Quick Specs at a Glance
Demand Cycle
Year-Round
Film
BOPET / BOPA / LLDPE
Up to 10 Colors
MOQ
10,000 Units
01. Why Birthday Programs Anchor Year-Round Party Retail
Birthdays are the only party category that runs twelve months a year without a seasonal peak. For retail chains, party brand owners, and e-commerce sellers, that means inventory planning is continuous rather than windowed, and reorder cadence is predictable. Sourcing from a direct manufacturer rather than a trading intermediary matters for holding a consistent specification across repeated production runs and for keeping the compliance documents current across the year. Buyers building the full party catalog can review the Mylar balloon line for a general format reference.
We operate a manufacturing facility in Jiangsu, established in 2007 and registered with 5 million RMB capital. The production infrastructure covers CNC-milled aluminium weld tooling, 10-color rotogravure presses, and pre-shipment pressure testing on every batch. This guide covers the weld engineering, film, print, and compliance decisions behind this product family.
02. Weld Engineering for Letter and Number Geometry
Alphabet letters such as B, O, R, and S and numeric shapes such as 2, 5, and 8 are geometrically harder to weld than round or heart shapes. They carry V-shaped interior corners, hollow centres, and narrow channels between the main body and secondary chambers. During inflation, those junctions concentrate mechanical stress, and the seam is where the product fails first.
Three Weld Engineering Interventions
Radial Corner Radiusing. Every interior V-shaped intersection is re-engineered with a CAD-driven radial curve before the mould is cut. The rounded corner distributes tensile stress evenly along the weld instead of concentrating it at a single point. This is the single biggest durability difference between our letter and number lines and lower-grade equivalents.
Internal Micro-Channel Bridges. Hollow-centred characters such as O, P, and B have internal bypass channels between chambers. The channels keep the fill low-turbulence during inflation so that pressure does not spike inside a single chamber while the gas is still entering the next.
High-Precision CNC Aluminium Weld Tooling. The sealing die is machined on high-speed CNC centres with a dual-ridge pattern that produces a 7 mm redundant weld seam. The wider seam gives a mechanical safety margin at the interior corners where a single-wire seal is most vulnerable. Standard shape weld behaviour at lower stress levels is documented in our standard shapes foil balloon line.
03. Film Engineering and Child Safety Documentation
Birthday balloons are handled by children. The two risk categories are chemical migration from inks and film additives, and the mechanical reliability of the valve under repeated handling. The envelope in this product family runs a multi-layer co-extruded film, and the print and valve components run against the current SGS test scope.
BOPET Outer
The structural core holds the letterform flat under internal pressure. High tensile strength keeps the printed character outline sharp from batch to batch.
BOPA Nylon Middle
The elastic middle layer absorbs drop impact and handling stress. This is where the film survives being squeezed by a child or compressed in a party bag.
LLDPE Inner and Valve
The inner sealant provides the hermetic weld and the self-sealing valve flap. The valve closes under internal pressure when the nozzle is withdrawn and holds against backflow during handling.
SGS RoHS
Report SHAHG2207652301, issued 27 June 2022. Cadmium, lead, mercury, hexavalent chromium, the sum of polybrominated biphenyls, the sum of polybrominated diphenyl ethers, and all four restricted phthalates were not detected against RoHS Directive (EU) 2015/863 limits.
SGS EN 71
Report SHTY130500007975-01, issued 07 June 2013. Covers EN 71 Part 1 mechanical and physical properties, EN 71 Part 2 flammability, and migration of certain elements under European Directive 2009/48/EC. A current re-test for buyers requiring certificates issued within the last 24 months is available on request.
North America and Packaging
Buyers sourcing into North America should request the CPSIA test package as a separate submission, which we commission per order. Retail packaging support covers GS1 barcode placement, multi-language instructions, suffocation warnings, and mixed letter and number set combinations.
04. Sizing Grid and Specification Matrix
The sizing grid below covers the standard configurations. Custom sizes and custom character silhouettes outside this grid use the same tooling workflow but add a sample development round.
| Product Category | Inflated Dimensions | Gas Capacity | Gas Type |
|---|---|---|---|
| 16-Inch Mini Alphabet / Number | Approx. 33 x 23 cm | Approx. 5.1 L | Air-filled only (no float) |
| 32-Inch Standard Alphabet / Number | Approx. 66 x 45 cm | Approx. 26.9 L | Helium (float) or air |
| 40-Inch Jumbo Alphabet / Number | Approx. 86 x 61 cm | Approx. 43.9 L | Helium (float) or air |
| Custom 3D Character Shape | Varies (up to approx. 91 cm) | Variable | Helium or air |
Float behaviour per size is documented in our float time reference. Air-filled display options are documented in our air versus helium comparison.
05. Rotogravure Print and Licensed Character Programs
Birthday programs that carry licensed characters or brand IP depend on print registration. Off-shade colour, misaligned character eyes, or drift between the letterform outline and the printed graphic is a licensing review issue. We run the print on rotogravure presses with electronic web-guide alignment and colour calibration against Pantone reference values per run.
Registration Control
Electronic web-guide alignment holds per-run registration through the print cycle. Fine character detail stays crisp at retail viewing distance. Per-batch registration documentation is available on request.
Colour Calibration
Ink viscosity and colour are calibrated against Pantone reference values per production run. Colour variance documentation is available on request per batch.
Ink Compliance
Water-based, heavy-metal-free inks. Printed film and valve components are tested under SGS RoHS report SHAHG2207652301. Test scope is documented on our RoHS compliance verification page.
06. OEM Terms and Seasonal Program References
Birthday letter and number programs are commonly bundled with adjacent seasonal SKUs in the same production run, which reduces tooling cost per design when the calendar is scheduled. The relevant lines for reference are documented under the adjacent SKU families: custom starburst foil balloons, custom Halloween foil balloons, custom Christmas foil balloons, Valentine's Day foil balloons, and standard shape foil balloons. The dedicated letter and number catalog SKUs are documented on the jumbo foil letter balloon line, the jumbo foil number balloon line, and the wholesale alphabet foil balloon line.
We manufacture at the Jiangsu facility. We ship direct. We do not sell through distributors. If you are sourcing custom birthday foil balloons or alphabet number Mylar balloons for retail chain, party brand, or e-commerce channels, send the target market, the SKU list, and the order volume you are planning, and we will tell you directly whether the program is viable for your channel. Email xia@foilballoon.cn. Put the market, the SKU list, and the volume in the subject line. An inquiry without a market and a volume is not actionable on our side and will not receive a production-ready answer.
Factory Capacity and Lead Time
Our Jiangsu facility runs approximately 1 million units per month. Standard production lead time for orders in the tens of thousands is around 20 days. Larger volumes require production scheduling review, and lead time is confirmed at order stage. Custom tooling and sample development run approximately 12 days. Minimum order quantity for custom printed production is 10,000 units. Buyers who want to visit the factory are welcome to do so, and we arrange factory visits directly through our sales team.
Direct factory contact for this product line:
Kunshan Fair Craft Products Co., Ltd. | Established 2007 | Jiangsu, China | xia@foilballoon.cn