Effects of Printing Temperature and Filling Percentage on the Mechanical Behavior of Fused Deposition Molding Technology Components for 3D Printing

Additive manufacturing (AM) has the advantages of providing materials with lightweight microporous structures and customized features, and being environmentally safe. It is widely used in medical sciences, the aerospace industry, biological research, engineering applications, and other fields. Among the many additive manufacturing methods, fused deposition modeling (FDM) is relatively low-cost, wastes less raw material and has a lower technical threshold. This paper presents a study on 3D printing based on FDM by changing two printing parameters, namely the printing temperature and filling percentage. The produced polylactic acid (PLA) material was analyzed through tensile and Shore D hardness tests and the differences in mechanical properties before and after the UV curing process were analyzed. The results show that increasing the filling percentage or increasing the printing temperature can effectively improve the tensile Young’s modulus, ultimate tensile strength, elongation, and Shore hardness of the material. The UV curing process could enhance the rigidity and hardness of the material significantly but reduced the strength and toughness of the material. These findings could benefit researchers studying FDM with the goal of achieving sustainable manufactured materials.

Process Simplification on Integration of UV Cure Machine with Tape Saw Singulation

Strips that have undergone tape saw singulation will not be completed without the ultraviolet (UV) curing process. To detach the units from the tape, the singulated strips have required further assistance to be loaded for UV cure. Otherwise, hard-to-pick units will be the outcome and sticky residues were usually observed to be attached on the units. Since tape sawn strips requires UV cure, suppliers were asked to engage on upgrading their machine to equip the singulation machine with UV cure. The principle is that after sawing, the singulated strips will be washed and dry normally at the spinner. Then instead of unloading the singulated strips, the machine will pass it first to the inline UV cure machine and then unload when successfully completed the whole process. Through adding the UV curing process in the package singulation sequence, singulated strips unloaded are now ready for the next succeeding process. That way, it would be much help to lessen the handling of sawn strips from one machine to another. The introduction of inline UV cure has simplified the process by automation which increased the security of the units’ quality as well as the productivity of manpower.

UV-Cured Biodegradable Methacrylated Starch-Based Coatings

Promising UV-curable starch-based coatings were fabricated by utilizing methacrylated starch. The aqueous methacrylated starch solution was cast on a glass substrate, and UV-cured after drying. The efficiency of UV-curing process was monitored with gel percentage measurements. The thermal and mechanical properties of the fabricated UV-cured coatings were investigated through differential scanning calorimetry and tensile test and compared with the starch-based uncured casted coatings. A complete characterization of the surface properties was performed by means of pencil hardness, adhesion, solvent resistance, and surface tension measurements. The cross-linking by UV-curing significantly enhanced the mechanical and surface properties of the coating. The effect of UV-curing on the biodegradability of the coating was evaluated by following the enzymatic degradation by α-amylase by determining the amount of glucose and maltose released from the coatings. UV-cured methacrylated starch based coating with promising material and surface properties and retained biodegradation potential was demonstrated.

STUDY OF THE INFLUENCE OF SPACER ON FEATURES OF UV CURING OF PHOSPHOROSE-CONTAINING METACRYLATES OF VARIOUS FUNCTIONALITY

The article presents the results of studies of the features of photorecovery of trifunctional and tetrafunctional phosphorus-containing methacrylates with various spacers in the structure. It was found by differential scanning calorimetry that the introduction of spacers leads to a decrease in the overall thermal effect of the UV-curing process in comparison with a spacerless sample. With the help of a photocell for an E7-25 immittance meter, which is capable of recording changes in dielectric properties over time, the influence of the spacer and its structure on the degree of completion of the UV-curing process was determined. The effect of the introduced spacer on the formation of a crosslinked polymer is shown, which is manifested by different times of the induction period.

