CN109694535B

CN109694535B - Engineering plastic alloy composite building template and preparation method thereof

Info

Publication number: CN109694535B
Application number: CN201811615385.7A
Authority: CN
Inventors: 史京兵
Original assignee: Dongguan Senlan New Material Technology Co ltd
Current assignee: Hebei Jinxiangjin Housing Industry Technology Co ltd
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2021-02-19
Anticipated expiration: 2038-12-27
Also published as: CN109694535A

Abstract

The invention provides an engineering plastic alloy composite building template and a preparation method thereof, wherein an engineering plastic alloy is compounded on the surface of a polyvinyl chloride foam core material through a specific formula and a specific process technology by a co-extrusion process; and then co-extruding and molding the polyvinyl chloride foam core material and the engineering plastic alloy to directly obtain the engineering plastic alloy with two surface layers. The engineering plastic alloy further meets the requirements of rigidity strength, toughness and temperature resistance through blending modification, thereby further meeting the requirements of the invention. The engineering plastic composite building board solves the problem that the bending elastic modulus, the impact strength and the yield strength of the traditional plastic building board cannot be synchronously improved; the problem of compatibility of recycled materials is solved, the production process is simple, the cost is relatively low, and the market popularization is easy to accept. Once popularized in a large number, can greatly reduce deep forest felling, reduce building rubbish, reduce environmental pollution, and is environment-friendly.

Description

Engineering plastic alloy composite building template and preparation method thereof

Technical Field

The invention relates to an engineering plastic alloy composite building template and a preparation method thereof.

Background

In the process of high-speed urbanization in China, the infrastructure scale is huge, wherein the market share of the templates is about 5000 hundred million, 160 hundred million square wood building templates are consumed each year, 50 percent of the total cutting amount of commercial forests in China is consumed each year, about 2000 thousand mu of forests are consumed by low quality, and the construction waste is generated in half a year. The wooden building template not only cuts down forest resources, but also manufactures a large amount of building wastes to pollute the environment, and under the huge environmental protection pressure of China, people invest in the new material industry and use plastics as the building template.

In the building engineering, the template engineering is an important component of concrete molding, and the quality of the template not only affects the engineering progress, but also determines the concrete quality of the reinforced concrete engineering structure. The mainstream of the building template in the market at present is wood plywood, the formaldehyde content is high, the production link pollutes the environment, and the environment is polluted after the use; the turnover frequency of the wood board is reduced by about 5-8 times, and resources are wasted. The plastic template can be recycled and circulated for more than 50 times, and is an environment-friendly template; the plastic template is convenient and quick to use, and the civilized construction requirement of 'four sections and one environment protection' can be met, so that the composite plastic building template has wide application prospect.

The plastic does not absorb water, and can be used for clear water engineering; the characteristic of recycling the plastic just fits the big trend of environmental protection in China, and a plurality of companies are invested in researching and developing plastic templates. The plastic template on the market at present has the following problems: the product has low rigidity strength (bending elastic modulus), large contractibility, deformation and slurry leakage, poor flame retardance, frequent fire accidents, poor weather resistance and easy cracking in a complex use environment of a construction site; poor temperature resistance leads to uneven concrete body, influences quality and finally leads to limited market popularization.

The plastic building templates in the prior art mainly comprise the following types; the hard PVC skinning foaming plastic building board and the pp hollow plastic building template have the following performance parameters:

performance comparison table

Sheet material with thickness of 15 mm	Modulus of elasticity in bending	Flame-retardant	Shrinkage mm	Temperature resistant	Impact of drop hammer
						Wood formwork	4000-6000	High ignition point	Swelling after absorbing water		More than 40
PVC skinning	1600-2600	V0	0.5	62-75	5-8
						Pp is hollow	1800-2200	B2	3	80	12-18
The invention	2200-3800	V0	0.6	90-110	10-20

Through the comparison, the overall strength of the PVC foaming plate and the pp hollow plate is lower, the difference between the PVC foaming plate and the pp hollow plate is larger than that of a wood plate, particularly, the temperature resistance is low, a large amount of heat is released in the concrete solidification process, the temperature can reach 70-75 ℃, the temperature resistance of the PVC plate material and the pp plate material is lower, the bending elastic modulus strength at high temperature is greatly reduced, and the wave pattern of a concrete body is caused to influence the engineering quality; in addition, the impact performance of the PVC plate is too low, the shrinkage of the pp plate is large, the flame retardance is poor, and the performance defects of the two plates seriously restrict the development of the plastic building template. The composite template of the CPVC engineering plastic and ABS engineering plastic alloy material clamping PVC core plate layer has the advantages of greatly improved product performance, particularly greatly improved bending elastic modulus, small contractibility, good flame retardance, improved temperature resistance and small plate rigidity change in the high-temperature curing process of concrete.

