DB22 Microcellular Foaming Efficiency in PVC Slippers and Mats
DOBO Technical R&D TeamUpdated 9 on Nov 2026Oct 26, 2026
How DB22 Balances Plasticizing and Foaming in PVC Microcellular Foam for Slippers, Mats, and Boards: Cell Structure Control, Process Windows, and Defect Checklist
DB22 Microcellular Foaming Efficiency in PVC Slippers and Mats
Foaming efficiency in a PVC slipper or mat refers to how effectively the material expands during production to create a lightweight, cushioned structure with uniform air pockets. High foaming efficiency typically means better insulation, improved comfort, reduced material usage, and lower density without compromising durability.Foaming efficiency measures how well a plasticizer system maintains gelation, melt strength, and blowing agent decomposition within the same processing window. This ensures the foam expands to the target density and retains a fine, uniform cell structure. DB22 is engineered for PVC foaming applications such as slippers, floor mats, and foam boards, where plasticizing and foaming performance must be balanced rather than optimized independently. Foaming ratio and process parameters should be validated through trials on your own equipment.
Why the plasticizer determines cell structure
In chemically blown PVC foam, the plasticizer does more than soften the resin. It controls gelation timing, melt behavior during gas release from the blowing agent, and the extent to which cell walls can stretch before rupturing. If gelation occurs before gas release, the compound becomes too stiff to expand, resulting in a dense skin with poor expansion. If the melt remains too soft, gas escapes through the surface, causing cells to coalesce into a coarse, uneven structure.
A foaming plasticizer must be compatible enough to cleanly gel the resin, yet slow enough to provide a usable processing window. That balance is what DB22 is designed for.
| Process variable | Direction that improves cell quality | What it controls |
|---|---|---|
| Plasticizer type | Excellent plasticizing and foaming compatibility | Gelation timing versus gas release |
| Plasticizer loading | Raised to meet foam density target | Melt viscosity and expansion ratio |
| Blowing agent level | Matches the plasticizer system | Available gas volume for expansion |
| Mold or oven temperature | Configure decomposition to occur within the gelation window | Cell Growth vs. Cell Collapse |
| Filler loading | Consistent across trials | Density, Hardness, and Surface Finish |
Inspecting foam: surface quality and resilience
Two quality signals matter most for slippers and mats. First, the surface: a fine, closed, and even skin indicates uniform cell growth and proper gelling timing. Second, resilience and rebound, which reflect consistent cell size throughout the thickness. A part may appear acceptable on the surface while the core is coarse, often revealing itself later as a soft spot or visible depression.
DB22 is engineered to keep plasticizing and foaming behaviors tightly synchronized, ensuring a dense, uniform cell structure and consistent surface quality and resilience under conventional foaming processes.
| Formulation and Process Factors | Troubleshooting effect | Practical action |
|---|---|---|
| Plasticizer loading too low | Poor expansion, heavy component | Increase load incrementally and re-test hardness. |
| Plasticizer loading exceeds limit | Sticky surface; collapse at the mold wall | Reduce load, rebalance blowing agent |
| Blowing agent level too high | Coarse cells, blistered surface | Reduce level, verify decomposition profile |
| Gelation occurs too quickly | Dense edge, uneven expansion | Adjust the temperature profile or plasticizer blend |
| Insufficient mixing | Localized defects, uneven density | Extend mixing time and verify dispersion |
Common production methods for slippers and mats
Slippers, floor mats, and foam boards share a common base structure: suspension PVC. This formulation includes a plasticizer package (providing the primary load-bearing capacity), filler (for cost control and hardness adjustment), a blowing agent, and a stabilizer/lubricant system to preserve color and ensure smooth release.
| Component | Typical role | Foamed System Notes |
|---|---|---|
| PVC resin | Matrix | Grade selection influences gelation behavior |
| DB22 (or a DB22 blend) | Plasticization and foaming balance | Primary driver for expansion and cell quality |
| Filler (e.g., calcium carbonate) | Cost and hardness | Maintain consistency across trials |
| Blowing agent | Expansion | Decomposition temperature must match the process requirements. |
| Stabilizer and lubricant | Color and release | Preserves appearance despite heat exposure |
Since DB22 is a proprietary in-house formulation with no public CAS Registry Number, the recommended approach is to determine the optimal parameters through testing: begin with the loading that achieves the target hardness, adjust the blowing agent to match the resulting melt viscosity, and then fine-tune the temperature profile until both the surface and core match the reference sample.
Molding line defect checklist
| Defect | Most likely cause | Verify via |
|---|---|---|
| Coarse or open cells | Blowing agent level too high or melt too soft | Reduce, hold, and compare cut sections |
| Compressed or glossy skin | Gelation occurs too quickly, resulting in low expansion. | Check temperature profile and load |
| Uneven density across the sides | Uneven dispersion or mold temperature | Mixing sequence and mold heating |
| Post-molding shrinkage | Insufficient curing or excessive gas | Cure time and blowing agent level |
| Color variation | Heat history or stabilizer level | Temperature Logging and Stabilization Package |
Frequently asked questions
Can DB22 be used with a general-purpose plasticizer?Yes. Blending is common when a foam compound must meet both density and cost targets. The blend ratio is confirmed through trial runs.
Does a higher plasticizer loading always result in a lower-density part?Only up to a certain point. Beyond the strength limit of the melt, additional loading reduces cell stability and may cause the part to collapse or absorb water.
What to check first if the foam looks right but feels hard?Verify the actual density and filler loading, then review the blowing agent level. Resilience is typically a matter of density and cell uniformity before it becomes a plasticizer issue.
How long does a trial typically last?A short trial series of 3–4 load cycles on your own line is typically sufficient to identify the working window. We can supply the trial material.
Request a sample and recommendation
Our application team will review your current slipper or mat formulation and recommend an initial loading for DB22, backed by a complimentary 1kg testing sample shipped globally via DHL or FedEx. Trial order MOQ is 1 MT, with bulk shipments dispatched in 23 MT flexitank containers from Ningbo or Shanghai.
Related grade
DB22 · DB22 Plasticizer for PVC Foaming
Regulatory and standards references
The links below lead to official EU, US, and ISO sources for the compliance frameworks discussed on this page. DOBO does not control third-party content; the official text and regulations of the buyer's market take precedence.
- ECHA — Understanding REACHEU registration, evaluation, authorisation and restriction of chemicals (REACH), including the Candidate List of substances of very high concern.
- EUR-Lex — Directive 2011/65/EU (RoHS 2)Restriction on the use of certain hazardous substances in electrical and electronic equipment; Annex II lists restricted substances and their maximum concentrations.
- eCFR — 21 CFR 175.300US FDA regulations for resinous and polymeric coatings intended for repeated use as food-contact surfaces, including extraction testing conditions.
- ASTM — Plastic and plasticizer standardsASTM International publishes the test methods referenced in our TDS, including plasticizer sampling and chemical analysis, tensile properties, and heat-aging procedures.
- ASTM — Plastic and Plasticizer Testing StandardsASTM International has published the test methods referenced in the TDS, covering sampling and chemical analysis of plasticizers, as well as tensile properties and thermal aging procedures.
- ISO — ISO 10993-1Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk management process, establishing the foundation for biocompatibility programs.
Request a 1 kg Free Sample & Full COA/TDS
Test DB22 using your own formulation. The request below is pre-filled with the grade discussed in this whitepaper, along with the specification, documentation, and sample shipping confirmation.
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