Daniel Walczyk's research while affiliated with Rensselaer Polytechnic Institute and other places

Publications (77)

Article
This paper describes the application of a new manufacturing process for low-cost and rapid consolidation and curing of advanced thermoset composites that avoids the use of expensive prepreg, autoclaving, and thermally induced curing. The process, called VIPE, uses a novel tooling design that combines vacuum infusion (VI) of a dry preform with resin...
Conference Paper
Full-text available
Interest in biocomposites is growing worldwide as companies that manufacture high-performance products seek out more sustainable material options. Although there is significant research on biocomposite material options and processing found in the literature from at least the last two decades, there are few experimentally based case studies publishe...
Article
Components made from thermoplastic composites (TPC) by additive manufacturing (AM) and automated fiber placement (AFP) are gaining popularity because of the material system’s inherent advantages over thermosets, but high material costs and limited production flexibility are hindering more widespread use. This paper discusses prototyping, fluid flow...
Article
Due to the increasing popularity of additive manufacturing with continuous fibers thermoplastic composites (TPC), this paper investigates the process of in situ impregnation of dry fiber tow with molten thermoplastic resin as a means to reduce material cost. To better understand impregnation with high-viscosity polymer melts, a 1D version of Darcy’...
Article
This technical brief discusses material degradation issues and potential remedies related to advanced thermoset composites manufacturing using a new out-of-autoclave consolidation and curing process called ‘Electron Beam processing of Specialized Elastomeric Tooling combined with Resin Infusion’ (EB-SETRI). The design process for EB-SETRI tooling b...
Article
Full-text available
Purpose This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing technologies, including powder-based, material extrusion, solid-sheet and liquid-based systems. Detailed information about each process, including materials used and process...
Conference Paper
To become a more competitive alternative to synthetic fibers, the variability of natural bast fiber material properties must be understood. Standardizing the relationship between these fibers and their associated material properties will broaden the range of applications to include more technical industries. Initial tensile testing showed variabili...
Article
Full-text available
A new approach to manufacture biocomposite sandwich structure is introduced with all materials naturally derived, including jute, flax and cellulose textile as reinforcement skin; mycelium-bound agricultural waste as lightweight cores; and a soy-based bioresin as a matrix. This new material could be used to replace many of the plastic products that...
Article
Simple analytical models for designing rapid heating (via electric resistance or fluid flow in conformal channels) and cooling (via fluid flow in conformal channels) capabilities for composites manufacturing tooling are presented and demonstrated. The electric resistance heating and conformal channel cooling models are implemented for design purpos...
Article
A new approach to manufacture biocomposite sandwich structure is introduced with all materials naturally derived, including jute, flax and cellulose textile as reinforcement skin; mycelium-bound agricultural waste as lightweight cores; and a soy-based bioresin as a matrix. This new material could be used to replace many of the plastic products that...
Article
Graphene oxide (GO) slurries were deposited onto copper foil for use in lithium-ion battery anodes to determine the best deposition method(s) for research or high-volume manufacturing. Four deposition methods were tested: doctor blade, Mayer rod, slot die, and low volume low pressure (LVLP) spray. Analytical models that link tooling and process cha...
Article
A low-cost, low-waste manufacturing method for advanced thermoset composite parts could improve market penetration of composites compared to other engineering materials such as aluminum or steel. Such a method could combine some of the new trends in composites manufacturing such as resin infusion (eliminates need for prepreg), out-of-autoclave cons...
Article
Full-text available
Roller infusion by nip rollers is widely used in the infusion industry with broad applications, which is also adopted as one of the 7 steps of a newly developed manufacturing process for making fungal mycelium based biocomposites. One important technical issue related to infusion textile reinforcements for such biocomposites is how to predict and c...
Article
In this paper, the capabilities of Specialized Elastomeric Tooling for Resin Infusion, a low-cost and low-energy autoclaving alternative for consolidating and curing resin-infused thermoset composite parts, are expanded to biobased composites. Specifically, multiple flat laminate parts (10-ply stack of woven cellulose fiber with a high bio-content,...
