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Zhongfu Zhao - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and structure–property relationships of SIS-g-PB copolymers and their application in hot-Melt Pressure-sensitive adhesives
RSC Advances, 2020Co-Authors: Zhongfu Zhao, Chunqing Zhang, Yandong Zhang, Fanzhi Meng, Yifu Ding, Tao TangAbstract:A “graft onto” method was combined with an epoxidation reaction and living anionic polymerization to successfully synthesize a series of SIS-g-PB copolymers with defined branch numbers and branch lengths. These copolymers were utilized to formulate various hot-Melt Pressure-sensitive adhesives (HMPSAs). Their molecular structure and bulk properties were characterized by 1H-nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and rheometry. The adhesion performances were characterized in terms of holding power and 180° peel strength. The epoxidation reaction alone would negatively influence the rheological properties of the parent SIS copolymers, particularly for low-temperature applications. Controlled addition of the low-Tg PB blocks can significantly improve the low-temperature properties of the SIS copolymers. Both η* and G′ increased in the lower shear frequency regime ( 101 rad s−1) with branch number and branch length, in which branch length had a greater effect than the branch number. As a result, the 180° peel strength of the SIS-g-PB based HMPSAs displayed reached 0.23 kN m−1, which is more than twice the value for SIS-based HMPSAs.
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Hot-Melt Pressure-sensitive adhesives based on SIS-g-PB copolymer for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2019Co-Authors: Zhongfu Zhao, Chunqing Zhang, Shiyun Li, Yandong Zhang, Fanzhi MengAbstract:Abstract SIS-g-PB copolymers were successfully synthesized by grafting living polybutadiene (PB) lithium macroanions onto epoxidized SIS copolymers. Their molecular structures and thermal properties were characterized by TGA, 1H-NMR and DSC, respectively. SIS, epoxidized SIS (ESIS) and SIS-g-PB copolymers were Melt-blended with tackifiers to develop hot-Melt Pressure-sensitive adhesives (HMPSAs), respectively (named of H-SIS, H-ESIS and H-SIS-g-PB). Their adhesive performances were measured in terms of 180° peel strength and holding power. A modified Franz type horizontal diffusion cell was used to carry out In vitro drug release experiments, in which geniposides were chosen as hydrophilic model drugs. The results showed that H-SIS-g-PB has two times as high a 180° peel strength as H-SIS. Meanwhile H-SIS-g-PB has a slightly lower drug cumulative release rate than H-ESIS. It is indicated that the PB branches not only could impart good adhesive performance to H-SIS-g-PB via improving the compatibility between the epoxidized main chains and tackifier resins but also provide release channels to hydrophilic drugs by retaining most of the epoxide groups in the SIS-g-PB copolymers.
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SISO-based hot-Melt Pressure-sensitive adhesives for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2017Co-Authors: Zhongfu Zhao, Chunqing Zhang, Ruijie Zhang, Qing WangAbstract:Abstract A monomer-activated anionic polymerization approach was utilized to synthesize poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) tetrablock terpolymers (SISO), which were Melt-mixed with tackifiers and plasticizer to develop polar SISO-based hot-Melt Pressure-sensitive adhesives (HMPSAs) for transdermal delivery of hydrophilic drugs. Their hydrophilic performance was characterized using contact angle analysis. Their adhesive performances were measured in terms of 180° peel strength and holding power. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cell, in which geniposide was chosen as a hydrophilic model drug. The results show that poly(ethylene oxide) (PEG) blocks exhibit substantial effects on adhesive performance and the release behavior of the model drug. The shorter PEG molecular chains enhance adhesive performance and the cumulative release rate of the model drug in the SISO-based HMPSAs. The longer PEG molecular chains tend to crystallize. Their crystallization structures have negative effects on adhesive performance and limit the dissolution and diffusion of drugs in the SISO-based HMPSAs. Therefore, appropriate PEG molecular chains are required to fabricate SISO-based HMPSAs with excellent adhesive performance for transdermal delivery of hydrophilic drugs.
