Wet process of fabricating fiber wall panels

Abstract

This invention discloses a wet process of fabrication of fiber wall panel, which includes the following steps: 1) slurry making: mix nontimber type natural plant fiber slurry with grass family slurry according to 1:01.5 dry weight ratio, and add water to dilute this slurry; 2) slurry storage: pour the mixed slurry into slurry storage tank and add water for dilution; 3) suction straining and forming: pour slurry into mold cavity for cold pressing, dewatering, and forming, to yield wet blanks; 4) hot pressing, forming, and drying: move the Wet blanks to the hot pressing mold for hot pressing and remove moisture generated during hot pressing, to yield fiber wall panel. Fiber Wall panel made by this process features environment friendliness and high strength.

Claims

1. A wet process of fabricating fiber wall panels with a decorative convex-concave pattern surface, comprising the steps of: 1) providing a grass slurry, being made by a process comprising steps of (a) breaking dried grass plant stalk or lawn grass to lengths of 1-5 cm, (b) soaking the grass plant stalk or lawn grass from step (a) for 30-72 hours, and (c) rubbing and grinding the plant stalk or lawn grass from step (b) into the grass slurry using a rubbing and grinding thread separator; 2) providing a fiber slurry separate from the grass slurry; 3) making a mixed slurry, comprising mixing the fiber slurry and the grass slurry, at a weight ratio of the dry ingredients of the fiber slurry to the dry ingredients of the grass slurry of 1.01.5 to yield a raw material and adding water to the raw material for dilution to yield the mixed slurry in which the dry weight of the raw material accounts for 3.0-5.0% by weight; 4) storing the mixed slurry, comprising pouring the mixed slurry into a slurry storage tank, and adding water for dilution to yield a final slurry in which dry weight of the raw material accounts for 0.3-0.6% by weight; 5) forming a wet blank, comprising transferring the final slurry into a mold for cold pressing, dewatering, and forming, to form the wet blank the weight of which is 1.0-10.0% of the weight of the final slurry added in the mold; and 6) forming a fiber wall panel, comprising transferring the wet blank into a hot pressing mold to perform hot pressing for 18-60 seconds at a pressure of 0.5-5.0 Kg/cm.sup.2 and a temperature of 98-280 C. for obtaining the fiber wall panel.

2. The wet process of claim 1, wherein step 1) further comprises adding a waterproofing agent and/or flame retardant, the waterproofing agent being 2.0-15.0% of dry weight of the raw material, and the flame retardant being 1.0-45.0% of dry weight of the raw material.

3. The wet process of claim 1, further comprising a step of making a spraying liquid containing a waterproofing agent and flame retardant in a water solution; and a step of spraying the wet blank formed in step 5) for a first time with the spraying liquid and then during step 4) for a second time with the spraying liquid, in which the amount of the waterproofing agent is 2.0-15.0% of the dry weight of the raw material added in the mold when two spraying operations are combined, and the amount of flame retardant is 1.0-45.0% of the dry weight of the raw material added in the mold when two spraying operations are combined.

4. The wet process of claim 1, wherein the fiber slurry is bamboo pulp, sugar cane, straw pulp, reed pulp, or waste paper pulp; and the grass slurry is made from grass family straw stalk or grass family lawn grass.

5. The wet process of claim 4, wherein the grass slurry is prepared by first removing contaminated matters from a dried grass plant stalk or lawn grass, breaking up the grass plant stalk or lawn grass to lengths of 1-5 cm, soaking the grass plant stalk or lawn grass in water for 60-72 hours, and finally rubbing and grinding to a state of a slurry.

6. The wet process of claim 5, wherein the cereal plant stalk is rice stalk, corn stalk, wheat stalk, corn cob, sorghum stalk, or barley stalk; and the lawn grass is tall fescue, ryegrass, or annual meadowgrass.