Article
Full-text available
The manufacture and use of natural, textile-reinforced and shaped skins to replace rigid tooling for fungal mycelium-based, biocomposite sandwich structures are investigated. The motivation is a new manufacturing process proposed for such biocomposites that includes: cutting individual natural textile plies; impregnating multi-ply layups with natur...
Article
Full-text available
A manufacturing cost model is created that includes all labor, material and overhead costs for novel mycelium-based biocomposite sandwich structures produced by a commercial firm. This model is implemented through a spreadsheet to calculate the equivalent uniform annual costs (UAC) of all manufacturing facilities. A simulation model of the manufact...
Article
The capabilities of specialized elastomeric tooling (SET), a low-cost and low-energy autoclave alternative for consolidating and curing thermoset and thermoplastic composite parts made of "prepreg" material, are expanded to allow vacuum infusion of dry fiber preforms through a simple demonstration project. In this case, SET was designed to allow va...
Conference Paper
Full-text available
A new approach to manufacturing biocomposite sandwich structures is introduced. Materials used in the biocomposite are natural textile reinforcement, mycelium-bound agricultural waste as core, and bioresin. This paper focuses on three specific steps of the manufacturing process: filling pre-stamped textile shells with core mixture; allowing the cor...
Poster
Full-text available
As an alternative to synthetic reinforcement fibers, resin, and core materials used for advanced composites that are non-sustainable, a new biocomposite material comprised of natural fibers as reinforcement, agricultural waste material (e.g., seed husks) as core, and fungal mycelium as matrix has been developed collaboratively by Ecovative Design,...
Article
Specialized elastomeric tooling (SET) is a patented process that can replace autoclaving for consolidating and curing advanced thermoset and thermoplastic composite parts. The process mimics autoclave conditions of uniform pressure and temperature by clamping an uncured laminate or sandwich structure with known force between a temperature-controlle...
Article
To address the industrial need for manufacturing advanced thermoplastic composite parts with less energy, waste, and time and at lower cost, the feasibility of automated fiber placement using ultrasonic consolidation (UC) is investigated as an alternative to hot gas torch, laser, and infrared (IR) heating. The flexural stiffness and strength of sim...
Conference Paper
Full-text available
Advanced composite materials made from non-renewable (synthetic) feed stocks are used in parts that require high specific stiffness and strength and also tailored properties. Bio-composite materials, although not currently able to provide the same level of performance as their synthetic counterparts, are improving as new constituent materials and m...
Article
Major efforts are underway to reduce fuel cell manufacturing costs, thereby facilitating widespread adoption of fuel cell technology in emerging applications, such as combined heat and power and transportation. This research investigates new methods for fabricating membrane electrode assemblies (MEAs), which are at the core of fuel cell technology....
Poster
Full-text available
As an alternative to synthetic reinforcement fibers, resin, and core materials used for advanced composites that are non-sustainable, a new biocomposite material comprised of natural fibers as reinforcement, agricultural waste material (e.g., seed husks) as core, and fungal mycelium as matrix has been developed collaboratively by Ecovative Design,...
Article
Thermal press curing (TPC) is an alternative process to autoclaving for consolidating and curing thermoset and thermoplastic prepreg composite parts by pressing them between a heated "curing mold" and a customized rubber-faced "base mold" that are engineered to provide uniform temperature and pressure conditions. A study was performed with a kayak...
Article
Ultrasonic bonding of low-temperature PEM membrane electrode assembly (MEA) components together has been shown previously to cut both cycle time and energy input of that manufacturing step by over an order of magnitude as compared to the industry standard of thermal pressing. This paper compares performance between ultrasonically and thermally bond...
Article
Reconfigurable discrete die tooling is attractive for reducing the lead time, initial costs, and recurring costs associated with stretch forming of sheet metal parts such as aircraft body panels and wing skins as well as automotive and marine components. Current tooling for the stretch forming process requires substantial lead time for fabrication...
