    \n    Request Full Configuration Quote<\/a><\/div>\n<\/div>\n<\/div>\n

    \u7f16\u8f91\uff1aCxm<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

    Rubber Top Polyurethane Top K-Attachment A-Attachment Conveyor Chain \u00b7 Surface Modifications Rubber-Top and Attachment Chain: Functional Surface Modifications for Conveyor Applications Standard roller chain carries nothing \u2014 it transfers rotation. Attachment chain and rubber-top chain convert that same drive element into a conveying surface, a part carrier, a product spacer, or a positioning fixture. Selecting […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[6634],"tags":[],"class_list":["post-3309","post","type-post","status-publish","format-standard","hentry","category-chain-sprocket"],"_links":{"self":[{"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/posts\/3309","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/comments?post=3309"}],"version-history":[{"count":2,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/posts\/3309\/revisions"}],"predecessor-version":[{"id":3311,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/posts\/3309\/revisions\/3311"}],"wp:attachment":[{"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/media?parent=3309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/categories?post=3309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sprocket-chain.net\/zh\/wp-json\/wp\/v2\/tags?post=3309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}