PP woven bags are an essential part of daily life, widely used for packaging in agriculture, construction, and industrial applications. Manufacturers constantly seek to enhance their whiteness, brightness, and durability to improve appearance and product quality. To achieve this, optical brightening agents (OBAs) are commonly added during production. However, many producers find that even after adding whitening agents, their woven bags begin to yellow or fade over time.
So what causes this problem, and how can it be effectively solved? Let’s explore the reasons for yellowing in woven bags and how choosing the right OBA for woven bags can make a difference.
Why Woven Bags Turn Yellow
There are two main reasons behind the yellowing and discoloration of woven bags:
1. UV Radiation Damage
Ultraviolet (UV) rays from sunlight are highly destructive to polypropylene (PP) materials. Studies show that under direct sunlight, the strength of woven bags can decrease by 25% within one week and by up to 40% after two weeks. This degradation not only weakens the bag but also leads to noticeable yellowing and dullness on the surface.
2. Low-Quality Whitening Agents
Another common reason for yellowing is the use of low-quality fluorescent whitening agents. The production of PP woven bags involves high-temperature processing, so only high-temperature-resistant OBAs can maintain their whitening effect throughout the extrusion and weaving process.
Some manufacturers, in an effort to cut costs, choose low-priced whitening agents that are often diluted or impure. These products require higher dosages and still deliver weaker whitening results, reducing efficiency and long-term performance. Therefore, when selecting an OBA for woven bags, it’s important to consider cost-effectiveness, purity, and stability—not just price.
The Ideal Solution: Optical Brightener OB-1 for Woven Bags
Among the various whitening agents available, Fluorescent Whitening Agent OB-1 has proven to be one of the most effective OBAs for woven bags.
OB-1, produced by Shandong Grand Chemical Co., Ltd., is a high-performance optical brightener designed specifically for polypropylene and other thermoplastic materials. It offers exceptional thermal stability, whitening efficiency, and color retention under harsh environmental conditions.
Key Advantages of OB-1 Include:
- Excellent whitening and brightening effect on PP woven bags
- High heat resistance, stable up to 375°C
- Low dosage requirement for strong, lasting results
- Good dispersibility and uniform whitening performance
- Wide applicability, suitable for woven bags, films, and even textile whitening pastes
Manufacturers who have adopted OBA OB-1 in their PP woven bag production consistently report improved whiteness, anti-yellowing performance, and better overall product quality.
Conclusion
Choosing the right OBA for woven bags is crucial for achieving bright, durable, and long-lasting results. While UV exposure and poor-quality additives are the main causes of yellowing, using a high-purity, high-temperature-resistant optical brightener like OB-1 effectively prevents discoloration and maintains the bag’s original appearance.
If you’re looking for a reliable, cost-effective optical brightener for woven bags, Shandong Grand Chemical Co., Ltd. offers Fluorescent Whitening Agent OB-1—trusted by manufacturers for its stability, efficiency, and outstanding performance.
At Shandong Grand Chemical Co., Ltd., we specialize in producing and supplying a wide range of high-performance fluorescent brighteners for plastics, coatings, detergents, and textiles.
📩 Contact us for product data sheets, samples, or technical guidance:
Email: sales@obachemical.com
WhatsApp: +86 13173009832