Disclosure of Invention

The invention provides an engineering plastic composite building template and a preparation method thereof, wherein an engineering plastic alloy is compounded on the surface of a polyvinyl chloride foam core material through a specific formula and a specific process technology by a co-extrusion process; co-extruding and molding the polyvinyl chloride foam core material and the engineering plastic alloy to directly obtain an engineering plastic composite building template with two surface layers made of engineering plastics and a core layer made of polyvinyl chloride foam core layer; the engineering plastic alloy layer and the polyvinyl chloride foam core layer are directly fused, and no obvious contact interface exists between the engineering plastic alloy layer and the polyvinyl chloride foam core layer; the plate finally forms a three-layer structure with two outer surfaces being engineering plastic alloy layers and a core layer closely attached to the inner side being a polyvinyl chloride foaming layer. The engineering plastic alloy further solves the problems of mutual matching balance of rigidity strength, toughness requirement and temperature resistance and processability through blending modification, and optimizes the material performance of the alloy material, thereby further meeting the requirements of the invention. The engineering plastic alloy composite building board solves the problem that the bending elastic modulus, the impact strength and the yield strength of the traditional board cannot be synchronously improved; the problems that the temperature resistance of the plastic building template is poor, and the bending elastic modulus of the plate is sharply reduced at the high temperature of the heat release of the concrete are solved; the difficult problem that fire safety accidents are easily caused due to poor flame retardance of the plastic building template is solved; the problem of compatibility of recycled materials is solved, the production process is simple, the cost is relatively low, and the market popularization is easy to accept. Once popularized in a large number, can greatly reduce deep forest felling, reduce building rubbish, reduce environmental pollution, and is environment-friendly.

Furthermore, the inventor also finds that the second auxiliary agent and the first auxiliary agent in a specific proportion are respectively added into the CPVC material and the PVC material, so that the composite strength and the processing performance of the two materials can be improved, and the inner core material and the surface material can meet the requirements of different performances of the template. The first auxiliary agent is added with the auxiliary agent of a specific component to increase the composite hardness of the inner core, and the impact property is improved under the condition of reducing the toughness of the material in the minimum range; the fiber can increase the elastic modulus and reduce the cost;

further, the inventor also finds that the CPVC is a product of further chlorination of PVC, the chlorine content of the CPVC is between 61 and 68 percent, the physical and mechanical properties of the CPVC are greatly increased due to the increase of polar elements, but the brittleness of the CPVC is also increased synchronously, and the CPVC is not suitable for the requirements of the use environment performance of the building boards; furthermore, the intermolecular attraction is increased, the processing viscosity is high, and the processing performance is poor; the processing temperature of the CPVC is similar to that of ABS, and the compatibility of the ABS and the CPVC material is good; further, ABS belongs to a material with strong fluidity, and the ABS with strong fluidity inside an extruder screw can be separated out on the surface of the CPVC material, so that the processing resistance is reduced; further ABS is blended in the alloy system, so that the friction among CPVC molecules can be reduced, and the processing performance is improved; when 15-30 parts of ABS is further added, the impact strength of the alloy composite system on the bending strength of the CPVC material is small, the impact strength of the alloy composite system on the tensile strength of the material system is neutral, and the impact strength is increased from 11.5KJ/m2 of the CPVC to 39.5KJ/m 2; further, when 100 parts of CPVC and 15-30 parts of ABS in the second auxiliary agent are added, the performance of a blending system in which the second auxiliary agent is synchronously added is more optimized, and the tensile strength, the impact strength, the bending elastic modulus and the temperature resistance of the alloy of the blending system are kept high in balance; and the second additive is further added to improve the weather resistance elastic modulus and the processing performance of the surface layer, and the processing fluidity is improved. The CPVC has large fluidity difference and intermolecular resistance, the processing aid can be separated out from the material, and the addition of the ACR as the processing aid can well improve the processing performance, but the addition limit of the components is below 6; according to the invention, ABS semi-compatible with CPVC is used as a processing aid, so that compatibility between the ABS and CPVC is maintained, and performance complementation is realized. (reference 1001-9278,2013,10-0032-04) the ABS melt in the screw rod of the mixed material has low viscosity and strong fluidity, and the ABS is separated out of the CPVC/ABS more mixed system and is used as a lubricant, so that the stability is good; the combination of ABS and CPVC can improve the weather resistance and toughness of the product, and also improve the processability, thereby ensuring the uniform quality and complementary performance of the plastic template.