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Optimization of SIS-based hot-Melt Pressure-sensitive adhesives for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2016Co-Authors: Zhongfu Zhao, Chunqing Zhang, Yongsen Zhou, Zhansheng LiAbstract:Abstract To optimize hot-Melt Pressure-sensitive adhesives (HMPSAs) for transdermal delivery of hydrophilic drugs, styrene–isoprene–styrene copolymer (SIS), epoxidized SIS (ESIS), tackifiers, and plasticizer were Melt-mixed with polyethylene glycol 2000 (PEG2000) or poly (ethyl acrylate-co-methyl methacrylate-co-trimethylammonioethyl methacrylate chloride) (RLPO). Their compatibility was studied with DSC and FT-IR. Their 180° peel strength and holding power was measured for their adhesive performances. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cell, in which geniposide was chosen as a hydrophilic model drug. Although PEG2000 can greatly enhance the accumulative release rate of geniposide in a manner of burst release, its poor compatibility with the components of SIS/ESIS-based HMPSAs makes the adhesive performance hardly meet the practical requirement of transdermal drug delivery. RLPO not only provides sustained release behavior to geniposide through its low content of quaternary ammonium groups but also preserves excellent adhesive performance due to its partial compatibility with the components of SIS/ESIS-based HMPSAs. Therefore, RLPO is preferred to develop ideal SIS/ESIS-based HMPSAs for transdermal delivery of hydrophilic drugs.
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Preparation and characterization of polarity-modulated SIS-based hot-Melt Pressure-sensitive adhesives
Journal of Adhesion Science and Technology, 2014Co-Authors: Zhongfu Zhao, Zhanyue Wang, Chunqing ZhangAbstract:In order to develop polarity-modulated hot-Melt Pressure-sensitive adhesives (HMPSAs), epoxidation of styrene-isoprene-styrene (SIS) copolymers, using in situ prepared per-formic acid was studied. ...
Qing Wang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of pH sensitive amphiphilic hot-Melt Pressure sensitive adhesives for transdermal drug delivery system
International Journal of Adhesion and Adhesives, 2020Co-Authors: Xiao Tong, Xiaohui Li, Qing Wang, Hai-xia Wang, Wei WuAbstract:s EPO abstract Based on the blend of styrene-isoprene-styrene (SIS) thermoplastic elastomer and acrylic resin Eudragit s EPO, amphiphilic hot-Melt Pressure sensitive adhesives (HMPSAs) were fabricated. Compatibility and micromorphology of SIS/EPO blends (SEBs) were analyzed with differential scanning calorimetry (DSC), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results showed that when the mass ratio of SIS to EPO was 1:1 � 1:2, bicontinuous structure was formed. Following the addition of an appropriate amount of polyethylene glycol (PEG), mineral oil and C5 resin, the amphiphilic HMPSAs were prepared. Because of the compatibility between SIS and EPO, as well as the hydrogen bond interaction between EPO and PEG, amphiphilic HMPSAs showed good thermostability. The adhesive performance of HMPSAs was measured with 1801 peeling strength and holding power. Geniposide and oleanolic acid were used as model drugs to investigate drug release behavior. When the mass ratio of PEG to SEB was 13:30 � 16:30, the HMPSAs could maintain good adhesion performance and achieve continual release of both hydrophilic and lipophilic drugs. In weakly acidic conditions, the HMPSAs exhibited good hygroscopicity and release profile, it was shown that pH sensitive amphiphilic HMPSAs were more suitable for transdermal drug delivery system (TDDS).
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SISO-based hot-Melt Pressure-sensitive adhesives for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2017Co-Authors: Zhongfu Zhao, Chunqing Zhang, Ruijie Zhang, Qing WangAbstract:Abstract A monomer-activated anionic polymerization approach was utilized to synthesize poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) tetrablock terpolymers (SISO), which were Melt-mixed with tackifiers and plasticizer to develop polar SISO-based hot-Melt Pressure-sensitive adhesives (HMPSAs) for transdermal delivery of hydrophilic drugs. Their hydrophilic performance was characterized using contact angle analysis. Their adhesive performances were measured in terms of 180° peel strength and holding power. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cell, in which geniposide was chosen as a hydrophilic model drug. The results show that poly(ethylene oxide) (PEG) blocks exhibit substantial effects on adhesive performance and the release behavior of the model drug. The shorter PEG molecular chains enhance adhesive performance and the cumulative release rate of the model drug in the SISO-based HMPSAs. The longer PEG molecular chains tend to crystallize. Their crystallization structures have negative effects on adhesive performance and limit the dissolution and diffusion of drugs in the SISO-based HMPSAs. Therefore, appropriate PEG molecular chains are required to fabricate SISO-based HMPSAs with excellent adhesive performance for transdermal delivery of hydrophilic drugs.
