Investigation of formalin and urea formaldehyde condensates based formaldehyde urea resins and effect on the quality of medium density fiberboard
Message:
Article Type:
Research/Original Article (دارای رتبه معتبر)
Abstract:
The aim of this study was to investigate the effect of the primary material of urea formaldehyde adhesive on the physical and mechanical properties of the medium density boards. In this study, two types of urea formaldehyde adhesive based on formalin and urea formaldehyde condensates were used. The adhesives made with both primary materials had low molar ratio of formaldehyde to urea (grade E1). The effect of press factor on the four levels (8, 8.2, 8.4, 8.6 s/mm) and the amount of adhesive at four levels (9, 9.5, 10, 10.5) percent on the physical properties such as thickness swelling and mechanical properties including flexural modulus, elastic modulus and internal bonding of the resulted boards of two different types of adhesives were studied. The results showed that the resulting boards with formalin-based urea formaldehyde adhesive had the highest flexural strength, elastic modulus and internal bonding, and also the least percentage of thickness swelling compared to the boards made with the urea formaldehyde-based adhesive. By increasing the press factor, the boards made with formalin-based adhesive compared to the adhesive based on the formaldehyde condensate had the same performance in lower consumption percentage. The use of formalin, despite the high quality of the resulting boards, requires a special maintenance requirement in the industry, in comparison to the urea-based adhesive based boards, due to high temperature instability.
Language:
Persian
Published:
Journal of Forest and Wood Products, Volume:71 Issue: 4, 2019
Pages:
347 to 356
magiran.com/p1949883  
دانلود و مطالعه متن این مقاله با یکی از روشهای زیر امکان پذیر است:
اشتراک شخصی
با عضویت و پرداخت آنلاین حق اشتراک یک‌ساله به مبلغ 990,000ريال می‌توانید 70 عنوان مطلب دانلود کنید!
اشتراک سازمانی
به کتابخانه دانشگاه یا محل کار خود پیشنهاد کنید تا اشتراک سازمانی این پایگاه را برای دسترسی نامحدود همه کاربران به متن مطالب تهیه نمایند!
توجه!
  • حق عضویت دریافتی صرف حمایت از نشریات عضو و نگهداری، تکمیل و توسعه مگیران می‌شود.
  • پرداخت حق اشتراک و دانلود مقالات اجازه بازنشر آن در سایر رسانه‌های چاپی و دیجیتال را به کاربر نمی‌دهد.
دسترسی سراسری کاربران دانشگاه پیام نور!
اعضای هیئت علمی و دانشجویان دانشگاه پیام نور در سراسر کشور، در صورت ثبت نام با ایمیل دانشگاهی، تا پایان فروردین ماه 1403 به مقالات سایت دسترسی خواهند داشت!
In order to view content subscription is required

Personal subscription
Subscribe magiran.com for 50 € euros via PayPal and download 70 articles during a year.
Organization subscription
Please contact us to subscribe your university or library for unlimited access!