The specific scheme is as follows:

the utility model provides an engineering plastic alloy composite formwork, engineering plastic alloy composite formwork includes that two-layer engineering plastic sheet layer is the top layer, and the polyvinyl chloride foaming layer is the sandwich layer, two sides engineering plastic alloy sheet layer centre gripping polyvinyl chloride foaming sandwich layer, its characterized in that: the engineering plastic alloy composite template is obtained by co-extruding a polyvinyl chloride foam core material and an engineering plastic alloy through a double-machine method, directly compounding in a mould to obtain a composite structure of a polyvinyl chloride foam core layer clamped by two engineering plastic alloy plate layers, and cooling and shaping to obtain the engineering plastic alloy composite building template; the engineering plastic of the engineering plastic alloy composite template is selected from an extrusion-grade CPVC material, a CPVC \ ABS binary alloy material, a CPVC \ PVC \ ABS ternary blending alloy material, a CPVC \ ABS \ MBS ternary blending alloy material, a CPVC \ ABS \ POE ternary blending alloy material, a CPVC \ ABS \ ACR ternary blending alloy material, a CPVC \ CPE \ ABS ternary blending alloy material, a CPVC \ ABS \ AMS blending alloy material, a CPVC \ ASA \ ABS blending alloy material or a CPVC alloy material obtained by processing through a modified formula; the engineering plastic can be a new material or a recycled material, the foamed core layer material of the engineering plastic composite template is selected from polyvinyl chloride SG-5 or SG-7 in the model number, or a recycled and recycled polyvinyl chloride mixed material is used, the surface layer and the core layer of the engineering plastic alloy composite template are directly subjected to in-mold composite extrusion through double-machine co-extrusion, no obvious contact interface exists between the surface layer and the core layer, the compatibility of the two materials is high, and the double-machine co-extrusion equipment of the engineering plastic composite template is a conical double-screw extruder; the method is characterized in that a core layer material is extruded to form a main machine, a surface layer material is extruded to form an auxiliary machine, the expression is expressed by the main machine and the auxiliary machine, the thickness of the surface layer of the engineering plastic composite template is adjusted by adjusting the rotating speed ratio of the auxiliary machine to the main machine, the thickness of the two surface layers is 0.2-2 mm, and the overall thickness of the engineering plastic alloy composite template is 12-65 mm. The standard thickness is 15/16/18 mm.

Furthermore, the CPVC engineering plastic is an extrusion-grade material and is suitable for extrusion molding.

Further, the core layer is a hard PVC foaming core layer, and the material of the core layer also comprises calcium carbonate, a stabilizing agent, an internal lubricant, an external lubricant, an ACR processing aid, a foaming regulator, an initiator, an organic foaming agent and an inorganic foaming agent; a wood or glass fiber component; further, the core layer comprises the following raw materials in percentage by mass: 100 parts of PVC, 8-50 parts of calcium carbonate powder and 5-20 parts of wood fiber or glass fiber; 0.2-1 part of organic foaming agent; 0.1-1 part of inorganic foaming agent; 3-8 parts of stabilizer lead sulfate tribasic; 1-3 parts of dibasic lead phosphate; 0.5-2 parts of epoxidized soybean oil; 0.2-1 part of initiator, 2-6 parts of foaming regulator and a first auxiliary agent, wherein the first auxiliary agent accounts for 2-5% of the raw material of the core layer; the first auxiliary agent comprises the following components in percentage by mass:

further, the engineering plastic CPVC surface layer comprises CPVC; and a second auxiliary agent accounting for 30-40% of the CPVC by mass, wherein the second auxiliary agent comprises the following components in percentage by mass:

further, the template is applied, and the template is set according to the performance requirement of the building template and is used for manufacturing the plastic building template.