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Studies on In Vitro Release Performance of Hydrophilic Drugs and Lipophilic Drugs in Amphiphilic SIS-Based Hot-Melt Pressure Sensitive Adhesives
Applied Mechanics and Materials, 2013Co-Authors: Yong-nan Hu, Xiaohui Li, Qing Wang, Hai Hong ZhangAbstract:In order to fabricate a kind of amphiphilic hot-Melt Pressure sensitive adhesives (HMPSAs) suitable for transdermal drug delivery systems (TDDS) of natural medicines, SIS-based hot-Melt Pressure sensitive adhesives were modified by a Melt-blending method, in which a kind of hydrophilic poly (ethyl acrylate-co-methyl methacrylate-co-trimethylammonioethyl methacrylate chloride) (RLPO) and polyethylene glycol 2000 (PEG2000) were utilized. Functional RLPO and its plasticizer PEG2000 worked as a hydrophilic skeleton of amphiphilic HMPSAs. SEM and FT-IR results indicated that RLPO and SIS were partially compatible with each other through n-π complex between the n electrons of the carbonyl group of RLPO and the π electrons of the benzene rings of SIS and their compound had a good thermal stability. The phase microscope images showed that PEG could improve the compatibility between RLPO phase and SIS phase. As the ratio of SIS/RLPO/PEG equaled to 1/2/1.6, their compounds obtained bi-continuous structures. Geniposide (logP
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Development of hot-Melt Pressure–sensitive adhesives for transdermal drug delivery
Journal of Adhesion Science and Technology, 2013Co-Authors: Zhongfu Zhao, Bing Fang, Xiaohui Li, Qing WangAbstract:Styrene–isoprene–styrene (SIS) copolymer was epoxidized by in situ epoxidation to prepare a series of epoxidized SIS resins (ESIS). Their epoxidation degrees, phase structures, and compatibility with hydrocarbon resin were characterized with 1H nuclear magnetic resonance spectroscopy, atomic force microscopy, and differential scanning calorimetry, respectively. These ESIS resins were Melt-mixed with synthetic hydrocarbon resin, mineral oil, and antioxidants to fabricate a series of ESIS-based hot-Melt Pressure–sensitive adhesives (HMPSAs), which were used as carriers of transdermal drug delivery system. Their adhesive performances were measured, including holding power and 180o peel strength. Geniposide and oleanic acid were representatively chosen as hydrophilic and lipophilic drug, respectively. Their in vitro release behaviors in ESIS-based HMPSAs were investigated using a modified Franz-type horizontal diffusion cells. Although the introduction of epoxide groups could alter the compatibility and phase...
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Fabrication of Amphiphilic Hot-Melt Pressure Sensitive Adhesives for Transdermal Drug Delivery
Journal of Adhesion Science and Technology, 2012Co-Authors: Yang Li, Qing Wang, Yong-nan Hu, Zhongfu ZhaoAbstract:Abstract Styrene-isoprene-styrene (SIS) copolymer and tackifier resins can be utilized to prepare hot-Melt Pressure sensitive adhesives (HMPSAs) for the transdermal delivery of high lipophilic drugs. To meet the requirement of transdermal delivery of Chinese medicine (containing different ingredients including lipophilic, amphiphilic and hydrophilic drugs), amphiphilic HMPSAs were developed by Melt-blending HMPSAs, poly(ethyl acrylate-co-methyl methacrylate-co-trimethylammonioethyl methacrylate chloride) (RLPO) and polyethylene glycol 2000 (PEG2000). Their morphological structures and miscibility were characterized with phase microscopy and differential scanning calorimetry. Their 180° peel strength and holding power were measured for their adhesive performances. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cells, in which three ingredients of gardenia fruit (oleanic acid, luteolin and geniposide) were chosen as representatives of lipophilic, amphiphi...
