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Article
Publication date: 3 February 2012

Ling Zou and Chris Hunt

The purpose of this paper is to present a new test method (tape peel method) to evaluate conformal coating adhesion to electronic assemblies.

Abstract

Purpose

The purpose of this paper is to present a new test method (tape peel method) to evaluate conformal coating adhesion to electronic assemblies.

Design/methodology/approach

The key issue for this method is the low cohesive force of conformal coatings, and hence selection of a supporting material to peel the coating from the substrate is critical. A suitable cloth material (35 per cent cotton +75 per cent polyester with 20 per cent open area) has been selected as a peel tape, and achieved the best bonding with coatings, and the smallest affect on the coating curing process. Using the tape, the peel force of the coating from the electronic assembly, can be measured quantitatively, and hence the adhesion performance of the conformal coating assessed.

Findings

The method was validated using different coating types, substrate materials (bare laminate with and without resist, copper clad laminate, and contaminated laminate material), assemblies and components. The results demonstrated that the tape peel test is a sensitive method for measuring coating adhesion on different materials found on PCB assemblies. Coating adhesion was found not to be effected by a wide range flux residues, but components and some resists presented a far greater coating challenge, with some coatings achieving very low adhesion values.

Originality/value

This new method for evaluating conformal coating adhesion to electronic assemblies will be of benefit to coating developers and users, and help to minimise adhesion failures in service. The test has been demonstrated to be sensitive to a number of process and material variables.

Details

Soldering & Surface Mount Technology, vol. 24 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 September 2006

Rudolf Wiechmann

Peel strength numbers are part of a laminate's specifications and should characterize the specific bond performance (copper adhesion) under test conditions. Unfortunately…

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Abstract

Purpose

Peel strength numbers are part of a laminate's specifications and should characterize the specific bond performance (copper adhesion) under test conditions. Unfortunately, from both a theoretical and a practical point of view they are not able to do that. This study seeks to address this issue.

Design/methodology/approach

This paper has been written to show the main impacts on the measured peel strength numbers in the IPC‐TM‐650 peeling test. From an extensive database regarding peel numbers for diverse foil types, foil thicknesses and treatment roughnesses it is possible to show the influence of prepreg type, foil thickness and roughness on the measure peel strength.

Findings

Copper adhesion to laminating resin is insufficiently described by peel strength data because of the impacts of foil thickness, stiffness on bending (physical bending work, stress distribution underneath the peeling line) and the treatment roughness. The latter works reinforcing regarding the (low) resin strength and this influence is measured on resin strength instead of real bond. Fracture due to peeling is cohesive, mostly with a totally intact copper‐resin interface. This is especially true in high performance laminates that show low peel strengths not because of bad copper bonding but because of brittle resins (filled and unfilled).

Originality/value

Users have to understand the limited benefit of the IPC peel test in characterizing copper‐resin bonds. Peel increase on (low bond) high performance resins by increased foil roughness is not a practical way in the field because of no bond improvement (interface) and heavy disadvantages in dielectric thickness (HiPot tests at thin core laminates), respectively.

Details

Circuit World, vol. 32 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 23 September 2021

Ryuichi Kobayashi, Takashi Kigure and Ming Yang

This paper aims to describe a new process for suppressing the formation of orange peel, which is a polymer laser sintering (LS) process error.

Abstract

Purpose

This paper aims to describe a new process for suppressing the formation of orange peel, which is a polymer laser sintering (LS) process error.

Design/methodology/approach

The target for controlling the suppression of orange peel is securing the contact between the molten polymer and the surrounding powder. The authors set the powder bed temperature closer to the melting temperature than that for a typical LS. Alternatively, the authors use a low-power laser to irradiate the powder bed surrounding the parts being built. The surface finish of the built parts was evaluated using a three-dimensional scanner.

Findings

Both approaches were effective in suppressing orange peel. From the viewpoint of reusability of the used powder, the process that includes low-power laser irradiation is practical. The presence or absence of contact between the surrounding powder and the molten polymer determines whether the orange peel is formed.

Research limitations/implications

The authors have not tested orange peel suppression for complex shapes.