Further, a method of making the template is characterized by: the extruder for preparing the plate is a conical twin-screw extruder, wherein the extruder is generally called a main machine for extruding the core layer material, and the extruder is called an auxiliary machine for extruding the surface layer material; adding the foaming core layer PVC material, the foaming auxiliary agent, the stabilizer, the lubricant and other processing auxiliary agents and the first auxiliary agent into a high-speed mixer, mixing and stirring for 20-60 minutes, conveying the mixture into a main machine through a feeding machine, extruding the mixture, pushing the melt into a main machine runner through a screw of a main machine conical double-screw extruder, and allowing the melt to enter a distributor and enter a mold; the CPVC engineering plastic and a second auxiliary agent are put into a high-speed mixer together to be mixed for 15-30 minutes, dried for 20 minutes at 70 ℃, then enter an auxiliary machine of a conical double-screw extruder through a feeding machine to be extruded, and then a melt is pushed to a runner through the auxiliary machine to enter a distributor and then enters a die cavity through the distributor; in the die cavity, engineering plastic CPVC alloy materials are uniformly distributed on the surface of a PVC foaming material, the material treated by the distributor enters a die opening for foaming, enters a shaping plate, is shaped, cooled and cut, and the continuous molding of the template is completed through a tractor.

Further, the main machine twin-screw extruder is divided into five sections between the feed inlet and the head outlet of the extruder, wherein the temperature distribution is as follows: a first heating section of 180 ℃; a second heating section of 170 ℃; a third heating section of 170 ℃; a fourth heating section of 160 ℃; the fifth hot stage is 160 ℃; the auxiliary machine is divided into five sections between the feed inlet and the head outlet of the extruder, wherein the temperature distribution is as follows: a first heating section of 190 ℃; a second heating section of 190 ℃; a third heating section of 180 ℃; a fourth heating section of 170 ℃; the fifth heating stage is 160 ℃.

The invention has the following beneficial effects:

1. the engineering plastic CPVC alloy surface layer and the foaming PVC core layer are compounded through double-machine co-extrusion, so that the product structure is optimized, the product performance is improved, the defects of a PVC material are effectively compensated, and the recovery compatibility is excellent;

2. the corresponding auxiliary agent is added into the CPVC and the PVC, so that the performance matching of the CPVC and the PVC is further improved, and the processing stability is improved;

3. the first auxiliary agent increases the elastic modulus of the inner core, and the second auxiliary agent improves the processing performance, the strength and the weather resistance of the surface layer;

4. the long glass fibers in the inner core improve the bending impact strength of the core layer, further optimize the strength of the core layer foaming layer and reduce the cost;

5. the CPVC disclosed by the invention has high temperature resistance, exceeds the setting exothermic temperature of concrete by more than 20 ℃, and has small strength change due to high temperature resistance of one surface directly contacting with high-temperature concrete. The side of the outer side which is not contacted with the cement is contacted with the environment, the temperature is between the average temperature of normal temperature and the concrete temperature and is about 35-45 ℃, the temperature resistance is high, and the influence on the strength is small.

6. The CPVC board disclosed by the invention is poor in thermal conductivity, can delay the temperature rise of a PVC foaming layer of the core layer, prolongs the heat dissipation and absorption time, and reduces the use temperature of the board, so that the influence of temperature resistance is further reduced.

7. ABS, which should be suitable for extrusion molding, functions as a processing aid and a toughening agent in the material; the heat stabilizer is a tribasic lead sulfate and dibasic lead phosphite composite stabilizer; the calcium stearate and the zinc stearate are composite auxiliary stabilizers and have a synergistic effect with a heat stabilizer; the ACR is a processing aid and is a toughening synergistic aid simultaneously; the epoxy ester is a processing aid and is a stabilizer synergistic aid; the calcium carbonate is nano-grade calcium carbonate which is a synergistic additive and has synergistic effect on material toughening and temperature resistance. The second auxiliary agent component is not the only choice, and the components with similar functions can realize the following substitution test data in consideration of the requirements of environmental protection, cost, physical properties and the like

Note: the longer the concrete body is insulated, the better the concrete strength is.

The composite plastic building template prepared by the invention has good mechanical property, meets the requirement of building template performance, and has simple process, low cost and easy large-scale production.

