Loose vs Spot-Welded vs Rimmed Extruder Screen Packs

Choose the Assembly Around Your Replacement Requirements

Loose mesh screens, spot-welded packs and rimmed packs are different ways to supply a replaceable extrusion filtration consumable. The choice affects layer handling, edge construction and the finished part specification.

Start with the equipment-approved screen arrangement. Maidong reviews your drawing and cloth schedule before quoting a replacement or a proposed construction change.

Custom round, annular and oval mesh filter screens
Round, annular and oval screen examples.

Three Descriptions, Two Assembly Features

Loose describes separate mesh layers. Spot-welded describes attachment at defined points. Rimmed or framed describes an edge-retaining feature. A pack can be both spot-welded and rimmed.

Record attachment and edge treatment separately on the drawing. For the complete product range, see extruder screens and screen packs.

Loose Screens and Layer Sets

Woven wire mesh discs showing weave detail
Woven mesh detail; exact construction confirmed in the specification.

Loose supply keeps the screens separate. This can suit an existing procedure in which the buyer assembles an approved layer schedule, provided the equipment and handling instructions allow it.

Identify each cloth and the quantities needed per set. Keep similar-looking mesh grades distinguishable in packaging, and confirm the direction before installation.

RFQ detail: specify individual pieces or complete sets. For an illustrative five-layer configuration, 100 complete sets contain 500 individual screens; this is a quantity example, not a recommended pack.

Spot-Welded and Rimmed Packs

Oval mesh screen with weld points around the edge
Oval screen with visible edge weld points.

Spot-Welded Layers

Defined weld points hold the layers together for handling. Specify weld quantity and positions, any areas to remain clear, and the finished thickness.

Attachment does not verify layer orientation or create an automatic filtration rating. Include every mesh layer in the approved specification.

Circular mesh screens with formed metal rims
Rimmed screen constructions; rim alloy specified separately.

Rimmed / Framed Edges

A formed rim retains the mesh edge. Specify rim alloy, width, cross-section and overall dimensions, plus whether internal spot welds are required.

Review rim contact and recess depth with the housing drawing. A rim does not by itself guarantee sealing, operating pressure capability or compatibility.

Existing Maidong photos illustrate visible constructions only. Alloy and hidden layers cannot be confirmed from these images.

Comparison for Purchasing and Replacement

CheckLoose screens / setsSpot-welded packRimmed pack
Layer handlingSeparate pieces; confirm identificationLayers attached at specified pointsEdge retained; may also include welds
Drawing detailEach layer and assembly directionAdd weld locations and attachment detailsAdd rim section, alloy and contact dimensions
Finished thicknessSpecify the complete installed stackConfirm complete assembled thicknessConfirm both overall and rim thickness
Order unitPieces or complete setsAssembled packsAssembled packs; state internal construction
Filtration specificationEvery cloth must be definedWelding is not a retention ratingRim material is not mesh specification
Replacement reviewCheck approved sequence and supportsCheck support, thickness and weld clearancesCheck recess, edge contact and fit
Cost comparisonInclude sorting and packing requirementsQuote against defined assembly workQuote against rim and assembly requirements

No construction is universally best. Compare the requested replacement against the actual filter housing, support, handling procedure and commercial requirements.

Keep the Mesh Schedule Constant When Comparing

To compare assembly options fairly, use the same dimensions, alloy, mesh count, wire diameter and weave for every layer. Otherwise a price difference may reflect different cloth rather than the attachment method.

Reference / custom available: a schedule such as 20/40/80/40/20 mesh still needs wire diameters, weave, material and flow direction. Read the screen pack layer-order guide for schedule preparation.

SS304, SS316 and SS316L mesh may be reviewed against your requirements. Rim materials and availability require separate confirmation; no standard alloy is inferred from a photograph.

Before Changing the Construction

  • Confirm which approved drawing or sample governs the replacement.
  • Compare total thickness, outer profile and any central opening.
  • Check contact areas, cavity depth and equipment support.
  • Identify reverse-flow cleaning or other special duty.
  • Agree layer identification, packing and acceptance requirements.

Do not treat an attachment change as automatic approval for reuse, backflushing or a different operating limit. Review any proposed substitution before placing the repeat order.

Send a Comparable Screen Pack RFQ

Send: drawing/revision, dimensions and tolerances, every mesh layer, flow direction, attachment method, rim details where applicable, overall thickness, quantity and destination.

If comparing alternatives, ask for the same cloth schedule in each option and identify the proposed assembly differences. Mark unknown requirements “to confirm.”

Screen Pack Construction FAQ

Loose screens are supplied as separate pieces or a defined set. Spot-welded packs have layers attached at specified points. Both require a complete cloth schedule and a confirmed installation direction.

Yes, a rimmed construction may also include spot welds. Specify both features rather than assuming welded and rimmed are mutually exclusive categories.

No general sealing guarantee follows from the rim alone. The rim geometry, housing contact, assembly fit and equipment requirements must be reviewed together.

Spot welding attaches layers. It does not by itself establish a finer opening or retention rating. Compare each cloth specification and the complete assembly separately.

Only after confirming dimensions, total thickness, rim contact and the equipment-approved arrangement. Matching mesh counts alone does not establish interchangeability.

Use the approved drawing or submit the attachment requirement for review. There is no universal weld count; locations and areas to remain clear must be defined for the part.

No. Specify the rim material independently from each mesh layer. Appearance or color is not reliable proof of the alloy.

Compare quotes for the same cloth, dimensions, quantities and packing requirements. Assembly work and handling needs differ; no universal price ranking is provided.

State whether the quantity means individual screens, complete loose layer sets or assembled packs. For a five-layer set, 100 sets and 100 individual screens are different orders.

Request a Replacement Mesh Screen Pack Quote

Send your screen specification to Maidong Metal Wire Mesh Products Co., Ltd. We will review the construction and prepare a quotation against the confirmed requirements.