David Kazmer - One of the best experts on this subject based on the ideXlab platform.
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Validation of moulding productivity with two self-regulating Melt Pressure valves
Plastics Rubber and Composites, 2020Co-Authors: David Kazmer, V. Kudchadkar, Ranjan NageriAbstract:AbstractA self-regulating Melt Pressure valve has been developed to proportion Melt Pressure relative to a control force without the need for a Pressure transducer or a closed-loop controller. The lean and agile plastics injection moulding, realized through the use of multiple self-regulating Melt Pressure valves that provide independent zone-based control of the polymer Melt Pressure and flow rate, is characterized. The process productivity of a hot-runner injection moulding process with two self-regulating Melt Pressure valves is validated with respect to flexibility and clamp tonnage requirements. With respect to flexibility, the use of the two self-regulating valves provided the individual tuning of two cavities of varying geometry. The resulting mouldings could not be produced to specification without the self-regulating valves or changes in the mould design. Furthermore, the consistency (as measured by the standard deviation of part weights) of the moulded parts with the self-regulating Melt pressur...
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Design and performance analysis of a self‐regulating Melt Pressure valve
Polymer Engineering and Science, 2020Co-Authors: David Kazmer, Dheeraj Gupta, Mahesh Munavalli, Vijay Kudchadkar, Ranjan NageriAbstract:Net shape manufacturing of plastic products through injection molding, extrusion, and other polymer processing methods has been limited by a lack of observability and controllability of the state of the polymer Melt. A self-regulating valve is developed and validated that regulates the output Melt Pressure in proportion to an input control force. The valve relies on a valve pin that adjusts the juncture loss to balance the control force with the force exerted by the Melt Pressure on an exposed surface of the valve pin. Since the valve pin position is adjusted in accordance to natural laws, an open loop system design is feasible without need of any instrumentation or control system for closed loop feedback control. The design is analyzed using a three-dimensional flow analysis that utilizes independent shear and elongational viscosities for the polymer Melt. Pressure drops and shear stresses through the valve are analyzed to estimate the steady state error in the output Pressure when the valve pin is controlled in an open loop mode (i.e. without Melt Pressure feedback). Guidelines for the valve design are provided to achieve a reasonable trade-off between flow and structural requirements. Finally, experimental validation indicates an excellent level of response and consistency given the simplicity of the design. POLYM. ENG. SCI. 46:549–557, 2006. © 2006 Society of Plastics Engineers
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Validation of moulding consistency with a self-regulating Melt Pressure valve
Plastics Rubber and Composites, 2020Co-Authors: David Kazmer, V. Kudchadkar, Ranjan NageriAbstract:AbstractNet shape manufacturing of plastic products through injection moulding, extrusion and other polymer forming processes has been limited by a lack of observability and controllability of the state of the polymer Melt. For this reason, a self-regulating Melt Pressure valve has been developed that utilizes a valve pin to adjust the juncture loss to balance a provided control force with the force exerted by the Melt Pressure on an exposed surface of the valve pin. Since the valve pin position is adjusted in accordance with natural laws, an open-loop control system design is feasible without the need for any instrumentation or process feedback for closed-loop control. The process capability of a hot-runner injection moulding process with two self-regulating Melt Pressure valves is validated with respect to part weight consistency. A resolution four fractional factorial design characterized the main effects for conventional hot-runner injection moulding and injection moulding with the self-regulating val...
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Validation of an In-Mold Multivariate Sensor for Measurement of Melt Temperature, Pressure, Velocity, and Viscosity
International Polymer Processing, 2017Co-Authors: Guthrie Gordon, David Kazmer, Xinyao TangAbstract:Abstract A multivariate sensor (MVS) is described for measurement of Melt temperature, Melt Pressure, Melt velocity, and Melt viscosity. Melt Pressure and temperature are respectively obtained through the incorporation of a piezo-ceramic element and infrared thermopile. Melt velocity is derived from the initial response of the Melt temperature as the polymer Melt flows across the sensor lens. The apparent Melt viscosity is then derived based on the Melt velocity and the time derivative of the increasing Melt Pressure. The response of the MVS is analyzed using an instrumented mold including piezoelectric Pressure sensors, an infrared pyrometer, and thermocouples. A 12-run, blocked half-fractional design of experiments (DOE) was run to characterize the effect of Melt temperature, mold temperature, packing Pressure, and ram velocity. The results show that the MVS provides excellent measurement of Melt temperature and Pressure. The accuracy of the Melt velocity estimations depended on the ram velocity set-poi...
