The Science Behind Golf Balls
by Michelle Brown
Golf is a favored pastime for many people, young and old, novice and experienced alike. Whether playing the game to achieve a day that is filled with conversation and relaxation amongst good friends or competing professionally, golf is a game that we can all take enjoyment from.
The History of Golf Balls
Before the well-known white, dimpled golf ball, there were a few other prior attempts at perfecting the ball for this admired game. From cowhide and feathers to sap and rubber and finally, urethane blends, golf balls required quite a few centuries of trial and error to finally perfect, lending its aerodynamic design to obtain the greatest distance- hopefully assuring the balls' destination on the furthest green.
In the beginning, wooden balls were used in the game. These originated in the early 1400s. As well, the first golf clubs were, too, made from wood. The effectiveness of these man-made balls was meager at best. As you can imagine, technology in achieving a perfectly spherical ball was lacking in the 1400s.
During the 17th century, the "featherie" ball took the place of the man-made wooden balls. Featherie balls were made from goose or chicken feathers stuffed into a small cowhide pouch. The chosen feathers were boiled and then placed in the pouch. The pouch would shrink as it would cool while the feathers would expand, making a tight, compact ball.
The featherie ball was so well constructed that it remained the golf ball of choice for more than two centuries. However, there were some shortcomings. A featherie ball maker could only make a few balls a day. This fact made the balls fairly expensive. A featherie would cost equivalent to about $20 each in the 17th century. It was also extremely difficult to make a featherie perfectly spherical to achieve maximum force. In addition, the stitches that kept the cowhide together would rot if they became wet. So playing in the rain would become problematic.
It was then in 1848, Dr. Robert Adams Paterson invented the "guttie" golf ball. The guttie was made from Sapodilla tree sap. The sap had rubber-like qualities, allowing for the sap to be heated and the guttie to be shaped into spherical ball. Through the actual act of creating these balls, the guttie would have nicks and abrasions. It was then realized that when the guttie had these abrasions, it would fly higher and further than a guttie without these imperfections.
Following the guttie, golf balls were then made from a solid- or liquid-filled inside with a layer of rubber on the outside. It was finally in the 21st century where golf balls were made from synthetic materials. These balls either have a two-piece, three-piece or four-piece classification depending on the number of layers the ball consists of.
The Modern Golf Ball
The two-piece golf ball is made from a solid rubber inside with an ionomer resin outside. The three-piece ball consists of a solid- or liquid-filled core with rubber thread wrapped around it with a balata rubber cover. In the 1970s, the interior of the golf ball was improved further by using a material called polybutadiene reinforced with zinc. This three-piece type is most difficult to make taking about one month to produce. They also require 80 different steps in manufacturing and 32 different inspections. On the other end of the spectrum, two-piece balls take about half of this time and half the steps.
The inside of a two-piece golf ball, the most common type, is made from several different chemicals that, in the end, make a rubber-type compound. To form the outer cover, a process called injection molding is used. In this process, the core is centered within a mold cavity by pins, and molten thermoplastic is injected into the dimpled cavity surrounding the core. The heat and pressure cause the cover material to flow and join with the center.
Once the material is cooled, two coats of paint are applied to the golf ball. The paint is applied by paint-guns so that the ball is painted uniformly. Once the paint is dry, a logo is stamped on the ball and, finally, a clear coat is applied for a gloss sheen and scuff resistance. Once the gloss is applied, the golf balls are placed into large dryers and are then ready to be packaged, shipped, and sold. Though not as sophisticated as the three-piece ball, the two-piece is easier to compress and drive for the low- and medium handicap golfer.
The three-piece ball is less popular than the two-piece merely because they are so much more expensive due to their lengthy manufacturing process. However, these are especially desired because of their unique characteristic of curving in the air or stopping quickly on the green.
Three-piece and two-piece balls are manufactured differently and therefore have different requirements when undergoing quality control. Three-piece balls are x-rayed to ensure that the core is perfectly rounded. In addition, compression ratings are used to measure compression-molded, wound golf balls. When it comes to checking two-piece balls, quality control is based on co-efficiency ratings.
Golf balls are also tested to ensure the balls' performance meet the United States Golf Association's standards. Many machines are used to test these, including wind tunnels, which test the ball's wind resistance and lift action. Another machine is the Iron Bryon. This machine tests both the club's fitting and the ball's endurance with varying speeds.
Perceptibly, the improvements of golf balls have come quite a ways and will continue with the advancements in technology. Though this sounds promising, many professional golf players complain that some golf balls are traveling too far and desire producers to reduce the drives about 10%.
Golf Balls and Dimples
As mentioned previously, golf enthusiasts noticed that balls with the normal wear and tear traveled significantly further than ones that were completely smooth on the outside. These nicks acted as turbulators meaning they created turbulence in the layer of air that touched the ball- known as the boundary layer. The dimples on the modern golf ball are a symmetrical and formal way of creating turbulence in the boundary layer.