Conference Paper
Full-text available
Sustainable composites that use renewable materials and provide better end-of-life options are of great interest to industry. This paper describes an investigative study into high-production manufacturing approaches for a biocomposite material with these characteristics consisting of natural fiber reinforcement and agricultural waste cores bound to...
Poster
Full-text available
As an alternative to synthetic reinforcement fibers, resin, and core materials used for advanced composites that are not sustainable, a new biocomposite material comprised of natural fibers as reinforcement, agricultural waste material (e.g., seed husks) as core, and fungal mycelium as matrix has been developed collaboratively by Ecovative Design,...
Conference Paper
Ultrasonic bonding of low temperature PEM membrane electrode assemblies has shown to cut the cycle time and energy input of manufacturing by over an order of magnitude each as compared to the industry standard of thermal pressing. Ultrasonic bonding uses high-frequency mechanical oscillations to convert electrical energy into heat energy which bond...
Poster
Full-text available
The use of polymer matrix composite (PMC) materials, such as E-Glass fibers in an epoxy matrix, has grown and continues to grow steadily in a variety of markets, because their structure and processing can be tailored to applications requiring high strength, high stiffness, low weight, and/or low thermal conductivity. Unfortunately, traditional PMC...
Article
An alternative process to autoclaving, called Thermal Press Curing (TPC), is proposed, whereby an uncured composite laminate is pressed between a heated curing mold and customized rubber-faced mold that are designed to provide uniform temperature and pressure conditions. TPC was demonstrated by designing a complex 3-D ‘benchmark’ part shape, applyi...
Article
A novel process for curing advanced thermoset composites, thermal press curing with specialized elastomeric tooling (TPC-SET), is an alternative to the very expensive autoclaving process that reduces energy consumption, cost, and preparation time. The process presses material between a heated metal mould and a matching elastomer-lined mould, cuttin...
Article
Curing and consolidating thermoset composite laminates and sandwich structures typically involves vacuum bagging an uncured and formed layup over a thin-walled mold, placing it in an autoclave, and subjecting the entire unit to temperature, vacuum, and pressure cycles as prescribed by the manufacturer. Autoclaving is generally considered the major...
Conference Paper
Ultrasonic bonding, with its extremely fast cycle times and energy efficiency, is being investigated as an important manufacturing technology for future mass production of fuel cells. The objectives of the authors’ research are to (1) create a multi-physics simulation model that predicts through-thickness energy distribution and temperature gradien...
Conference Paper
Automated manufacturing techniques are needed to reduce production costs for polymer electrolyte membrane (PEM) fuel cell electrodes. The work presented in this paper focuses on the use of a low pressure, low volume direct spray valve that uses air pressure to atomize fluids and transfer them to a gas diffusion layer (GDL) to produce a gas diffusio...
Conference Paper
The most critical step in high temperature proton exchange membrane (PEM) MEA manufacturing is sealing of the membrane between the two electrodes. This sealing process is typically conducted using a precision hydraulic thermal press. In order to achieve cost-effective high-volume MEA manufacturing, it is important to reduce the variability in MEA p...
Article
The feasibility of an alternative fuel cell architecture, called a ribbon membrane electrode assembly (MEA), is demonstrated for low-temperature polymer electrolyte membrane (PEM) fuel cells used in portable power applications by comparing it to a traditional bipolar "stack" architecture. A ribbon MEA consists of adjacent PEM cells sharing a common...
Conference Paper
Accelerated durability testing of polybenzimidazole (PBI)-based polymer electrolyte membrane fuel cells (PEMFC) was performed using test protocols designed to simulate real life operating conditions. The membrane electrode assemblies were fabricated using a novel ultrasonic sealing method, that reduces process cycle times by 98%. The accelerated du...
