DESC:FIELD
The present disclosure relates to a polymer composition.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used to indicate otherwise.
Canopy: The term “canopy” refers to a cover that spreads out and covers an area. In automotive vehicles, canopy is also known as a bubble canopy or a cockpit canopy.
Aspect ratio: The term “aspect ratio” refers to the ratio of the width to the height of a particle. In respect of the present disclosure, the aspect ratio of the filler corresponds to the width to the height of a filler particle.
Warpage: The term “warpage” refers to extent or result of being bent or twisted out of shape, typically as a result of the effects of heat or damp.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Challenges in the automotive industry are increasing for vehicle safety, performance, and customer perceived quality, and environmental concerns. Canopy structure plays a pivotal role as a shielding protection for the vehicle in terms of avoiding entry of dust and water inside the vehicle and withstanding heat during day. Conventional canopy structures used in the vehicle are made from either metal or polyamide composition.
However, these conventional canopies are heavier in weight and have low thermal and dimensional stability under sun, and moderate mechanical properties while the vehicle is in motion. Further, the water repellant property of the conventional canopy significantly reduces after a certain amount of time.
There is, therefore, felt a need for a composition for preparing the canopy structure that mitigates the drawbacks mentioned hereinabove.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a polymer composition.
Another object of the present disclosure is to provide a polymer composition for canopy structure.
Still another object of the present disclosure is to provide a canopy structure with improved thermal and dimensional stability.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a polymer composition. The polymer composition comprises a polypropylene copolymer compound; glass fibers; and mica as a filler. The ratio of glass fibers to mica filler in the polymer composition is 1:1.
The polymer composition of the present disclosure used in automotive canopy structure. The canopy structure is prepared from the polymer composition of the present disclosure has improved mechanical, thermal and dimensional strength.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 represents a graphical representation of comparison between density of a canopy structure prepared from conventional composition and a canopy structure prepared from the polymer composition in accordance with the embodiments of the present disclosure.
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
Conventionally, the automotive canopy structure is made from metal and polyamide composite material. However, the canopy structures made from metal and polyamide composite material are heavier in nature and do not have the desired mechanical strength and thermal properties.
The present disclosure therefore provides a polymer composition, which is capable of providing enhanced mechanical, thermal and dimensional strength to an automotive canopy structure.
In an aspect of the present disclosure, there is provided a polymer composition. The polymer composition of the present disclosure is particularly used for preparing a half tail canopy structure.
The polymer composition comprises a polypropylene copolymer compound in an amount in the range of 65 to 75 wt%; a glass fiber in an amount in the range of 10 to 20 wt%; and mica filler in an amount in the range of 10 to 20 wt%.
In accordance with the embodiments of the present disclosure, a polypropylene copolymer in an amount in the range of 68 to 72 wt%; glass fibers in an amount in the range of 12 to 18 wt%; and mica as a filler in an amount in the range of 12 to 18 wt%.
In accordance with an exemplary embodiment of the present disclosure, the polymer composition comprises a polypropylene copolymer compound in an amount of 70 wt%; a glass fiber in an amount of 15 wt%; and mica filler in an amount of 15 wt%.
The polypropylene copolymer is a polypropylene block copolymer having the ethene content in the range of 5 to 15%. In accordance with the exemplary embodiments, the polypropylene block copolymer has the ethene content of 10%.
Glass fibers are selected from glass roving, glass chopped strand, or glass milled fiber which are commonly used for reinforcement of polymer. Typically, the length of the glass fibers is in the range of 3 mm to 5 mm and the diameter of the glass fibers is in the range of 9 µm to 14 µm.
Typically, the aspect ratio of mica is in the range of 20 to 40.
In accordance with the embodiments of the present disclosure, the ratio of glass fiber to mica filler is 1:1.
In accordance with the present disclosure, the polypropylene copolymer is modified by incorporation of glass fiber and mica, the two fillers exhibit a synergistic effect in providing the composition with improved durability, tensile strength along with reduced weight.
The polymer composition of the present disclosure comprising the combination of polypropylene copolymer compound with glass fibers and mica as a filler exhibit optimum MFI, tensile strength, flexural modulus and HDT properties, which further helps in complying stringent structural accelerated durability test criteria.
Optimum MFI of the polymer composition ensures uniform filling and warpage optimization of the canopy structure. Optimum tensile strength and flexural modulus of the polymer composition ensure very low deflection of the canopy structure under vehicle vibration, sun load and aerodynamic drag load. Optimum HDT of the polymer composition ensures dimensional stability of the canopy structure.
In accordance with the present disclosure, if the quantity of mica is less than 10 wt%, the synergistic effect with glass fiber is not sufficient to improve tensile strength and moldability. Moreover, if the quantity of mica is more than 20 wt%, the tensile strength, impact resistance, and moldability are adversely affected. Also, the higher amounts of the filler lead to increased weight of the polymeric composition and hence increased weight of canopy structure.
In another aspect, there is provided a process for preparing the polymeric composition. The process comprises mixing a polypropylene copolymer with glass fiber and mica to obtain a blend. The so obtained blend is melt kneaded at a temperature in the range of 200 to 250°C using an extruder to obtain the polymeric composition.
