Welcome to our detailed guide on the manufacturing process of PU foam stress balls at our company. Here, we will walk you through each of the critical steps—from receiving raw materials to the final shipment of the finished product. In this article, we will help you understand the process, quality, and expertise that go into each stress ball, making us your ideal partner for high-quality, customizable stress ball solutions.
PU foam stress balls are manufactured through a 9-step process that includes stress ball foam material acceptance, foaming, trimming, spray painting, pad printing (if needed), transfer printing (if needed), packing, inspection, and shipping. Each step involves strict quality control measures to ensure the durability, comfort, and safety of the product.
This guide explains each step in detail, from raw material inspection to final shipment.
| Step Number | Step Title |
| 1 | Accepting and Evaluating Raw Materials |
| 2 | Foaming: The Critical Process |
| 3 | Trimming for a Smooth Finish |
| 4 | Precision Spray Painting |
| 5 | Pad Printing (For Single-Color Logos) |
| 6 | Transfer Printing (For Multi-Color Logos) |
| 7 | Secure Packaging and Quality Control |
| 8 | Comprehensive Inspection Before Shipment |
| 9 | Coordinated Shipping for Timely Delivery |
PU Foam Stress Ball Manufacturing Flow Diagram
1. Raw Material Acceptance
The journey of a PU foam stress ball starts when we accept the raw materials. The primary materials we use are polymer polyols (commonly referred to as A-material) and liquefied modified MDI (commonly referred to as B-material). We also use auxiliary materials like paint, color paste, and ink.
- Supplier Evaluation: We have a strict supplier evaluation process. We only put suppliers on our approved vendor list if they meet our standards.
- Quality Assurance: Every year, we sign quality commitment agreements with our suppliers. These agreements state that all the materials they sell us meet the toy safety standards of the countries we import into.
- Material Testing: Suppliers have to provide us with material test reports that show they meet the safety standards. These reports have to be less than 12 months old from the date of supply. If the standards change, we need new reports.
- Third-Party Testing: If suppliers are unable to provide the necessary documentation, we conduct third-party testing to ensure compliance.
2. Foaming: The Critical Process
The foaming stage is the most important part of making a PU foam stress ball. This is where we mix the A-material and B-material together and make foam.
- Temperature Control: We keep the A-material and B-material at an initial temperature of 20-25°C. This is the best temperature for the catalyst to work.
- Mixing and Spraying: Materials are placed in separate containers and connected to the same machine head via valves. Upon activation, the materials are sprayed, mixed at high speed (30-40 revolutions per second), and injected into molds heated to 40-50°C..
- Molding: Workers close the molds and rotate it by hand within 15 seconds, to make sure the liquid flows through the mold fully. Then they put them in an 80°C constant temperature oven for about 10 minutes to allow the foam to react and mature.
- Impact on Quality: Proper foaming ensures the final product has the desired texture and resilience. Inadequate foaming can result in different densities, affecting the stress ball’s durability and comfort.
3. Trimming
After foaming, the stress balls are taken out of the molds, and any extra material edge along the mold lines is trimmed off.
- Manual Trimming: Workers use custom-made scissors to carefully trim extra edges, ensuring a smooth finish.
- Quality Control: This step ensures that each stress ball has a uniform appearance and no sharp edges.
4. Spray Painting
For products that require spray painting, a copper mold is used to ensure precision.
- Painting Process: The stress balls are placed in the copper molds and sprayed with paint using a 1.5mm nozzle spray gun.
- Accuracy Testing: Before full production, a test is conducted using defective products to ensure accurate alignment.
5. Pad Printing (If Needed)
Pad printing is used for adding logos with one color or other designs to the stress balls.
- Preparation: A high-resolution steel plate carries the design you want, and we transfer that design onto the stress balls using a silicone pad.
- Printing Process: The design is transferred to the stress ball using a pad printing machine. Test runs are conducted to ensure alignment before mass printing
6. Transfer Printing (Decal, If Needed)
For multi-color logos, transfer printing is used.
- Decal Application: Workers manually apply decals to the designated spots on the stress balls.
- Quality Assurance: Each decal is carefully placed to ensure consistency and accuracy.
7. Packing
Once the stress balls are fully processed, they are ready for packing.
- Packaging Requirements: The products are packed according to specific packaging requirements to prevent damage during transit. Normal packing is each PC in a poly to save cost.
- Quality Check: Each package is inspected to ensure all components are included and correctly packed.
8. Inspection
Packaged products undergo a thorough inspection.
- Internal and External Inspection: Products are inspected by our in-house team or by a third-party inspection company as requested by the customer.
- Inspection Criteria: Products are checked for defects, make sure they’re right, and make sure they’re good.
9. Shipping
After passing inspection, the products are prepared for shipping.
- Timely Delivery: We ensure that products are shipped promptly to meet customer deadlines.
- Shiping Coordination: Our logistics team coordinates with shipping companies to ensure smooth delivery.
Manufacturing Process Summary Table
| Process | Details |
|---|---|
| Raw Material | Evaluation, QA, material testing, third-party testing |
| Foaming | Temperature control, mixing, spraying, molding, texture, resilience |
| Trimming | Trimming excess material, smooth finish |
| Spray Painting | Copper mold, spray gun, accuracy testing |
| Pad Printing | Design preparation, pad printing machine, alignment testing |
| Transfer Printing | Manual decal application, consistency, accuracy checks |
| Packing | packaging requirements, quality check |
| Inspection | Internal and external inspection, defect, specification adherence |
| Shipping | Timely delivery, logistics coordination |
Conclusion:
The serious nine-step process of manufacturing PU foam stress balls at istressball ensures that every product meets the highest standards of quality and safety. By understanding each stage, B2B buyers can appreciate the craftsmanship involved and the rigorous quality control measures that guarantee the best stress balls on the market.
For procurement officers, promotional companies, and distributors seeking top-quality, customizable stress balls, istressball is the perfect partner. Our commitment to excellence ensures you receive products that not only meet but exceed your expectations.
Ready to learn more or place an order? Contact us now.