Article
The most important component of the fuel cell is the membrane electrolyte, having the fundamental responsibility of separating protons and electrons. Minor defects (e. g., pin holes) in the film will cause premature and/or catastrophic failure. As such, special attention should be given to the manufacturing of this fuel cell component. Increased in...
Article
In this paper, a complex system of theoretical models, which predicts flow rate as a function of pressure drop, formulated previously by Harris et al. (2007, "Manufacturing of High-Temperature Polymer Electrolyte Membranes-Part I: System Design and Modeling," ASME J. Fuel Cell Sci. Technol., 7, p. 011007), are validated through a case study. Specif...
Conference Paper
Two of the largest barriers to PEMFC commercialization are the materials costs for individual components, especially platinum catalyst, and the fact that few large-scale manufacturing capabilities currently exist. This paper focuses on the development of a testbed which will be used for evaluating coating technologies for use in the manufacture of...
Conference Paper
With the current economic and environmental situation, the development of affordable and clean energy sources is receiving much attention. One leading area of promise is PEM fuel cells. Presently, manufacture of high temperature Polybenzimidizole (PBI) based PEM Membrane Electrode Assemblies (MEAs) is usually performed by sealing in a thermal press...
Article
This paper investigates the mechanical behavior and design of a patent pending device called a load range weight bearing indicator (LWBI), which provides upper and lower range indication to patients with lower extremity injuries as part of a partial weight bearing rehabilitation. The LWBI consists of two opposing stacks (a.k.a. double stack) of sna...
Article
A reconfigurable fixturing device (RFD) is a computer-controlled reconfigurable bed-ofpins used for holding a compliant workpiece during manufacturing operations. A new RFD design, based on controlled clamping of loose pins descending on a positioncontrolled platen, is much simpler in design and is estimated to be significantly less expensive to ma...
Article
The viscosity behavior of various compositions of polymer electrolyte membrane solutions, which are later hydrolyzed into proton conducting membrane film for fuel cells, is characterized. Using the Carreau-Yasuda model and time–temperature superposition, an empirical model relating the viscosity as a function of temperature and shear strain rate ha...
Article
Thermoforming is a popular manufacturing process for creating useful shapes out of heated thermoplastic sheets using a porous tool under differential pressure. For large, heavy-gauge parts, thermoforming tools are typically made by CNC machining a billet of material or sand casting from an inexpensive master pattern. Although these tooling methods...
Article
A weight bearing indicator (WBI) has been developed and is undergoing clinical trials and commercialization. The most recent version of the device includes load range indication ability. The WBI is installed in a patient’s medical appliance (e.g. cam walker boot, surgical shoe) and allows patients recovering from lower extremity injuries to self mo...
Article
Of all the rapid tooling (RT) methods currently available, thick-layer laminated tooling is the most suitable for large- scale, low-cost dies and molds. Currently, the determination of a lamina's contour or profile and the associated slicing algorithms are based on existing rapid prototyping (RP) data manipulation technology. This paper presents a...
Article
The idea of using a bed-of-pins as a completely reconfigurable discrete tool surface (referred to as a reconfigurable pin-type tool) for forming or molding of mechanical components has been around for at least 140 years. Interestingly, the state-of-the-art today differs little from early patents except for the introduction of powered actuation and...
Article
Purpose To determine the feasibility of sealing and finishing conformal cooling/heating channels in profiled edge laminae (PEL) rapid tooling (RT) using abrasive flow machining (AFM). Design/methodology/approach Sample PEL tools constructed of both aluminum and steel were designed and assembled for finishing by AFM. A simple design of experiments...
Article
Rapid tooling (RT) methods allow for almost complete flexibility in routing of conformal cooling or heating channels within a mold for enhanced thermal control, but tool size is currently limited. A notable exception is the profiled edge laminae (PEL) method, which is a thick-layer laminated RT method intended for large-scale tooling applications....
Article
Background. Partial or nonweight bearing is a useful treatment prescribed by medical professionals (e.g., orthopedists, podiatrists) for patients rehabilitating from lower extremity injuries However, there is significant variability in patient conformance with the commonly used, but very imprecise "weight scale method." Furthermore, the few commerc...
