Study on the UV Curing Reactivity of Micro-Injection UV-Curing Molding

2018 ◽  
Vol 777 ◽  
pp. 65-69
Author(s):  
Jia Wei Li ◽  
Jian Yun He ◽  
Xi Dan Luo ◽  
Chang Song Zhao ◽  
Peng Cheng Xie ◽  
...  

In this paper, UV irradiation curing technology is used in the processing and manufacturing of micro structure parts and a micro-injection molding method of UV-curable molding was proposed to process microstructures. The special material for UV light curing injection of microstructural products was developed. The light curing reactivity of the micro injection light curing special material and its effect on the processing molding are studied. The kinetics of light curing reaction of UV curing injecting material were studied by online infrared spectroscopy (RT-IR). The contribution of mono functional monomers to the double bond conversion rate of microstructures is higher than that of high functional monomers. Under the same condition, the mono functional monomer can make the UV curing reaction more complete. Under the same process conditions, the rate of UV curing reaction of high functional monomers is higher than that of mono functional monomers.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1195
Author(s):  
Anda Barkane ◽  
Oskars Platnieks ◽  
Maksims Jurinovs ◽  
Sigita Kasetaite ◽  
Jolita Ostrauskaite ◽  
...  

Typical resins for UV-assisted additive manufacturing (AM) are prepared from petroleum-based materials and therefore do not contribute to the growing AM industry trend of converting to sustainable bio-based materials. To satisfy society and industry’s demand for sustainability, renewable feedstocks must be explored; unfortunately, there are not many options that are applicable to photopolymerization. Nevertheless, some vegetable oils can be modified to be suitable for UV-assisted AM technologies. In this work, extended study, through FTIR and photorheology measurements, of the UV-curing of epoxidized acrylate from soybean oil (AESO)-based formulations has been performed to better understand the photopolymerization process. The study demonstrates that the addition of appropriate functional comonomers like trimethylolpropane triacrylate (TMPTA) and the adjusting of the concentration of photoinitiator from 1% to 7% decrease the needed UV-irradiation time by up to 25%. Under optimized conditions, the optimal curing time was about 4 s, leading to a double bond conversion rate (DBC%) up to 80% and higher crosslinking density determined by the Flory–Rehner empirical approach. Thermal and mechanical properties were also investigated via TGA and DMA measurements that showed significant improvements of mechanical performances for all formulations. The properties were improved further upon the addition of the reactive diluents. After the thorough investigations, the prepared vegetable oil-based resin ink formulations containing reactive diluents were deemed suitable inks for UV-assisted AM, giving their appropriate viscosity. The validation was done by printing different objects with complex structures using a laser based stereolithography apparatus (SLA) printer.


2013 ◽  
Vol 683 ◽  
pp. 266-270 ◽  
Author(s):  
Jia Le Song ◽  
Peng Wei Hao ◽  
Chao Qiang Ye ◽  
Li Xin Chen ◽  
Wei Guang Li

The kinetics of UV curable thiol-hyperbranched polysilazanes (HBP) was studied by differential photo-scanning calorimeter (DPC) technology. The effects of photo initiator concentration [I], light intensity I0and temperature on the UV curing rate and the final unsaturated double bond conversion of thiol-HBP were investigated. The results indicate that the dependence of polymerization rate Rp on [I] and I0, respectively, was found to fit with theoretical predictions very well at [I] no more than 0.50wt% and I0lower than 19.40mW/cm2. The kinetic parameters were calculated by autocatalytic model, and correspondingly, the total apparent reaction exponent and apparent activation energy are 8.76 and 13.97kJ/mol, respectively.


2010 ◽  
Vol 174 ◽  
pp. 397-400 ◽  
Author(s):  
Ping Xiu Ni ◽  
Xian Fu Wei ◽  
Pei Qing Huang ◽  
Wei Wei

In order to make different UV curing inkjet ink system and test the relationship between the dynamic elastic modulus and UV curing time, the same monomer and pre-polymer were mixed in different proportions, and different functional monomers and pre-polymer were mixed. The results show that the larger the proportion of the pre-polymer and the greater the number of monomer functional groups, the shorter the induction period of the UV curing of UV inkjet ink system and the faster the UV curing rate. Then, the UV curing kinetics of UV inkjet inks was analyzed preliminarily.