PEGDA drug delivery scaffolds prepared with UV curing process

Individually tailored drug delivery systems (DDSs) are considered one of the most promising therapeutic tools for the creation of safe and effective treatments. DDSs as a novel approach should be beneficial in curing systemic as well as local ailments, where a high topical concentration of the drug and a reduction of side effects are desirable. It could also be favorable for patients requiring customized treatments, showing atypical profiles of drug metabolism. Development of particular drug delivery devices require the selection of a suitable scaffold material, which should exhibit proper mechanical and biological properties, but also enable adjustment of the drug release according to a specific need. Thus, it is extremely important to expand the knowledge concerning potential DDS components. Poly(ethylene glycol) diacrylate (PEGDA) according to its properties can be easily used as a DDS resin and shaped into a desired structure with the employment of techniques based on photopolymerization, including some novel 3D printing techniques. As a continuation of our previous works, in this paper drug release studies from conventionally prepared PEGDA scaffolds are presented. We have shown that in PEGDA materials, the release profile of the low molecular weight model drug acetylsalicylic acid can be altered by water content. PEGDA as a delivery material should be further investigated to specify its potential as a comonomer and a matrix for pharmaceutical agents.

Study on the Transparent Electronic Isolation Layer Material - A Photoresist Composition which is Stable at High Temperature and Humidity

A negative resist composition composed of an acrylic-copolymer-binder resin, a crosslinker, photoinitiators, some agents and solvents has been UV-cured and developed for OverCoat (OC)-Bridge of One Glass Solution (OGS) touch panel (TP) sensor, wherein acrylic-copolymer-binder resin as a key element consisting of N-Phenylmaleimide (N-Pm), Methacrylic acid (MA), Styrene (St) and Isobornyl methacrylate (iBMA) monomers, being designed and synthesized to control the acid value (90-110mgKOH/g), molecular weight (Mw:10,000-20,000) and approximate solubility parameter [10.67-11.05(cal/cm3)1/2]. Here,we demonstrate a OC photoresist applies between two ITO line-films by UV-curing process technology deveoled for OC-Bridge pattern with a kind of acrylic-copolymer-binder resin by ours. Acting as TP sensor, the OC patterns have adequate resistance to solvents, acids and alkalis, good thermal and humid stability, and with excellent transparency and insulation. This OC photoresist, coupled with the acrylic-copolymer-binder resins, provides an unprecedented approach to realize supporting high temperature and humidity OC-Bridge.

Facile fabrication of photoinduced superhydrophobic–superhydrophilic surfaces on cellulose substrate without strength loss

A novel strategy was reported on the design and fabrication of functional photosensitive hybrid sols (FPHSs) by non-alcoholic emulsification in the presence of a TiO2 nanoparticle and photoinitiator via a sol-gel process using tetraethylorthosilicate, γ-methacryloxypropyltrimethoxysilane (MPS) and hydrophobic silane coupling agents as precursors. Smart cellulose substrates with alterable superhydrophobic–superhydrophilic conversion were fabricated using FPHS via the ultraviolet (UV) curing process. The liquid FPHS was photocured into solid gel during UV irradiation for 40 s with MPSs in FPHS, which was verified via Fourier transform infrared spectra. The cellulose substrates were modified with FPHSs, and the water contact angles of the modified cellulose substrates were more than 150°. The superhydrophobicity was improved by the gathering of hydrophobic chains and particle deposition of hybrid gel on the fiber surface. Nevertheless, the water contact angles of the modified cellulose substrates were receded with UV irradiation from 158° to 0° in 200 min, due to TiO2 photoinduction. The irradiated cellulose substrates were placed in the dark, and the water contact angles were recovered to about 130°, gradually. What is more, the reversible process can be repeated more than eight times. The modified cellulose substrate presented excellent washing fastness, even suffering 10 times washing processing. The mechanical properties, including breaking strength and elongation rate, were improved after the coating and UV curing process, which considerably remedied the defects of the heating curing process on the mechanical properties.