Home » Knowledge Base » Knowledge Base Article What's New  |  Site Map 

 

 
   
   
 
 


Today's
Sponsors:


Schmalz, Inc.

Schultz Forming Products

Scientific Dust Collectors

SCM Group USA, Inc.

SCM Group

SCM

SDN Contracting

Seagrave Coatings Corporation

Sears Trostel Lumber Co.

Shade Dri

Shomaker Lumber Company

ShopBot

SII Dry Kilns

Silvaris

Simantech

SIS Machinery

Nebraska Tool

NEMI

New England Kiln Drying Association

Newman Whitney

Norment and Lambert

North Pacific Lumber

Northtech Machinery

NPO BARS

Nydree Flooring

Nyle Dry Kiln Systems

O'Shea Lumber Company

Old Mississippi Brick and Heart Pine Company

OMGA, Inc.

Omnitech Systems

Onsrud Cutter

Opti-Sand

Original Saw Company

Osolnik Machinery & Supplies

Patton Cabinet Doors

Paul Saws and Systems

People Logic Software Corp.

Pinske Edge

Pioneer Lumber Company

Planit Solutions Inc.

plastiMACH

Plogic Solutions Ltd.

Pond Cove Paint

Porter-Cable

Precision Drive Systems

Precision Saw Sharpeners

Premium Specialty Hardwoods

Pricecutter.com

Prime Estimating and Software Services, LLC

Pro.Woodworker.com

Pro100

Professional Hardware & Supply Co.

Quality VAKuum Products, Inc.

Quick Machinery Company

Quickscrews International Corporation

QuickScribe

QuickWood

QuikDrawers

Quis Machinery

R&R Drummond, Inc.

R.A.W.

R.D. Billhofer Company

Rangate

Rawles-Aden Lumber Corp.

RazorGage

Reliance Building Products

Restoration Specialists

Rex Lumber Company

Riethmiller Lumber

Ritter Manufacturing Inc.

Rockler Woodworking and Hardware

Roger Shaw and Associates

Rose Machinery

Routech

Royce Ayr Cutting Tools

RT Machine Co.

Safety Speed Cut

Sand-Rite Manufacturing

Sandman Products

Saw Trax Mfg.

Sawmill and Woodlot Magazine



WOODWEB DISCLAIMS any and all RESPONSIBILITY and LIABILITY for the accuracy and application of the information below. Readers agree to evaluate the significance and limitations of the information provided, and accept full responsibility for the application of this information. Read More ...

Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?



Inconsistencies in HDF production       Problems with production of high-density fiberboard with MUF adhesive. June 6, 2001

Question
We produce high-density fiberboards with MUF adhesive. Recently, our product's elastic modules decreased by 25%, and linear expansion increased 50%, but the wood, adhesive and technology were unchanged. Why?

Forum Responses
Are you sure that everything was unchanged? How do you control the quality of your adhesive? Why do you use a melamine fortified UF-resin--stability or water resistance reasons? Or is it a real MUF-resin? Who is the producer of your adhesive? Or do you produce it on your own?



I don't have any obvious solutions for you, but it's important to point out that when dealing with wood (a natural substance), you are dealing with constant variations and change. Your process is never the same from day to day.

Jeff Pitcher, forum technical advisor



MUFs as well as UFs are very sensitive to pH conditions of the wood. If your MUF is added in the blowline, then the high temperature will aggravate the situation. It sounds like something is causing a pre-reaction in the blowline to cause properties to change that much. Or perhaps you did not change to a summer formulation for the MUF and hot weather is causing a problem during storage.


From the original questioner:
I produce hdf for laminating flooring and use MUF to increase the IB and water resistance. We prepare MUF by ourselves. The amount of F is about 7%. We got better results in January, February and March of this year. But the water resistance became worse since May. We add MUF in blowing line. How can I change to the summer formulation?


How does the climate change from winter to summer in your country? If you maybe have got problems with your formulation, I need more information (e.g. molar ratio at the beginning and end of condensation process, F quality, pH and temperature during condensation, viscosity, water solubility, condensation time).


From the original questioner
20 degrees in winter, 30s degree in summer. Molar ratio is 1.2. Which item of F quality influences the MUF property?

How can I get the article "Thermochemical analysis of wood/aminoplastic adhesives joints cross-linking-UF, MUF, PMUF" by Yin Suzhou, Deglis, Xavier Masson, Daniel.



The main items of the formaldehyde quality are the concentration (> 40%) and the methanol content (< 1% for best resins). The article you are looking for was published in "Holzforschung (1995)".
Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Adhesives, Gluing and Laminating

  • KnowledgeBase: Adhesives, Gluing and Laminating: Glues and Bonding Agents

  • KnowledgeBase: Primary Processing: General

  • KnowledgeBase: Wood Engineering

  • KnowledgeBase: Wood Engineering: Wood Properties

  • KnowledgeBase: Knowledge Base




    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.



    Refer a Friend || Read This Important Information || Site Map || Privacy Policy

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2008 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    RR4 Box 265A
    Montrose, PA 18801

    Contact WOODWEB