Polyurethane Finish Research Articles

A study on the effect of material type, structure tightness and finishing process on the physical and thermo-physiological properties of sandwich terry socks for winter wear

Compared to other textiles, socks are made at the lowest cost and have the highest consumption rate, making them one of the least-lasting fabric goods in the clothing industry. Socks are available in a wide range of fibers blends, that is, cotton, wool, nylon, acrylic, polyester, olefin, spandex, etc. As an element of footwear, socks act in tandem with the foot and shoe, influencing the temperature and moisture levels of the feet. The comfort of clothing next to the skin in terms of temperature and moisture is gaining more and more attention. Pilling is a serious issue with wool items, and less pilling is required since it negatively impacts the esthetic, comfort, and longevity of the fabric. This research has investigated socks pilling tendency and thermo-physiological comfort properties, that is, air permeability and thermal resistance made by wool/polypropylene blend yarn. Three different combinations of wool/polypropylene yarns on the main and platting side of the socks were used at two different tightness levels. Polyurethane finish has been applied to check the socks’ behavior after the finish application. Statistical analysis showed that finished samples knitted with wool/polypropylene as a main yarn offer the best results against the pilling test while sample code ANL, an unfinished sample, offers the best results regarding air permeability, thermal resistance, and overall moisture management capacity.

Polyurethane dispersions prepared from vegetable oil and their application as textile finishes

One of the major challenges facing the polymer industry now is finding sustainable and renewable alternatives to petroleum-based raw materials. To overcome such challenges, these novel water-borne polyurethane dispersions were prepared from bioresources (vegetable oil). Vegetable oil-based polyol is synthesized by epoxidation and hydroxylation methods from vegetable oil. Consequently, polyurethane dispersions are prepared by reacting the vegetable oil-based polyol with isophorone diisocyanate and dimethylol propionic acid to form the polyurethane prepolymer, which further reacts with 1,4-butanediol, and the final product is obtained by the addition of water. Fourier transform infrared analysis is used for the structural confirmation of the prepared vegetable oil-based polyol and polyurethane dispersions. A number of textile tests, including mechanical (tear strength (ASTM 1424) and tensile strength (ASTM D-5034)) and antibacterial, were conducted on poly/cotton plain weave fabrics after applying the synthesized dispersions by pad dry-cure methods. The hemolytic test method was used to check the biocompatibility of the synthesized dispersions. Results reveal that these finishes effectively increase the tensile strength of the treated fabric samples, such as white fabric samples, which show tensile strength values of (248, 255, 268 and 325 N from untreated 240 N) in the warp direction. The biological outcomes show the antibacterial and hemolytic activity of the dispersions are influenced by the presence of natural polyols in the dispersions. These results indicate that covering poly/cotton fabrics with vegetable oil-based polyurethane dispersions improve their tensile strength and antibacterial properties and they can replace petroleum-based polyurethane finishes.

Quality of surface finish on furniture doors of MDF board

Quality of Surface Finish on Furniture Doors of MDF Board. The paper deals with the assessment of the quality of furniture door surface. The properties were tested on the following types of the surface finish on MDF doors: PVC foil (glossy and matt), acrylic foil, and PUR pigmented coating material. The following physical and mechanical properties of the surfaces were assessed: the film hardness, the impact resistance, and the resistance against scuffing. The polyurethane surface finish and the glossy PVC foil achieved the same film hardness. The impact resistance of the polyurethane finish was significantly lower than the impact resistance of the PVC foils and the acrylic foil. The resistance against scuffing was lower for the polyurethane finish if compared to the foiled surfaces.

Quality of surface finishes for beech stairs

Quality of surface finishes for beech stairs. The article deals with quality of oil varnish surface finish when compared with a standard polyurethane finish. The manufacturer recommends both surface finishes to be used for stairs. The tested surface finishes were created on beech wood according to producer recommendations. The quality comparison was based on three mechanical properties of the surface finishes: the surface hardness, impact resistance, and resistance to abrasion. The selected properties gave a good indication for suitability of the tested coating materials for stairs. Both surface finishes achieved the same surface hardness – grade of 11, as measured by the pencil scratch test. The impact resistance measured at low drop height (50 and 100 mm) was better for the oil varnish surface than for polyurethane one. At higher drop heights, the impact resistance of both surfaces was the same. The resistance to abrasion of the oil varnish was better than the resistance of the polyurethane one

A Proposed Method and Its Development for Wood Recovery Assessment in the Furniture Manufacturing Process

A proposed method for assessing wood recovery involves application of a machining station approach with volume and mass measurements. A medium wood furniture company located in Jepara, Indonesia was selected to develop the method. Batch measurements of the inputs and outputs for different types of indoor-furniture products at every station were collected and analysed. For the volume method, three dimensions were measured on each specimen: the length, width, and thickness. For the mass method, the specimens were weighed before and after each processing station using a balance. Based on the mass method, the average total wood recovery rate was 26.2% ± 2.3%. For individual products and per station, the significant difference in the wood recovery rate occurred only at the resawing and edging, and trimming stations. The relationship between the teak quality, product dimensions, and type of finish was significantly different, where A-quality teak, large dimensions, and polyurethane finish resulted in a higher wood recovery rate. Both methods were reliable because of insignificant differences in the wood recovery rates. However, the mass method was more efficient and practical. The proposed protocol using the mass method is a suitable and effective system because the contribution of the variance component of the method was 2.71%.

