JPS62109739A - Drum made of synthetic resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin drum having a structure suitable as a container for transporting chemicals and the like. More specifically, the top plate and the base plate are integrally formed by blow-molding an olefin polymer, and the top plate or the base plate is provided with a grip portion, and the base of the grip portion is at least 15 meters from the outer periphery.
The present invention relates to a synthetic resin drum which is provided on the inside of the synthetic resin drum and further has a gripping part having an inclined compression width of at least 15IIll, and which has a structure suitable as a container for transporting chemicals and the like. The purpose is to

The use of resin for large containers such as the Yorimen JΣ Hidekari drum is considered to be extremely effective in reducing weight, improving durability, and improving rust prevention.
Various types of synthetic resin drums are already in use in Europe and America. In Japan as well, studies are rapidly progressing into using resin for closed drums, which are currently mostly made of metal.

However, due to the prevalence of existing steel drums,
Although the value of resin is recognized, there are some problems with handling and other issues.

In order to solve this handling problem, synthetic resin drums are being developed by fitting a synthetic resin ring formed by injection molding onto the top of the drum body, which is formed by blow molding an olefin polymer. A method [hereinafter referred to as "Method (1)"], a method in which a gripping portion is integrally formed during hollow molding on the outer periphery of the drum [hereinafter referred to as "Method (2)"]
''], a method [hereinafter referred to as ``Method (3)''] has been proposed in which a grip portion is integrally formed at a part of the corner of the top plate and the outer periphery. However, individual synthetic resin drums manufactured by these methods have the following problems.

In the synthetic resin drum manufactured by method (1),
Although it is possible to transport the steel drum using a handling jig, it is not only more complex than a drum formed integrally by hollow molding, but also requires an injection molded ring to be fitted. 1Not only does the weight increase,
The cost will be high. Furthermore, a step of fitting the drum body into a hollow-molded drum body is required, which leads to an increase in costs. Furthermore, since the ring is formed by injection molding, the average molecular weight of the synthetic resin used is low, so the impact strength is low, and this is the main cause of breakage due to impact such as when the drum is dropped.

Furthermore, in the case of the synthetic resin drum manufactured by method (2), the handling jig for the steel drum currently on the market hits the top plate of the chucking part, making it impossible to grip it. . Furthermore, in order to serve both as a steel drum and as a handling jig, it is necessary to form the gripping portion as close to the top plate or base plate as possible. Therefore, due to the difference in blow ratio during blow molding, which is a disadvantage of the blow molding method, a difference in wall thickness occurs between the parting line direction of the product and the direction perpendicular to the parting line, resulting in notches and buildup on the inner surface of the grip. , and the concentrated stress applied to the gripping part during a fall may cause it to break.

Furthermore, the synthetic resin drum manufactured by method (3) can be transported using a handling jig for the steel drum, but the blowing during blow molding is more difficult than forming a grip part integrally on the side of the drum. The difference in ratio is too sharp and the balance of wall thickness is poor. From this, the weight should be reduced by 15% to 20%.
Since it is necessary to increase the percentage, the cost will increase. In addition, similar to when a gripping part is attached to the outer periphery of a drum, notches or buildup may occur on the inner surface of the gripping part, which may break due to impact when dropped.

Furthermore, if the gripping part is integrally formed on the side of the drum body or at the corner between the top plate and the outer periphery during hollow molding, there will be a large difference in blow ratio in the circumferential direction of the drum, and the inner surface of the gripping part will Notches and build-up occur, reducing the impact strength when dropped.

From the above, the present invention does not have these drawbacks (problems), namely, it eliminates the notches and build-up that occur on the inner surface of the grip part that is integrally formed during blow molding (hollow molding). prevent,
To obtain a synthetic resin drum with improved breakage by improving impact strength when dropped.

. According to the present invention, these problems can be solved by forming the top plate and the base plate integrally by blow-molding an olefin polymer, and providing a gripping portion on the top plate or the base plate. The base of the grip portion is provided at least 15 mm inward from the outer periphery, and the width of the inclined compressed portion of the grip portion is at least 15 mm.
This can be solved by a synthetic resin drum having m trays. The present invention will be explained in detail below.

The olefin polymers used in the present invention are, among others, ethylene homopolymers with a density of 0.935 g/crn" or more, and ethylene and α-olefins containing ethylene as the main component (usually having 3 to 12 carbon atoms). , the copolymerization ratio is at most 15% by weight).The molecular weight of these ethylene homopolymers and copolymers of ethylene and α-olefin depends on the size and (capacity) of the container. Although different, the melt flow index (JIS
Measured according to K-13780 at a temperature of 180°C and a load of 21.6 kg, hereinafter r HLMERJ
For example, in the case of a container with a capacity of 200 liters, it is generally 5.0 g/10 minutes or less, and 4.
0 g/10 minutes or less is preferable, especially 3.5
g 710 minutes or less is suitable. Also, the capacity is 2
For containers with 0 sentences, the HLMER is usually between 5 and 5071.
0 minutes, preferably 10 to 50 g/10 minutes, particularly preferably 10 to 40 g/10 minutes.

