Unlock instant, AI-driven research and patent intelligence for your innovation.

Method of Making Medium Density Fiberboard

a fiberboard and medium density technology, applied in the direction of non-fibrous pulp addition, cellulose treatment using microorganisms/enzymes, transportation and packaging, etc., can solve the problems of unprocessed fibers, high energy inputs, and unsatisfactory water repellency properties, so as to improve water repellency properties and energy efficiency

Inactive Publication Date: 2008-10-30
WISCONSIN ALUMNI RES FOUND +2
View PDF7 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0014]Briefly, in one aspect, the present invention is a novel method for producing an MDF board from pulp from a fibrous lignocellulose material using a treatment or pretreatment step which exposes the material to oxalic acid or oxalic acid derivatives (particularly dialkyl ester derivatives, particularly in the vapor phase). The treated wood is then subjected to a sugar extraction wash and refined using any one of the several pulping methods to produce a final pulp product. Once this is done the pulp is used to make MDF boards having improved water repellency properties.

Problems solved by technology

In particular, high energy inputs are generally required to obtain fiber separation in woods rich in lignin as such woods typically call for extended refining periods and higher refining temperatures or pressures.
Recent studies have also suggested that even thermal or chemical softening treatments of such woods do not guarantee a lower total energy consumption.
This is because unprocessed fibers which are only mildly separated by the thermal or chemical treatments are difficult to fibrillate during the mechanical refining process.
As a result, high energy consumption in TMP and CTMP processes has been generally necessary in today's pulping practices.
Along with the problems of the high energy cost of pulping.
MDF has the problem of generally having low moisture tolerance.
MDF, therefore, often swells when contacted with water and is therefore of more limited use in outdoor settings and in applications that encounter moisture such as furniture surfaces.
Absorption of moisture also often causes significant deterioration in the mechanical integrity of the MDF.
In particular, the methods described below produce MDF that has, in-part, improved water repellency, a resulting characteristic that is not observable in the papermaking process.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method of Making Medium Density Fiberboard
  • Method of Making Medium Density Fiberboard
  • Method of Making Medium Density Fiberboard

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0055]Properties of MDF made from wood pretreated with OA and DEO. Red pine logs were obtained from SENA. Logs were debarked and chipped at FPL to a nominal size of 6-14 mm. Chips were placed in barrels and frozen to prevent the growth of contaminating microorganisms. Their moisture content was 42%.

[0056]Processing of control chips. Untreated (control) red pine wood chips were placed in a large rotating digester and steam was introduced to displace air and bring the chips to temperature (135-140° C.). External temperature measurement was used as well as an internal probe as a secondary source of temperature measurement. The chips were cooked for 30 minutes at 135° C. Following the cook, the wood chips were subjected to a sugar extraction procedure consisting of atmospheric hot water washing (˜240 liters, a water to wood ratio of 8:1) at a temperature of 80° C. for 30 minutes to collect the extractives including the sugars, etc. for fermentation. The wood chips were then collected an...

example 2

[0063]Materials and Methods. Wood chips. Red pine logs were obtained from SENA. Logs were debarked and chipped at FPL to a nominal size of 6-14 mm. Chips were placed in barrels and frozen to prevent the growth of contaminating microorganisms. Moisture content was 42%. After the experimental cooking procedures, the wood chips were collected and stored at 4° C. until TMP processing for MDF fiber.

[0064]Experimental cooks. Control red pine wood chips were subjected to time and temperature and extraction protocols, but without chemical cook (positive control). Following the cook, the wood chips were subjected to the extraction procedure consisting of atmospheric hot water washing (˜240 liters) to collect the extractives including the sugars, etc. for fermentation.

[0065]Oxalic acid dihydrate obtained from Sigma-Aldrich was used in a quantity of 35 grams into 7500 ml. water at 70° C. (0.33% solution of oxalic acid) per 2.5-kilograms oven dried wood chips. A rotating digester was used to co...

example 3

[0072]Pilot scale data were generated at the Andritz Research and Development Laboratory in Springfield, Ohio. The Andritz facility is known to provide refining results similar to industrial scale such that data obtained can be used for scaled up with confidence. The procedures used to process both the red pine and the spruce wood used in the refining tests at Andritz were the same procedures as described above for materials and methods.

TABLE 3Pilot-scale refining results from Andritz on spruce.BendingInternalWater soak (24 hour)CarbohydrateWoodMORMOEbondSwellAbsorptionreleased %treatment(N / mm2)(Nmm2)(N / mm2)(%)(%)Wood chipSpruce13.515580.1831.2110.01.2ControlSpruce14.819510.4114.866.63.5Oxalic AcidSpruce DEO19.319510.4410.032.14.0Note:MDF properties from boards containing 93.5% fiber, 6% resin and 0.5% wax. Carbohydrate is the total identified carbohydrate (mannose + xylose + arabinose + glucose + galactose, in decreasing order) released as a percentage of the weight of the wood chi...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Temperatureaaaaaaaaaa
Fractionaaaaaaaaaa
Login to View More

Abstract

The present invention provides a method for producing an MDF board from pulp from a fibrous lignocellulose material using a treatment or pretreatment step which exposes the material to oxalic acid or oxalic acid derivatives (particularly dialkyl ester derivatives, particularly in the vapor phase). The treated wood is then subjected to a sugar extraction wash and refined using any one of the several pulping methods to produce a final pulp product. Once this is done the pulp is used to make MDF boards having improved water repellency properties.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application Ser. No. 60 / 824,383 filed on Sep. 1, 2006STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]This invention was made with United States government support awarded by the following agency: DOE Grant # R530539 and DOA # DE-FG45-02R530539. The United States has certain rights in this invention.BACKGROUND OF THE INVENTION[0003]Lignocellulosic materials are sources for the generation of a variety of products. Some of the products retain significant structural components of the lignocellulose such as mechanical pulp Fibers from wood chips. Other compounds such as sugars derived from the carbohydrate in lignocellulose are made into products by fermentation or chemical conversion. The lignocellulose can be made into products that represent a continuum of structured to molecular products. The continuum of products is generated by a variety of physical, chemical, biol...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): D21C3/04D21H17/33
CPCC08J5/045D21C1/04Y10T428/1303D21C5/005D21C11/0007D21C3/04
Inventor AKHTAR, MASOODKENEALY, WILLIAM R.HORN, ERIC G.SWANEY, ROSS E.WINANDY, JERROLD
Owner WISCONSIN ALUMNI RES FOUND