Development of eco-friendly wall insulation layer utilising the wastes of the packing industry

Our plain-English summary of Development of eco-friendly wall insulation layer utilising the wastes of the packing industry, by A.K.K. Alsaffar, S.S. Alquzweeni, L.R. Al-Ameer, et al (Heliyon, 2023).

The study

• Authors: A.K.K. Alsaffar, S.S. Alquzweeni, L.R. Al-Ameer, A.H. Ali, A. Mohamed, H.M. Aldaihani, A. Reham, N. Al-Ansari, O. Al-Hashimi, A. Shubbar, M.A. Khan, K. Hashim
• Journal: Heliyon
• Published: 2023;9(11):e21799
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Efficient thermal insulation materials considerably lower power consumption for heating and cooling of buildings, which in turn minimises CO2 emissions and improves indoor comfort conditions. However, the selection of suitable insulation materials is governed by several factors, such as the environmental impact, health impact, cost and durability. Additionally, the disposal of used insulation materials is a major factor that affects the selection of materials because some materials could be very toxic for humans and the environment, such as asbestos-containing materials. Therefore, there is a continuous research effort, in both industry and academia, to develop sustainable and affordable insulation materials. In this context, this work aims at utilising the packing industry wastes (cardboard) to develop an eco-friendly insulation layer, which is a biodegradable material that can be disposed of safely after use. Experimentally, wasted cardboard was collected, cleaned, and soaked in water for 24 h. Then, the wet cardboard was minced and converted into past papers, then cast in square moulds and left in a ventilated oven at 75 °C to dry before de-moulding them. The produced layers were subjected to a wide range of tests, including thermal conductivity, acoustic insulation, infrared imaging and bending resistance. The obtained results showed the developed material has a good thermal and acoustic insulation performance. Thermally, the developed material had the lowest thermal conductivity (λ) (0.039 W/m.K) compared to the studied traditional materials. Additionally, it successfully decreased the noise level from 80 to about 58 dB, which was better than the efficiency of the commercial polyisocyanurate layer. However, the bending strength of the developed material was a major drawback because the material did not resist more than 0.6 MPa compared to 2.0 MPa for the commercial polyisocyanurate and 70.0 MPa for the wood boards. Therefore, it is recommended to investigate the possibility of strengthening the new material by adding fibres or cementitious materials.

© 2023 Published by Elsevier Ltd.

In plain English

This was a laboratory study of building materials, not a study of asbestos or health. Asbestos-containing materials appear only in the abstract, as an example of insulation that can be very toxic for humans and the environment. The authors made wall insulation layers from waste cardboard boxes collected from shops in Liverpool, UK. The cardboard was soaked, mixed into a paste, moulded and oven-dried. One version was left untreated (S1) and another was wrapped in aluminium tape (S2). Both were compared with commercial polyisocyanurate and wood boards. In thermal conductivity tests, S1 had the lowest value (0.039 W/m.K) and S2 had the highest. After 20 minutes of heating, the polyisocyanurate surface recorded no more than 19 degrees C, compared with 22 degrees C for S2, 24.7 for S1 and 26.2 for wood. In noise tests, S1 lowered an 80 dB source to about 58 dB. Wood lowered it to about 37 dB, and polyisocyanurate reduced it by 16 dB. Both cardboard layers had bending strengths under 1 MPa, against about 2.0 MPa for polyisocyanurate and about 70.0 MPa for wood. The authors concluded the material could be a promising eco-friendly alternative but needs strengthening.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory materials-testing study comparing a newly made cardboard insulation layer with commercial insulation materials
• Who was studied: No people were studied. Test samples were made from waste cardboard boxes collected from local shops in Liverpool, UK. One type was untreated (S1) and one was wrapped with aluminium insulation tape (S2). They were compared with commercial polyisocyanurate (PO) and wood boards (WB). No study dates are given.
• Exposure: No asbestos exposure was studied. Asbestos-containing materials are mentioned only in the abstract, as an example of insulation materials that could be very toxic. The materials tested were cardboard-based insulation layers, polyisocyanurate and wood boards.
• Main results:
  • Infrared imaging showed no industrial defects (cracks or holes) in the cardboard samples (S1 and S2) or the reference samples.
  • After 20 minutes of heating, the measured surface temperatures were: polyisocyanurate no more than 19 degrees C, S2 22 degrees C, S1 24.7 degrees C, and wood boards 26.2 degrees C.
  • The untreated cardboard layer (S1) had the lowest thermal conductivity (0.039 W/m.K), followed by wood boards and polyisocyanurate. The aluminium-wrapped layer (S2) had the highest.
  • Starting from an 80 dB noise source, the measured levels were: wood boards about 37 dB, S1 about 58 dB, S2 about 62 dB. Polyisocyanurate reduced the noise by 16 dB.
  • Bending strength was less than 1 MPa for both cardboard layers (S1 and S2), about 2.0 MPa for polyisocyanurate, and about 70.0 MPa for wood boards.
• The authors' conclusion: The authors concluded that the developed cardboard material could be a promising eco-friendly alternative to traditional insulation materials. They recommended investigating ways to strengthen it, such as adding fibres or cementitious materials.
• Limitations the authors state:
  • The authors described low bending strength as the main drawback of the developed material itself (a property of the material, not a weakness of the study design). They said the material needs strengthening.

Topics

Medical terms in this study, explained in our Lexicon: Thermal System Insulation (TSI), Asbestos-Containing Material (ACM).

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• Hydrothermal process development for the treatment of crocidolite asbestos waste — C.T. Nzogo Metoule, S. Delaby, et al. (2019)

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