The above olefin polymers are processed by blow molding, which is commonly performed in the field of olefin polymers.
The present invention can be achieved by manufacturing a drum having a top plate and a base plate with side plates and a gripping portion as described below, etc., by a method. At this time, the molding temperature is usually 180~250°c-c', and especially 180~23°C.
0°C is preferred.

In manufacturing the synthetic resin drum of the present invention, one of the features is that in order to reduce the difference in blow ratio, gripping parts are provided on the top plate and the base plate, and the base of this gripping part is set at least 151 mm from the outer periphery of the drum. By providing this on the inside, the distance that the parison stretches is reduced, preventing notches and buildup that occur on the inner surface of the integrally formed grip part during blow molding, and improving strength against impact when dropped. It is to let

Furthermore, in order to integrally form the gripping part, it is necessary to operate a part of the molds for the top plate and the base plate to weld the parison which has been pre-blown once during blow molding. In order to improve the welding strength of the welded gripping portion and to prevent notches and build-up from occurring on the inner surface of the gripping portion, it is possible to tilt the welded gripping portion in the outer circumferential direction and compress the pre-blown parison by 15 mm or more. is necessary. Furthermore, by inclining the gripping portion and bringing the tip closer to the outer periphery of the drum, it becomes possible to easily transport it with a handling jig for steel drums.

Second, if gripping portions are formed on the outer periphery and on a portion of the corners of the top plate and the base plate, stacking of the drums is impossible. In addition, if a grip part is formed on the outer periphery, it is necessary to form irregularities on the top plate and base plate and fit them.
The appearance of the product deteriorates.

In contrast, in the present invention, it is possible to form the grip portions on the top plate and the base plate, and the grip portion formed on the base plate surface is made to have a slightly smaller diameter than the grip portion formed on the top plate surface. This makes it easier to stack the drums, which was impossible with conventional drums, and makes it easier to store and transport the drums.

Hereinafter, a specific example of a synthetic resin drum according to the present invention will be described in more detail with reference to FIGS. 1 to 5, in which it is illustrated, and compared with a comparative example.

FIG. 1 is a side view of the synthetic resin drum of the present invention. In this figure, l is the drum body.

2 is a grip provided on the top plate, and 3 is a grip provided on the base plate.

2-A and 2-B are enlarged longitudinal cross-sectional views of a portion of the drum near the gripping portion (indicated as A in FIG. 1). In these figures, 4 and 8 are gripping parts, and 5 and 9 are top plates. Also, 6 and 10
is the outer periphery (side plate). Further, 7 is a padding on the inner surface of the gripping portion, and 11 is a notch on the inner surface of the gripping portion. Moreover, a is the dimension from the outer periphery to the base of the gripping part, and b is the width of the inclined compression part. Additionally, Figures 3-A and 3
-B is an enlarged longitudinal sectional view of a portion near the grip portion (indicated as A in FIG. 1). In these figures, 12 and 17 are gripping parts, and 13 and 18 are top plates. Further, 14 and 19 are outer peripheries. Further, 15 and 20 are notches on the inner surface of the grip part, and 16
is the padding on the inner surface of the grip. a and b are the same as above. Moreover, FIG. 4 is a partially enlarged cross-sectional view when stacking at the grip portion. In this figure, 21 and 25 are the outer periphery, and 22 is the base plate. Further, 23 is a grip portion provided on the base plate, and 24 is a grip portion provided on the top plate. Furthermore, 26 is a top plate. moreover,
FIG. 5 is a cross-sectional view of a hollow mold for forming the grip portion. In this figure, 27 is an operating mold;
8 is a grip portion. 29 is a hydraulic cylinder. Further, 30 is the inner surface of the mold for forming the grip portion.

If the base of the grip provided on the top plate and base plate is installed less than 15 mm (for example, 10 mm) from the outer periphery, Figure 3-A (partial enlarged sectional view of the grip in the parting direction) and Figure As shown in Figure 3-B (partially enlarged cross-sectional view of the gripping part in the direction perpendicular to the parting), notches 15 and 20 and build-up 16 are generated on the inner surface of the gripping part, so the impact when dropped is It joins intensively and is easy to destroy. On the other hand, as shown in Figure 2-A (partially enlarged sectional view of the gripping part in the parting direction) and Figure 3-B (partially enlarged sectional view of the gripping part in the direction perpendicular to the parting line), The base of the grip part provided on the top plate and the base plate should be set at least 15 mm from the outer circumference (depending on the embodiment, the padding 7 and notch 11 on the inner surface of the grip part are gentle, so that the impact is not applied intensively, Improved strength against impact when dropped.