Study of the UV protective and antibacterial properties of aqueous polyurethane dispersions extended with low molecular weight chitosan

A series of aqueous dispersions of polyurethane (PU) and low molecular weight chitosan (CS(LMW)) has been prepared in two steps synthetic process. In first step PU prepolymer, with NCO termini were prepared by reacting isophrone diisocyanate (IPDI), poly (caprolactone) diol (CAPA, Mn 1000), and 2,2-dimethylol propionic acid (DMPA), followed by neutralization of PU prepolymer with triethylamine (TEA). In second step PU prepolymer chain was extended by low molecular weight chitosan followed by dispersion formation by adding calculated volume of water. Molecular characterization of CS(LMW)-PU finishes was done by FTIR and application on poly-cotton blended fabric samples was confirmed by scanning electron microscopy (SEM). Antimicrobial and UV protective performance of treated fabrics was performed by AATCC 100 and AATCC TM183 methods respectively. Furthermore, it shows that the addition of chitosan remarkably increases antimicrobial and UV protective properties of PUs.

Studies on the loss of gloss of shellac and polyurethane finishes exposed to UV

Wood finishes protect the surface of wood from external agents, enhance its looks and improve its gloss (luster). On constant external exposure, UV rays gradually degrade the film coating resulting in loss of gloss. In this study, two commonly used finishes namely spirit shellac and polyurethane finish were used to investigate the pattern of loss of gloss due to UV interference. Two coatings of polyurethane (PU) and spirit shellac finish were applied on the surface of eucalyptus samples. The gloss levels of these and unfinished samples were monitored for different times of exposure of them to UV light. Gloss was measured at 600 gloss head using a Tri micro gloss meter regularly for 20 hours durations of UV exposure. Observations and analysis revealed that the natural gloss of uncoated samples of eucalyptus were least affected on UV exposure with only 8,3%-10% loss in gloss. The PU and shellac coated surfaces also showed very little reduction in gloss (6,9%-15,4%) most of which happened in the first 40 hours of exposure. Thus both the finishes in this study were found effective to a good extent in maintaining the gloss of the finished surface against exposure to UV light.

Optical performance of finished and unfinished tropical timbers exposed to ultraviolet light in the field in Costa Rica

This study evaluated wood color change (ΔE*) and the surface quality in 10 tropical wood species painted with three finishes (composed of wax and polyurethane). Two weathering conditions were tested: natural weathering (NW) and artificial weathering (AW). The results showed that the application of these finishes, decreased the luminosity (L*), increased the redness (a*) and the yellowness (b*) parameters in all species. ΔE*, after weathering exposure, was affected significantly by L*, a*, and b, whereas for finished or pretreated wood, L* and b* are the main parameters affecting ΔE* in the 10 tropical species studied. ΔE* values found in different finishes and pretreatments are cataloged as total change of color. Other important results were that tropical light colored timber with natural pretreatment produced higher ΔE* than dark colored timber. The stains and fungal development were observed in polyurethane finishes in NW, but not in AW. The irregular and mosaic flaws were not observed in any kind of finish or pretreatment of surface. The values of the quality index created, which considered long and short lines and switch flaws, were lowest in NW and in waxy finish, while the highest value was obtained with the polyurethane finish.

Influence of relative humidity on surface quality and adhesion strength of coated medium density fiberboard (MDF) panels

The objective of this study is to evaluate surface roughness and adhesion strength of commercially manufactured medium density fiberboard (MDF) panels as function of relative humidity exposure levels. Surface roughness of the samples conditioned at 65%, 75% and 85% relative humidity was measured using a surface profiler. Adhesion strength of the samples coated with polyurethane finish was also determined by employing pull-off type test set up. Roughness values of the panels increased as they are exposed to higher relative humidity levels ranging from 65% to 85%. The highest adhesion strength value was found as 2.20 N/mm 2 for the samples made from unrefined fibers exposed to 65% relative humidity. Majority of the failures took place within adhesion line between coating and the substrate with a very limited torn fibers. Overall adhesion strength characteristics of the samples adversely influenced by increased value of relative humidity exposure.

Environmentally friendly two-pack high solids acrylic polyurethane finish

Environmentally friendly two-pack high solids acrylic polyurethane finish

Use of Shredded Wheat Biscuits To Illustrate Fiber Content

Nutrition professionals often look for unique approaches when presenting nutrition information to the public. The objective of this project was to visually show the amount of dietary fiber in a variety of food items. This project was originally developed for a cancer prevention display at our medical center. Colorful food models, food containers, and product labels were posted on a four-panel display board. Shredded wheat biscuits were coated with a polyurethane finish and velcro strips were glued to the back of the biscuit. The biscuits were then attached to the display, next to the corresponding food model. One biscuit was analogous to one gram of fiber. Nutrition information about fiber was available at the display. Participants were captivated by the visual displays of fiber content. It was an effective tool for generating interest and educating staff and visitors. Although it was originally designed for a cancer prevention program, this high-impact display could be incorporated into a variety of wellness events.

Two Coat Aircraft Finishing Saves Money and Time

POLYURETHANE exterior finishing schemes for aircraft have until now required at least a three stage process and, recently, even four coat schemes using an additional clear coat have been proposed in order to extend gloss retention of the earlier polyurethane finishes.