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In-mold multivariate sensing of colored polystyrene
Polymer Engineering and Science, 2015Co-Authors: Guthrie Gordon, David Kazmer, Xinyao TangAbstract:The role of colorant in polymer processing was investigated with respect to Pressure and infrared (IR) sensing. Polystyrene was combined with blue, black, and purple color additives using twin-screw extrusion. Injection molding was then conducted using these three materials with a mold instrumented with a suite of commercial sensors as well as a custom multivariate sensor (MVS) capable of sensing Melt temperature, mold temperature, Melt Pressure, Melt velocity, and Melt viscosity. Melt Pressure and Melt temperature are, respectively, obtained through the incorporation of a piezoceramic element and IR thermopile within the sensor head. Melt velocity was derived from the initial response of the Melt temperature as the Melt flows across the sensor's lens. The apparent Melt viscosity was then derived based on the Melt velocity and the time derivative of the increasing Melt Pressure given the cavity thickness. The accuracy of the temperature, Pressure, velocity, and viscosity results were evaluated. Results indicated that the velocity estimates obtained with the commercial sensors and MVS had a coefficient of determination, R2, of about 0.99 regardless of colorant. The temperature measurements and viscosity estimates were similarly and correctly found to be invariant of the colorant blend. POLYM. ENG. SCI., 55:2794–2800, 2015. © 2015 Society of Plastics Engineers
Chunqing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and structure–property relationships of SIS-g-PB copolymers and their application in hot-Melt Pressure-sensitive adhesives
RSC Advances, 2020Co-Authors: Zhongfu Zhao, Chunqing Zhang, Yandong Zhang, Fanzhi Meng, Yifu Ding, Tao TangAbstract:A “graft onto” method was combined with an epoxidation reaction and living anionic polymerization to successfully synthesize a series of SIS-g-PB copolymers with defined branch numbers and branch lengths. These copolymers were utilized to formulate various hot-Melt Pressure-sensitive adhesives (HMPSAs). Their molecular structure and bulk properties were characterized by 1H-nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and rheometry. The adhesion performances were characterized in terms of holding power and 180° peel strength. The epoxidation reaction alone would negatively influence the rheological properties of the parent SIS copolymers, particularly for low-temperature applications. Controlled addition of the low-Tg PB blocks can significantly improve the low-temperature properties of the SIS copolymers. Both η* and G′ increased in the lower shear frequency regime ( 101 rad s−1) with branch number and branch length, in which branch length had a greater effect than the branch number. As a result, the 180° peel strength of the SIS-g-PB based HMPSAs displayed reached 0.23 kN m−1, which is more than twice the value for SIS-based HMPSAs.
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Hot-Melt Pressure-sensitive adhesives based on SIS-g-PB copolymer for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2019Co-Authors: Zhongfu Zhao, Chunqing Zhang, Shiyun Li, Yandong Zhang, Fanzhi MengAbstract:Abstract SIS-g-PB copolymers were successfully synthesized by grafting living polybutadiene (PB) lithium macroanions onto epoxidized SIS copolymers. Their molecular structures and thermal properties were characterized by TGA, 1H-NMR and DSC, respectively. SIS, epoxidized SIS (ESIS) and SIS-g-PB copolymers were Melt-blended with tackifiers to develop hot-Melt Pressure-sensitive adhesives (HMPSAs), respectively (named of H-SIS, H-ESIS and H-SIS-g-PB). Their adhesive performances were measured in terms of 180° peel strength and holding power. A modified Franz type horizontal diffusion cell was used to carry out In vitro drug release experiments, in which geniposides were chosen as hydrophilic model drugs. The results showed that H-SIS-g-PB has two times as high a 180° peel strength as H-SIS. Meanwhile H-SIS-g-PB has a slightly lower drug cumulative release rate than H-ESIS. It is indicated that the PB branches not only could impart good adhesive performance to H-SIS-g-PB via improving the compatibility between the epoxidized main chains and tackifier resins but also provide release channels to hydrophilic drugs by retaining most of the epoxide groups in the SIS-g-PB copolymers.