Detailed Description

The present invention will be described in more detail below with reference to specific examples, but the scope of the present invention is not limited to the examples.

Example 1

Core layer raw materials: 100 parts of PVC, 40 parts of calcium carbonate powder and 5 parts of wood fiber; 0.2 part of organic foaming agent; 0.1 part of inorganic foaming agent; 3 parts of stabilizer lead sulfate tribasic; dibasic lead phosphate 1; 0.5 part of epoxidized soybean oil; 0.2 part of initiator, 2 parts of foaming regulator and a first auxiliary agent, wherein the first auxiliary agent accounts for 2% of the mass of the raw materials;

the first auxiliary agent comprises the following components in percentage by mass:

the second auxiliary agent comprises the following components in percentage by mass:

adding a core layer raw material and a first auxiliary agent into a high-speed mixer for stirring, then feeding the core layer raw material and the first auxiliary agent into a main machine conical double-screw extruder, pushing a melt into a main machine distributor through a screw of the main machine, and then feeding the melt into a mold cavity; adding 100 parts of CPVC material and 30% by mass of second auxiliary agent into a high-speed mixer for stirring and drying, then conveying the mixture into an auxiliary machine, and pushing the melt into a distributor through a screw of the auxiliary machine; and then entering a die cavity, and compounding the core layer and the surface layer in the die cavity.

The temperature zone of the main machine conical double-screw extruder is divided into five sections, and the temperature distribution is as follows: a first heating section of 180 ℃; a second heating section of 180 ℃; a third heating section of 170 ℃; a fourth heating section of 160 ℃; the fifth heating section is 150 ℃; the temperature zone of the auxiliary cone double-screw extruder is divided into five sections, and the temperature distribution is as follows: a first heating section at 200 ℃; a second heating section of 190 ℃; a third heating section of 190 ℃; a fourth heating section of 180 ℃; the fifth heating section is 170 ℃, and the rotating speed of a screw of the host extruder is 220 r/min; the CPVC material is uniformly distributed on the surface of the PVC material, extruded through a die orifice, subjected to shaping, cooling and cutting, and the molding of the template is completed under the traction action.

Example 2

Core layer raw materials: 100 parts of hard PVC, 30 parts of calcium powder, 10 parts of wood fiber and 0.2 part of organic foaming agent; 0.1 part of inorganic foaming agent; 3 parts of stabilizer lead sulfate tribasic; 1 part of dibasic lead phosphate; 0.5-2 parts of epoxidized soybean oil; 0.5 part of initiator, 3 parts of foaming regulator and 3 percent of first auxiliary agent, wherein the first auxiliary agent accounts for 3 percent of the mass of the raw materials.

adding a core layer raw material and a first auxiliary agent into a high-speed mixer for stirring, then feeding the core layer raw material and the first auxiliary agent into a main machine conical double-screw extruder, pushing a melt into a main machine distributor through a screw of the main machine, and then feeding the melt into a mold cavity; adding the CPVC material and a second auxiliary agent with the mass percentage of 30% into an auxiliary machine, and then pushing the melt to the distributor through a screw of the auxiliary machine; the main machine is divided into five sections between the feed inlet and the head outlet of the extruder, wherein the temperature distribution is as follows: a first heating section of 180 ℃; a second heating section of 170 ℃; a third heating section of 170 ℃; a fourth heating section of 150 ℃; the fifth heating stage is 140 ℃; the temperature zone of the auxiliary machine screw extruder is divided into five sections, wherein the temperature distribution is as follows: a first heating section at 200 ℃; a second heating section of 190 ℃; a third heating section of 180 ℃; a fourth heating section of 170 ℃; the fifth heating section is 170 ℃, and the rotating speed of a screw of the extruder is 260 r/min; and co-extruding the two materials through the distribution, uniformly distributing the CPVC material on the surface of the PVC material, putting the material treated by the distributor into a mould, and shaping, cooling and cutting to complete the molding of the template.