Article
This paper describes research work associated with development of a casting test bed for a polyphosphoric acid (PPA) based membrane material used in high-temperature PEM fuel cells with operating temperatures up to 160°C. Casting of this material is difficult due to its high viscosity, temperature-dependent rheological properties, curing tendencies...
Article
Rapid tooling (RT) methods have been shown to reduce the cost and time of tooling development (i.e., design and fabrication). Profiled edge laminae (PEL) tooling, an RT method intended for large-scale dies and molds, involves the assembly of an array of laminations whose top edges are simultaneously profiled and beveled using a line-of-sight cuttin...
Article
Purpose To provide an advanced cutting trajectory algorithm for the profiled edge laminae (PEL) rapid tooling (RT) process, which is ideally suited for large‐scale dies and molds. The process involves assembling an array of laminae whose top edges are simultaneously profiled and beveled using a line‐of‐sight cutting method based on a CAD model of t...
Article
Profiled Edge Laminae (PEL) tooling is a thick-layer Rapid Tooling (RT) method that involves assembling an array of laminae-each having a uniquely profiled and beveled top edge-together in a precise and repeatable manner by registering each lamina's bottom edge and an adjacent side edge to a fixture that has precisely machined edges. The processed...
Conference Paper
Due to their superior strength-to-weight ratios, advanced composite parts are increasingly being used by the aircraft industry. This industry is constantly looking for less costly, faster, and more reliable methods to produce advanced composite parts, while still maintaining the very high safety and reliability standards required. This paper descri...
Conference Paper
Profiled Edge Laminae (PEL) tooling is a thick-layer Rapid Tooling (RT) method that was developed a decade ago. Even with demonstrable advantages for large-scale tool applications over conventional CNC-machining of a solid billet and other commercially available RT methods, PEL tooling has not seen widespread use by industry because prior research...
Article
Profiled Edge Laminate (PEL) tooling is a rapid tooling method that uses a stacked array of vertically orientated thick laminae with profiled and beveled top edges to provide the desired surface shape for part forming or molding. Since this method is being developed for commercial use, there is a need to be able to predict the response of PEL tools...
Article
The application of composites in the aircraft industry has increased significantly over the past few decades. With traditional composite laminate shaping, each layer is made to conform to the mold surface by hand before subsequent layers are added. This is a very labor- and time-intensive process. There is a great deal of interest in developing an...
Article
Focuses on Profiled Edge Lamination (PEL) tooling and the development of a new alogrithm, the Adaptively Vectored profiles Projection (AVPP), Describes the geometrical relationships and heuristics for determining the abrasive water jet (AWJ) cutting orientation, position, and cutting sequence. The algorithm has ben implemented in a software program...
Article
Profiled Edge Lamination (PEL) tooling is a promising Rapid Tooling (RT) method involving the assembly of an array of laminations whose top edges are simultaneously profiled and beveled based on a CAD model of the intended tool surface. To facilitate adoption of this RT method by industry, a comprehensive PEL Tooling Development System has been pro...
Conference Paper
As part of a 5-year NSF-sponsored project, a design and fabrication system is being developed for Profiled Edge Laminated (PEL) tooling. The PEL tooling method is a thick-layer Rapid Tooling (RT) approach that offers distinct advantages over both conventional CNC machining of billets and other RT processes. Furthermore, the method is ideally suited...
Conference Paper
This paper addresses the research and development of a Computer-Aided Manufacturing (CAM) software package used for fabricating Profiled-Edge Lamination (PEL) tooling. Background research in PEL tooling is reviewed and possible applications for PEL tooling in seven different manufacturing processes are examined. The general PEL tooling process is o...
Article
An automatically reconfigurable discrete tool (matrix of pins) has been developed and demonstrated for sheet metal part forming and composite part molding in the aerospace industry. A GUI-based control system positions each of the hydraulically-actuated pins according to a computer model of the intended tool surface. Open-loop position control of i...