Next, the formation of the grip portion in the present invention will be explained based on FIG. 5. A parison of the molten olefin polymer is sandwiched between molds, and then pre-blown to extend it to the mold inner surface 30 for forming the gripping part of the parison, and the working mold 27 is heated from 0 part to C° part. It is moved by a hydraulic cylinder 29 to form a grip portion 28. Thereafter, the synthetic resin drum of the present invention can be formed by blow molding (hollow molding) under the above conditions.

7. The present invention will be explained in more detail with reference to Examples below.

In addition, in the Examples and Comparative Examples, the impact resistance due to dropping of each obtained olefin polymer drum was determined according to Section 6-A.
A reverse diagonal drop test [hereinafter referred to as r(1)J] as illustrated in the figure and a lateral drop test [hereinafter referred to as (II)J] as shown in Figure 6-B were conducted. Ta. In these figures, 31 and 32 are plug parts. Further, 33 is a top plate, and 34 is a bottom plate. Furthermore, 35 is a grip portion.

In addition, the drum body has a density of 0.955 g/ct
High density polyethylene (HLMER2, Og/
10 minutes), and the ring has a density of 0.955 g/
High density polyethylene (MFR4,0g
/io minutes) was used.

Example 1, Comparative Examples 1 to 3 Using the above-mentioned high-density polyethylene, the resin temperature was 200°
A high-density polyethylene drum was manufactured by blow molding using C.

Example 1 has a grip portion in which a is 20 m5+ and b is 30 mm in Fig. 2-A, and the total weight is 8.8 kg. Further, in Comparative Example 1, a grip portion was attached to a part of the corner of the top plate and the side plate, and the total weight was 11.5 kg. In Comparative Example 2, a grip portion was attached to the outer periphery (side plate) approximately 5011 Il below the top plate, and the total weight was 10.0 kg.

Furthermore, Comparative Example 3 is a case where a pre-molded ring is fitted, and the total weight is 12.0 kg.

The capacity of these drums is all 210 m, the dimensions are height 890-930 m, outer diameter (maximum)
is 580-800 am.

Each of the olefin polymer drums obtained in this way was filled with 220 kg of a mixed solution of ethylene glycol and water, and then pre-cooled in a cold bath at -18 to -23°C. A reverse diagonal drop test ((I)) and a lateral drop test ((II)) were performed on 10 pieces each on a side iron plate so that each drop point was a parting part.
I did it. The results are shown in Table 1. The numbers shown in Table 1 are the number of items broken out of 10 in each drop test I.

1st Omote Hikari JL! ZIJI The synthetic resin (olefin polymer) drum of the present invention exhibits the following effects (characteristics) including its manufacturing process.

(1) It can be transported using a steel drum handling jig.

(2) It has excellent impact strength when dropped, and will not break if dropped from a height of 1.0 to 1.6 m, even if it is filled with contents.

(3) Cooking is easy when stacking.

(4) It can be manufactured at low cost and can be manufactured easily.

(5) It is lightweight.

[Brief explanation of drawings]

FIG. 1 is a side view of a synthetic resin drum. Figures 2-A and 2-n are enlarged vertical cross-sectional views of part A of the drum of the present invention, and Figures 3-A and 3-B are enlarged longitudinal cross-sectional views of part A of the drum of the comparative example. It is a diagram. Moreover, FIG. 4 is a partial enlarged cross-sectional view when the 4711+ and ¥ portions are screwed together, and FIG. 5 is a hollow molding die for forming the gripping portion. Furthermore, FIG. 6-A is a state diagram of a reverse diagonal drop test, and FIG. 6-B is a state diagram of a lateral drop test. 1...Drum body 2...Grip part 3 provided on the top plate...
Grip portion provided on the main plate 4.8.12.17...
・Grip part 5.9.13.18.26...Top plate 6
．． 10.14.19.21.25...Outer circumference 11
．． 15.20... Notch 7.1 on the inner surface of the grip part
6...Thickening on the inner surface of the grip 23...
Grip portion 24 provided on the base plate... Grip portion 22 provided on the top plate... Base plate

Claims (1)

[Claims] The top plate and the base plate are integrally formed by blow-molding an olefin polymer, and the top plate or the base plate is provided with a gripping portion, and the base of the gripping portion is at least 15 mm from the outer periphery.
A drum made of synthetic resin, which is provided on the inside and further has a width of at least 15 mm in the inclined compression part of the grip part.