Example 3

Core layer raw materials: 100 parts of hard PVC, 30 parts of calcium powder, 10 parts of wood fiber and 0.2 part of organic foaming agent; 0.1 part of inorganic foaming agent; 3 parts of stabilizer lead sulfate tribasic; dibasic lead phosphate 1; 0.5-2 parts of epoxidized soybean oil; 0.5 part of initiator and 3 parts of foaming regulator; the first auxiliary agent accounts for 2% of the mass of the raw materials;

the first auxiliary agent comprises the following components:

adding the core layer raw material and the first auxiliary agent into a high-speed mixer for 30 minutes and drying for 20 minutes, then adding the core layer raw material and the first auxiliary agent into a main machine conical double-screw extruder, pushing a melt into a main machine distributor through a screw of the main machine conical double-screw extruder, and feeding the melt into a die cavity; adding the CPVC alloy material raw material and a second auxiliary agent with the mass percentage of 33% into an auxiliary double-screw extruder, and then pushing the melt to the distributor through a screw of the auxiliary double-screw extruder; in a die cavity, CPVC alloy material is uniformly attached to the surface of the PVC foaming core layer in the die cavity and is extruded out through a die orifice; the temperature zone of the main machine conical double-screw extruder is divided into five sections, and the temperature distribution is as follows: a first heating section of 170 ℃; a second heating section of 170 ℃; a third heating section of 160 ℃; a fourth heating section of 150 ℃; the fifth heating stage is 140 ℃; the auxiliary cone double-screw extruder is divided into five sections between the feed inlet and the head outlet of the extruder, and the temperature distribution is as follows: a first heating section of 180 ℃; a second heating section of 180 ℃; a third heating section of 160 ℃; a fourth heating section of 150 ℃; the rotating speed of a screw of the host extruder is 260r/min at the fifth heating section of 140 ℃; the CPVC alloy material is uniformly distributed on the surface of the PVC material, the material treated by the distributor enters a die, and the die is foamed at the outlet, shaped, cooled and cut to complete the molding of the template.

Example 4

Core layer raw materials: the components by mass ratio are as follows: 100 parts of PVC, 25 parts of calcium carbonate powder and 15 parts of wood fiber; 0.2 part of organic foaming agent; 0.2 part of inorganic foaming agent; 3 parts of stabilizer lead sulfate tribasic; 1 part of dibasic lead phosphate; 0.5 part of epoxidized soybean oil; 0.2 part of initiator, 2 parts of foaming regulator and a first auxiliary agent, wherein the first auxiliary agent accounts for 3% of the mass of the raw materials;

the first auxiliary agent comprises the following components in parts by mass:

stirring the core layer raw material and the first auxiliary agent through a high-speed mixer, drying at 70 ℃, adding the core layer raw material and the first auxiliary agent into a main machine conical double-screw extruder through a feeding machine, and pushing a melt to the distributor through a screw of the conical double-screw extruder; adding the engineering plastic CPVC and 40% of a second auxiliary agent into an auxiliary cone double-screw extruder, and then pushing the melt into the auxiliary distributor through a screw of the auxiliary cone double-screw extruder; the temperature zone of the main double-screw extruder is divided into five sections, wherein the temperature distribution is as follows: first heating to 180 ℃; a second heating section of 170 ℃; a third heating section of 170 ℃; a fourth heating section of 160 ℃; the fifth heating stage is 140 ℃; the auxiliary cone double-screw extrusion temperature zone is divided into five sections, wherein the temperature distribution is as follows: a first heating section at 200 ℃; a second heating section of 190 ℃; a third heating section of 170 ℃; a fourth heating section of 160 ℃; the fifth heating section is 140 ℃, and the rotating speed of a screw of the extruder of the main extruder is 260 r/min; and co-extruding the two materials through the distribution, uniformly distributing the CPVC material on the surface of the PVC material, allowing the material treated by the distributor to enter a die, foaming through a die outlet, shaping, cooling and cutting to complete the molding of the template.

Comparative example 1

Commercially available PVC skinning template, PP hollow template, PVC co-extrusion template

TABLE 1

Through the comparison, the change of the first auxiliary agent in the range of the invention has little influence on the performance, the distribution interval is proved to be reasonable, and the processing system of the invention has stronger stability; the content of ABS in the second auxiliary agent accounts for 15-25 mass percent of the total components, and the impact and modulus of the product material and the overall performance of the temperature resistance are not greatly changed; in addition, according to the experiment, when the ABS is powder, the ABS, the CPVC and the auxiliary agent are mixed well, and the product performance is superior to that of a granulating material.