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SISO-based hot-Melt Pressure-sensitive adhesives for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2017Co-Authors: Zhongfu Zhao, Chunqing Zhang, Ruijie Zhang, Qing WangAbstract:Abstract A monomer-activated anionic polymerization approach was utilized to synthesize poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) tetrablock terpolymers (SISO), which were Melt-mixed with tackifiers and plasticizer to develop polar SISO-based hot-Melt Pressure-sensitive adhesives (HMPSAs) for transdermal delivery of hydrophilic drugs. Their hydrophilic performance was characterized using contact angle analysis. Their adhesive performances were measured in terms of 180° peel strength and holding power. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cell, in which geniposide was chosen as a hydrophilic model drug. The results show that poly(ethylene oxide) (PEG) blocks exhibit substantial effects on adhesive performance and the release behavior of the model drug. The shorter PEG molecular chains enhance adhesive performance and the cumulative release rate of the model drug in the SISO-based HMPSAs. The longer PEG molecular chains tend to crystallize. Their crystallization structures have negative effects on adhesive performance and limit the dissolution and diffusion of drugs in the SISO-based HMPSAs. Therefore, appropriate PEG molecular chains are required to fabricate SISO-based HMPSAs with excellent adhesive performance for transdermal delivery of hydrophilic drugs.
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Optimization of SIS-based hot-Melt Pressure-sensitive adhesives for transdermal delivery of hydrophilic drugs
International Journal of Adhesion and Adhesives, 2016Co-Authors: Zhongfu Zhao, Chunqing Zhang, Yongsen Zhou, Zhansheng LiAbstract:Abstract To optimize hot-Melt Pressure-sensitive adhesives (HMPSAs) for transdermal delivery of hydrophilic drugs, styrene–isoprene–styrene copolymer (SIS), epoxidized SIS (ESIS), tackifiers, and plasticizer were Melt-mixed with polyethylene glycol 2000 (PEG2000) or poly (ethyl acrylate-co-methyl methacrylate-co-trimethylammonioethyl methacrylate chloride) (RLPO). Their compatibility was studied with DSC and FT-IR. Their 180° peel strength and holding power was measured for their adhesive performances. In vitro drug release experiments were carried out using a modified Franz type horizontal diffusion cell, in which geniposide was chosen as a hydrophilic model drug. Although PEG2000 can greatly enhance the accumulative release rate of geniposide in a manner of burst release, its poor compatibility with the components of SIS/ESIS-based HMPSAs makes the adhesive performance hardly meet the practical requirement of transdermal drug delivery. RLPO not only provides sustained release behavior to geniposide through its low content of quaternary ammonium groups but also preserves excellent adhesive performance due to its partial compatibility with the components of SIS/ESIS-based HMPSAs. Therefore, RLPO is preferred to develop ideal SIS/ESIS-based HMPSAs for transdermal delivery of hydrophilic drugs.
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Preparation and characterization of polarity-modulated SIS-based hot-Melt Pressure-sensitive adhesives
Journal of Adhesion Science and Technology, 2014Co-Authors: Zhongfu Zhao, Zhanyue Wang, Chunqing ZhangAbstract:In order to develop polarity-modulated hot-Melt Pressure-sensitive adhesives (HMPSAs), epoxidation of styrene-isoprene-styrene (SIS) copolymers, using in situ prepared per-formic acid was studied. ...
Xinyao Tang - One of the best experts on this subject based on the ideXlab platform.