Originality/value

The authors have demonstrated a concrete process that can suppress orange peel formation even for powders with low melt-flow rates. Furthermore, a mechanism for the formation/suppression of orange peel based on the experimental results was proposed.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 11 September 2020

Seok Shin Tan, Seok Tyug Tan and Chin Xuan Tan

Salak (Salacca zalacca) is an underutilised fruit. The bioactivities of this fruit have rarely been studied scientifically. Thus, the present study aimed to determine the…

Abstract

Purpose

Salak (Salacca zalacca) is an underutilised fruit. The bioactivities of this fruit have rarely been studied scientifically. Thus, the present study aimed to determine the antioxidant activity of extracts derived from the peel, fruit and kernel of the Salak fruit, as well as the hypoglycemic and anti-hypertensive properties of Salak peel extracts.

Design/methodology/approach

The peel, fruit and kernel of the Salak were extracted using distilled water, methanol and ethanol. Antioxidant activities, angiotensin-converting enzyme (ACE) and alpha-amylase inhibition properties of the extracts were estimated via in vitro standard methods. Besides, the total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were also determined in the present study. The antioxidant activities of different parts of Salak extracts were determined by ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) methods. Percent of radical scavenging properties were calculated via DPPH assay. The hypoglycemic and anti-hypertensive properties of Salak peel were evaluated using alpha-amylase inhibition and ACE assays, respectively.

Findings

Fruit extracts of Salak in methanol were found to exhibit the highest TPC (10.27 ± 0.12 mg GAE/g), TFC (11.04 ± 0.89 mg CE/g) and antioxidant properties amongst all samples whereby the TPC and TFC were strongly correlated with antioxidant activities. On the other hand, distilled water extracted Salak kernel showed to have the lowest TPC (0.53 ± 0.05 mg GAE/g), TFC (0.37 ± 0.01 mg CE/g) and antioxidant properties amongst all the Salak extracts. Peel extracts exhibit comparable antioxidant activities with fruit extracts in the current findings. In addition, peel extracts indicated some extend of ACE and alpha-amylase inhibition activities regardless of the solvents used. Methanol and ethanol peel extracts indicated no significant difference (p < 0.05) ACE (98%) and alpha-amylase (90%) inhibition activities. However, distilled water extracted Salak peel showed significantly lower ACE and alpha-amylase inhibition in comparison to methanol and ethanol peel extracts.

Originality/value

The present findings suggested that the fruit of Salak exhibits the highest antioxidant properties, followed by the peel and lastly, the kernel, which shows the lowest antioxidant properties amongst all the samples. The results also indicated that the peel extracts have ACE and alpha-amylase inhibition activities.

Details

British Food Journal, vol. 122 no. 10
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 21 May 2020

Amel Ibrahim, Sameh Awad and Mahmoud El-Sayed

The effect of pomegranate whole and inside peels before and after extraction of the tannic acid have been carried out in stimulated media and in gastrointestinal conditions

Abstract

Purpose

The effect of pomegranate whole and inside peels before and after extraction of the tannic acid have been carried out in stimulated media and in gastrointestinal conditions

Design/methodology/approach

Adding pomegranate peels with and without tannins at different levels to bio-stirred yoghurt to study its effect as prebiotic, in addition to evaluating the effect on physiochemical, sensorial and rheological properties

Findings

The results reveal that pomegranate peels before and after removing tannins had no effect on the viability of a single strain of Lb. acidophilus in stimulated media, while the growth of mixed probiotic culture (Lb.acidophilus and Bifidobacterium bifidum) was enhanced when pomegranate peels (whole and inside part) free from tannins were used. Tannin-free pomegranate peels enhanced the viability of probiotic culture under gastrointestinal conditions. In this study, all probiotic cultures were maintained counts around log 8 cfu /g in stirred bio-yoghurt supplements with pomegranate peels after 21days. Bio-yoghurt supplemented with pomegranate peels at 0.5% gained high scores for overall acceptability.

Originality/value

Pomegranate has been recognized as a good source of antioxidant and antimicrobial activities. Some researchers have utilized pomegranate peel in fermented milk, but most of the studies have found that tannins inhibit the bacterial culture. This study recommended that the supplementation of low-fat bio-yoghurt with tannin-free pomegranate peels enhanced the texture properties, viscosity of the product, as well as the viability of probiotic culture during shelf life. Therefore, the tannin-free pomegranate peel could be used as a prebiotic in functional fermented dairy products.