In still another aspect, the present disclosure provides a canopy structure prepared by using the polymer composition. The canopy structure has a three piece assembly of a rigid structure on which a canopy sheet is wrapped and mounted. The packing used is of high mounted stop lamp (HSML) at the top trim of the plastic structure that has wiring harness rooting. The packaging technique used avoids additional components in an electrical system. Canopy structure of the present disclosure is used as a half tail door canopy that can replace door sealing which covers raw edge of the sheet metal.
The canopy structure prepared using the polymer composition of the present disclosure is light weight as compared to conventional metal canopy. Further, the optimized flow behavior, tensile strength, modulus, impact strength, thermal properties and dimensional stability of polypropylene copolymer compound provides improved mechanical, thermal and dimensional strength to a canopy structure.
It is observed that there are no abnormalities like crack, deformation, softening, war page, visual discoloration and loosening, when the polymer composition of the present disclosure is subjected to long term heat and humidity aging tests. The heat and humidity aging tests are performed at 80 °C for 500 hours and 40±2 °C at 95±5% relative humidity for 168 hours, respectively.
No cracks are found in any of the points on canopy structure made from the polymer composition of the present disclosure, when subjected to cold impact test, performed at -30 °C for 5 hours.
It is further observed that there is no shearing and material chip off on the polymer composition of the present disclosure, when subjected to torque test and serviceability test, performed at the torque specification of 5 Nm.
Further, after completion of 100 cycles no cracks are seen on canopy structure made from the polymer composition of the present disclosure when subjected to vehicle durability test.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Experiment-1: Preparation of polymer composition in accordance with the present disclosure
Initially, Polypropylene block copolymer having ethene content of 10% (70 gm) was mixed with glass fiber (15 gm) and mica (15 gm) to obtain a blend. The so obtained blend is melt kneaded at a temperature of 250°C using an extruder to obtain the polymeric composition.
Experiment-2: Comparative example
The similar experimental procedure was followed as disclosed in experiment 1, excluding glass fibers. The polymer composition was prepared using Polypropylene copolymer (70 gm), and mica filler (30 gm).
Experiment-3: Comparative example
The similar experimental procedure was followed as disclosed in experiment 1, excluding of mica (filler). The polymer composition was prepared using Polypropylene copolymer (70 gm), and glass fibers (30 gm).
Various tests were performed such as component level test, long term heat aging test, humidity aging test, cold impact test, torque test, serviceability test, vehicle level test, structural durability test and tooling test on the polymer composition of the present disclosure.
The results are summarized in Table-1 below.
Table 1: Comparison of the properties of the polymer compositions
Properties Conventional Polymer composition (PA6+30%GF) Polymer composition of the present disclosure example 1 Comparative example 2 Comparative example 3
MFI
g/10min NA min 9 min 3 min 9
Density
gm /cc max 1.38 max 1.16 max 1.16 max 1.18
Mpa min 160 min 80 min 80 min 32
Flexural modulus
Mpa min 6400 min 6000 min 5400 min 4400
Notched Izod impact strength
kJ/m2 min 8.3 min 8.5 min 9 min 2.5
HDT
°C max 220 max 155 max 160 max 140
It is evident from Table-1 that the polymer composition of the present disclosure has lower density as compared to the conventional polymer composition used for canopy. Further, the polymer compositions prepared in accordance with comparative examples 2 and 3 also exhibit lower density as compared to the conventional polymer composition. However, flexural modulus, notched Izod impact strength and HDT of the polymer compositions prepared in accordance with comparative examples 2 and 3 also decreases along with reduction in density. Whereas, the polymer composition of the present disclosure exhibit comparable flexural modulus, notched Izod impact strength and HDT with respect to the conventional polymer composition along with reduction in density.
Therefore it is found that the polymer composition of the present disclosure is capable of providing the canopy structure with excellent balance in mechanical, thermal and dimensional stability properties along with reduced weight.

TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a polymer composition comprising polypropylene copolymer, glass fiber and mica filler for canopy structure having:
- High durability, strength and reliability of canopy structure;
- Improved safety measures; and
- Reduced weight.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A polymer composition comprising:
a. a polypropylene copolymer in an amount in the range of 65 to 75 wt%;
b. glass fibers in an amount in the range of 10 to 20 wt%; and
c. mica as a filler in an amount in the range of 10 to 20 wt%.
2. The composition as claimed in claim 1 comprising:
a. the polypropylene copolymer in an amount in the range of 68 to 72 wt%;
b. glass fibers in an amount in the range of 12 to 18 wt%; and
c. mica as a filler in an amount in the range of 12 to 18 wt%.
3. The composition as claimed in claim 1 comprising:
a. the polypropylene copolymer in an amount of 70 wt%;
b. glass fibers in an amount of 15 wt%; and
c. mica as the filler in an amount of 15 wt%.
4. The composition as claimed in claim 1, wherein the ratio of glass fiber to mica is 1:1.
5. The composition as claimed in claim 1, wherein the length of the glass fibers is in the range of 3 mm to 5 mm and the diameter of the glass fibers is in the range of 9 µm to 14 µm.
6. The composition as claimed in claim 1, wherein the aspect ratio of mica is in the range of 20 to 40.
7. A process for preparing the polymer composition comprising the following steps:
a. mixing a polypropylene copolymer with glass fiber and mica to obtain a blend; and
b. melt kneading said blend to obtain the polymeric composition.
8. The process as claimed in claim 7; wherein said step of melt kneading is carried out at a temperature in the range of 200 to 250°C.
9. A canopy structure prepared from the polymeric composition as claimed in claim