Article
Based on a survey of small- to medium-sized companies that supply sheet metal parts to the major aircraft manufacturers, there is a need for a more simplified, flexible and inexpensive method to design, fabricate and register part fixtures used for CNC post forming operations (e.g., trimming, drilling). Consequently, a method has been developed tha...
Article
A method is presented for fixtureless assembly of simple sheet metal parts (i.e. consisting of flat patterns and simple bends) used in the aircraft industry. Current industry practice relies on manually intensive procedures and rigid fixtures for part assembly. The present method relies on carefully toleranced alignment holes that are computer nume...
Article
The need for rapid, low-cost die fabrication and modification methods is greater than ever in the sheet metal forming sector of industry. Consequently, three fabrication methods, suitable for rapid die development schemes, are being compared experimentally based on cost, lead-time, shape resolution and flexibility issues. The candidate methods incl...
Article
To significantly cut the time and cost of tooling development, a reconfigurable discrete die (that is, matrix of individually actuated pins) is being developed for aircraft fuselage parts made by forming sheet metal or molding of composite materials. Each pin in the die is a simple hydraulic actuator outfitted with an in-line NC solenoid valve to c...
Article
Discrete dies have been investigated for sheet metal forming since the early part of the 20th century. The reconfigurable nature of these dies lends itself well to flexible manufacturing systems; unfortunately, the state of knowledge on how to design and analyze discrete dies consisting of densely packed pins is very limited, thereby hindering indu...
Conference Paper
Based on a survey of small- to medium-sized companies that supply sheet metal parts to the major aircraft manufacturers, there is a need for a more simplified, flexible and inexpensive method to design, fabricate and register part fixtures used for CNC post forming operations (e.g., trimming, drilling). Consequently, a method has been developed tha...
Article
Sheet metal forming dies constructed of laminations offer advantages over more conventional tooling fabrication methods (e.g. CNC-machining) in terms of tooling accessibility, reduced limitations opt die geometry and faster fabrication with harder die materials. Furthermore, the recently introduced Profiled Edge Lamination (PEL) tooling method impr...
Article
This paper discusses the development of a new manufacturing technology, called a Variable Lip Slot Die (VLSD), used for automatically patterning viscous liquid materials (e.g., adhesives, sealants) in a controlled manner. This is not easily done due to the characteristic properties of these types of materials, i.e., high viscosity, temperature-depe...
Article
Bevel cutting of steel laminations used in profiled-edge laminated tooling allows for a more accurate representation of the intended die surface, since stair-stepping at the edges is eliminated. Based on experiments involving maximum cutting speed, bevel angle and kerf quality, the three recommended methods for bevel cutting steel are (best to wors...

Citations

... Their experiments showed CFRTP CF-PLA composites with 40% CF have higher tensile and flexural strength than composites with 22% CF and 33% CF [133]. Recently, a refined manufacturing technique was proposed to manufacture continuous fiber reinforced thermoplastic filament [135] and the manufactured filament has better prepreg quality and volume fraction. However, they did not report the mechanical properties of 3D printed part by using the new filament. ...
... Although this method is easy to use and applicable to the standard FDM based printers, obtained mechanical properties are relatively low. Pre-impregnated fiber filament is being used to in the literature to further increase the mechanical properties [15][16][17][18]. Pre-impregnation process requires a preliminary process of mixing the continuous fibers and polymer matrix. ...
... This can be performed by adding a second phase to the polymer feedstock, e.g., in the form of nanofibers or nanoparticles, in this way creating a composite material [11][12][13]. Such a composite feedstock is often prepared to improve the mechanical properties of a 3D-printed object [14,15]. However, it is also possible to make 3D-printed objects conductive, at least to a certain amount [16][17][18], or make them magnetic by adding suitable nanofibers or nanoparticles. ...