Details

British Food Journal, vol. 122 no. 9
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 29 April 2014

Seok-Hwan Huh, Kang-Dong Kim and Keun-Soo Kim

The purpose of this paper is to evaluate the relationship between the Cu trace and epoxy resin and to check the validity of surface and interfacial cutting analysis system…

Abstract

Purpose

The purpose of this paper is to evaluate the relationship between the Cu trace and epoxy resin and to check the validity of surface and interfacial cutting analysis system (SAICAS) by comparing its results to those of the 90° peel test.

Design/methodology/approach

In this study, the effects of surface morphology on the adhesion strength were studied for a Cu/epoxy resin system using a SAICAS. In order to evaluate the peel strength of the sample, the curing degree and surface morphology of the epoxy resin were varied in the Cu/epoxy resin system.

Findings

The results indicated that the peel strength is strongly affected by the curing degree and the surface morphology of the epoxy layer. As the pre-cure time increased, the interactions between the epoxy resin and permanganate during the adhesion promotion process decreased, which decreased the surface roughness (Ra) of the resin. Therefore, the surface roughness of the epoxy resin decreased with increasing pre-cure time. The curing degree was calculated with the FTIR absorption peak (910 cm−1) of the epoxy groups. The high curing degree for the epoxy resin results in a coral-like morphology that provides a better anchoring effect for the Cu trace and a higher interfacial strength.

Research limitations/implications

It is necessary to study the further adhesion strength, i.e. the friction energy, the plastic deformation energy, and the interfacial fracture energy, in micro- and nanoscale areas using SAICAS owing to insufficient data regarding the effects of size and electroplating materials.

Originality/value

From findings, it is found that measuring the peel strength using SAICAS is particularly useful because it makes the assessment of the peel strength in the Cu/epoxy resin system of electronic packages possible.

Details

Circuit World, vol. 40 no. 2
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 14 September 2015

Sourab Dua, Z. F. Bhat and Sunil Kumar

The purpose of this study is to explore the possibility of utilization of lemon peel extract as a natural antioxidant source in muscle foods. The products incorporated…

Abstract

Purpose

The purpose of this study is to explore the possibility of utilization of lemon peel extract as a natural antioxidant source in muscle foods. The products incorporated with lemon peel extract were assessed for various oxidative stability and storage quality parameters.

Design/methodology/approach

The study was designed to evaluate the effect of lemon peel extract on the oxidative stability and storage quality of Tabak-Maz, a popular traditional meat product. The products were prepared and treated with different concentrations of lemon peel extract (0.5, 1, 1.5 per cent) and were aerobically packaged in low-density polyethylene pouches and assessed for lipid stability and storage quality parameters under refrigerated (4 ± 1°C) conditions.

Findings

Lemon peel extract showed a significant (p < 0.05) effect on the lipid stability of the products as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid-reactive substances (TBARS) (mg malonaldehyde/kg) and free fatty acid (FFA) (per cent oleic acid) values for the entire period of storage. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as lemon peel extract treated products showed significantly (p < 0.05) lower values for total plate count, psychrophillic count and yeast and mould count throughout the period of storage. Coliforms were not detected throughout the period of storage. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the treated products.

Originality/value

Lemon peel extract successfully improved the oxidative stability and storage quality of Tabak-Maz during refrigerated (4 ± 10°C) storage and may be commercially exploited as a natural antioxidant source in muscle foods.

Details

Nutrition & Food Science, vol. 45 no. 5
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 13 July 2015

Ana Carolina Conti-Silva and Renata Ferreira Roncari

The purpose of this paper is to substitute wheat flour by passion fruit peel flour in Brazilian honey bread (pão de mel), with evaluation of the breads’ sensory features…

Abstract

Purpose

The purpose of this paper is to substitute wheat flour by passion fruit peel flour in Brazilian honey bread (pão de mel), with evaluation of the breads’ sensory features, chemical composition and physical properties.

Design/methodology/approach

Honey breads with wheat flour (standard) and with replacement of this ingredient by 10 to 50 per cent passion fruit peel flour were produced. Two sensory tests were applied, to identify how different formulations with passion fruit peel flour were when compared to the standard formulation, and also the acceptability of the products. The selected honey breads, through sensory results, were evaluated regarding to chemical composition and physical properties.