7. The wet process of claim 2, wherein said flame retardant is organic silicon flame retardant, P-N system flame retardant, or inorganic flame retardant; and said waterproofing agent is organic silicon series waterproofing agent or environment friendly waterproofing agent.

8. The wet process of claim 2, wherein the flame retardant is water-soluble organic silicon flame retardant.

9. The wet process of claim 8, wherein in step 6) hot pressing is performed at a pressure of 1.5-2.5 Kg/cm.sup.2 and a temperature of 170-265 C. for 18-60 seconds.

10. The wet process of claim 9, wherein in step 5) cold pressing is performed at a pressure of 0.5-2.0 Kg/cm.sup.2.

Description

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS OF THE INVENTION

(1) The following further describes this invention in combination with preferred embodiments, which however do not limit this invention.

Preferred Embodiment 1

A Wet Process of Manufacture of Fiber Wall Panels, Including the Following Steps

(2) 1. Slurry Making:

(3) Pour the primitive color bamboo pulp of 90% dry weight obtained from the market into a beater and add water for dilution. Run the beater for 20 min. Degree of beating shall be 1415SR. Then, transfer the resultant liquid into a compounding pool for 5 min of mixing, to obtain a mixed slurry. Dry weight of the primitive color bamboo pulp shall be 3% of the weight of mixed slurry.

(4) 2. Slurry Storage:

(5) Place the mixed slurry in a slurry storage tank and add water for dilution. Use a 1012 r/min mixer to stir to evenness, and obtain a final slurry. Dry weight of the primitive color bamboo pulp is 0.3% of the final slurry weight.

(6) 3. Suction Straining and Forming:

(7) The final slurry prepared is sent via pipeline to the mold cavity of a fully automatic paper pulp molding forming machine manufactured by Hangzhou Asia-Europe Equipment Co. Ltd., which adopts a suction straining with vacuum pumping method. Water content which is 90% by weight of the slurry is removed in the mold cavity by means of pressing at 1.0 Kg/cm.sup.2 and straining, so that wet blanks are obtained. In other words, the weight of wet blanks is 10% of slurry weight in the mold cavity.

(8) 4. Hot Pressing, Forming, and Drying

(9) Transfer the wet blanks into the hot pressing mold of this forming machine. Under a closing force 1.5 kg/cm.sup.2, the hot pressing upper mold and lower mold are closely mated together. The moisture in the wet blanks is vaporized and taken away by vacuum in the hot pressing lower mold. The temperature of the hot pressing upper mold is controlled at 18 C.2 C. and temperature of the lower mold is controlled at 200 C. The total duration of hot pressing is 30 s. The product (fiber wall panel) is obtained at the end of this process.

(10) 5. Cutting of Edge and Inspection of Finished Product

(11) After hot pressing and forming, compressed air is used to blow finished products onto the conveying belt, and then to edge trimming cutter to remove burrs. Finally, after passing quality inspection, the products are packed and moved into the warehouse. The mold size used by this preferred embodiment is 4646 cm. The fiber wall panel thickness is 9 mm. Convex-concave depth is 5 mm. The solid convex-concave pattern can be changed by using a different mold. The designed pattern for this preferred embodiment is the Chinese knot. Of course, patterns are not limited to this.

(12) The compression strength of this fiber wall panel is 200 N. Its plane tensile strength is 0.78 Mpa. The density of the panel is 0.68 g/cm.sup.3.

Preferred Embodiment 2

A Wet Process of Manufacture of Fiber Wall Panels, in Which Step 1, i.e. Slurry Making, is Adjusted as Follows

(13) 1. Slurry Making:

(14) Pour the primitive color bamboo pulp of 90% dry weight obtained from the market into a beater and add water for dilution. Run the beater for 20 min. The degree of beating shall be 1415SR. Then, transfer the resultant liquid into a compounding pool for 5 min of mixing, and add the waterproofing agent of 5% dry weight of the primitive color bamboo pulp and the flame retardant of 20% dry weight of the raw material. After mixing in a 10 rpm mixer for 6 min, a mixed slurry is obtained. Dry weight of primitive color bamboo pulp shall be 3% of weight of mixed slurry.