... Various su strates are compared in scientific analyses or combined as mixtures in different propo tions. Combinations of various substrates in scientific experiments, described in 85 scie tific publications [21,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][40][41][42]45,46,[49][50][51][52][53][57][58][59][60][61][62][63][64][65][66][67][68]70,[72][73][74][75][76][77][78][79][80][81][82][83][84]111,112], are p sented in Figure 8. The size of the circle shows the popularity of the substrate and the lin indicate the most frequently used comparisons of substrates in scientific publications. ...
... Thus, via loading the drugs on the polymer nanoparticles [10], the efficacy of drugs can be significantly increased, leading to the usage of low doses and, at the same time, targeted to the desired site of action [11]. Such a loading strategy helps to protect the liver free from toxicity thanks to the absence of harmful side effects [12][13][14]. Biopolymers in nanoparticle form are more favorable to be used as a carrier for many drugs than both bulk biopolymer molecules and synthetic polymers. The favorability can be attributed to the high surface area, active small particle size, availability, cost-effectiveness, biocompatibility, and biodegradability [15]. ...
... Based on the conventional cohesive pressures used for advanced compounds and the resin supplier's recommended healing guidelines, SET is one of several alternative processes for integrating / modifying thermoset and thermoplastic manufacturing systems under one temperature, high pressure and temperature conditions. [38].The fiber-matrix interface plays an important role in determining the mechanical properties of the composite material. Creating compounds Therefore, increase the mechanical properties, The statistical design of experiments based on the eligibility method to obtain integrated results between parameters will vary between factor levels. ...
... It digests and bonds to the surface of damp agricultural byproducts in 5e7 days without additional energy input to adequately colonize reinforcement fibers and core material, thereby acting as natural, selfassembling glue. This process has been successfully commercialized (Ecovative, 2015), and investigated by the authors (Jiang et al., 2013;Jiang et al., 2014a,b;Jiang et al., 2016;Jiang et al., 2017a,b;Jiang et al., 2018) and another research group (Travaglini et al., 2013(Travaglini et al., , 2014 for use in biocomposites. An SEM image of mycelium hyphae growing on a natural fiber is shown in Fig. 1(a) (Jiang et al., 2017a,b). ...
... Laminates fabricated by VARTM usually have low and spatially varying fiber volume fraction due to the low and nonuniform compaction pressure compared to resin transfer molding (RTM) and autoclave molding [14][15][16][17][18]. Postfilling actions such as bleeding the excess resin from the exit gate may help decreasing the nonuniformity along the preform and also slightly increasing fiber volume fraction [19][20][21][22]. On the other hand, noteworthy improvements in fiber volume fraction can be achieved by utilizing external sources of pressure on the preform which involves magnetic compaction [23][24][25][26], compression in between rigid molds [27], and external pressurization with a liquid (i.e., silicone oil) [28] or air [29][30][31][32] on the preform. Recent studies have shown that applying external air pressure on the mold by employing a simple pressure chamber sufficiently removes the excess resin, increases the fiber volume fraction, reduces the void content, and improves the laminate uniformity [29][30][31]. ...
... Various su strates are compared in scientific analyses or combined as mixtures in different propo tions. Combinations of various substrates in scientific experiments, described in 85 scie tific publications [21,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][40][41][42]45,46,[49][50][51][52][53][57][58][59][60][61][62][63][64][65][66][67][68]70,[72][73][74][75][76][77][78][79][80][81][82][83][84]111,112], are p sented in Figure 8. The size of the circle shows the popularity of the substrate and the lin indicate the most frequently used comparisons of substrates in scientific publications. ...
... The foams were formulated recently [19,24], however, some details of production and the fungal species involved, remain undocumented. Sandwiches and hybrids have also been formulated incorporating resins in different substrates, obtaining variable results [16,17,25], some with the disadvantage of including non-compostable materials in the composition of composites [20]. Haneef et al. [23] carried out a revision and characterization of these materials using strains of Ganoderma lucidum and Pleurotus ostreatus. ...