How to use the surface tension to determine whether the paper towel is "clean"?

According to statistics, China's per capita annual consumption of paper towels is about 6000 grams of paper towels have long been integrated into every scene of our lives, whether it is wiping hands, wiping faces or wiping tables, they are inseparable from paper towels, but in the face of many paper towels on the market, many people do not know how to choose today's small editor spent a lot of money to bring you 4 categories of paper towel evaluation, I hope that everyone will not be so "paper" confused after seeing this evaluation is not the absorbency, flexibility, and delicacy of paper towels, only from the perspective of additive residue to analyze the cleanliness of paper towels
。
The first part: paper towels and toilet paper are mostly recycled paper, raw materials are complex sources, generally fiber materials mixed with native wood pulp recycling soaked re-pulping, and then degreasing and deinking bleaching made, this series of processes make toilet paper inside the inevitable residue of some harmful substances
to the human body.

According to the health standards set by the state, the total number of bacterial colonies contained in each gram of toilet paper is less than or equal to 600
.

The tissue paper can only be made using native pulp, and is not allowed to be manufactured using recycled fiber raw materials such as waste paper, and the total number of bacterial colonies on each gram of tissue paper must be less than or equal to 200 to meet the use standard
.

Therefore, from the perspective of cleanliness and hygiene, try not to use toilet paper to wipe your mouth! Experimental part of the liquid to be measured: 60×60mm paper towel samples are soaked in 40mL of pure water (surface tension of pure water: 72.
8 mN/m), stirred for 10 s and then allowed to stand for 5 min, stirred again for 10 s, remove suspended impurities and let stand for 10 min to be the liquid
to be measured.

Experimental instrument: KRÜSS surface tension meter K100 is used to detect the surface tension value
of the liquid to be measured.

Results and Discussions This assessment examines six brands of extracted paper, rolls, and handkerchief paper, and the results are shown in
Figure 1.

The surface tension value of most paper towels is greater than 70mN/m, which is close to pure water, indicating that the vast majority of paper towels do not contain or contain a small amount of additives
.

Compared with other paper towels, the surface tension value of No.
4 extractive facial tissue is low, indicating that the additive content in the paper towel is high and the cleanliness of the tissue is poor
.

At the same time, the surface tension value of No.
2 and No.
4 rolls, as well as No.
6 handkerchief paper, is lower than 65mN/m, and the paper towels contain more additives
.

The second part: cotton soft towel cotton soft towel is a non-woven fabric (non-woven fabric) processed by non-woven technology such as cotton and viscose as raw material, by spunlace and other non-woven processes, spunlace for the physical processing process, that is, cotton through high-pressure spunlace, directly into cloth, because there is no additional ingredient added, very friendly
to sensitive skin and infants.

Although there are no additional ingredients added to the cotton towel, the presence of
additives cannot be completely avoided during the production process.

For example, in the spunlace process, raw cotton needs to be degreased and bleached to ensure the high cleanliness of
the finished product.

Or some manufacturers in order to achieve the effect of whitening and giving, add some fluorescent brighteners
.

In addition, in the process of cotton fiber planting, in order to prevent the invasion of pests, pesticides may be used, although pesticides will be removed in the subsequent production and processing of cotton fibers, there is still a risk of
pesticide residues.

The above additives can cause many hazards when directly in contact with the skin, especially sensitive skin or infant skin
.

This time, the residue of cotton towel additives is tested
based on the ASTM D1331 standard.

The results and discussion used seven brands as common cotton soft towels as research objects, and the results of the cleanliness exploration were shown in
Figure 2.

As can be seen from the figure, the surface tension value of cotton towel is lower than that of pure water, which proves that cotton towel contains different degrees of additives, and the content order is: D<B<C<F<E<G<A<b136>.

A cotton towel surface tension value is the smallest, the additive content is the highest
.

SummaryWhether it is toilet paper, paper drawing, or cotton soft towels, the country has strict manufacturing standards
.

These additives, which belong to the part of the manufacturing process, have a clear amount of use, regular manufacturers manufactured, quality of qualified tissue paper, although it will not affect human health, but we must do a good job of knowing that in the case of conditions, try to buy safer products
.