Regarding paper, a question often asked by customers is, do you sell A4 paper?

It seems that the public’s understanding of paper products only stays in our commonly used printing paper, notebooks and other civilian products. But today we will introduce a kind of paper that you have never heard of with high probability – sulfur-free paper.

When we talk about the name of sulfur-free paper, if you have not touched it, you may be wondering a question. Is there any connection between sulfur and paper?

This is about the production of modern paper. In the papermaking process of modern paper, a very important inorganic substance is usually used – aluminum sulfate (another name for it is alum)

Paper mills add aluminum sulfate as a sizing agent in the papermaking process, giving the paper anti-wear, anti-water, anti-emulsion, anti-corrosion properties, and at the same time improving the smoothness of the paper and giving it water-based printing adaptability.

In this process, it is inevitable that the produced paper products will contain sulfur.

However, in some industrial high-end civil use scenarios, the sulfur content in paper needs to be controlled within a very low range.

Faced with this demand, paper mills kept trying to improve the production process formula of paper, and finally sulfur-free paper was born.

Papers used in different fields have their own differences, such as industrial paper and household paper.

Industrial paper such as printing paper, sulfur-free paper, oil-absorbing paper, wrapping paper, kraft paper, dustproof paper, etc., household paper such as books, napkins, newspapers, toilet paper, etc.

Then let us explain the difference between sulfur-free paper and our commonly used ordinary paper.

Sulfur-free paper

Sulfur-free paper is a special backing paper for PCB silver processing in circuit board manufacturers. The main rationale for using this type of paper is to avoid the chemical reaction of silver with sulfur in the air, causing it to turn yellow. And the use of sulfur-free paper can avoid the reaction between sulfur and silver, which may lead to some defects of pcb.

At the same time, sulfur-free paper also avoids the chemical reaction between the silver in the electroplating finished product and the sulfur in the air, resulting in the product turning yellow. Therefore, the product should be packaged with sulfur-free paper as soon as possible after the product is completed, and sulfur-free gloves should be worn when touching the product, and should not touch the electroplated surface.

Features of sulfur-free paper: sulfur-free paper is clean, dust-free, ROHS-compliant, does not contain sulfur (S), chlorine (CL), lead (Pb), cadmium (Cd), mercury (Hg), hexavalent chromium (CrVI), polybrominated biphenyls and polybrominated diphenyl ethers. It can be better applied to PCB circuit board electronics industry and hardware electroplating industry.

Sulfur-free paper application: mainly used for silver-plated packaging, such as circuit boards, LEDs, circuit boards, hardware terminals, food protection products, glass packaging, hardware packaging, stainless steel plate separation, food packaging, etc