At 70 ℃, the modulus of the product is reduced. At high temperatures, the core layer has poor temperature resistance, which results in slippage at the material interface, and thus the modulus is greatly reduced. However, the temperature resistance of the surface layer of the CPVC composite material is higher than that of the traditional product by more than 20 ℃, and the CPVC composite material has small heat conductivity coefficient, so that the temperature of the outer layer of the plate becomes low in the actual use process, the heat preservation time of a concrete body is prolonged, and the heat dissipation becomes slow, so that the PVC foam material with poor temperature resistance of the core layer is weakened by temperature influence factors, the strength of the PVC foam material is improved, the impact strength and the tensile strength of the outer layer of the surface layer are further far greater than those of the traditional pp and PVC, so that the PVC foam material keeps very strong performance in the slow expansion process of the inner side pressure, the deformation degree is small, more support effect is provided for the core layer, the influence of the curing temperature of. Therefore, the performance of the invention is superior to the normal temperature performance plate on the market at 70 ℃.

Compared with ABS in the surface layer material, the ABS has toughening effect, and the optimal mixing ratio of the ABS to the CPVC material is 15-30% to achieve optimal performance. The outer skin layer maintains higher impact and elongation at break, so the strength is higher. The first auxiliary agent and the second auxiliary agent are beneficial to improving the product performance.

Material properties are compared in table 2.

Comparative description 1:

the impact strength and the flexural modulus of the CPVC co-extruded PVC foamed sheet in the table 1 are greatly improved, the balance improvement is achieved, and the product performance is optimized.

Comparative description 2;

under the condition of 70 ℃, the flexural modulus of the product is higher, the temperature loss time of the concrete body is delayed, and the influence of temperature resistance is reduced.

Comparative description 3:

the analysis of the table 2 shows that the alloy prepared by combining the engineering plastic CPVC with high bending elastic modulus, high tensile strength, low impact strength and poor fluidity and the engineering plastic ABS with high bending elastic modulus, high impact strength and good fluidity has complementary advantages, and the impact strength bending elastic modulus and the temperature resistance processing fluidity are balanced. The impact strength of the alloy system far exceeds that of single CPVC or ABS.

Comparative description 4:

compared with the traditional pp plate, the invention solves the problems of flame retardance and 4-6 mm contraction of the abutted seam of two plates. CPVC has a self-flame resistance exceeding that of all commercial products of the same type and has low shrinkage.

Comparative description 5;

the product provided by the invention has the advantages of greatly improved tensile strength, bending strength and bending modulus, good toughness, high strength and difficult deformation.

Comparative description 6;

the PVC core layer with good weather resistance and poor weather resistance does not contact the natural environment, the compatibility of the skin layer material and the core layer material is good in the recovery process, and the skin layer material serves as a reinforcing material for reprocessing the core layer material after recovery, so that the plate is low in cost and suitable for the recycling characteristic of various building plates.

Other comparisons describe 7: the present invention relates to material comparison.

Compared with the invention experiment, the fiber is added in the material components of the core layer, and the good complementarity between the calcium powder and the fiber can properly improve the bending elasticity and the high modulus of the product, but the impact on the overall performance of the plate is little, and the material cost is reduced.

Comparative description 8;

compared with the traditional PVC or PP, the bending elastic modulus of the product is greatly improved in a use environment of 70 ℃, because the alloy material of the skin layer has high temperature resistance and high mechanical strength, and changes little at high temperature, and further the bending elastic modulus impact strength of the alloy material is twice as high as that of the traditional material, so that the plate can be provided with stronger bending strength.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. The invention mainly protects the CPVC, the CPVC/ABS modified material with different performance components and the co-extrusion of PVC foaming, which belong to the protection range of the invention.

Although the core layer PVC material is limited by the invention, the polyvinyl chloride SG-5 or SG-7 series is generally selected, the core layer material is not limited only, but preferably, the PVC material recycled in the market, the hard plate material and the pipeline material plastic steel door and window material can be mixed with each other for use after the ash filling ratio is determined. Thereby achieving the purpose of the invention.

Therefore, the protection range of the invention is mainly limited in the building board industry, and the main performance is designed aiming at the building template.