e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianyun He ◽  
Jinping Xiong ◽  
Bingqian Xia

AbstractOrganic-inorganic hybrid films were prepared using tetraethylorthosilicate (TEOS) oligomer and special acrylated polyester (SAP) via a UV-curing process. TEOS oligomers were prepared in the presence of water and ethanol using hydrochloric acid as the catalyst and characterized using 1H NMR, 29Si NMR and MALDI-TOF mass spectra. Special acrylated polyester was synthesized by 1,4-cyclohexane dimethanol, neopentyl glycol, 1,4-butanediol, maleic anhydride, adipic acid, and acrylic acid. Hybrid films were cured by UV light and the thermal properties, dynamic mechanical properties, and tensile properties of the hybrid films were evaluated as the function of TEOS oligomer content. The morphology of the hybrid films was examined using atomic force microscopy (AFM). The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. The results indicated that after incorporating the TEOS oligomer, the strength and thermal stability of the hybrid films were enhanced.


2015 ◽  
Vol 731 ◽  
pp. 588-592 ◽  
Author(s):  
Qing Kai Wang ◽  
Bei Qing Huang ◽  
Xian Fu Wei ◽  
Hao Chen Shen

UV-Curable Coatings, Have been Widely Used in Machinery, Chemical Engineering, Biology, Medicine, Electronics and so on, due to their Fast Curing, Low Curing Temperature, Low VOC Emissions and Low Energy Cost. however, the Volume Shrinkage during the Curing Process Have a Great Influence on the Performance of the Coating, which Ofen Lowering Coating Adhesive Strength and Accelerating the Aging Process of Coatings Film.The Paper Select Different Kinds of Monomers (EOEOEA, HDDA, TPGDA, NPGDA, TMPTA and EO3- TMPTA) and Light Cured Resin (free Radical Type: Polyester Acrylate Resin 5600, Polyurethane Acrylate UA VP 2396, the Pure Acrylic 6536-1,cationic Resin: Epoxy Cationic Resin Omnilance OC3005) to Prepare the UV Curing Coatings. Study on the Influence of Amount of Monomer and Polymer on Polyreaction Reaction by Using Orthogonal Experimental Design Method in Order to Choose the Monomer and Polymer that has the Least Volume Shrinkage Rate, then Develop Photocureable Coating Based on Free Radical Type and Cationic Resin above. the Results Indicate that the UV-Light Photocureable Coating Prepared by Single Functionality Monomer EOEOEA and the DPGDA that Doesn’t Have Neat Molecular Structure has the Less Volume Shrinkage Rate; however, in the Aspect of Prepolymer, the Preparation of UV-Light Photocureable Coating Based on Polyester Acrylate 5600 has the Least Volume Shrinkage Rate. Rely on the Experiment Results above, Prepare the New Kind of UV-Light Photocureable Coating that has Little Volume Shrinkage Rate.


Segmented thermoset polymeric materials properties mainly classified through its carbonyl hydrogen bonding. The addition of graphite particle loading in polymeric materials tailored the functional characteristic of the composites. Therefore, the carbonyl hydrogen bonding in the hard segments of the synthesized segmented ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites was identified. This composites based green polymer incorporated with varying graphite particles loading were prepared through slip casting method which cure upon UV light. These result in an enhancement of the carbonyl hydrogen bonding which tribute to degree of phase separation (DPS %) in the TPU-G composites ranged from 10-20%, as compared to that in the pure TPU. In addition, the spectroscopy detects the formation of carbonyl hydrogen groups within the TPU-G composites although they are prone to chain scission and undergo photo oxidation subjected to ultraviolet (UV) curing. Upon UV curing, higher graphite weight loading (TPU-G20, TPU-G25 and TPU-G30 composites), shows higher and stable DPS% value, attribute to soft segment- soft segment and hard segment- hard segment establishment. Therefore, the graphite particles dominantly absorb the incident radiation instead of thermoset polyurethane without changing its based.