(15) The waterproof agent can be FT-556 waterproofing agent manufactured by Hangzhou Yuanda Chemical Auxiliary Factory. Flame retardant can be ZR-BB01 flame retardant manufactured by this factory.

(16) Different upper molds and lower molds are selected. Other conditions are the same as those of preferred embodiment 1.

(17) The thickness of the fiber wall panel obtained is 2.5 mm. Convex-concave depth is 5 mm.

(18) The compression strength of this fiber wall panel is 200N. Its plane tensile strength is 0.71 Mpa and its panel density is 0.69 g/cm.sup.3.

(19) Waterproofing properties meet testing standards GB13341-2003 and GB/T1540-2002, and flame retarding effect meets state testing standards GB/T5464-1999 and GB/T 8627-1999.

Preferred Embodiment 3

A Wet Process of Manufacture of Fiber Wall Panels, in which Step 1, i.e. Slurry Making, is Adjusted as Follows

(20) 1. Slurry Making:

(21) Add the waterproofing agent and flame retardant in a predetermined proportion in a storage barrel. Add water and stir for dissolution. After mixing using the mixer for 6 min, add the primitive color bamboo pulp of 90% dry weight. Add water for dilution. Fully stir the liquid in the slurry storage pool. After 20 min, a mixed slurry is obtained. The waterproofing agent is 2.5% of the dry weight of the primitive color bamboo pulp, and the flame retardant is 18% of the dry weight of the primitive color bamboo pulp. The dry weight of the primitive color bamboo pulp in the mixed slurry is 3% by weight.

(22) An upper mold and lower mold with a convex-concave pattern are used. All other conditions are the same as those of preferred embodiment 2.

(23) The thickness of the fiber wall panel is 2.5 mm and the depth of the convex-concave is 5 mm.

(24) Of the fiber wall panel formed, compression strength is 200N, plane tensile strength is 0.73 Mpa, and panel density is 0.70 g/cm.sup.3.

(25) Both waterproofing effect and flame retarding effect meet Chinese state testing standard.

Preferred Embodiment 4

A Wet Process of Manufacture of Fiber Wall Panels, Including the Following Steps (in the Order as Presented)

(26) 1. Pretreatment

(27) Remove any contaminated materials from the dried sorghum stalk and break them up to lengths of 15 cm. Soak the resultant matter in water for 60-72 h and then place it in the rubbing and grinding thread separator. High concentration mill will perform rubbing and grinding thread separation to obtain a mechanic pulp of certain concentration (i.e. sorghum stalk mechanic pulp).

(28) In this pulp, the dry weight of the sorghum stalk is 10%.

(29) 2. Slurry Making

(30) Mix the primitive color bamboo pulp of 60% dry weight with the sorghum stalk mechanic pulp of 10% dry weight (as a grass plant pulp) according to a dry weight ratio of 1:1, to yield the raw material. Place this raw material in a beater, and add water and run the beater for 25 min. The degree of beating is 1415SR. Transfer this liquid to the compounding pool. Add the waterproofing agent of 9% dry weight of raw material and flame retardant of 25% dry weight of the raw material. Use a 10 rpm mixer to mix for 7 min to obtain a mixed slurry. The dry weight of the primitive color bamboo pulp+dry weight of the sorghum stalk mechanic pulp=raw material dry weight. The dry weight of the raw material in the mixed slurry is 5% by weight.

(31) 3. Slurry Storage:

(32) Place the mixed slurry in the slurry storage tank, add water for dilution, and then use a 1012 r/min mixer to mix it even, to obtain final slurry. Dry weight of the raw material in the slurry weight is 0.4%.

