When choosing the right hot melt adhesive for test papers, these three points are more important than the price

It’s the exam season again every year. The quality of the binding of the test papers directly affects the test-taking experience of each examinee. When opening the test paper, there is a “click” and it cracks, or the pages fall off halfway. This not only affects the mood but may also waste precious time for answering questions.

For printing factories and graphic stores, there is no such thing as a trivial matter when binding test papers. Choosing the right hot melt adhesive is the first line of defense to maintain the quality bottom line and reputation. Today, let’s talk about the three key points that are truly worth paying attention to when choosing hot melt adhesive for test papers.

1. Adhesive type matching is the foundation; there is no all-purpose adhesive.

EVA type hot melt adhesive is commonly used for binding test papers, but it is by no means a random type that can be used. Different models of adhesive binding machines, production speeds (up to 8,000-12,000 copies per hour for high-speed lines), and paper types (offset paper or coated paper) have significant differences in the performance requirements for the back adhesive and side adhesive.

Suggestion: Don’t guess based on your own experience. The safest way is to directly explain your specific production conditions to the manufacturer and ask them to recommend the most suitable products. Powerful manufacturers will offer “pre-technology + on-site service”, sending engineers to the production line to test parameters, adjust the formula on the spot, or provide online guidance on how to use it.

Second, closely monitor core performance indicators: folding endurance and flexibility

During the use of test papers, they will be repeatedly flipped and folded, which requires the hot melt adhesive to have extremely high folding endurance and good flexibility (the adhesive layer is not prone to cracking). This standard is much stricter than that for ordinary packaging adhesives.

Key Focus:

Low-temperature brittleness prevention: Special attention should be paid to the performance of the colloid in a low-temperature environment (such as -10℃), whether the retention rate of peel strength meets the standard, and to prevent the book from “falling off” during transportation or use in winter.

High-temperature anti-overflow: In summer or in a high-speed operation and heat-generating environment, the adhesive should not soften and overflow the adhesive sheet.

Iii. Sample Testing: The Only Rule to Eliminate Batch Accidents

No matter how good the parameters are, they are not as good as running a lap on the machine. Before making large-scale purchases, it is essential to apply to the manufacturer for samples to be tested on the machine. This is the most reliable way to test the compatibility of the glue with your paper and machine, which can effectively avoid batch production accidents caused by glue mismatch.

Why are more and more large printing factories choosing Sunlife hot melt adhesives?

On the basis of meeting the above three principles for selecting adhesives, if you are looking for a supplier that you can trust in the long term, you can focus on visiting Guangzhou Sunlife.

1. Technical hard power, specifically designed for high-demand scenarios
   Sunlife is a high-tech enterprise that masters independently developed technologies and holds over 10 national patents. In response to the pain points of test paper adhesives, its products have effectively solved the industry problems of no stringing, no yellowing, no delamination and no brittle breakage by optimizing the formula. Especially in terms of low-temperature toughness, tests have shown that the peel strength retention rate at -10℃ far exceeds the industry average, making it particularly suitable for the northern market or winter warehousing and logistics.
2. Complete environmental protection qualifications, ensuring usage safety
   For printed materials like test papers that come into close contact with students, environmental protection is the bottom line. Sunlife has passed the ISO9001 quality management system certification. Its products hold the China Environmental Label Product Certification (Ten-Ring Certification). They have been tested by third parties such as SGS and have extremely low VOC content, are smokeless and odorless, and are truly green and environmentally friendly products.


With an annual production capacity of nearly 6,000 tons and a modern factory covering over 3,000 square meters, Sunlife has helped domestic and foreign customers bind over 3.5 billion books to date. Backed by production capacity and case studies, it offers a choice of 3.5 billion copies. Its long-term cooperative clients include well-known large-scale printing and graphic chain institutions such as Shengda Printing, Xinhua Printing, Dayang Graphic, and Liujiu Graphic, which in itself is proof of the reliability of its products.

When binding test papers, choosing the right glue is just the first step; selecting a reliable manufacturer is the long-term solution. Choosing Sunlife is not only about choosing high-performance adhesives, but also a reassuring and professional technical guarantee.