Claims

1. The utility model provides an engineering plastic alloy composite formwork, engineering plastic alloy composite formwork includes that two-layer engineering plastic sheet layer is the top layer, and the polyvinyl chloride foaming layer is the sandwich layer, two-layer engineering plastic sheet layer centre gripping the polyvinyl chloride foaming layer, its characterized in that: the engineering plastic alloy composite template is obtained by co-extruding a polyvinyl chloride foam core material and an engineering plastic alloy through a double machine, directly compounding in a mould to obtain a composite structure of a polyvinyl chloride foam layer clamped by two engineering plastic plate layers, and cooling and shaping to obtain the engineering plastic alloy composite template; the engineering plastic plate layer of the engineering plastic alloy composite template is a CPVC alloy material obtained by processing through a modification formula; the CPVC alloy material comprises CPVC; and a second auxiliary agent accounting for 30-40 mass% of the CPVC, wherein the second auxiliary agent comprises the following components in percentage by mass:

the polyvinyl chloride foaming layer of the engineering plastic alloy composite template comprises the following core layer raw materials in percentage by mass: 100 parts of PVC, 8-50 parts of calcium carbonate powder and 5-20 parts of wood fiber or glass fiber; 0.2-1 part of organic foaming agent; 0.1-1 part of inorganic foaming agent; 3-8 parts of stabilizer lead sulfate tribasic; 1-3 parts of dibasic lead phosphite; 0.5-2 parts of epoxidized soybean oil; 0.2-1 part of initiator, 2-6 parts of foaming regulator and a first auxiliary agent, wherein the first auxiliary agent accounts for 2-5% of the raw material of the core layer; the first auxiliary agent comprises the following components in percentage by mass:

the surface layer and the core layer of the engineering plastic alloy composite template are directly subjected to in-mold composite extrusion through double-machine co-extrusion, the surface layer and the core layer do not have obvious contact interfaces, the compatibility of the two materials is high, and the double-machine co-extrusion equipment of the engineering plastic alloy composite template is a conical double-screw extruder; the method is characterized in that a core layer material is extruded to form a main machine, a surface layer material is extruded to form an auxiliary machine, the expression is expressed by the main machine and the auxiliary machine, the thickness of the surface layer of the engineering plastic alloy composite template is adjusted by adjusting the rotating speed ratio of the auxiliary machine to the main machine, the thickness of the two surface layers is 0.2-2 mm, and the overall thickness of the engineering plastic alloy composite template is 12-65 mm.

2. The use of the engineering plastic alloy composite template of claim 1, wherein the engineering plastic alloy composite template is set for the performance requirements of a building template and is used as a plastic building template.

3. A method of preparing the engineering plastic alloy composite template of claim 1, wherein: the extruder for preparing the engineering plastic alloy composite template is a conical double-screw extruder, wherein the conical double-screw extruder is generally called a main machine for extruding a core layer material, and the auxiliary machine for extruding a surface layer material; adding the raw materials of the polyvinyl chloride foaming layer into a high-speed mixer, mixing and stirring for 20-60 minutes, conveying the raw materials into a main machine through a feeding machine, extruding, pushing a melt into a main machine runner through a screw of a main machine of the conical double-screw extruder, and allowing the melt to enter a distributor and enter a die; putting the raw materials of the CPVC alloy material into a high-speed mixer together, mixing for 15-30 minutes, drying for 20 minutes at 70 ℃, then feeding the mixture into an auxiliary machine of a conical double-screw extruder through a feeding machine for extrusion, then pushing the melt into a runner through the auxiliary machine, feeding the melt into a distributor, and then feeding the melt into a die cavity through the distributor; in the mould cavity, the CPVC alloy material is uniformly distributed on the surface of a PVC foaming material, the material treated by the distributor enters a mould opening for foaming, enters a shaping plate, is shaped, cooled and cut, and the continuous shaping of the engineering plastic alloy composite template is completed through a tractor.

4. The method for preparing an engineering plastic alloy composite template according to claim 3, wherein the main machine is divided into five sections between the feed inlet and the head outlet of the extruder, wherein the temperature distribution is as follows: a first heating section of 180 ℃; a second heating section of 170 ℃; a third heating section of 170 ℃; a fourth heating section of 160 ℃; the fifth hot stage is 160 ℃; the auxiliary machine is divided into five sections between the feed inlet and the head outlet of the extruder, wherein the temperature distribution is as follows: a first heating section of 190 ℃; a second heating section of 190 ℃; a third heating section of 180 ℃; a fourth heating section of 170 ℃; the fifth heating stage is 160 ℃.