## 2 Problem Formulation  
There are many studies available that focus on surface preparation, treatments, and other parameters modifications. In this study, we will analyse the adhesion problems of ink printing on different types of polymers. Energy treatment methods such as corona discharge, plasma discharge or gas flame treatment at atmospheric pressure were also reviewed.  
These surface treatments remove organic contaminants, trigger oxidation processes, and increase the polarity and wettability of polymeric surfaces to increase adhesion to printing inks, [PERSON] and [PERSON] [14]. Here, a plasma is created by exciting a gas with electrical energy to make it highly reactive. The quality of inkjet printing mainly depends on the control of the printheads, the behaviour of the droplets in flight and the distribution of droplets on the target surface, as well as its wettability, [PERSON] [15].  
Inkjet printing technology is applied to the fabrication of thick electro-adhesive devices with a main polyimide dielectric layer, [PERSON] et al. [16]. Inkjet printing is becoming one of the most efficient, inexpensive, and flexible techniques to fabricate thin-film devices for flexible electronics applications, such as micro-supercapacitors, [PERSON] et al. [17; 18]. Mention may be made of the study of polymers in inkjet printing from various perspectives. The advantage of inkjet printing in achieving transverse conductivity in Poly(3,4-ethylenedioxythiophene)/Poly(styrenesulfonate) (PEDOT/PSS) compared to spin coating is given by [PERSON] et al. [19]. It was observed ([PERSON] et al. [20]) that both in-plane conductivity and contact resistance increased with the concentration of dimethyl sulfoxide (DMSO) in the printing ink. It has been demonstrated that inkjet printed thin films offer comparable and even better surface and electrical properties to layers deposited by the more commonly used spin coating technique, [PERSON] et al. [21].  
In the analysis of different polymers, surface treatment for ink counting is very important to improve the sufficient surface adhesion strength. It should be noted that polymers generally have a very low surface energy (20-22 mN/m). For various printing methods, it is necessary to achieve a stable surface energy of 45 mN/m to 71 mN/m on the surface, [PERSON] [22]. A typical method for measuring the static and dynamic surface tension of inks, as well as the properties of the substrate surface, is the analysis of the contact (wetting) angle of droplet.  
To test the adhesion of the printed layer, it is best to use ASTM D3359 standard Cross-Cut test methods [23] to measure the adhesion using tape. The printed substrate samples are scratched with a special cutting tool and a special certified tape is used. These test methods cover procedures for evaluating the adhesion of coating films to metallic substrates by applying and removing pressure-sensitive tape on cuts made in the film. Numerical simulations with COMSOL can help you see the shape of the droplets on a variety of treated and non-treated surfaces.  
There are many problems with inkjet droplet adhesion with HDPE, PP and PET polymers. These polymers have very low surface free energy values, so it is important to increase this to an acceptable level for coating. It is important to keep the visual characteristics of the surface and the acceptability of food contact. This study is designed to analyse various surface treatment methods for inkjet printing.  
The aim of the research is to analyse different polymer surface treatments and their influence on surfaces, investigate how surface energy and surface tension are measured and describe how the surface of the polymers must be treated to ensure that ink is properly fixed. The focus of the study is to demonstrate the differences in the interaction of inkjet droplets with the surface.