(33) 4. Suction Straining and Forming:

(34) Slurry prepared is sent via pipeline to the mold cavity of the fully automatic paper pulp molding forming machine manufactured by Hangzhou Asia-Europe Equipment Co. Ltd., which adopts a suction straining using vacuum pumping method. Use a pressure of 1.0 Kg/cm.sup.2 to press and remove moisture that is 99% of slurry weight in the mold cavity, to obtain wet blanks. In other words, the weight of wet blanks is 1% of the slurry weight in the mold cavity.

(35) 5. Hot Pressing, Forming, and Drying

(36) Transfer the wet blanks to the hot pressing mold of this forming machine for forming and drying. Under the closing force of 1.5 Kg/cm.sup.2, the hot pressing upper mold and lower mold are closely mated together. Moisture in wet blanks is vaporized and taken away by vacuum in the hot pressing lower mold. The temperature of the hot pressing upper mold is controlled at 180 C.2 C. and temperature of the lower mold is controlled at 200 C. Total hot pressing duration is 18 s. Final products are obtained at the end of this process.

(37) 6. Cutting of Edge and Inspection of Finished Product

(38) After the hot pressing and forming step, compressed air is used to blow the finished products onto a conveying belt, and then to an edge trimming cutter to remove the burrs. Finally, after passing quality inspection, the products are packed and moved into the warehouse.

(39) The thickness of the fiber wall panel is 2.5 mm and the depth of convex-concave is 5 mm.

(40) Of the fiber wall panel formed, the compression strength is 200N, plane tensile strength is 0.67 Mpa, and the panel density is 0.64 g/cm.sup.3.

(41) Both waterproofing effect and flame retarding effect meet Chinese state testing standard.

Preferred Embodiment 5

A Wet Process of Manufacture of Fiber Wall Panels, Including the Following Steps (in the Order as Presented)

(42) 1. Pretreatment:

(43) Same as preferred embodiment 4. In this sorghum stalk mechanic pulp, the dry weight of sorghum stalk is 40%.

(44) 2. Slurry Making:

(45) Mix the primitive color bamboo pulp of 60% dry weight with the sorghum stalk mechanic pulp of 40% dry weight by dry weight proportion 3:2, to yield the raw material. Place this raw material in a beater and add water for dilution. Run the beater for 25 min. The degree of beating is 1415SR. Then, transfer the resultant liquid into a compounding pool and add the waterproofing agent of 8% dry weight of the raw material, for 5 min of mixing (using the 10 rpm mixer), to obtain a mixed slurry. The dry weight of the primitive color bamboo pulp+dry weight of the sorghum stalk mechanic pulp=raw material dry weight. The dry weight of raw material in the mixed slurry is 5% by weight.

(46) 3. Slurry Storage:

(47) Place the mixed slurry in the slurry storage tank, add water for dilution, and then use a 10.Math.12 r/min mixer to mix it even, to obtain final slurry. Dry weight of the raw material is 0.3% of the slurry weight.

(48) 4. Suction Straining and Forming:

(49) The slurry prepared above is sent via pipeline to the mold cavity of the fully automatic paper pulp molding forming machine manufactured by Hangzhou Asia-Europe Equipment Co. Ltd., which adopts a suction straining using vacuum pumping method. Use a pressure of 1.5 Kg/cm.sup.2 to press and remove moisture that is 95% of slurry weight in the mold cavity, to obtain wet blanks. In other words, the weight of wet blanks is 5% of slurry weight in the mold cavity.

(50) 5. Hot Pressing, Forming, and Drying

(51) Transfer the wet blanks to the hot pressing mold of the forming machine for forming and drying. Under a closing force of 1.5 Kg/cm.sup.2, the hot pressing upper mold and lower mold are closely mated together. Moisture in wet blanks is vaporized and taken away by vacuum in the hot pressing lower mold. The temperature of the hot pressing upper mold is controlled at 180 C.+/2 C. and temperature of the lower mold is controlled at 200 C. Total hot pressing duration is 20 s. Final products are obtained at the end of this process.

