SHENZHEN, 12 November 2026 — SZ PUFENG PACKING MATERIAL LIMITED (PUFENG) has scaled up its programme for 3 mm microcellular polyurethane foam gaskets, formalising PORON L-24 stock as a standing line item for device builders in North America and Europe who are tightening gap tolerances and compressing engineering change cycles.

The move answers a shift procurement and engineering teams on both sides of the Atlantic have felt for two years: enclosures are thinner, wall stacks are denser, and the gasket is no longer a commodity bought by the metre. It is a specified component with a drawing number, a compression target and a documentation trail. PUFENG has built its L-24 programme around that, combining Rogers PORON and INOAC grade foam with in-house die-cutting, adhesive lamination and lot-level inspection.

Why 3 mm Became the Default Call-Out

Three millimetres is where closed-cell foam still has enough body to absorb moulded steps, screw bosses and connector cut-outs, yet compresses far enough to seal a housing closed without visible fasteners. Below 2 mm it has little tolerance for an uneven flange; above 5 mm it begins to load the clips and cosmetic surfaces. The design band demands a predictable compression curve rather than a vague “soft”.

PORON L-24 sits inside that band. At 240 kg/m³ it holds gauge under sustained load, and a compression set of 2.7 percent means the part does not go slack after the thermal cycling a device sees in transit, in a vehicle cabin or in an outdoor cabinet. Behind a display, a battery, a speaker chamber or an LED module, that recovery behaviour keeps the seal working in year three, not just at first article.

Material Data That Travels With The Part

Every quotation is issued against measured values, so an engineering team in Detroit or Munich can compare the grade with the datasheet already on file.

Testing follows JIS K 6401 for density and compression set, K 6251 for tensile strength and elongation, K 6252 for tear strength and K 6254 for compressive load deflection, so a European design office compares the grade with the datasheet already in its files.

Conversion, Not Just Roll Supply

The difference between a material and a component is the cut. PUFENG runs L-24 through rotary and flatbed die-cutting, adds acrylic pressure-sensitive adhesive where a part must hold position during vertical assembly, and supplies finished outlines with pull tabs, finger lifts and window cut-outs. Standard rolls are 500 mm wide in 10 to 50 metre lengths; width, thickness and adhesive configuration stay open to the drawing.

• L-24 thickness options from 3 mm through 15 mm, cut from one lot where an assembly uses several gauges
• Adhesive backing with PET or glassine liner
• Kiss-cut sheets for pick-and-place lines, through-cut parts for hand assembly
• Prototype volumes from one roll for compression-curve validation

Documentation for European and North American Procurement

Approval in these markets is rarely a price conversation alone. SGS RoHS test reports accompany shipments, and material declarations are prepared per part number to support REACH screening and the restricted-substance reviews purchasing teams now run on every new component. Each carton carries model, thickness and lot identification, so receiving inspection in Rotterdam, Hamburg or Chicago can trace a gasket back to its roll. A certificate of conformance travels with every lot.

Supply Position

Capacity stands at 1,000 rolls per day, shipped three to seven working days after sample approval, with a one-roll minimum. The same plant converts 3M, tesa, Rogers and Bergquist materials, so a single purchase order can cover a full stack of tapes, foams and thermal pads.

Brands Behind the Programme

PUFENG operates as a precision die-cutting converter rather than a material house: it adds geometry, adhesive, inspection and documentation around branded foam. Device builders in Europe and North America increasingly want one accountable partner that takes Rogers PORON, INOAC PORON or NanNex stock and returns a finished, traceable part, instead of coordinating a mill, a converter and a forwarder separately.

Founded in 2014 with two plants in Shenzhen, PUFENG exports to more than twenty markets and set up a dedicated overseas-facing entity in 2024. Enquiries on the 3 mm L-24 programme, including compression-curve data and samples, are answered within twelve hours.

Technical enquiries: admin@pufengpacking.com — WhatsApp 86 19129912095