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Validation of an In-Mold Multivariate Sensor for Measurement of Melt Temperature, Pressure, Velocity, and Viscosity
International Polymer Processing, 2017Co-Authors: Guthrie Gordon, David Kazmer, Xinyao TangAbstract:Abstract A multivariate sensor (MVS) is described for measurement of Melt temperature, Melt Pressure, Melt velocity, and Melt viscosity. Melt Pressure and temperature are respectively obtained through the incorporation of a piezo-ceramic element and infrared thermopile. Melt velocity is derived from the initial response of the Melt temperature as the polymer Melt flows across the sensor lens. The apparent Melt viscosity is then derived based on the Melt velocity and the time derivative of the increasing Melt Pressure. The response of the MVS is analyzed using an instrumented mold including piezoelectric Pressure sensors, an infrared pyrometer, and thermocouples. A 12-run, blocked half-fractional design of experiments (DOE) was run to characterize the effect of Melt temperature, mold temperature, packing Pressure, and ram velocity. The results show that the MVS provides excellent measurement of Melt temperature and Pressure. The accuracy of the Melt velocity estimations depended on the ram velocity set-poi...
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In-mold multivariate sensing of colored polystyrene
Polymer Engineering and Science, 2015Co-Authors: Guthrie Gordon, David Kazmer, Xinyao TangAbstract:The role of colorant in polymer processing was investigated with respect to Pressure and infrared (IR) sensing. Polystyrene was combined with blue, black, and purple color additives using twin-screw extrusion. Injection molding was then conducted using these three materials with a mold instrumented with a suite of commercial sensors as well as a custom multivariate sensor (MVS) capable of sensing Melt temperature, mold temperature, Melt Pressure, Melt velocity, and Melt viscosity. Melt Pressure and Melt temperature are, respectively, obtained through the incorporation of a piezoceramic element and IR thermopile within the sensor head. Melt velocity was derived from the initial response of the Melt temperature as the Melt flows across the sensor's lens. The apparent Melt viscosity was then derived based on the Melt velocity and the time derivative of the increasing Melt Pressure given the cavity thickness. The accuracy of the temperature, Pressure, velocity, and viscosity results were evaluated. Results indicated that the velocity estimates obtained with the commercial sensors and MVS had a coefficient of determination, R2, of about 0.99 regardless of colorant. The temperature measurements and viscosity estimates were similarly and correctly found to be invariant of the colorant blend. POLYM. ENG. SCI., 55:2794–2800, 2015. © 2015 Society of Plastics Engineers
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Quality control using a multivariate injection molding sensor
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: Guthrie Gordon, David O. Kazmer, Xinyao TangAbstract:Injection molding part quality is modeled using a multivariate sensor. Melt Pressure and temperature are respectively obtained through the incorporation of a piezo-ceramic element and infrared thermopile within the sensor head. Melt velocity is derived from the transient response of the Melt temperature as the polymer Melt flows across the sensor’s lens. The apparent Melt viscosity is then derived based on the Melt velocity and the time derivative of the increasing Melt Pressure given the cavity thickness. Quality metrics taken into account are finished part thickness, width, length, weight, and tensile strength. A 12-run, blocked half-fractional design of experiments was performed to derive predictive models for part mass, dimensions, and structural properties. Several predictive part quality models were created using data from the machine, a suite of commercial sensors, the multivariate sensor, and combinations thereof. The results indicate that multiple orthogonal streams of process data yield higher-fidelity models with coefficients of determination approaching one. Furthermore, best subset analysis indicates that the most important process data are gathered from in-mold sensors, where the acquired information is closest to the states of the polymer forming the final product.
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A Multivariate Sensor for Intelligent Polymer Processing
IEEE ASME Transactions on Mechatronics, 2015Co-Authors: David O. Kazmer, Guthrie W. Gordon, Gabriel A. Mendible, Stephen P. Johnston, Xinyao TangAbstract:A multivariate sensor is described for intelligent polymer processing that incorporates a piezoelectric ring to acquire Melt Pressure as well as a thermopile to acquire Melt temperature and mold temperature. The mechatronic system analyzes the process states according to mechanistic relations to estimate the Melt velocity and Melt viscosity. Validation experiments are implemented to characterize the sensor's performance against an array of commercial sensors. Models of product quality with the described sensor far outperform those based on data from commercial sensors. While system identification of the transient thermopile voltage indicates an underdamped response that limited the model fidelity, the existing capability suggests a new standard for mold design that incorporates multivariate sensors into the runner system to provide a consistent set of physical states for process tuning irrespective of molding machine manufacturer and model.