(52) 6. Cutting Edges and Inspection of Finished Products

(53) After the hot pressing and forming step, compressed air is used to blow the finished products onto a conveying belt, and then to an edge trimming cutter to remove the burrs. Finally, after passing quality inspection, the products are packed and moved into the warehouse.

(54) The thickness of the fiber wall panel is 2.5 mm and the depth of convex-concave is 5 mm.

(55) Of the fiber wall panel formed, the compression strength is 200N, plane tensile strength is 0.69 Mpa, and panel density is 0.65 g/cm.sup.3.

(56) The waterproofing effect meets Chinese state testing standard.

Preferred Embodiment 6

A Wet Process of Manufacture of Fiber Wall Panels, Including the Following Steps (in the Order as Presented)

(57) 1. Pretreatment:

(58) Remove contaminated materials from the dried wheat stalk and break them up to lengths of 15 cm. Soak the resultant matter in water for 60 h and then place it in the rubbing and grinding thread separator. High concentration mill will perform rubbing and grinding thread separation to obtain a mechanic pulp of certain concentration (i.e. the wheat stalk mechanic pulp).

(59) In this pulp, the dry weight of wheat stalk is 40%.

(60) 2. Slurry Making:

(61) Mix the bamboo pulp of 60% dry weight with the wheat stalk mechanic pulp of 40% dry weight (as a grass plant pulp) according to dry weight proportion 1:1.5, to yield the raw material. Place this raw material in the beater and add water for dilution. Run the beater for 30 min. The degree of beating is 1415SR. Then, transfer the resultant liquid into the compounding pool and using a 10 rpm mixer for 7 min of mixing, to obtain a mixed slurry. The dry weight of the raw material is 4% of weight of mixed slurry.

(62) The dry weight of bamboo pulp+the dry weight of wheat stalk mechanic pulp=raw material dry weight.

(63) 3. Slurry Storage:

(64) Place the mixed slurry in the slurry storage tank, add water for dilution, and then use a 1012 r/min mixer to mix it even, to obtain the final slurry. The dry weight of the raw material is 0.5% of the slurry weight.

(65) 4. Suction Straining and Forming:

(66) The slurry prepared is sent via pipeline to the mold cavity of the fully automatic paper pulp molding forming machine manufactured by Hangzhou Asia-Europe Equipment Co. Ltd., which adopts a suction straining using vacuum pumping method. Use the pressure of 1.0 Kg/cm.sup.2 to press and remove moisture that is 99% of slurry weight in the mold cavity, to obtain wet blanks.

(67) 5. Prepare the Spraying Liquid:

(68) Fully dissolve the waterproofing agent of 5% total dry weight of raw material and flame retardant of 18% total dry weight of raw material in water. For example, the concentration of waterproofing agent in the spraying liquid can be controlled at 10% by weight.

(69) 6. First Spraying:

(70) Spray a half of the spraying liquid prepared above on all wet blanks. In other words, the amount of spraying liquid used on each wet blank equals the amount of the spraying liquid prepared in step 5 divided by 2 and then further divided by the number of the wet blanks.

(71) 7. Hot Pressing, Forming, and Drying

(72) Transfer the wet blanks after first spraying to the hot pressing mold of this forming machine for forming and drying. Under a closing force of 1.5 Kg/cm.sup.2, the hot pressing upper mold and lower mold are closely mated together. During hot pressing, the remaining half of the spraying liquid is evenly sprayed on all Wet blanks in the hot pressing mode. Moisture in wet blanks is vaporized and taken away by vacuum in the hot pressing lower mold. The temperature of the hot pressing upper mold is controlled at 1802 C. and temperature of the lower mold is controlled at 200 C. Total hot pressing duration is 25 s. Final products are made at the end of this process.

(73) 8. Cutting Edges and Inspection of Finished Products

(74) After the hot pressing and forming step, compressed air is used to blow the finished products onto a conveying belt, and then to an edge trimming cutter to remove the burrs. Finally, after passing the quality inspection, the products are packed and moved into the warehouse.

