Rotating Drum Handle Placement for High-Speed Bag Manufacturing
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Solution Overview
Problem
Existing methods for manufacturing bags with handles, such as those described in US Pat. No. 3,439,591 and US 5,609,556, face limitations in production rate due to sudden acceleration of handles and lack of reinforcement, leading to potential tearing and restricted bag size for storage and transport.
Innovation Solution
A method and machine that involves a rotatably mounted handle laying drum where the handle is turned over before placement on the bag wall, allowing legs to be positioned forward and glued, with optional reinforcement sheets applied, enabling continuous and high-speed handle laying without sudden acceleration, and adjustable drum speed for variable bag lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If handles are inserted using a fixed station with brutal acceleration from very low speed to tape speed, then handles can be positioned on the bag wall, but the manufacturing rate is limited
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed station with a rotating drum that moves at variable speeds. The drum rotates slowly during handle placement to avoid sudden acceleration, then speeds up for continuous operation. This dynamic speed adjustment allows handles to be positioned gently while maintaining high manufacturing rates, resolving the contradiction between productivity and acceleration speed.
2Ease of operation
If handles are made to protrude from the bag opening, then they are easy to carry, but the bag size for storage and transport is increased
Solution Approach 1:
The patent applies inversion by positioning the handle legs forward (toward the opening) rather than backward, and by making the legs foldable rather than fixed. This allows the handles to protrude when needed for easy carrying, but fold back against the bag body for compact storage, resolving the contradiction between ease of operation and storage volume.
3Strength
If reinforcement sheets are not placed on handle legs, then the manufacturing process is simpler, but the connection strength between handle and bag wall is reduced
Solution Approach 1:
The patent applies preliminary action by pre-attaching reinforcement sheets to the handle legs before the handles are positioned on the bag wall. This ensures strong connection strength is achieved without adding complex reinforcement mechanisms during the main manufacturing process, resolving the contradiction between strength and process complexity.
4Productivity
If a drum is used for laying handles with continuous rotation, then greater manufacturing rates are achieved, but the handle acceleration must be controlled to avoid tearing
Solution Approach 1:
The patent applies dynamics by using a rotating drum that can adjust its speed continuously. The drum rotates slowly when handles are being placed to prevent tearing from sudden acceleration, then maintains steady high-speed rotation for continuous manufacturing. This dynamic speed control achieves both high productivity and reliable handle bonding, resolving the contradiction between manufacturing rate and bonding reliability.
Data Source
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Figure 6~7a
AI summary
The invention relates to a method for manufacturing a bag: a wall (1, 1a) of the bag is passed along a placement drum (30) for rotatably mounted handles (4); a handle (4) is hooked onto the drum (30), legs (41) of the handle (4) extending backwards along a perimeter of the drum (30) in the direction of rotation of the drum (30), the legs (41) being connected by a cross member (40); same is completely turned over using a turnover drum (37) so that the legs (41) are at the front on the placement drum; and the handle (4) is deposited on the wall.