2012 ◽  
Vol 549 ◽  
pp. 457-461
Author(s):  
Jun Gang Gao ◽  
Feng Li Zhu ◽  
Jiang Bo Yang ◽  
Xiao Qian Liu

In ouder to prepare the waterborne UV-curable polyurethane acrylate coatings, the anionic polyurethane acrylate emulsifier and bisphenol-S eopxy acrylate were synthesized. The curing process, kinetics and properties of waterborone UV-curable epoxy acrylate/polyurethanes acrylate coating were investigated by FTIR, DSC and DMA. The results show that the static initial curing temperature Ti is 52.36 oC, peak temperature Tp is 71.58 oC, the finished temperature Tf is 89.15 oC. The curing reaction can be described by two-parameter autocatalytic Šesták-Berggren (S-B) model.This coating has a better UV-curing property. The dynamic mechanical analysis showed that the glass transition temperature Tg of coating film is 52.70 oC.


2021 ◽  
Author(s):  
Farbod Ahmadzadeh

Soft lithography techniques has been used widely in the past decade to fabricate microfluidic chips used in biomedical applications. Abrasive jet machining (AJM) has been used to fabricate similar chips using particle erosion mechanisms. This thesis proposes a new technique using a UV light sensitive self-adhesive mask (RapidMask) and AJM to fabricate a three dimensional flow focusing microfluidic chip where the depth of the channel is allowed to vary along the channel length. A detailed characterization of the effect of curing parameters of a UV light curing self-adhesive mask on the resulting feature resolution is reported. Instead of relying on the manufacturer recommended curing parameters which were vaguely described for specific UV curing units, it was found that measured energy density could be used to quantify a recommended cure that is independent of the curing unit. The best achievable pattern on borosilicate glass using RM and AJM was found and reported along with the erosion rates of uncured, cured RM during AJM. A new methodology was introduced to use multiple layers of the RM in order to increase the achievable feature aspect ratio. The results of the RM curing and multiple layer investigation were then used to fabricate a three dimensional flow focusing chip with a varying depth at the focusing junction. The chip was then sealed and tested to demonstrate its capabilities and potential in healthcare and biomedical applications. To the best knowledge of the author, this thesis is the first to report using a double layer RM to fabricate a microfluidic chip using AJM.


2021 ◽  
Author(s):  
Farbod Ahmadzadeh

Soft lithography techniques has been used widely in the past decade to fabricate microfluidic chips used in biomedical applications. Abrasive jet machining (AJM) has been used to fabricate similar chips using particle erosion mechanisms. This thesis proposes a new technique using a UV light sensitive self-adhesive mask (RapidMask) and AJM to fabricate a three dimensional flow focusing microfluidic chip where the depth of the channel is allowed to vary along the channel length. A detailed characterization of the effect of curing parameters of a UV light curing self-adhesive mask on the resulting feature resolution is reported. Instead of relying on the manufacturer recommended curing parameters which were vaguely described for specific UV curing units, it was found that measured energy density could be used to quantify a recommended cure that is independent of the curing unit. The best achievable pattern on borosilicate glass using RM and AJM was found and reported along with the erosion rates of uncured, cured RM during AJM. A new methodology was introduced to use multiple layers of the RM in order to increase the achievable feature aspect ratio. The results of the RM curing and multiple layer investigation were then used to fabricate a three dimensional flow focusing chip with a varying depth at the focusing junction. The chip was then sealed and tested to demonstrate its capabilities and potential in healthcare and biomedical applications. To the best knowledge of the author, this thesis is the first to report using a double layer RM to fabricate a microfluidic chip using AJM.


2011 ◽  
Vol 380 ◽  
pp. 117-120
Author(s):  
Ling Ya Gu ◽  
Bei Qing Huang ◽  
De Ping Zhao ◽  
Wei Yuan

In order to obtain good watermark on paper by printing, vegetable oil system and UV light-curing system watermark varnish were prepared by changing the type of vegetable oil, prepolymer and monomer, then test its permeability and refractive index, study the effects of these components on the performance of watermark varnish. Print watermark varnish by screen printing to examine the watermark. The results show that watermark varnish prepared with different type of vegetable oil has different permeability, but refractive index is very close. Adding prepolymer can improve permeability and refractive index of vegetable oil system watermark varnish. If the specific gravity of prepolymer and monomer is greater, permeability of UV curing system watermark varnish is higher. If refractive index of prepolymer and monomer is bigger, refractive index of varnish is bigger. Printing effect of UV curing system watermark varnish is better than vegetable oil system watermark varnish.


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