(75) The thickness of the fiber wall panel is 2.5 mm and the depth of convex-concave is 5 mm.

(76) Of the fiber wall panel formed, the compression strength is 200N, plane tensile strength is 0.63 Mpa, and panel density is 0.62 g/cm.sup.3.

(77) Both waterproofing effect and flame retarding effect meet Chinese state testing standard.

Preferred Embodiment 7

A Wet Process of Manufacture of Fiber Wall Panel

(78) Mix the primitive color sugar cane pulp of 70% converted dry weight with a treated rice stalk mechanic pulp of 30% dry weight according to dry weight proportion of 2:1, to yield raw material. Dry weight of the primitive color sugar cane+dry weight of rice stalk mechanic pulp=dry weight of raw material. Place this raw material in the beater and add water for dilution. Run the beater for 30 min. Then, transfer this slurry into the compounding pool, and add the waterproofing agent and flame retardant for mixing of 10 min. The amount of the waterproofing agent is 9% of the raw material dry weight and the flame retardant is 25% of the raw material dry weight. This will yield a mixed slurry. Place this mixed slurry in the slurry storage tank and add water for dilution so that raw material dry weight is 0.35% of weight of mixed slurry. Control the hot pressing upper mold temperature at 240 C. and the lower mold temperature at 260 C. Hot pressing duration shall be 20 s. All other details are the same as preferred embodiment 4.

(79) The thickness of the fiber wall panel is 2.5 mm and the depth of convex-concave pattern is 5 mm.

(80) Of the fiber wall panel formed, compression strength is 200N, plane tensile strength is 0.66 Mpa, and panel density is 0.61 g/cm.sup.3.

(81) Both the waterproofing effect and flame retarding effect meet Chinese state testing standard.

Preferred Embodiment 8

A Wet Process of Manufacture of Fiber Wall Panels

(82) Change the primitive color bamboo pulp of 60% dry weight in preferred embodiment 4 to a white sugar cane pulp of 77% dry weight. Change the sorghum stalk mechanic pulp of 10% dry weight to a wheat stalk mechanic pulp of 23% dry weight. Mix them by dry weight proportion 1:1. Do not add the waterproofing agent or flame retardant. For hot pressing, control the upper mold temperature at 110 C. and the lower mold temperature at about 120 C. Total hot pressing duration is 60 s. Other details are the same as preferred embodiment 4.

(83) The thickness of the fiber wall panel is 2.5 mm and the depth of the convex-concave pattern is 5 mm.

(84) Of the fiber wall panel formed, the compression strength is 200N, plane tensile strength is 0.63 Mpa, and panel density is 0.60 g/cm.sup.3.

Preferred Embodiment 9

A Wet Process of Manufacture of Fiber Wall Panels

(85) Change the primitive color bamboo pulp of 60% dry weight in preferred embodiment 4 to a white reed pulp of 90% dry weight. Change the sorghum stalk mechanic pulp of 10% dry weight to a corn stalk mechanic pulp of 10% dry weight. Mix these according to the dry weight proportion of 1:1. Add the waterproofing agent in the amount of 10% of the dry weight of the raw material and flame retardant in the amount of 30% of the dry weight of the raw material. Other details are the same as those of preferred embodiment 4.

(86) The thickness of the fiber wall panel is 2.5 mm and the depth of the convex-concave pattern is 5 mm.

(87) Of the fiber wall panel formed, compression strength is 200N, plane tensile strength is 0.64 Mpa, and panel density is 0.63 g/cm.sup.3.

(88) Both waterproofing effect and flame retarding effect meet the Chinese state testing standard.

(89) Finally, it is understood that the above described is only a number of particular preferred embodiments of this invention. Of course, this invention is not limited to these preferred embodiments and may have many variations, which can be made by people with ordinary skill in the art and shall be deemed within the protection scope of this invention.