If a professional golfer hit a smooth golf ball, it would only go as far as a golf ball that had dimples. On average, a golf ball has between 300 and 500 dimples reaching a depth of about .010 of an inch. The lift and drag is quite sensitive to the depth, size and shape of the dimples. Though traditionally dimples have been spherical in shape, it is possible to use other shapes to get the same if not better drag and lift.
In aerodynamics, force is broken down into two components: lift and drag. Drag acts to directly oppose motion, while lift acts in a direction perpendicular to motion. The dimples on a golf ball create that boundary layer, clinging to the balls surface. The air clings further back on the ball, thus making the dimpled ball travel further than the smooth ball.
In addition to drag, dimples also affect lift. When in flight, the ball's backspin creates this lift. The spinning action makes the air pressure on the bottom of the ball higher than the pressure on the top thus creating an upward force on the ball. The ball spin, even on smooth balls, creates about half of the ball's lift. The dimples provide the improved lift force.
Golf Ball Dimensions
The diameter of the golf ball must be at least 42.67 millimeter. The smaller ball will drive further due to less air resistance, therefore, many manufactures tend to create the balls on the smaller side- though not going smaller than the 42.67mm (or 1.680 inches) requirement.
The weight of the golf ball cannot exceed 1.620 ounces (45.93 grams). The heavier the golf ball, the less it is slowed by air resistance, so many manufactures will produce balls that is closer to the heavier weight- again, not exceeding the 1.620 ounce requirement.
Keeping this in mind, if one is a novice when it comes to the game of golf, picking a smaller yet heavier ball will get the maximum play.
Golf Balls for Beginners
Besides looking for the smallest and heaviest balls, there are certain other aspects a beginner should look into when considering the purchase of golf balls. As a beginner, though purchasing the most expensive, top-of-the-line are certainly an option, one should perhaps look at more reasonably priced balls.
Firstly, as a beginner, one should look into getting some much-needed practice at the driving range. Only worry about getting bucket after bucket of golf balls to practice with- don't be concerned with questions like if this a two- or three-piece. Or are the dimples deep enough to get the most drive.
There are certain golf balls called X-outs that many beginners can purchase at a much cheaper price. The x-outs have, in one way or another, suffered a minor slip-up in production. These mistakes are mostly cosmetic and have no affect on the actual performance of the golf ball.
Another option is using and purchasing used golf balls. Though it may not be the most glamorous solution, it is certainly more than acceptable for a newbie to conclude to. A novice golfer can find used golf balls at garage sales, online, and even some on-course golf shops carry used balls for purchase. Refurbished golf balls can also be an option. Though more expensive than used balls, refurbished ones are still much cheaper than brand new golf balls.
Online golf shops are a great resource for inexpensive golf balls. As these companies are offering new, top-of-the-line golf balls, they are also offering closeout prices on brands that have been discontinued. Again, these are much less expensive than any brand new items.
If new balls are something that may be more desirable, some manufactures offer "vale" golf balls. These are brand name balls that are marketed at lower price points. These balls are built to maximize distance, minimize spin and resist the normal wear and tear.
Golf Ball Studies
Aerodynamics plays a significant role, if not the primary role in golf ball science. The design of golf balls has come a long way since the 1400s. In fact, some manufactures claim that their design in golf balls can be driven 400 yards due to ever-advancing technology. On the other hand, however, some experts believe that golf balls have reached their limit in distance and perfection and will not likely improve further within the next twenty years. Manufactures thrive to make the next ball that will fly higher, drive further, and stop quicker on the greens. It is also in their interest to create different types of balls with different characteristics that cater to different types of trajectories depending on the goal of the golfer.
Trick Golf Balls
There are numerous novelty items that can be purchased for friends and loved ones who are golf fanatics. There are trick golf balls that play merely as a practical joke as well as "cheater" balls that do not fit within the realm of the USGA's regulated rules and dimensions of golf balls.
Breakaway golf balls do just that- as the golfer hits the golf ball, it breaks away and shatters into small pieces. Exploding golf balls do something similar, except rather than breaking into small pieces, the ball utilizes a small explosive device in which the golf ball disintegrates.
There are other types of novelty golf balls that react when struck as well. For example, a jet streamer will unravel into 12 feet or more of ribbon once hit. A phantom ball is filled with water and when struck will create the illusion that it has evaporated when water explodes out of it.
There are also laughing golf balls, which will laugh and giggle after being hit. These types of balls will usually continue laughing while they are in motion.
Staller golf balls are much softer than regular golf balls. When the golfer hits a staller, the ball will go much higher and travel a far less than normal distance.
Many times, golf balls are hit into a nearby pond, sinking to the bottom. But floaters, another type of novelty golf ball will simply float and bob at the surface.
Lastly, there are the super-distance golf balls. These are much heavier and have dimples that are much deeper than normally allowed. Manufactures of these types promise a 12-yard gain if their super-distance golf balls are used.
- image courtesy of marbla123 of Flickr - http://www.flickr.com/photos/56705607@N00/3968362036/