Findings

Formulations with 10 and 20 per cent substitution were the least different to formulations with only wheat flour, and were as acceptable as the wheat flour sample. Physical and chemical characteristics of breads with 10 and 20 per cent passion fruit peel flour were similar; however, honey bread with 20 per cent passion fruit peel flour had higher fibre content, ash quantity and hardness value; a lower specific volume; and a different colour from the wheat flour sample.

Practical implications

This study offers an opportunity to food industries through utilization of an agro-industrial by-product on the formulation of a Brazilian traditional product.

Originality/value

This study presents the feasibility of using an agro-industrial by-product to Brazilian honey bread, enhancing the nutritive value of this product and reducing the impact of passion fruit peel flour on the environment.

Details

Nutrition & Food Science, vol. 45 no. 4
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 25 August 2021

Ali Shams Nateri and Ehsan Dehnavi

This work aims to study the effect of mordanting method as pre-mordanting (on-chrome), meta-mordanting (meta-chrome) and post-mordanting (after-chrome) on wool dyeing with…

Abstract

Purpose

This work aims to study the effect of mordanting method as pre-mordanting (on-chrome), meta-mordanting (meta-chrome) and post-mordanting (after-chrome) on wool dyeing with madder natural dye without tannin and pomegranates peel, as a natural dye contains tannin.

Design/methodology/approach

The woolen yarn was dyed with madder and pomegranate peel natural dyes by three methods as pre-mordant, meta-mordant and pos-mordant. The color parameters and reflectance spectra of dyed samples were analyzed by using derivative spectroscopy and the principal component analysis (PCA) techniques.

Findings

The obtained results indicate that the color difference between the samples dyed with madder by pre-mordanting, and the samples dyed by other methods is more than the color difference between the samples dyed by meta-mordanting and post-mordanting. However, the color difference between samples dyed with pomegranate peel by pre-mordanting and meta-mordanting methods is less compared to other pairs. Also, analysis of reflectance spectra and color depth (K/S) values indicate that the color depth of dyed sample with madder by pre-mordanting method is more than other dyeing methods. But, the color depth of sample dyed with pomegranate peel by post-mordanting method is less compared to other methods. The analysis of first-, second-, third- and fourth-order derivatives of reflectance spectra and the study of the first, second, third and fourth PCs of reflectance spectra indicate that the reflectance of dyed samples with madder and pomegranates peel depends on the mordanting method.

Originality/value

Evaluation of the effect of mordanting method on color and reflectance of wool dyed with madder and pomegranates peel natural dyes using derivative spectroscopy and the PCA techniques

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 24 February 2020

Anita M. Chappalwar, Vikas Pathak, Meena Goswami and Arun Kumar Verma

The purpose of this study is to develop functional chicken patties with incorporation of mango peel powder as a fat replacer.

Abstract

Purpose

The purpose of this study is to develop functional chicken patties with incorporation of mango peel powder as a fat replacer.

Design/methodology/approach

Low-fat chicken patties were developed by incorporating mango peel powder as fat replacer at 1.0, 2.0 and 3.0% level to replace 50% vegetable oil in the formulation. The product was evaluated for various physico-chemical properties and sensory attributes.

Findings

There was a significant difference (p < 0.05) between control and treatments for all physico-chemical properties except product pH and protein content. The emulsion pH, emulsion stability, water activity, fat and cholesterol content of mango peel treated chicken patties were significantly (p < 0.01) lower, however, cooking yield, moisture content, fat retention and moisture retention values were significantly (p < 0.01) higher than control. All mineral content decreased significantly (p < 0.05) in treatments except potassium and phosphorous content. Incorporation of mango peel powder had a significant (p < 0.05) effect on textural and colour parameters. Sensory scores decreased significantly (p < 0.05) in treatments, however, the product was well acceptable up to 2% of mango peel powder incorporation.

Originality/value

Fat has an important role in comminuted meat products, its reduction results in rubbery and dry textured products and poses difficulties in terms of flavour and texture. Meat products with high-fat content may exert a great harmful effect on human health such as obesity and high blood cholesterol level. Hence, there is a need for using suitable ingredient, which is able to replace fat without affecting quality. Mango peel may be used as suitable fat replacer at 2% to replace 50% added vegetable fat without affecting quality parameters.

Details

Nutrition & Food Science , vol. 50 no. 6
Type: Research Article
ISSN: 0034-6659

Keywords

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